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Chromosome Number: 16
Taxonomic Classification
Class
:
Liliopsida
Order
:
Asparagales
Family
:
Alliaceae
Genus
:
Allium
 
Garlic is an important crop. It is mainly used for flavouring and seasoning vegetables and meat dishes. Madhya Pradesh, Gujarat, Orissa, Maharashtra, Uttar Pradesh and Rajasthan are major garlic-growing states. More than 50% production, however, comes from Madhya Pradesh and Gujarat only. The area, production and productivity and per caput availability of garlic have improved considerably. Indore and Mandsour in Madhya Pradesh, Angul in Orissa, Junnar Taluka in Maharashtra, Mainpuri, Etah and Etawa in Uttar Pradesh, Sikar, Jhunjhun, Ajmer and Udaipur in Rajasthan are major garlic-growing pockets. In India smaller-cloved garlic varieties are being grown in plains. Recently excess larger-cloved garlic cultivation has been introduced in north Indian plains and Madhya Pradesh. Larger-cloved garlic varieties are also cultivated in Himachal Pradesh and Nilgiri hills.
   
Climate and soil  

Garlic grows under a wide range of climatic conditions. It, however, cannot withstand too hot or too cold temperature. It is frost hardy requiring cool and moist period during growth and relatively dry period during maturity of bulbs. Bulbing takes place during longer days and at high temperature. Exposure to low temperature subsequent to bulb formation favours the process. Garlic can be grown well up to 1,000–1,300m above mean sea-level. There are 2 types of varieties suitable for long and short day conditions. In general, cool growing period gives more yield than warm. Garlic should be planted early to promote vegetative growth under short day conditions and cool temperature. Late planting affects vegetative growth adversely, resulting in lower yield. The critical day length for bulbing is 12hr. Along with the day length, temperature also affects bulbing. Exposure of dormant cloves or young plants to temperature of around 20°C or lower for 1–2 months depending upon varieties hastens subsequent bulbing. Plants that are not exposed to such conditions may fail to form bulbs. Since climatic conditions in an area varies from year-to-year, performance of a variety in a particular area is not alike every year. Too much exposure to low temperature may cause initiation of cloves in the axils of leaves near the bulb surface i.e. further from bulb centre than usual. During growing season these cloves develop green tops which appear as lateral shoots to the false stem.
Garlic requires medium black, fertile, well-drained loamy soils rich in humus with fairly good content of potash. The crop raised on sandy or loose soil does not grow well and the bulbs too are lighter in weight. In heavy soils, the bulbs produced are deformed and during harvesting, many bulbs are broken and bruised. Such bulbs are not good for storage. Bulbs become discoloured in poorly drained soils. The soils having pH of 6–7 are suitable for good crop. Highly alkaline and saline soils are not suitable for garlic cultivation.

 
Varieties
The improved varieties of garlic are: Godavari, Sweta, HG 1, HG 6, Pusa Sel 10, LCG, 1 ARU 52, Agrifound White (G 41), Yamuna Safed and Yamuna Safed 2, G 282 and Agrifound Parvati. All varieties except G 282 and Agrifound Parvati are small-cloved and have more than 20–30 cloves. G 282 and Agrifound Parvati have bigger-sized bulbs with bigger cloves fewer in number. G 282 develops good bulbs in southern hills and northern plains. Agrifound Parvati is long day type and can be grown only in northern hills. Agrifound White, Yamuna Safed and Yamuna Safed 2 have been released for commercial cultivation.
   
Propagation

Garlic is propagated by single clove. Bulbils produced in some varieties are also used as planting material. Tissue culture technique has also been developed to produce healthy garlic bulbs. Garlic being a narrow-spaced crop is highly labour-intensive. Since in many areas labour rates have increased manifold, broadcasting method or sowing in furrow is used which does not give good yield of quality bulbs. This method is now very common in Gujarat. In Lahaul and Spiti districts of Himachal Pradesh, bulbils are first sown in nursery and after one and half months they are planted in main field at proper spacing. Three methods of garlic sowing are in practice—dibbling, furrow planting and broadcasting. In dibbling, field is usually divided into small plots convenient for irrigation. The cloves with growing end upwards are dibbled with hand about 5–7.5cm deep. These are then covered lightly with soil. In furrow planting, furrows are prepared at appropriate spacing with handhoe. Cloves are dropped by hand in these furrows and covered with soil. In broadcasting, the cloves are scattered evenly with hand in well-levelled seed bed. They are then covered by harrowing. The field is divided in beds and channels for irrigation. Irrigation is given immediately after planting in all the methods.
While planting, bigger-sized cloves are selected which are on the outside of the bulbs. Long slender cloves in the centre should be discarded since such cloves give poorly developed bulbs. About 500kg of 8–10mm diameter cloves are required to plant one hectare area.

   
Cultivation  

Planting
Since excessively hot/cool and long days are not conducive for proper development, the crop is usually planted in winter and harvested when the summer season sets in. The time of planting differs from region-to-region. It should be planted from August–October in Madhya Pradesh and Maharashtra, Karnataka and Andhra Pradesh and from September–November in northern plains of India. In Gujarat, planting is done during October–November. March–April is proper time for planting in higher hills. It, however, can also be planted during September– October. In West Bengal and Orissa, October–November is best time of planting. In Nilgiri hills, it is planted early in May and October.
The field is prepared well by ploughing 4–5 times. The ploughing should be shallow as most of roots penetrate to a depth of not more than 8–10cm. The planking should be done for proper levelling. The field is then divided into small plots and channels. The width of beds should be such that intercultural operations are possible to be taken up by sitting on bunds. The length of the beds should be according to the level of the land.
The planting is done at appropriate spacing, depending upon the variety to enable the plants to develop the bulbs properly. The planting distance varies in different regions of India. In Punjab, Madhya Pradesh and other pockets a spacing of 15cm × 8cm is recommended. A spacing of 10cm × 7.5cm is suitable in Haryana and 15cm × 10cm is desirable for varieties with bigger bulbs/cloves. Too wide spacing results in thick-necked bulbs, whereas too close spacing causes more disease attack, particularly purple blotch.
Manuring and fertilization
Garlic responds very well to organic manures. Therefore, apply farmyard manure @ 50 tonnes/ha at the time of field preparation. A dose of 100kg N, 50kg P and 50kg K/ha through chemical fertilizer is recommended. Micronutrients are also effective in increasing the yield. Application of B (0.5–1.0ppm) is recommended for higher yield of garlic. Application of a mixture of 75kg NPK in ratio of 18:2:3 with 5kg B, Zn and Mo is ideal. Half of the N and full dose of P and K should be applied basally and the remaining N should be applied one month after planting.
Aftercare
Since garlic is a closely planted crop, manual weeding is tedious, expensive and often damages the plants. However, it is necessary to keep fields weed-free. First weeding is done one month after planting and second one month after first weeding. Hoeing just before the formation of bulb loosens the soil and helps in setting of bigger neck filled bulbs. The crop should not be weeded out or hoed at a later stage because this may damage the stem and impair the keeping quality of cloves already formed. Application of Pendimethaline and Oxidiazon as pre-emergence are effective weedicides. Tribunil at 1.5kg/ha, Nitrofen 2.0kg/ha or Basalin at 2–2.5 litres/ha diluted in 625 litres of water may be sprayed 7–15 days after planting. Basalin should be used 2 days before planting. Pendimethaline @ 3.5 litres/ha + 1 hand-weeding 45 days after planting is recommended to control broad-leaved weeds.
Irrigation
First irrigation is given just after planting. Later the crop is irrigated after every 10–15 days till the season warms up. At this stage irrigations are required at 8–10 days interval. The optimum soil moisture for emergence is 80–100% of field capacity. There should be no scarcity of moisture during the growing season otherwise bulb development is affected. For a high yield of good quality 2 irrigations (20mm) during August–September and 3 irrigation during October–November are necessary if early planting is done.

   
Harvesting & Postharvest management

Garlic becomes ready for harvesting when its tops turn yellowish or brownish showing signs of drying up and bending over. The bulbs mature 130–180 days after planting depending on cultivar, soil and season. G 282 is earliest-maturing variety. Good quality bulbs could be stored for a longer period. Early harvesting results in poor quality bulbs where losses due to driage are more. Delayed harvesting results in splitting and resprouting in field itself. In India, harvesting is done manually by hand digger. In some regions where soil is loose, the plants are pulled out by hand or pulling is done by loosening the soil with country plough. Bulbs are taken out along with their tops and windrowed gathering several rows in each row. The yield of bulbs varies from 100 to 200q/ha depending upon variety and region. The longer the day length given to the variety higher is the yield.
About 25–50% losses take place if garlic is not stored properly. Its bulbs are windrowed in the field covered with the tops for field curing. Curing is necessary to remove excess moisture and to allow the bulbs to become compact and go into dormant stage. It is done for about a week in the field to dry the bulbs thoroughly. Bulbs are also cured for 7–10 days in shade either with tops or after cutting the tops, leaving 2.5cm above the bulbs to avoid the sun injury. Curing in shade may be on floor having ventilation from bottom or it can be on wire racks.
After curing the bulbs are run over a grader or graded manually. The thick-necked, splitted, injured, diseased or bulbs with hollow cloves are sorted out. Size grading is done after sorting depending upon the demand of the market. After that they are packed in open mesh jute bags. Usually 90 and 40–60kg packs are used.
Thoroughly cured garlic bulbs keep fairly well in ordinary well-ventilated rooms. Garlic with dried tops are stored by hanging in well-ventilated rooms. This is, however, not possible on a large scale because space requirement is more. Since garlic stores well for marketing under wide range of temperature, controlled condition (low temperature) storage is not necessary. Cloves sprout quickly at temperature near 4.4°C as such prolonged storage in this temperature range should be avoided. Storage at 0.5°C appear satisfactory, but high humidity often accompanies the low temperature storage. Garlic stored at humidity higher than 70% at any temperature develops mould growth and starts root growth. Cold storage of garlic is possible at 0.5°–2.2°C temperature and 60–70% relative humidity.
Irradiation with 6 krad of gamma rays from 60cobalt source is also recommended for successful storage. Storage life of garlic is prolonged and loss in weight is reduced by spraying 3,000ppm MH on the crop before harvesting.

