Moisture Hysteresis Studies on Seeds of Some Varieties of Wheat

Moisture sorption and desorption study of 13 cultivated wheat varieties belonging to Triticum aestivum and Triticum durum species has been carried out. Moisture desorption and absorption isotherms for 50 seeds each of these varieties in five replications were recorded at 30°C and 85% R.H.(relative humidity). Analysis of data reveals that: (1) Varieties classified under rainfed cultivation have negative or smaller area under their moisture hysteresis loops compared to that for seeds of cultivars classified for irrigated cultivations. As such, area under hysteresis curve can be used as a basis for segregation between the rainfed and irrigated varieties. (2) Rehydration of seeds of rainfed varieties is very fast in the first 2 hours and in 3 of the 4 cases rehydration curve overshoots the dehydration curve. As such, the ratio of moisture status of desorption and absorption after 2 hours is also a good index for segregation between the rainfed and irrigated varieties.