INVESTIGATION OF BIOCHEMICAL NUTRIENTS AND REDUCTION OF DROPPING OF LITCHI FRUITS CV. BOMBAI UNDER DIFFERENT LEVELS OF 2,4-DPA

Abstract

Litchi is one of the major fruits in Bangladesh and popular to its high palatable, glorious style, and flavor. Litchi fruit dropping are the prime problem resulting in low production and reduction in the cash income of growers in Bangladesh. An experiment was conducted to investigate biochemical nutrients and to reduce dropping of Litchi fruits cv. Bombai under four levels of 2,4-DPA. The study was laid out in Randomized Complete Block Design using 2,4-DPA with following four levels for each i.e. control, 20 ppm, 30 ppm, 40 ppm respectively. The results revealed that 2,4-DPA improved litchi fruit quality and food nutrient values. The maximum fruit retention (33.25 per bunch), fruit weight (25.16g), fruit pulp weight (19.42 g), average ration of pulp to seed weight (5.99), pulp to peel ratio (7.79), fruit length (3.83 cm), fruit diameter (3.64 cm), seed diameter(1.39 cm), % ash (2.44 %), Vitamin C (4.63 mg/100g), Ca (30.06 mg/100g), P (24.59 mg/100g) , Zn (42.86 mg/100g), Fe (42.56 mg/100 g) and Carotenoid (4.22 mg g-1) in leaf with the spray of 20 ppm 2,4-DPA. At 30 ppm 2,4-DPA Chlorophyll a was maximum content (20.29 mg g-1) and Chlorophyll b was (8.850 mg g-1). The minimum content of chlorophyll a (13.91 mg g-1) and Chlorophyll b (6.18 mg g 1 ) were in H1 (control). The maximum % moisture content (84.03 %) was found at control and minimum (82.19 %) at 40 ppm. Again the maximum seed weight (3.61 g) and peel weight (2.89 g) were observed under control. The maximum seed length was (3.50 cm) by 40 ppm 2,4-DPA. The pH was maximum (4.08) by control and the minimum was (3.27) by 20 ppm 2,4-DPA. The highest reducing sugar was (3.97%) by 40 ppm 2,4-DPA while the minimum (2.77%) in control treatment. These results suggests that the foliar application of 20 ppm 2,4-DPA thrice at pea size, marble size and pre-harvest stages after fruit set may be suitable in litchi cultivating for the reduction of fruit dropping and improving food nutrients.