   
Physiological Disorders
Sprouting of bulbs in the field occurs at maturity particularly when there are winter rains or excessive soil moisture and supply of nitrogen. This disorder is, however, not of permanent nature. It varies from variety-to-variety. Early planting also causes sprouting. Rubberization has been noticed in Nilgiri hills of Tamil Nadu. The causes and possible remedies are being studied. Splitting is also noticed sometimes in some varieties which is due to delayed harvesting or irrigation after long spell of drought.
Nutritional Value
 
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Chromosome Number: 22
Taxonomic Classification
Class
:
Liliopsida
Order
:
Zingiberales
Family
:
Zingiberaceae
Genus
:
Zingiber
 
Ginger is one of the oldest spices with a distinct flavour and pungency. It has a wide range of uses that include culinary, flavourant in soft drinks, alcoholic and non-alcoholic beverages, confectionery, pickles, pharmaceutical preparations. India is the largest grower of ginger and also the largest producer of dry ginger in the world. Other countries cultivating ginger extensively are West Indies, Brazil, China, Japan and Indonesia. In India Kerala, Orissa, Andhra Pradesh, Himachal Pradesh, Meghalaya and West Bengal are important ginger growing states. About 60% of the area is confined to Kerala, accounting for 25% of the country's total production.
   
Climate and soil  
Ginger grows well in warm and humid climate. It is cultivated up to 1,500m above mean sea-level. However, an optimum elevation for its successful cultivation is 300–900m. Moderate rainfall at sowing till the rhizomes sprout, fairly heavy and well-distributed showers during the growing period and dry weather about one month before harvesting are optimum requirements for its successful cultivation. Early planting helps in better growth and development of rhizomes and higher yields. A rich soil with good drainage and aeration is ideal for its cultivation. It grows well in sandy or clayey loam, red loam and lateritic loam soils. Drainage is absolutely necessary for the prevention of disease incidence. Ginger should not be grown in the same site year-after-year.
 
Varieties
Several cultivars are grown in different areas in India. Ginger is always propagated by cuttings of rhizomes known as seed rhizome or sets. Rhizome sets should be treated with 0.3% Dithane M-45 solution for 30 minutes to control fungal diseases. If required, they may also treated with 0.05% Malathion and 200ppm Streptocycline. For planting, rhizome bits of 15–20g @ 1,200–1,800kg/ha may be used.
   
Cultivation  

Planting

The land should be ploughed 4–5 times to bring the soil into fine tilth. Beds of 1m width, 15cm height and 3m length or of any convenient length are prepared at 40cm spacing. About 2,000 beds of 3m × 1m size are prepared in one hectare land. Being irrigated crop, ridges are formed 40cm apart. The optimum spacing is 30cm × 30cm under bed system of planting. A bed of 3m ×1m can accommodate 40 plants.

Manuring and fertilization

A basal dose of 25–30 tonnes of farmyard manure with NPK 75 : 50 : 50 kg/ha is recommended. Whole of P 2 O 5 and half of K 2 O may be applied at the time of planting. Half of N is applied 40 days after planting and the remaining N and K 2 O month after that. Application of neem cake (2 tonnes/ha) as basal dressing helps reduce the incidence of soft rot of ginger and increases the yield.

Weeding and mulching

Mulching enhances germination, increases organic matter, conserves soil moisture and prevents washing of soil due to heavy rains. Two weedings are generally given to the crop. The first weeding is done just before the second mulching and repeated depending on the intensity of weed growth. If necessary, weeding is to be repeated for the third time. Mulching of ginger beds helps in soil and water conservation. The first mulching is done at the time of planting with 12.5 tonnes of green leaves/ha and the second after 40 days with 5 tonnes of green leaves/ha.

Rotation and intercropping of ginger

The crops most commonly rotated with ginger in Kerala are tapioca, chilli, rice, gingelly, ragi, groundnut and maize. Ginger is also grown with maize as a mixed crop and as an intercrop in coconut and arecanut gardens.

   
Harvesting & Postharvest management

It is ready for harvesting in about 8 months, depending on variety, when the leaves turn yellow and start drying. The average yield is 15–30 tonnes/ha. If the crop is for green ginger , it is harvested in 5–6 months. Rhizomes are washed thoroughly in water 2 or 3 times to remove the soil and dirt and sun-dried for a day.

For dry ginger, the outer skin is removed with split bamboos having pointed ends. Only the outer skin is to be peeled since the essential oil of ginger remains near the skin, and dried in the sun for a week. The yield of dry ginger is 16–25% of the green ginger.

Big plumpy rhizomes free from diseases are selected immediately after harvesting. They are treated with a solution containing 0.05% of Malathion and 0.3% Dithane M-45 for 30 minutes. Drain the solution and dry the rhizomes under shade. Dried rhizomes are put in a pit of convenient size (2m × 1m) and covered with a plank fitted with 2–3 holes for aeration. In some areas, the rhizomes are loosely heaped over a layer of sand or paddy husk and covered with dry leaves in a thatched shed.

For processing into its products, ginger rhizomes are harvested 5 months after planting. The rhizomes are immature, tender and succulent. They are washed in water to remove soil and processed into salted ginger, preserved ginger in sugar syrup or brine and dry and crystallized ginger. 

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Gladiolus is very much liked for its majestic spikes containing attractive, elegant and delicate florets. These florets open in sequence over a longer duration and hence has a good keeping quality of cut spikes. There is a wide range of colours—self or bicolour with or without central mark varying from white to darkest crimson. The spikes of gladiolus are mainly used for garden and interior decoration, and for making bouquets. West Bengal, Maharashtra, Uttar Pradesh, Punjab, Haryana and Andhra Pradesh are the major gladiolus-growing states.
   
Climate and soil  

It can successfully be grown in a wide variety of climatic conditions. The planting should be adjusted in such a way that gladiolus crop enjoys favourable weather conditions throughout its growing, flowering, corm and cormel production period. The favourable temperatures are about 16°C (lower) and 23°–40°C (higher). There should not be rains especially during flowering period.

Gladiolus requires open sunny conditions. The longer day length improves its spike quality. About 12hr day length with high light intensities are preferred over short days with low light intensities. The site should also be well protected against strong winds by planting a hedge or windbreak.

Fertile and well-drained soil is better than heavier soils. The texture of heavy soils can be improved by mixing organic manure and sand. The soil reaction should be around neutral. If it is acidic or alkaline, it should be corrected.

 
Varieties

Gladiolus is very rich in its varietal wealth. The commercial life of a variety is about 10–15 years. Every year new varieties are introduced which replace the old ones. Promising varieties which are popular amongst growers of India are:

American Beauty: Florets reddish pink in colour (red group; 54B) with whitish throat and whitish blue anthers; spikes 70–75cm long; each with 15–16 florets; florets 9.5–10.5cm in size; each corm produces 70–80 cormels.

Anglia: Florets yellow (yellow group 8A); spikes 60–70cm long each having 13–14 florets; florets 9.5–10cm in diameter; each corm produces about 10–15 cormels.

Applause: Florets deep pink (red purple; 67C) with red throat; spikes 90–100cm long having 15–16 florets; florets 8.0–8.5cm in size, each corm produces about 20 cormels.

Blue Sky: Florets violet blue in colour (violet-blue group; 92C); spikes 80–90cm long each having 15–16 florets; florets about 10cm in diameter. Cormel production 25–30/corm.

Eurovision: Florets bright red in colour (red group; 45B); spikes 75–80cm long each having 18–20 florets; florets 10–10.5cm in size; cormel production 25–30/corm.

Friendship: Florets are carmine-rose (red group; 52C) with yellow throat; spikes, 90–100cm long, each bearing 18–20 florets of 9.5–10.5cm size. Each corm produces 15–20 cormels.

Her Majesty: Florets deep violet in colour (violet group; 83C), spikes 65–70cm long each with 13–14 florets; florets 8.0–8.5cm in size; cormel production about 20/corm.

Hunting Song: Floret scarlet red (red group; 40B) with maroon throat having yellow markings; spikes 95–100cm long; each with 17–19 florets; florets about 10cm diameter; cormel production about 20/corm.

