Wheat yield components as affected by low water stress at different growth stages. Effect on ear length, grain weight and number of grain per ear
1996
Jamal, M. (Barani Agricultural Research Project, Kohat (Pakistan)) | Nazir, M.S. | Ahmad, N. | Shah, S.H. (University of Agriculture, Faisalabad (Pakistan). Agronomy Dept.) | Shah, N.H. (Agriculture Research Station, Bannu (Pakistan))
Three varieties viz, Pak 81, Punjab 85 and Kohinoor were subjected to low water stress (-10 bars leaf water potential) at tillering, jointing, boot and anthesis. Crop was sown in a split plot design. Water potential of the central leaves was determined on alternate day using Pressure Bomb till the desired level of water stress (-10 bars) was achieved. At this stage water stress was terminated by applying 7.5 hectare centimeter water by calibrated buckets. Stressed plots were protected from rain water by poly-ethylene sheets placed over iron frames when needed. At maturity ear length and grain weight of 25 randomly selected plants was measured and averaged. It was concluded from the average of two years data that water stress significantly reduced ear length at all stages of growth over control. Among varieties Pak 81 had significantly longer ears. Punjab 85 and Kohinoor were found to be drastically affected by water stress at all stress stages. Grain weight per ear was also significantly reduced by low water stress but its effect was more pronounced when stress was given at anthesis stage. Among varieties Pak 81 produced significantly higher grain weight per spike than Punjab 85 and Kohinoor. All the three varieties had similar but significantly reduced grain weight at anthesis stage of water stress. Water stress at anthesis, proved to be the most critical for grain formation. Stress at tillering did not show any significant effect on number of grain/spike. Pak 81 produced significantly more grain/spike than Punjab 85. In case of grain yield maximum adverse effect was noted when plants were stressed at anthesis stage. Pak 81 maintained its superiority over other varieties alone and when stressed at various growth stages.
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