| Effect on seed viability of wheat varieties at various
maturity levels and moisture content P.D. BHARGAVA, P.C. TYAGI, M.A.Q. KHAN and R.P. CHANDOLA Government Agricultural Research Station, Durgapura, Rajasthan, India Wheat production in Rajasthan sometimes becomes very risky due to sudden variation in temperature and other climatic conditions like hail storm and high wind velocity after flowering. These hazards are very common in Rajasthan due to its geographical position and arid conditions. In order to save the crop or get higher yield or reduce the production cost it may be advantageous to harvest the crop early. No information is available on effect of harvesting the wheat crop at different stages of maturity in relation to the yield and viability of seeds. To acquire this knowledge present studies were taken-up to find out the effect on germination of wheat seeds with reference to different number of days to harvest after certain intervals from full flowering onwards. An experiment was taken at the State Agriculture Research Farm, Durgapura, Rajasthan, during Rabi 1966-67, with seven recommended wheat varieties having different maturity periods and suitable for different tracts of this State. The varieties studied were C. 281, R.S. 31-1, N.P. 718, Sonora-64, S. 227, C. 591 and Lerma Rojo. C. 281 started earing in 64 days, while the varieties R.S. 31-1, N.P. 718 and Sonora-64 flowered after 68 days of sowing. The variety S. 227 flowered after 77 days from sowing and variety C. 591 and Lerma Rojo started earing after 80 days from the date of sowing. Harvesting was started after 20 days of flowering and further on 25th, 32nd, 37th, 44th, 51st and finally on 59th days in all cases. In every harvest 50 earheads were collected. Each sample was hand threshed for a moisture-test and soon after the threshing, was divided in two lots - one was taken for an immediate moisture determination and another for drying at room temperature for 30 days. The average maximum and minimum temperatures during this period happened to be 30C and 17.5C respectively. In all cases the dried seed samples were tested for moisture content and were germinated between wet blotters in petridishes and in moist sand trays. The temperature was maintained at 20C. Data on days to flower, days to harvest, moisture content and germination percentage in all the studied varieties were recorded and are given in Table 1. From the results, it appeared that all the varieties if harvested at higher moisture percentage show a decline in germination percentage. As in wheat variety N.P. 718 at 45% moisture content the germination is 56% while the seed harvested at 27% moisture content, germination improved up to 86%. This type of moisture-germination relationship was observed in all the wheat varieties studied (Table 1). |
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