Jacksonville Gold: Florets light yellow (yellow group 10A) with bright yellow throat. Spikes 70–75cm long with 16–18 florets. Florets 9.5–10cm in diameter; each corm produces 10–15 cormels.

Jester: Florets deep yellow (yellow-orange group; 16A); with red throat; spikes 90–100cm long with 16–18 florets; florets (9.5–10.0cm in diameter; each corm produces 15–20 cormels.

Mascagni: Florets bright red (red group 44B); 9–10cm in diameter; spikes 80–90cm long each having 15–17 florets. Each corm produces 10–15 cormels.

Nova Lux: Florets yellow (yellow group; 12B) with deep yellow throat and purplish base; spikes 90–100cm long with 16–18 florets; florets 9–10cm in size and ruffled; each corm produces 15–20 cormels.

Oscar: Florets maroon in colour (red group: 45B); spikes 90–100cm long with 15–18 florets. Florets about 10.0cm in diameter. Each corm produces 25–30 cormels. This variety is highly susceptible to fusarial wilt.

Peter Pears: Florets orange-red (shrimp-red) (Greyed-orange group; 170D). Lip petal scarlet with light stripes; Florets 10.5cm in diameter; each corm produces about 25–30 cormels.

Priscilla: Spikes pinkish-mauve (red purple group: 71C) with prominent light yellowish-white bases; spikes 60–70cm with 14–15 florets; florets 8.0–9.0cm in diameter; each corm produces 20–25 cormels.

Rose Spire: Florets light pinkish mauve (red-purple group; 57C) with creamish white throat; spikes 95–100cm long, each having 17–18 florets of 10.5–11.0cm diameter; each corm produces about 25–30 cormels/corm.

Rose Supreme: Florets light pink (red group; 52D) with dark pink stripes and creamish throat; spikes 100–105cm long each with 16–18 florets of 10.5–11.0cm diameter; each corm produces 20–30 cormels.

Sancerre: Florets snow white (white group, 155B) in colour, spike length 85–90cm; 17 florets/spike floret size 10–11cm; each corm produces about 50 cormels.

Suchitra: Florets light pink (red group; 49A) with dark pink stripes; spikes 80–90cm long, each with 16–18 florets, florets 9–10cm in diameter; cormel production 80–90/corm.

True Yellow: Florets yellow (yellow group, 13C); spikes stout, 100–110cm long each with 13–15 florets; Florets nearly 10–11cm in diameter, ruffled, each corm produces about 8–10 cormels.

White Prosperity: Florets white in colour (white group, 155B), ruffled, spikes 90–110cm long each with 18–20 florets, florets 9.5–10.5cm in diameter. Cormel production about 30–40/corm.

Wind Song: Florets purplish mauve (violet purple group; 81B) with prominent light yellow throat. Spikes 90–95cm long each bearing 15–16 florets. Florets 10–11cm in diameter; each corm produces 20–25 cormels.

Yellow Stone: Florets sulphur-yellow (yellow group; 7B); highly ruffled, spikes 70–75cm long each with 14–16 florets; florets 10–11cm in diameter, each corm produces 3–4 cormels.

There is a demand of gladiolus flowers round-the-year. Nowadays gladiolus can be produced from October-end to April by adjusting the planting at 15 days or one month interval from July to December in plains of north India. Selection of varieties should be done accordingly. In hilly areas, March–April is planting time to get flowers from June–September. For quality flower production, planting in June, October and November is beneficial, whereas June, February, April and May plantings are better for cormel production. August, September, March and April are not very useful for flower production.
   
Propagation

Gladiolus is propagated through corms and cormels, seed and tissue culture.

Corms: Propagation of gladiolus through corms and cormels is most common and commercially used method. A single corm of gladiolus produces an average of 1–3 flower grade daughter corms in a season depending upon its size and cultivar. Normally large-sized corms may produce more daughter corms than small-sized ones. According to the North Amercian Gladiolus Council, there are 3 categories of corms based exclusively on their size—large,medium and small. Large-sized corms have been put into jumbo (5.1cm diameter) and no. 1 (>3.8–<5.1cm diameter) categories. Medium-sized corms have 2 categories—no. 2 (>3.2–<3.8cm diameter) and no. 3 (>2.5–3.2cm diameter), whereas small-sized corms commonly referred to as cormels have 3 categories—no. 4 (>1.9–<2.5cmdiameter), no. 5 (>1.3–<1.9cm diameter) and no. 6 (>1.0–<1.3cm diameter) respectively. Large and medium-sized corms are used for production of cut spike, whereas small-sized corms are used as planting stock for the production of flower grade corms for the subsequent planting season. Most varieties produce 1–2 flower grade daughter corms from the single parent corm. Gladiolus varieties Suchitra, Jackson Ville Gold or American Beauty produce up to 3–4 daughter-corms/corm.

The number of daughter corms/corm can also be increased by pre-planting (pre-storage or post-storage) treatment of corms with ethrel (500–5,000ppm for 30 min.) Ethrel breaks apical dominance and promotes the sprouting of lateral buds which eventually increases the number of daughter corms. The large-sized corms are more responsive to the treatment than the small-sized ones. In some cases high concentration of ethrel (1,000ppm or more) also causes some delay in flowering and decrease in spike length. Moreover, the efficacy of ethrel may vary in different cultivars and should be thoroughly tested before use.

Multiplication of gladiolus through corms is, however, a slow process and sometimes leading to high incidence of diseases in the daughter corms. It is cautioned that after few years of cultivation, the corms lose their vigour as a result of which the quality of the spike as well as daughter corm deteriorates considerably. The use of the same corm for more than 5–6 plantings is not recommended.

Cormels: Multiplication of gladiolus through cormels is an inexpensive and rapid method. The cormels also escape diseases or viruses even if the parent corm is infested. Therefore, corms produced through cormels are usually healthier than those raised from the corms.

The number of cormels produced by a corm varies with the cultivar and planting time. The cultivars producing 10 or less cormels are poor multipliers, whereas those producing >10–25, >25–50 and >50 cormels/corm can be categorised as moderate, fast and very fast multipliers. Production of cormels can be improved by shallow planting of corms, removing of flowering spike at an early stage, proper nutrition and improved cultural practices. The off-type plants should be uprooted from the field along with corms and cormels.

In sandy soils, cormels can be grown in flat beds, whereas in heavy soils with poor drainage, planting should be preferred on raised beds. If possible, growing of cormels on heavy soils should be avoided. Cormels are planted closely (3–5cm apart) in rows or ridges about 15–20cm apart and 2.5–3.5cm deep. Cormels should be planted early in the season which results in bigger-sized corms. Best time of planting cormels in north Indian plains is early to mid-September. In hilly areas (temperate region), the cormels should be planted in early spring. Before planting, the cormels should be soaked in water (15°–20°C temperature) for at least 24hr to facilitate their uniform germination. The diseased cormels normally float on water and hence, should be discarded. ‘Soak and Sun Method' is better in which soaking of cormels in large cloth bags overnight is done in tepid water. After soaking, the bags are kept in sun and turned once or twice a day so that all sides are exposed to the sun. The process is repeated for a week when the cormels start germinating. The large cormels show higher germination than the smaller ones. Cormels can also grow faster by pre-soaking in an aqueous solution of gibberellic acid (100ppm for 24hr). The response, however, varies with the cultivar. Cormels maturing under cooler climates show better growth than those maturing under warmer climates. The moist condition of soil facilitates the germination of cormels and also prevent the desiccation of tender plants produced by the cormels. Therefore soil should be kept moist by repeated light irrigations. Waterlogged conditions are, however, harmful.

Seeds

This method is not used commercially but practised only by the breeders to create new varieties. Mature seeds are collected and after a few days when they are completely dry, the seeds are extracted and stored in desiccators till the next season. The seeds of gladiolus do not possess any dormancy unlike corms and cormels and can be made to germinate immediately under favourable environment. Before sowing the wings of the seeds should be removed as it improves their germination. The wings can be removed by simply rubbing the seeds between the hands or against any rough surface. Only bold and healthy seeds should be selected for sowing. The seeds can be sown on flat or raised beds very closely (3–5cm) apart) in rows about 15cm apart and covered with about 2–3cm thick layer of leaf mold. The beds should be frequently irrigated to keep them moist as moist conditions facilitate seed germination.

Seeds normally take 15–20 days to germinate. A single seed on germination produces single leaf and a small cormel at its base. The cormels thus, produced, are harvested at maturity—when the leaves on the plant start turning yellow. It normally takes 3 years to produce flower grade corms from the seeds.

Tissue culture

This technique is especially useful for multiplying new cultivars; producing disease-free cormels and maintaining germplasm of the elite cultivars.

Various parts—axillary buds on corms or spike axes, or stem or floral buds—have successfully been used as explants for in vitro cormel production. The axillary buds on the corms or the spike axes are better because they can be made to form shoot buds directly without any intervening callus formation. The explants are washed with tap water containing detergent teepol (0.1%) and then in running tap water for 10–15 minutes. After this these should be surface-sterilized with sodium hypochlorite (2.5% w/v free chlorine) or mercuric chloride (0.1%) for 2 minutes.

