Effect of forchlorfenuron and N-acetyl thiazolidine 4-carboxylic acid on vegetative growth and fruit set of apricot (Prunus armeniaca L.) cv. New Castle

Being the third important stone fruit crops of India, apricot still requires a great improvisation in production point of view. Bio-regulators are being used by the growers to increase the yield by improving the yield attribute parameters. Keeping the objective to increase the yield, in the recent studies; twenty six-year-old apricot cv. New Castle trees were subjected to 11 treatments viz. Forchlorfenuron (CPPU) at 5 and 10 ppm and N-acetyl thiazolidine 4-carboxylic acid (NATCA) at 50 and 100 ppm and their combinations were applied at pink bud and petal fall stage during the year 2015 and 2016. Out of the two time of spray the petal fall stage was found to be superior in both the years. Foliar spray of CPPU at 10 ppm increased the vegetative character like tree height (17.40 %), tree spread (22.17 %), tree volume (27.82 %) over control. However an increase the fruit set (52.71%) and fruit retention (38.12%) was noticed by NATCA (100 ppm) at petal fall stage. Keeping all the observations in consideration CPPU 10 ppm at petal fall stage was found to be best among all the treatments.