Influence of chemical fruit thinning on thinning level, fruit yield and quality in nectarine cv. may fire

The present investigations were carried out on 12-year old trees of nectarine cultivar May Fire raised on wild peach seedling rootstocks during 2014 and 2015. Experimental trees were subjected to nine different treatments NAAat 40 and 60 ppm; Ethrel at 200 and 300 ppm applied one and two week after petal fall at 40 ppm when applied two weeks after petal fall resulted insignificantly higher thinning, decreased yield and increased fruit size and weight over the control. Fruit TSS, and total sugar contents were higher and fruit acidity and firmness were lower in the fruits from trees treated with NAA at 60 ppm when applied two weeks after petal fall. Fruit surface colouration was higher in fruits from trees treated with Ethrelat 300 ppm, two weeks after petal fall Fruit thinning percentage, yield, fruit size, fruit weight, fruit colouration, fruit TSS and total sugar contents were significantly lower and fruit firmness higher in control as compared to all the chemical thinning treatments.