The sterilized explants are cultured onto autoclaved MS medium containing sucrose (30g/litre), myo-inositol (100mg/litre) and benzylaminopurine (BAP, 5mg/litre) gelled with agar (7g/litre). The cultures should be maintained at 20°–25°C temperatures and 16hr light (about 3,000 lux intensity) and 8hr dark conditions.

The shoot bud cultures thus established should be subcultured on MS medium containing BAP (5mg/litre). Different cultivars of gladiolus may require different levels of hormones in culture medium for the maximum proliferation of shoot buds. Therefore, optimum medium composition for shoot morphogenesis in different cultivars may be required to be worked out.

The shoot buds are made to elongate on BAP-free MS medium. The bud clumps, each containing about 10 buds should be cultured on this medium. These buds start elongating in 7–10 days and attain the length of about 4–6cm in 4 weeks time.

When in-vitro raised shoots attain length of 4–6cm, half strength MS medium containing elevated level of sucrose (6%) and IBA, 2–4mg/litre) should be poured in the culture vessels. The IBA induces profuse root formation at the bases of the shoots, whereas high level of sucrose favours cormel formation. After 10–12 weeks of addition of half strength MS medium containing IBA and sucrose, the shoots start drying and the cormels turn brown. The cormels which are mature by that time should be collected from the culture vessels. These cormels show dormancy and should, therefore, be stored at low temperatures (3°–4°C) for about 2–3 months before planting. These cormels develop into flower grade corms in 2–3 years.

Corm dormancy

Corm/cormels of gladiolus undergo a period of dormancy or rest during which they do not sprout. Dormancy is more pronounced in cormels and corms produced under warmer climates than those produced under cooler climates. On the other hand they possess very little or even no dormant period. The dormancy of corms/cormel can be broken by storing them under low temperature (4°–5°C) for 3–4 months. The period of dormancy differs in different cultivars.

Physiological basis of corm or cormel dormancy has been ascribed to the accumulation of growth inhibitory substances, especially abscisic acid (ABA) in tissue as well as the scales encapsulating them. Dormant cormels contain as much as 5–10 times ABA than the non-dormant ones. The dormant corms can also be made to sprout by treating them with growth-regulatory substances like ethylene chlorohydrin, ethrel (1000ppm) and gibberellic acid (100–500ppm). Descaling also stimulates germination of dormant cormels. But since this operation cannot be carried out for a large number of cormels, it is of limited interest.
   
Cultivation  

Land preparation

Sterilize the soil by covering with a black polythene sheet during May–June. This kills all harmful fungi in the soil. Twenty tonnes of well-rotten farmyard manure should be mixed at least one month before planting corms; 40kg P 2 O 5 (250kg single superphosphate) and 40kg K 2 O (66kg muriate of potash)/acre should also be added.

Planting

Well rested corms measuring more than 5cm are used. This stage can be easily identified by the presence of rootlets at the basal disc. The corms after taking out from cold storage are kept under shade. They are descaled and treated with 0.2% Bavistin for 30 minutes. Corms raised through cormels produce better spikes than those raised through corms.

Gladiolus is generally planted in flat beds 30cm × 20cm apart and 7cm deep. Thus about 60,000 corms can be accommodated in an acre (1,50,000/ha). The distance between row-to-row or plant-to-plant can be increased or decreased. Higher plant population—80,000 or 1,00,000 corms/acre—can also be accommodated. If there is a danger of waterlogging even for a few days, planting should be done on ridges made 30cm apart. Every year field should be changed. After 3–4 years, the same field may be used again.

Manuring and fertilization

Corms of gladiolus are rich in stored food which is sufficient to sustain plant growth for initial few weeks. The cormels specially require fairly good amounts of fertilizers because they contain limited amounts of stored food on account of being small in size. Soils should have all essential nutrients in sufficient amounts to support good growth of gladiolus particularly at later crop growth stages. The nutrient application should preferably be based on soil tests.

Gladiolus requires both macro as well as micronutrients for good growth and flower production. The deficiency of these nutrients in the soil is generally expressed in the form of certain disorders on the plant. The deficiency problem is particularly severe in light sandy soils which can be corrected by the additional supply of the particular nutrient to the plant. It has been observed that N, P, K and iron nutrients have been found a limiting factor for successful growing of gladiolus.

Interculture

Weeding and hoeing are important intercultural operations in gladiolus. Since manual labour is involved to carry out operations, its cost of cultivation increases considerably. Weeds should be removed whenever they appear. Otherwise weeds compete with the main crop for nutrition and moisture. Weeding 4–5 times is required to raise a crop successfully. The application of 2.5litres Basalin/ha as preplanting treatment keeps field considerably clear for 70 days without any harmful effect on corm and cormel production. Earthing-up twice should be done at 3 and 6 leaf-stage which coincides with N application. This results in ridge formation if planting is done on flat land.

Irrigation

Irrigation schedule for gladiolus depends upon weather conditions, soil type and rainfall. Normally in sandy loam soils, it should be irrigated at 7–10 days interval.

   
Harvesting & Postharvest management

Normally single vegetative bud sprouts per corm, which inhibits the sprouting of other buds resulting in single spike formation on a corm. However, in many cases more than one buds sprout and depending on number of bud sprouts, number of spikes are produced. Thus the yield of spikes increases than the number of corms planted. It has been observed that about 10–15% more spikes are produced than actual corms planted. The yield of spikes also depends upon the density at which planting has been done. Thus 70,000–75,000 spikes are harvested when planting is done at a density of 60,000 corms/acre.

Spikes of gladiolus have better vase-life and can be transported for long distances when properly packed. The stage of harvesting of spikes depends upon the distance to be travelled. For distant market, spikes are harvested when basal floret of the spike shows colour, whereas for local market spikes are harvested when basal floret is fully opened.

For enhancing the vase-life of spikes, pulsing with 20% sucrose and 200ppm hydroxyquinoline citrate for 24hr is good. Cut spikes can be successfully stored for 2 weeks at 1°–2°C.

Cut flowers are packed in cardboard boxes. Generally cardboard boxes of 100cm × 25cm ×10cm size are used. Since these boxes are costly, other old suitable boxes like tube light boxes of other industries can also be used.

Corms and cormels are ready for lifting from the ground 6–8 weeks after harvesting of spikes. Irrigation is withheld at least 2–3 weeks before lifting the corms. Corms show the sign of maturity when yellowing of leaves start. After lifting the corms from the ground, they are kept in shade along with the leaves for drying for a week. Leaves are removed, corms and cormels are cleaned. These cleaned corms and cormels are then dipped in 0.2% Bavistin solution for 30 minutes. These are dried in shade for 2–3 weeks, packed in shallow wooden crates or gunny bags and kept in cold storage at 3°–4°C and 90% relative humidity till the next planting season.

   
Physiological Disorders
Gladiolus is an indicator plant for fluoride pollution because it expresses the effects of fluorine at very low—level 1 part/billion. The symptoms of leaf scorching appear as drying of tip of leaves and drying descends downwards with the increase in its accumulation. Further the tissues are dead. During humid conditions, saprophytic fungi appear. The fluoride present in atmosphere is absorbed and accumulated in the tips of leaves. Fluoride toxicity is also associated with heavy application of superphosphate. Rock phosphate contains hydrogen fluoride and is a source of fluoride in superphosphate. Different varieties show varying level of fluoride toxicity. Most sensitive varieties are Snow Princess, Trader Horn, Melody and Jacksonville Gold. No harmful effects have been recorded due to fluoride toxicity on flower, corm and cormel production. However, its injury can be reduced by spraying of 5% lime or magnesium sulphate.
TOP
 
Chromosome Number: 38
Taxonomic Classification
Class
:
Magnoliopsida
Order
:
Rhamnales
Family
:
Vitaceae
Genus
:
Vitis
 
Grape is a deciduous crop. Its natural habitat is temperate cli- mate. It was introduced into north India from Iran and Afghanistan in 1300 ad by the Muslim invaders; and into south India in 1832 by the Christian missionaries from France. However, grape was known in ancient India though it was not commercially cultivated until the 14th century. Wild grapes grown in Himachal Pradesh were used to prepare local wine.
Presently grape cultivation is concentrated in the peninsular India, accounting for 90% of the total area. Major grape-growing states are Maharashtra, Karnataka, Andhra Pradesh, Tamil Nadu, and the north-western region covering Punjab, Haryana, Delhi, western Uttar Pradesh, Rajasthan and Madhya Pradesh.
   
Climate and soil  

Temperature, humidity and light are important for grapes. Hot and dry climate is ideal. Areas with high humidity and high rainfall are not suitable. The climatic requirements of vinifera are different from those of labrusca grapes.

Mild temperature, not exceeding 35°C in summers, impairs the fruiting of vinifera grapes, particularly, in Thompson Seedless. Higher night temperatures (above 25°C) during ripening hamper the colour development in coloured grapes. Cool nights and hot days even though congenial for coloured grapes, pink pigmentation develops in green grapes if the diurnal differences are more than 20°C during ripening.

