Chemical Thinning of Wilk1Ng Mandarin

Wilking mandarin—a sister hybrid of Kinnow, has a heavy bearing behaviour with small and unattractive fruit size. In order to reduce the initial fruit set, NAA (300 ppm and 600 ppm), MH (1000 ppm and 2000 ppm), Carbaryl sevin (5000 ppm and 10000 ppm) and water spray as control; were sprayed on the full trees during fruiting seasons of 1982 and 1983. MH and Carbaryl were sprayed at full bloom stage, whereas NAA during May just before June drop. Though all the treatments significantly reduced the fruit set over control, NAA was observed to be more effective. Minimum fruit setting (5.31 per cent) was obtained with NAA (600 ppm) against coutrol (16.23 per cent) without mnch altering the fruit quality. Hence, spray of NAA (600 ppm on marble sized Wilking fruits (3rd week of May) is recommended for large sized and quality fruits.