Experimental site: The experiment was conducted at different locations of Barisal Sadar and Babuganj Upazila of Barisal district (located in between 22°27' and 22°52' north latitudes and in between 90°01' and 90°43' east longitudes) and Dumki Upazila of Patuakhali district (located in between 21°48' and 22°36' north latitudes and in between 90°08' and 90°41' east longitudes) in the year 2018. Eight (8) velvet apple germplasms were included for this study. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Samples of leaves, flowers and fruits were collected from each location and carried them to the laboratory of the Department of Horticulture, Bangladesh Agricultural University, Mymensingh for characterization. Data were recorded on various leaf characteristics (leaf shape, color, margin, apex, base, length, width, area, petiole length and width), flower traits (bud length, sepal color, length, width, petal color, length, width, pedicel length and flower position), fruit traits (fruit shape, skin color, flesh color, sweetness of flesh, fresh fruit weight, length, width, total soluble solids (TSS), moisture and dry matter content and vitamin C and seed characteristics (seed size, color, number, weight, length and width). Leaf area was determined by using leaf area meter (LI -3100C, LI-COR Bioscience, USA).
Determination of TSS (% Brix): TSS content of velvet apple pulp was determined by using Abbe’s Hand refractometer (Atago Co. Ltd., Japan). A drop of velvet apple juice squeezed from fruit pulp on the prism of the refractometer. Percent TSS was obtained from direct reading of the instrument. Temperature corrections were made by using the methods described by Ranganna (1979). Determination of moisture and dry matter content (%): Twenty grams (20g) of fruit flesh was taken in an aluminum foil and kept in an electric oven at 80°C for 72 hours until the weight became constant. Thereafter, the percent moisture content of fruit was calculated using the following formula: Percent dry matter content was calculated using the following formula:
% dry matter = 100 – % moisture content
Determination of vitamin C: It was determined according to the method of Plummer (1971). 6% metaphosphoric acid solution, 10% standard ascorbic acid solution and 2,6 dichlorophenol indophenol solution were used for the determination of vitamin C. Five ml of aliquot was taken in a conical flask and titrated with dye solution. The vitamin C content was calculated by using the formula.