Foliar sprays of KNO3 for flower induction in 'Pahutan' mango shoots.
Bondad N. D., Blanco E. A., Mercado E. L.
Author Affiliation: Department of Horticulture, College of Agriculture, UPLB, College, Laguna, Philippines.
Philippine Journal of Crop Science 3 : 251-255
Abstract : In 7 out of 8 monthly trials, flowering of 4.75 to 12.75 months old mango (Mangifera indica L. 'Pahutan') shoots occurred 1 week after spraying 10 to 160 g/liter KNO3. Induction was 33 to 100% in 7 to 14 days. The 9 months old shoots in December exhibited 100% flowering in 10 days. This was considerably better than the response of younger shoots except those in September which were sprayed twice with KNO3 because of rain. There was a general decrease in percentage flowering of treated shoots from January to April. In contrast, natural flowering which began in February tended to increase till May. Most newly emerged buds were plump and bent to star-like 1 to 2 days later. No consistent trend was observed in bud and panicle growth and those produced by KNO3 spraying appeared longer than natural. It was speculated that KNO3 may play a role in induction of floral differentiation probably via the nitrate assimilatory pathway. Single spraying with 10 to 160 g/liter KNO3 had practically no injurious effects on mango leaves but double spraying of 160 g/liter produced severe leaf scorching. Flowering of shoots at all levels and frequency of spraying KNO3 appeared normal. Under the conditions of these experiments single applications of up to 160 g/liter and double spraying of up to 80 g/liter were safe for 'Pahutan' mango.