Fruit retention, yield and leaf nutrient content of ber as influenced by foliar application of nutrients and growth regulators.

摘要

Foliar application of nutrients (urea 1.0%, ZnSO₄ 0.5% and potassium sulfate 1.0%) and growth regulators (GA₃ 50 ppm and NAA 20 ppm) significantly increased the fruit set, fruit retention and fruit yield of ber over control. Maximum fruit set (9.70 and 9.58%) and fruit yield (119.2 and 103.5 kg/tree) were obtained with foliar application of 0.5% zinc sulfate, closely followed by 20 ppm NAA treatment during 2002 and 2003, respectively. These treatments significantly reduced the fruit drop also and obviously increased fruit retention. However, potassium sulfate (1.0%) was not found effective for fruit set and fruit retention. Three numbers of sprays of these chemicals (at flower initation, 20 and 40 days after first spray) were found effective in increasing the fruit retention and yield. Leaf P and K contents increased by potassium sulfate (1.0%) and NAA (20 ppm) but decreased by urea sprays. Nitrogen and zinc contents of leaf increased by foliar application of urea and zinc sulfate.