WHEAT PHASIC DEVELOPMENT UNDER DIFFERENT SOWING WINDOWS UNDER RAINFED CLIMATE
In rainfed areas of Pakistan, erratic rainfall causes variation in sowing window of wheat starting from mid of October and extends until the end of December. The development of wheat plant is a continuity of vegetative phase, reproductive phase and the grain-filling phase. So, to determine the changes in timing of developmental events during the crop-growing season Wheat cultivar, Wafaq-2001, was planted in four sowing windows (22 October, 13 November, 4 December and 24 December) in the field area of National Agricultural Research Centre (NARC), Islamabad. Observations of crop phenology began at the emergence of first leaf and continued until the maturity when yield data was measured. The study revealed that environmental factors play an important role in determining the duration of each phase in the given agro-ecological conditions. The duration of these phases is strongly influenced by the changes in sowing dates. The major components of the environment that affect development are temperature and photoperiod. There are association between sowing window and the yield and also between the duration of phases and yield. So, it becomes important to be able to manipulate the duration of these phases to customize cultivars for specific environments and get the potential yield in a given environment on sustainable basis.
Keywords: Wheat, phasic development,phenology, sowing windows
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