Under high humid conditions, the vines put forth excessive vegetative growth at the expense of fruiting. Berries do not ripen properly. Disease incidence is high. The total amount of rainfall is not the criterion, but the timing, frequency and duration of rainfall are important considerations for grape cultivation. Rains associated with cloudy weather and poor sunlight during 45–60 days after back pruning in the tropical India reduce the fruitful buds in a vine. Rainfall during flowering, and berry ripening cause enormous damage to grapes. If rains coincide with flowering, the panicles are destroyed by downy mildew. Rains during ripening cause berry cracking and rotting.

Grapes are grown on a variety of soils in India, alluvial in north, heavy black clay in Maharashtra and north Karnataka, red loam in southern Karnataka and Tamil Nadu and very light sandy locally called ‘Chalka' soils in Andhra Pradesh. Soil with good drainage and water-holding capacity in a pH range of 6.5–7.5 is ideally-suited for grapes. Presence of excess salts, particularly sodium and free calcium is detrimental for grapes. Vines become weak and their productive life span is reduced. The electrical conductivity of the saturated extract of soil should be less than 4mmhos/cm, its exchangeable sodium content should be less than 15%. When the soil contains more free calcium than 12%, vines suffer from iron deficiency and the soil gradually becomes sodic. High content of sodium in soil poses drainage problems and the root growth is impaired. Soils of Maharashtra, Haryana and Punjab are saline-alkali. Free calcium content is also high in soils of Maharashtra.

 
Varieties

More than 20 varieties are under cultivation. However, only a dozen are commercially grown. They can be grouped under 4 categories based on colour and seeds. They are:

Coloured seeded

Bangalore Blue, Gulabi (Muscat)

Coloured seedless

Beauty Seedless and Sharad Seedless

White seeded

Anab-e-Shahi, Dilkhush (clone of Anab-e-Shahi)

White seedless

Perlette, Pusa Seedless, Thompson Seedless, and its clones Tas-A-Ganesh, Sonaka and Manik Chaman

Currently, Thompson Seedless is the ruling grape, occupying 55% of the area with its clones. Bangalore Blue occupies approximately 15% of the total area while Anab-e-Shahi and Dilkhush (15%), Sharad Seedless (5%), Perlette (5%) and Gulabi and Bhokri together (5%).

   
Propagation

Grape is mostly propagated by hardwood stem cuttings. Four-noded cuttings from well mature canes on proven vines are made. The diameter of cuttings should be 8–10mm. Cuttings are mostly obtained from October pruning in the peninsula. Rooting of cuttings is not a problem. However, Thompson Seedless roots are poorer than Anab-e-Shahi or Bangalore Blue. To increase the rooting of stem cuttings, they should either be soaked or dipped to cover the basal buds in IBA solution. For overnight soaking, 500ppm IBA solution is used, while 2000ppm solution is used for quick dipping for 10 sec. before planting the cuttings. Quick dip method is preferred. Cuttings after treating with IBA should be planted in the nursery or directly in the field.

Cuttings are planted in nursery either in beds or polybags for rooting. The beds or polybags should be under partial shade. The rooting media should have 30–40% well-decomposed cattle manure to retain moisture and similar proportion of sand to provide drainage. The beds or rooting medium should be treated with Chloropyriphos or Furadan granules to prevent termite damage. Light frequent watering is to be given to the cuttings.

For planting in field, 3–4 cuttings should be planted at each spot. Cuttings are covered with green twigs to provide shade. After rooting, one good cutting is retained at each spot. Gap filling should also be done at this stage.

Rootstocks are employed for grapes to overcome salinity, nematode damage and to impart vigour to vines. In normal soils with good and adequate water for irrigation, rootstock is not necessary. In nematode-prone soils, the rootstock 1613 can be used for Anab-e-Shahi or Thompson Seedless. In saline soils, Dogridge is better. Use of Dogridge in non-saline, nematode-free soils, particularly under mild climatic conditions makes the vines barren by imparting excess vigour.

   
Cultivation  

Planting

Before planting the rooted/unrooted cuttings in the main field, the land is cleared of all bushes and levelled. Trenches or pits 1m wide and 75cm deep are opened. When plant spacing within a row is less than 2m, continuous trenches are made. The pits/trenches are filled with farmyard manure, green manure/leaf-mould, bone-meal (1kg), superphosphate (1kg) and allowed to settle by watering. Cuttings are planted in their position by opening a small pit. A mixture of sand, well-rotten manure and superphosphate (0.5kg) is packed around the cutting in the pit. The soil around the planted cuttings is drenched with a solution of Chlorpyriphos.

October is ideal time for planting the unrooted cuttings directly in the field. Rooted cuttings are planted in January–February. When rootstock plants are planted, budding or grafting is done in July–August. Either chip budding or wedge grafting is employed. Wedge grafting is better.

Spacing of vines depends on the variety, vigour of vines and system of training. Generally Anab-e-Shahi and Dilkhush vines are spaced at 3.3m × 6.6m or 5.0m × 5.0m. The spacing of vines of seedless varieties varies from 1.2m to 2.0m within a row and 2.7 to 3.6m between rows when trained to ‘T' or ‘Y' trellis. For Thompson Seedless, the spacing of 1.8m × 2.5m and 1.8m × 3.0m is ideal for bower and ‘Y' trellies trained vines respectively.

Training and pruning

Different systems of training—head, kniffin, telephone, V, expanded Y and gable—are in vogue in India. Productive potential of vines is better exploited on bower than on any other system of training. But this system is expensive, encourages diseases, and is not suitable for mechanization of cultural operations. On head, kniffin and telephone systems of training not only the yields are low but the fruits are exposed to sun resulting in sun-burn of berries. The V and Y systems are slightly better than these systems in respect of sun-burn, but the yield is the same. The expanded Y with long arms and gable system connecting the side arms of adjacent rows are best-suited for training seedless grapes, since these systems possess the advantages of bower and at the same time do not have disadvantages associated with it.

In north India, vines are pruned in winter (December–January). Half of the canes are pruned to renew spurs and the rest for fruiting canes. One or two buds from the cordon (arm) are retained in renewed at spurs and 12 buds are retained on fruiting canes. The number of buds left on fruiting canes depend on variety and thickness of cane. Thick canes are pruned longer and the thin shorter. The fruited canes are pruned to renewal spurs and the canes developed from renewal spurs are pruned to fruiting canes in the next winter.

In Maharashtra, Andhra Pradesh and north Karnataka, vines are pruned twice (April and October). The April pruning is generally termed as back pruning or foundation pruning. While October pruning is called fruit pruning or forward pruning. All the canes are pruned to spurs at back pruning, irrespective of the variety or cane thickness. The number of buds retained on a cane at forward pruning depends on variety and cane thickness.

Manuring and fertilization

The nutrient status of vines is far in excess than required leading to certain nutrient imbalances, particularly Mg deficiency as a result of heavy doses of K.

Grape requires more K than N which in turn is required more than P. However, P is required at the time of fruit-bud formation when N requirements are less. The N is required more for shoot growth during the fruiting season. Whereas K is required after bud differentiation for shoot maturity and increasing the size of fruit-bud. It is also required after berry set until ripening.

More P and less K are required in Maharashtra and north Karnataka for Thompson Seedless grape, as the soils of this region are rich in K and fix more P. The doses are adjusted by regularly monitoring the petiole nutrient contents.

Petioles of leaves at fifth node from base are sampled on 45th day after back pruning, while those of leaves opposite to flower clusters at full bloom are sampled after October pruning in south India. It is better to sample on 45th day after back pruning. However in north India, sampling is done only at full bloom.

Nutrient applications in the subsequent years should be based on these petiole nutrient standards.

Heavy dose of cattle manure is applied to improve soil structure and to increase its moisture-holding capacity. About 25–50 tonnes of well-decomposed cattle manure, 5 tonnes of oil cake (deoiled) and 1,200kg of organic mixture should be applied every year in a hectare crop. When such organic nutrients are applied, the inorganic doses are proportionately reduced.

Among the nutrient deficiencies, Mg deficiency is universal. About 100–200kg of magnesium sulphate/ha/year should be applied depending upon the severity of its deficiency. While 50kg is applied after 30 days of April pruning, the rest is applied in 2 splits during the fruiting season once at berry set and again after a month. Magnesium is to be applied to soil at least one week prior to potash application to increase its uptake.

Iron deficiency is very common in black soils. Foliar application of 0.2% ferrous sulphate solution or chelated iron compound is recommended. Although all soils in India are deficient in Zn, its deficiency in the plant is not observed.

Irrigation

Grape is a shallow feeder. Light and frequent watering is better for grapes. Water requirements of grape are very high during berry growth. This period coinciding with hot and dry weather, more water is required at this stage. Least water is required during fruit-bud formation. This period if coincides with cloudy weather and rains, watering is totally to be stopped. Reduced irrigation during ripening, i.e. (one month prior to harvesting) improves the quality of grapes and hastens ripening. Too much stress during ripening can also increase the berry drop at and after harvesting.

Currently due to the shortage of water, grapes are irrigated through drips. The number of drippers/vine and their placement are very crucial in drip irrigation. The active feeder root zone is to be wetted by the water discharged through the emitters. Since the wetting pattern is more horizontal than vertical in clay soils but more vertical than horizontal in sandy soils, more emitters with low discharge rate for longer duration are advisable to get good results with drip irrigation in sandy soils. Inadequate wetting of root zone reduces shoot vigour and weakens the vines. Gradually they develop deadwood and go barren 7–8 years after planting.

