Leaf characteristics of non-deciduous fruit trees in relation to their suitability as host and non-host plants of Brevipalpus phoenicis (Geijskes).
Neena Singla, Sadana G. L.
Author Affiliation: Department of Zoology, Punjab Agricultural University, Ludhiana - 141 004, India.
Plant Protection Bulletin (Faridabad) 55 : 10-15
Abstract : A study was undertaken to determine the effect of various leaf characteristics on the suitability of plants as hosts and non-hosts of false spider mite, B. phoenicis. Kaghzi lime (Citrus aurantiifolia cv. Swingle), Kinnow (C. reticulata cv. Kinnow), Baramasi melon (C. limon cv. Baramasi), grapefruit (C. paradisi cv. Marsh Seedless) and galgal (C. limon var. galgal) and guava (Psidium guajava var. allahabadi) were the hosts plants, while mango (Mangifera indica var. desehari), cheeku (Manilkara achras [M. zapota] cv. Cricket Ball), jaman (Syzygium cumini), gulab jaman (Eugenia jambolana [Syzygium cumini]), pawpaw (Carica papaya cv. Pusa Dwarf) and banana (Musa paradisiaca) were the non-host plants. To determine the differences between the host and the non-host plants of B. phoenicis, size, shape and texture of leaves and nature of leaf surface with presence/absence of hair were recorded as qualitative, whereas frequency of stomata and moisture content of leaves were recorded as quantitative physical characteristics. The thin- and smooth-textured leaves and thick- and rough-textured leaves with hair and prominent leaf veins of the host plants may be responsible for their suitability as hosts of B. phoenicis. The thickness of upper and lower epidermis and spongy parenchyma of the non-host plants was found statistically greater than that of the host plants. However, the overall differences in the frequency of stomata, moisture content and thickness of upper and lower cuticle, hypodermis, palisade layer and total leaf thickness between the host and the non-host plants of B. phoenicis were found to be statistically non-significant, It can be stated that the physical and anatomical characteristics of leaves do help in preventing the reproduction of the mite from exceeding certain limits, but within the leaves it is the biochemical composition of the food that regulates fecundity.