Abstract
The seasonal fluctuation of the physical and biochemical characteristics of three tomato (Lycopersicon esculentum Mill.) cultivars, Lady First and Momotaro (large-fruited) and Minicarol (cherry-fruited), were studied at seven different sowing times at harvest intervals of 45 days. Seasonal variations were noted in the external and internal quality characteristics. Fruits ripened rapidly during the summer followed by a progressive decline towards the winter season. Fruits harvested during the early winter to spring had higher constituents compared to the summer season. The fruits that matured during the summer season showed higher accumulation of organic and ascorbic acid and the crop duration was shortened. On the other hand, the fruits that matured during the winter to spring season were firmer, had higher soluble sugars, and a longer growing period. The red colour formation was enhanced during the spring and winter seasons. Of the five climatic factors recorded, temperature was predominantly implicated in affecting tomato fruit quality. The results indicated that firmness, total soluble solids, and turning point of hue (arctan b*/a*) acted as the indicator of fruit maturity, and breaker-stage was the more appropriate stage of harvesting in all the seasons studied. Considering nutritional value, appearance, and fresh consumption, the pink stage of ripening was the best for harvesting. In the present study, although cropping season and growing temperature differed widely, the cumulative temperature (°C days; from flowering to maturation) difference among the growing seasons was small, and the most suitable harvest period was found to be around 1000°C day. Thus, for consumption, marketing and transportation, fruits should be harvested around 1000°C days.