The quantity of water to let through drip irrigation daily depends not only on the stage of growth of the vine but also the evapotranspiration in a vineyard.

Grape is sensitive to chlorides and total salts content in irrigation water. Water with electrical conductivity of less than 1mmhos/cm, chlorides less than 4m.e./litre, sodium adsorption ratio less than 8.0, residual sodium carbonate less than 1.25m.e./litre and boron less than 1.0mg/kg is considered safe for irrigating grapes.

Raising a bund of loose soil to an height of 1' along the vine rows and mulching the soil around the drip zone by sugarcane trash or paddy straw can conserve the soil moisture and save irrigation water.

Weed control

Farmyard manure and compost are the major sources of weed seeds from outside. The problematic weeds in vineyards are bermuda grass ( Cynodon dactylon ) and nut grass ( Cyperus rotundus ). The weed intensity is less in bower trained vineyards.

Mechanical control is most common means of weed control in India. Dhaincha and sunhemp are grown as intercrops to check the weeds in vineyards trained to T, V or Y trellises. Post-emergent weedicides-Paraquat (7.5 kg/ha) or Glyphosate (2.0kg/ha), is also recommended. Glyphosate offers a long time control of weeds as compared to Paraquat.

Use of growth regulators

Growth regulators—CCC, GA and hydrogen cyanamide—are being used commercially in grapes. The CCC is used to suppress the vigour of vines and increase the fruitfulness of buds. It is sprayed at 500 ppm concentration at 5-leaf stage after back pruning. If weather is cloudy, cool and rainy, it is sprayed on the foliage once again at 10-leaf stage. Gibberallic acid (GA) is used invariably in all seedless varieties. It is sprayed at 10 ppm to elongate the clusters, 22–25 days after forward pruning (4–5-leaf stage). It is also sprayed on clusters @ 40ppm at 50% bloom stage for thinning the berries. For increasing the berry size, the clusters are dipped in 60ppm GA alone or in a mixture of GA (30ppm) with 10ppm BA or 2ppm CPPU at pearlmillet or bajra grain-sized berries and again at redgram sized berries. Care must be taken not to treat the clusters with GA before bajra grain-sized berries. Otherwise, berries of uneven size form a cluster. For increasing berry size, vines are girdled. Girdling is a process of removing 2–3mm wide strip of bark around the stem without injuring the wood. This is also to be done at the bajra grain-sized berries.

Hydrogen cyanamide is used to hasten and increase the bud-break at winter pruning. Buds are swabbed with cotton soaked in 1.5% solution of hydrogen cyanamide 48 hr after pruning. Hastening the bud-break with hydrogen cyamide also hastens the ripening of grapes in the north. Thiourea (4.0%) mixed with 1% Bordeaux mixture is also used to increase bud-break in south.

   
Harvesting & Postharvest management

Grapes are harvested when fully ripe, since they do not ripen after harvesting. In seeded grapes, the seeds become dark brown when they are fully ripe, while in seedless varieties, their characteristic berry colour develops fully.

The yield potential of grape in India is highest in the world. Grape variety Anab-e-Shahi has recorded yield as high as 92 tonnes/ha, whereas Thompson Seedles has 48 tonnes/ha. The average yield of Anab-e-Shahi and Bangalore Blue is 40–50 tonnes/ha, while that of seedless varieties is 20 tonnes/ha.

Grapes should be harvested during cool time of the day. Harvested grapes are trimmed, graded and packed. For local markets, grapes are packed in bamboo strip baskets using newspaper and grape leaves as cushioning material. One basket contains 6kg of grapes. For distant markets (within the country), wood or corrugated cardboard boxes are used for packing. Old newspapers, hay and paper shreds are used as cushioning material. The size of packing is 6 or 8kg in wood boxes, and 2 or 4kg in cardboard boxes. Transport of grapes is mainly by trucks. Grapes are exported to middle-east, Europe and south Asian countries. Grapes are packed in ventilated cardboard boxes using dual release sulphur dioxide releasing pads (grape guard) as an inpacking material to check the postharvest diseases during transit and storage. Strict cold chain is maintained right from harvesting by precooling and cold storage. Boxes are stored at 0°–1°C temperature and 90–95% relative humidity in cold storage. They are transported by sea in refrigerated containers.

Most of the grapes produced in India, irrespective of variety, are consumed fresh. Negligible quantities of Bangalore Blue are crushed to make juice and wine for household consumption. Wine is also produced in India with French collaboration by some private industries growing certain French varieties.

Raisins are the only processed products in India. Approximately 30% of seedless grapes are dried to produce 15,000 tonnes of raisins. Golden bleached raisins are produced by shade drying the clusters after dipping in either boiling solution of sodium hydroxide (0.2–0.3%) and exposing to sulphur fumes. Dipping in soda oil (dipping oil) containing ethyl oleate and potassium carbonate and shade drying is the most common method of preparing raisins in India.

Seeded grapes of Anab-e-Shahi are also dried in very small quantities to make raisins.

   
Physiological Disorders

Of physiological disorders, uneven ripening, post-harvest berry drop, flower-bud and flower drop and pink berry formation are major ones.

Uneven ripening

Presence of green berries in a ripe bunch of coloured grapes is called uneven ripening. It is a varietal character and a problem in Bangalore Blue, Bangalore Purple, Beauty Seedless and Gulabi grapes. Within a variety this problem varies from bunch-to-bunch. Generally inadequate leaf area, and non-availability of reserves to a developing bunch is the reason. Cultural practices like cluster thinning, girdling and use of growth regulators can reduce uneven ripening. Application of Ethephon (250ppm) at colourbreak stage is recommended to reduce the problem.

Postharvest berry drop

This is due to weak pedicel attachment to the berries. This is common in Anab-e-Shahi, Cheema Sahebi and Beauty Seedless. Spraying of NAA (50ppm), a week prior to harvesting can minimize the post-harvest berry drop.

Flower-bud and flower drop

When panicles are fully expanded, the flower-buds drop before the fruit set. This is common in north India but not in the south. The reasons for this disorder are not known. Stem girdling about 10 days prior to full bloom can reduce the problem.

Pink berry formation

It is a common disorder in Thompson Seedless and its clone Tas-A-Ganesh in Maharashtra. Pink blush develops on a few ripe berries close to harvesting. The pink colour turns to dull red colour and the berries become soft and watery. They do not stand for long after harvesting. Although the definite cause of the disorder is not known, it is recommended to spray a mixture of 0.2% ascorbic acid and 0.25% sodium diethyl dithiocarbamate at fortnightly intervals commencing berry softening.

Nutritional Value
 
TOP
 
Chromosome Number: 22
Taxonomic Classification
Class
:
Magnoliopsida
Order
:
Myrtales
Family
:
Myrtaceae
Genus
:
Psidium
 
Guava is a very popular fruit. It is available throughout the year except during the summer season. Being very hardy, it gives an assured crop even with very little care. Its cost of production is also low because its requirements for fertilizer, irrigation and plant protection are not much. Further its nutritive value is very high. Therefore it is an ideal fruit for the nutritional security. Guava is also grown as a backyard fruit to a great extent. Best quality guavas are produced in Uttar Pradesh, particularly in Allahabad region.
   
Climate and soil  

Owing to its hardy nature, guava is grown successfully in tropical and subtropical regions up to 1,500m above mean sea-level. Best quality guavas are obtained where low night temperatures (10°c) prevail during winter season. It tolerates high temperatures and drought conditions in north India in summers but it is succeptible to severe frost as it can kill the young plants. An annual rainfall of about 100cm is sufficient during the rainy season (July–September). The rains during harvesting period, however, deteriorate the quality of fruits.

Guava is cultivated on varied types of soils—heavy clay to very light sandy soils. Nevertheless, very good quality guavas are produced in river-basins. It tolerates a soil pH of 4.5–8.2. Maximum concentration of its feeding roots is available up to 25cm soil depth. Thus the top soil should be quite rich to provide enough nutrients for accelerating new growth which bears fruits.

 
Varieties

The varietal characteristics in guava are not as distinct as found in majority of other fruits. Its propagation through seeds reduces the distinctive characteristics of a variety in commercial cultivation. Important guava varieties are:

Lucknow 49

Also known as Sardar, its fruits are large, roundish-ovate in shape, skin primrose-yellow and pulp white, very sweet and tasty. The TSS and vitamin C contents are high. The plants are vigorous.

Allahabad Safeda

The most famous variety of Allahabad, it has acquired large variations due to seed propagation. The fruits are large in size, round in shape, skin smooth and yellowish-white. The flesh is white, firm, soft having pleasant flavour, high TSS and vitamin C content. The seeds are numerous, bold and hard. The trees are tall with profuse branching and broad crown. It can withstand drought conditions.

Chittidar

This variety is very popular in western Uttar Pradesh. The fruits are characterized by numerous red dots on the skin, high sweetness, and small and soft seeds. It is otherwise similar to Allahabad Safeda fruits in size, shape and pulp. It has higher TSS content than Allahabad Safeda and Lucknow 49 but lower vitamin C content. The tree characters resemble to those of Allahabad Safeda.

