MATURITY INDEX AND QUALITY OF 'KLUAI KHAI' FRUIT AS RELATED TO GROWING SEASON

Maturity index is very important to determine the harvesting time for exporting banana. Nowadays, growers use number of days after male flower cutting or angularity of fingers to determine the harvesting time. This study was conducted during October 2010-August 2011 in three growing seasons of ‘Kluai Khai’ banana at Sukhothai Province (winter season) and Chantaburi Province (summer and rainy seasons). The objective of this study was to determine the optimum time for the relationships between harvesting bananas and growing seasons and find out on bagging bunch materials. The trial was harvesting at different physiological ages, including 30, 33, 35, 37, 40, 45 and 50 days after male flower cutting. The results indicated that the optimum time for harvesting bunches (70-80% maturity) in winter, summer and rainy seasons were 45-50, 37-40 and 33-37 days after male flower cutting, respectively. The older the physiological ages the higher the starch contents, which were 12.11-17.69%. Most quality criteria at different physiological ages were not significantly different. Bagging bunches with paper coated with polyethylene bag gave lower skin defects. The growing degree days from flower bloom to harvesting in winter, summer and rainy seasons were 918-1008, 676-731 and 613-690 Celsius degree days, respectively.