BETA-CAROTENE CONTENT OF POSTHARVEST ORANGE-FLESHED MUSKMELON FRUIT -EFFECT OF CULTIVAR, GROWING LOCATION AND FRUIT SIZE

The influence of two growing locations (soil types), six fruit sizes, and two years on the postharvest Beta-carotene content of muskmelon (C ucumis melo L. var. reticulatus Naud) fruit was studied with two diffe rent cultivars. Fully abscised commercial size fruit: 9, 12, 15, 18, 2 3, and 30 (fruit/0.04 M(3) shipping box) had highly variable Beta-caro tene contents (5.3 to 33.8 mu g/g fresh weight) that varied by size cl ass, soil type and cultivar. Beta-carotene content increased with frui t size up to a maximum, though fruit size continued to increase. Find sandy loam soil produced fruit with less Beta-carotene content than si lty clay loam soil. The cultivar Prime contained higher Beta-carotene content levels than cultivar Cruiser. Mesocarp percent moisture conten t for both 'Cruiser' and 'Primo' at both locations by fruit size was n ot significantly correlated (r = 0.40) with Beta-carotene content. Ind icating fruit cell dilution may not contribute to the differences in B eta-carotene content in different fruit size classes. Beta-carotene co ntent of size class '18' fruit from six cultivars grown on the silty c lay loam soil for two consecutive years, showed a year, and year by cu ltivar effect for some cultivars. Whereas, some cultivars did not diff er in Beta-carotene content between the two years. This indicates a po tential for controlling Beta-carotene content of muskmelon fruit at a constant, high level by careful selection of production cultivar.