Simulating growth, development, and yield of wheat in warmer areas.
1990
Aggarwal P.K.
A validated crop growth simulation model, WTGROWS, was used to determine potential and rainfed wheat yields in different parts of the warmer areas that contrasted in thermal and humidity regimes. Historical weather data of 288 locations in Asia, Africa, and South America were used. Detailed analyses were performed for representative locations of dry and humid climates of warm, hot, and very hot thermal regimes. The results indicated that the mean yield potential of irrigated wheat was 8.80, 5.66, and 3.15 t/ha, respectively. At dry locations, yield of irrigated wheat was higher than humid ones. Yield decreased after the optimal date as a function of thermal regime, i.e., the lower the temperature the higher the reduction in yield. In late sown crops a common occurrence the difference between irrigated and rainfed yields became smaller. Late maturing crops are expected to yield more in very hot regions, both in irrigated and rainfed conditions, provided such varieties have reasonable grain number. Sowing in hot and very hot regions was relatively less sensitive to sowing date. Rainfed wheat yields are generally lower, but in humid environments they can be similar to irrigated yields if the crop is raised on soils that are deep, well drained, and free of root restricting layers. Early flowering in hot and very hot regions restricts root extension growth. The model can be used for determining agronomic prospects of growing wheat in more specific locations having similar environments to those used in this study.
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