More female flowers in lychee and longan: the key is regulating flowers and fertilizer
In the early stage of flower bud differentiation and development, the male and female parts of the same flower in lychee and longan differentiate and develop together, and the sex of each flower is not determined until 20-25 days before flowering, so sex determination is highly plastic. The male-to-female ratio of a flower panicle is affected by a combination of ambient temperature, internal nutritional status and hormone levels. After years of observation...
In the early stage of flower bud differentiation and development, the male and female parts of the same flower in lychee and longan differentiate and develop together, and the sex of each flower is not determined until 20-25 days before flowering, so sex determination is highly plastic. The male-to-female ratio of a flower panicle is affected by a combination of ambient temperature, internal nutritional status and hormone levels. After years of observation and trials, the author has found that the following measures can increase the proportion of female flowers.
1. Spray Yuhualing No. 2 as soon as red spots appear on longan
This product is rich in the plant proteins needed for fruit trees to flower, can promptly supplement small-molecule organic nutrients, triggers the expression of flowering factors in fruit trees, and can effectively promote the conversion of vegetative growth into reproductive growth. After spraying, it provides sufficient nutrient accumulation for flower bud differentiation, promotes female flower differentiation, increases the number of female flowers and raises the proportion of female flowers. Yuhualing dosage: dilute each bottle (80ml) in 15-20 kg of water, spray on a sunny day, wetting the leaf surface and underside until it is about to drip.
2. Control fertilizer and flowers, cultivate robust flower panicles in the right amount, and increase the proportion of female flowers
① Control fertilizer and reduce flowers early, then increase fertilizer to strengthen flowers later. When awakening flower buds, the fertilizer amount should be small; generally apply only 150 grams of fertilizer per meter of canopy diameter, just enough to awaken and push out the panicles, using a small amount of fertilizer to control the number of flowers; generally 500-1000 flowers per panicle is sufficient. When the panicle has differentiated to the flower bud stage and the panicle length is already fixed, apply more organic fertilizer to strengthen the flowers. Without causing excessive vegetative vigor, increasing nitrogen fertilizer can raise the proportion of female flowers; for example, drenching with fermented peanut bran liquid or fermented chicken and duck manure liquid, applying 0.25 kg of peanut bran per meter of canopy diameter can enhance photosynthesis. In this way, each flower obtains more photosynthetic product, promoting female flower differentiation and increasing female flowers.
② Thin flowers in time to reduce flower number and ensure each flower gets sufficient photosynthetic product. Panicles that emerge early have a longer growth and differentiation period, become especially large, and carry too many flowers, which leads to excessive nutrient consumption at flowering and increases fruit drop during the small fruit stage. More importantly, when there are many flowers, each flower gets very little of the limited photosynthetic product, organic nutrition is insufficient, female flowers develop poorly, and there are fewer female flowers. Therefore, large panicles must be thinned into small panicles, keeping 500-600 flowers per panicle. When thinning, remove the tips of long branches and remove overly dense, overly long and weak flower branches. However, whether lychee or longan, the method of thinning whole panicles must not be used, otherwise it will stimulate summer shoots and worsen fruit drop.