Harijha

Harijha is more popular in Bihar because of profuse bearing. The trees are of medium vigour due to sparse branching. The fruit is round in shape, medium large in size and greenish-yellow in colour. Flavour is sweet with good keeping quality.

Hafshi

It is a red-fleshed guava having good taste. It is mainly grown in Bihar. Fruit is of moderately big-size, spherical in shape with thin skin. Trees are of medium vigour but productive.

Apple Colour

Its fruits are medium-sized and pink-coloured. They are sweet in taste with good keeping quality. They require temperature for the development of good pink colour. The trees are of medium vigour but their leaves are greener than others. However, it is a moderate-yielder.

Seedless

All the seedless varieties—Saharanpur Seedless, Nagpur Seedless and others—are the same. Two types of fruits, completely seedless and partly seeded, are borne on a plant of seedless variety. The completely seedless fruits develop on the shoots rising from the stem and these are bigger in size and irregular in shape. The partly seeded fruits are born on normal shoots at the periphery and are small in size and round in shape. Seedless variety is unfit for commercial cultivation because it gives very low yield. The plants are very vigorous.

Arka Mridula

This is a seedling selection of variety Allahabad Safeda. Its medium-sized fruits are of excellent quality with high TSS. The white pulp has only few soft seeds. The plants are of medium vigour but high-yielding.

Allahabad Surkha

Allahabad Surkha is an outstanding variety of large, uniform pink fruits with deep pink flesh. The plants produce up to 120kg fruits in its sixth year of fruiting. The fruit is sweet, strongly flavoured with few seeds and is slightly depressed at both ends. The plants are vigorous, dome-shaped and compact.

   
Propagation

Guava is propagated both by seeds and vegetatively. But vegetative propagation is commercially followed.

Seed propagation

The propagation of guava through seeds should not be encouraged because the seedlings have long juvenile phase, give lower yields and bear poor quality fruits. But the seedlings serve as rootstock material for grafting or budding. The seeds should be sown as soon as possible after extraction from the ripe fruits. Soaking of seeds in water for 12hr or in hydrochloric acid for 3 min. gives about 90% germination. About 1-year-old seedlings become ready for grafting or budding. For planting seedling, seeds should be collected from the plants producing high-quality fruits and high yield.

Vegetative propagation

In northern India, guava is propagated by inarching, giving a very high percentage of success during rainy season. But inarching is cumbersome and gives limited number of plants from the mother plant.

Budding has been adopted only on a limited scale in some parts of the country where the atmospheric humidity is high. The main problem encountered in this method is disbudding of rootstock making it labour-intensive. Among the various methods of budding—shield, forkert, patch and chip—the patch budding is ideal giving highest percentage of success. However, the best time of budding differs from locality-to-locality.

Layering is being commercially followed in the southern and western India with very good results. After bending the plant, its branches are covered with soil leaving the terminal portion open. In a few months the rooting of branches takes place which are then separated from the mother plants and planted in the nursery for further sale. Layering is a labour-intensive method. A limited number of plants can only be multiplied from a mother plant.

When mother plants are very tall, air-layering of shoots is done during the rainy season using polythene and moist sphagnum moss. Use of root-promoting plant growth regulator, IBA (3,000ppm), promotes the rooting of air-layers up to 100%. The main limitation of air-layering is the poor establishment of air layers in the nursery after detachment from the mother plant. Further, the method is very cumbersome and labour-intensive.

Stooling is the easiest and cheapest method of guava propagation. The self-rooted plants (cuttings or layers) are planted 0.5m apart in the stooling bed. These are allowed to grow for about 3 years. Then these are cut down at the ground level in March. New shoots emerge on the beheaded stumps. A 30cm wide ring of bark is removed from the base of each shoot rubbing the cambium of the exposed portion in May. All the shoots are mounded with the soil to a height of 30cm. The soil is covered with mulch to conserve the moisture. After a period of 2 months of the onset of monsoon, the shoots are detached from the mother plant at ringed portion and planted in the nursery. The shoots are headed back to maintain the root and shoot balance before planting in the nursery.

By following the technique of ringing and mounding of the shoots, second time stooling is done on the same mother stools in first week of September. The rooted stool layers are detached in first week of November. Thus stooling is done twice on the same mother stools in a year. The stooling of a mother stool can be done for many years. With the advancement in its age, the number of stool layers also increases every year. The growth and development of stool layers are better than seedlings. The application of rooting hormone is not required.

A semi-dwarfing rootstock for guava Aneuploid 82 has been developed.

   
Cultivation  

Planting

The field for planting is prepared during summer season by ploughing, levelling and removing weeds. The pits of 1m × 1m × 1m size are dug and filled with a mixture of farmyard manure and soil. If soil is good and irrigation facilities are available, the preparation of land and digging of pits are not required. The planting is done during the rainy season by adopting square planting system.

Guava is commercially planted at a distance of 5–8m. The exact planting distance is, however, decided according to variety, soil fertility and availability of irrigation facilities. Guava Lucknow 49 needs more spacing than Apple Colour and Allahabad Safeda. Under irrigation and high soil fertility, the plants become very vigorous requiring more spacing. In normal conditions, a planting distance of 7m is optimum. High-density planting reduces total soluble solids, sugars and ascorbic acid but increases titratable acidity. The lower plant population results in the spread of crown, while higher planting density causes erect growth of branches making the plant tall and compact. High-density planting gives higher yield/unit area in early years of fruiting.

Training/pruning

Traditionally, no pruning is done in guava because the plant bears heavily even without it. But no pruning results in the formation of narrow crotches, limb breakage due to heavy fruit load and overcrowding. Therefore, training of plants in young stage to build strong framework and to avoid weak crotches is necessary, whereas fruiting trees should be pruned to check overcrowding in the orchard. The plants should be trained as low headed trees to facilitate multiple hand pickings. The open centre or delayed open centre system may be adopted. The scaffold branches in young plants are to be tipped back to encourage secondary branching. The root suckers, water sprouts and criss-cross branches are to be removed altogether. In Maharashtra, bending of horizontal branches is practised to some extent by tying the branches of 2 adjoining plants to increase fruiting in young plants but it is labour-intensive and creates hindrances in cultural operations.

In every growing season, a large number of new shoots emerge in guava a majority of which are lateral and a few are terminal. These shoots produce fruits. After 1 year most of the lateral shoots dry out, while terminal shoots put forth the extension growth. Hence, to check the overcrowding and to control the plant height, the terminal shoots on the periphery may be headed back at about 40cm level in alternate years. Pruning also takes place during harvesting as the fruit is plucked along with the shoot on which it is borne. Pruning is usually recommended after harvesting or in spring. Summer pruning may damage the plant by sun burning.

Manuring and fertilization

Although guava is grown without the application of any manure and fertilizer, it responds very well to their application by giving higher yield and better quality fruits. For guava-growing regions of the country, different fertilizer schedules—600g N, 400g K in northern region; 260g N, 320g P and 260g K in eastern region; 900g N, 600g P and 600g K in southern region and 600g N, 300g P and 300g K/plant/year in western region—have been recommended. The fertilizer application should be based on leaf nutrient status of an orchard, wherever feasible.

Time of fertilizer application depends on the crop taken and the region. In north India, fertilizer is given in the first week of May for rainy season crop and in first week of July for winter season crop. In West Bengal, fertilizers are applied in 2 equal split doses, one in January and the other in August. At Bangalore, full K and 70% N are applied in June and full P and 30% N in September. Since 48% of feeder roots of guava are found in the surface soil up to 25cm depth, the fertilizer should be placed in 25cm trenches 1m away from the trunk for better uptake.

Sometimes guava suffers a deficiency which is characterized by reduction in leaf size, interveinal chlorosis, suppression of growth and dieback of leaders. It can be corrected by spraying of ZnSO 4 (0.45kg) and hydrated lime (0.32kg) in water (33 litres). Bronzing is another common problem in guava. It is caused by the deficiency of B, Zn, N, P and K due to low soil pH. The soluble P level of leaves is a better index for bronzing. Guava Lucknow 49 is more susceptible than Allahabad Safeda. It can be reduced by improving the soil pH and treating the soil with N, P, K and Zn at 200, 80, 150 and 80g/year respectively, or fortnightly foliar spraying of these nutrients each at 2% for 4 months.

Aftercare

Guava plants do not require much care after planting. The weeds are removed by shallow cultivation. Green manuring should be done during rainy season and clean cultivation during rest of the year. Leguminous crops can be grown as intercrops during first 3 years of planting to obtain more income and to increase the N content of the soil.

Both rainy and winter season crops are very heavy compared with spring crop. Fruit quality of the winter crop is best. Therefore, winter crop is preferred over the rainy season crop. In northern India, normally hot and dry summers along with low soil moisture do not allow summer flowers to set the fruits. But in mild summer and normal soil moisture, the summer flowers set fruits for rainy season crop which is known for its poor quality fruits and severe incidence of fruit fly and fruit-borer. The practice of taking winter crop instead of rainy season crop is known as crop regulation.

