Evaluation of various plant growth regulators in flower and fruit setting of litchi

Background: Huge economic loss of litchi was identified as a problem in Malda district of West Bengal in 2013-14. The loss of litchi is due to mainly litchi fruit drops. This problem occurs due to lack of growth regulators or absence of micronutrients which are responsible for flowering and fruiting such as naphthalene acetic acid (NAA), triacontanol, zinc, and boron. Objective: To solve this problem, we took up a trial during 2014-2015 at different locations in Malda district to assess the performance of different growth regulators to increase productivity of Litchi with four treatments and seven replication. Materials and Methods: The treatment was T1: Use of boron at 300 ppm + Zinc ethylenediaminetetraacetic acid at 1.5 g/L of water, T2: Triacontanol at 0.30 ppm, T3: NAA at 20 ppm, and T4: Farmers’ practice: No use of growth regulators from the trial. Result: It was found from the experiment that the highest fruit weight was about 23.26 g by application of NAA at 20 ppm. Conclusion: It can be concluded that the performance of growth regulators play a positive role in the production of litchi. It further revealed that T3, i.e., use of NAA at 20 ppm recorded the highest yield of 121.0 q/ha and B/C ratio was 1.83.