The rainy season crop can be removed by spraying of urea (10%) on Allahabad Safeda and 20% on Lucknow 49 at the time of peak flowering in summer season. Other methods of removing rainy season crop are hand removal of flowers and fruits, spraying of bioregulators, root exposure, withholding irrigation and pruning of  ¾th of flower-bearing shoots are either costlier or impractical or ineffective.

Irrigation

Guava is mostly grown under rainfed condition and irrigation is rarely practised wherever this facility is available. However, irrigation enhances the yield of guava by making the plant more vigorous and increasing the fruit set. Irrigation is especially desirable after planting for survival of the plants and thereafter for 2–3 years to obtain early good growth. Irrigation of fruiting plants depends upon the adoption of a particular cropping pattern. For the whole year, cropping pattern which is commercially adopted all over the country except the northern region, irrigation is given during summer and autumn season and for the rainy season crop, the irrigation is essential during summer season. Normally, winter season cropping pattern is adopted in north India which requires fortnightly irrigation during October–November. Irrigation is given to make the soil of root zone moist; thus heavy irrigation is unnecessary. The fruit quality of guava is adversely affected by high soil moisture content during harvesting.

   
Harvesting & Postharvest management

Guavas are harvested throughout the year (except during May and June) in one or the other region of the country. However, peak harvesting periods in north India are August for rainy season crop, November–December for winter season crop and March–April for spring season crop. In the mild climatic conditions of the other parts of the country, the peak harvesting periods are not so distinct.

Guava fruits develop best flavour and aroma only when they ripen on tree. In most of the commercial varieties, the stage of fruit ripeness is indicated by the colour development which is usually yellow. For local market, fully yellow but firm fruits are harvested, whereas half yellow fruits should be picked for distant markets. The fruits are harvested selectively by hand along with the stalk and leaves.

The plants begin bearing at an early age of 2–3 years but they attain full bearing capacity at the age of 8–10 years. The yield of a plant depends on its age, cropping pattern and the cultural practices. A 10-year-old plant yields about 100kg of fruits every year. If both rainy and winter season crops are taken, more yield may be obtained in the rainy season.

Ripening of guava starts on the tree and continues even after harvest. It is accelerated in rainy season due to high temperature and slows down in winter season due to low temperature. The fruits are packed in baskets made from locally available plant material. For distant markets, wooden or corrugated fibreboard boxes are used along with good cushioning materials—paddy straw, dry grass, guava leaves or rough paper. Good ventilation is necessary to check build up of heat. Guava is a delicate fruit requiring careful handling during harvesting and transporting. The fruits should reach the consumer in a firm condition.

Because of their perishable nature, guavas are disposed off immediately after harvesting in the local market and a very small quantity is sent to distant markets. Since fruits are sold at a cheaper price and are available for a very long period of the year, they are not kept in cold storage. However, shelf-life of guava can be extended up to 20 days by keeping them at low temperature of 5°c and 75–85% relative humidity. It can also be stored for about 10 days at room temperature (18°–23°c) in polybags providing a ventilation of 0.25%.

   
Physiological Disorders

Guava wilt

Guava plants are attacked by wilt, which alone causes heavy losses. It is very difficult to find out an orchard of guava more than 30 years in age because most of its plants die at about 20 years of age due to wilt. Varius fungi causing wilt are Fusarium roseum oxysporum f. psidii, F. solani, Macrophomina phaseolina and Gliocladium roseum . Resistant rootstock is the only solution. The planting material should not be obtained from a wilt-infected region or nursery. 

Nutritional Value
 
Usage

Food use

 

Fresh
Both ripe and green fruit are usually eaten raw. The fruit may also be stewed and used in shortcakes and pies. It is also dried into dehydrated slices.

Processed food
Guava fruit may be processed into juice or puree. Other processed products include clarified juices, nectar, jams, jellies, guava cheese and spread. Guava may be cut into cubes, halves or slices and canned in syrup.

The oil from guava seeds can be used in salad dressings.

 

Non-food uses

 

Fibre
The high tannin content in the leaves makes it suitable as a dye for cotton and silk fabric as well as woven mats.

Wood uses
The hard strong heavy guava wood has a specific gravity of 0.8 and makes excellent firewood and charcoal. The hard and even-grain wood is also used for making wood carvings, spears handles, chisels, catapults, fishing rods, tree-nails, household and agricultural implements, posts for small houses and fence-posts.

 
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Chromosome Number: 26
Taxonomic Classification
Class
:
Magnoliopsida
Order
:
Sapindales
Family
:
Burseraceae
Genus
:
Commiphora
 

Guggal or Indian bdellium is a large spinescent shrub to a small tree inhabiting drier parts of western India, mainly Rajasthan and Gujarat. Its gum-resin is used in Ayurvedic medicines as a remedy to reduce cholesterol content in blood. The active principle of gum-resin is Z and E gugglusterones which has anti-inflammatory and hypoglycemic properties. It has also utility in treatment of arthritis and obesity. The entire demand of gum-resin in pharmaceutical industry is being met from tapping of wild growing plants for centuries but the number of trees have dwindled in nature considerably now and a part of the demand is met by regular import from neighbouring Pakistan. Its small-scale cultivation has been established in Kutch (Gujarat) and western districts of Rajasthan. A large plantation exist (30ha) in Ajmer district of Rajasthan.

Guggal is a woody, perennial shrub to small tree, 3–5m tall with spirally ascending spinescent branching. The leaves are 1–3 foliate, thick, rhomboid to ovate in shape with irregular margins. The tree defoliates in rainy season. Stem is pale-green, covered with papery exfolding. The flowers are small, borne 2–3 in a fascicle, brown to pink in colour. Most flowers are bisexual but male and female plants are also reported to occur in nature. Fruit is a drupe, 6–8mm across, ovate in shape, green, changing to red on ripening. It has 2 stony seeds.

Guggal can be grown in well-drained calcareous, silty-loam to loamy soils of varying fertility. It grows luxuriouly under extreme temperature (summer 40°C and winter touching zero) in areas receiving low (10–40cm) rainfall, but abundant sunshine. These soils have low N and P but high in K, Fe, Mn, Zn and Cu. It is a very slow-growing plant, taking 7–8 years to reach maturity for tapping. There is no commercial variety identified or evolved for its commercial plantation. A new plantation can be raised from semi-woody stem-cuttings. The seeds are sowin in July. They germinate in 10 days and may continue up to 6 months, yielding 10–15% germination. For vegetative propagation, a 30–65cm long, semi-woody stem with a few nodes and of 10–15mm diameter treated with IBA solution on cut end is used. It is planted in well-prepared moist nursery beds during June. It takes 8–10 months to sprout. About 80% of these planted material yield new plants. These are ready for field planting in the next rainy season.Air-layering is successful. It can be done in June–August; after 2 months, these rooted plants could be separated and planted directly in field.

The land for field planting is well prepared, giving deep ploughing. The soil is exposed to hot sun for weathering to desiccate all pereniating weeds. It is given 20kg of Aldrin (10%) at land preparation to protect the plants from termite attack. The pits of 50cm × 50cm × 50cm size are dug out at 2m × 2m spacing, accommodating 2,500 plants/ha. The pits are filled with well-rotten farmyard manure mixed with a tablespoonfull of Aldrin or Gamaxine. The pits are given soaking irrigation before planting, followed by one irrigation/month till next rainy season. Use of N and P does not give any positive response either on growth or gum yield. But low level of irrigation gives positive response in registering high rate of growth in Rajasthan and Gujarat. Wherever, annual pruning of lateral branches is carried (leaving only 2–4 branches), the bushes attain better height and larger girth of main trunk and lateral branches in a shorter duration. The plantations are given 1–2 weeding-cum-hoeings in a year.

The plants attain 3–5m height in 7–8 years and 3–4cm thick main trunk and some lateral branches. The trunk is ready for tapping during autumn season (December–February). The tapping is done by giving 9–11cm long triangular or circular cut, 40cm above the ground. The depth of the cut should never exceed the thickness of the bark, as resin ducts inhabit this part and may injure pholem and cambium part, causing damage to trees besides obstructing outflow of gum-resin. A paste of gum-resin in water is applied at the incised spot and bandaged to potentiate flow of gum-resin (guggal). The flow of gum starts 3–7 days after tapping and is exhausted in next 15–20 days. Since gum-resin gets hardened on exposure to air, it is collected in earthen cups fixed below the cut part. Two to three collections of gum are possible in a season. Use of 40mg of ethephon (2-chloroethyl phosphoric acid) fed to the roots through injection can increase the flow of gum and maximize yield significantly. The yield of a tree may vary from 200–500g/ season. However, tapped branches or the entire tree die 8–10 months after yielding the gum. The cause (either physiological or pathological) is not yet known.

The gum is pale-yellow aromatic sap, which gradually hardens on exposure to form golden-brown to reddish-brown mass. It is a complex mixture of diterpenes, aliphatic esters, steroids, carbohydrates, inorganic ions and essential oil. The growing demand of guggal gum and rise in price has brought adulteration of several gums (like Katira, Damar and Senegal) in the market. Samples can be easily distinguished on chemical testing.

   
 
 
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