|Author:||Devi, K. B. S. ; Rao, V. P.|
|Book Group Author:||NA|
Field experiments were undertaken during the rabi season of 1992-93 and 1993-94 in Hyderabad, Andhra Pradesh, India, to study the water use and soil moisture extraction by maize hybrid DHM 105 to increase the water use efficiency (WUE) of the crop by minimizing yield losses under conditions of limited water supply. Seven irrigation treatments were designed to develop moderate to severe evapotranspiration deficit (Eta deficit) in one or more crop growth subperiods, i.e. vegetative (10-30 days after sowing (DAS)), tasseling-silking and pollination (30-80 DAS) and kernel development (80-116 DAS) subperiods, including a fully irrigated control treatment (10-116 DAS). Irrigation interval and depth of irrigation water for fully irrigated control (W-W-W) treatment was calculated based on soil crop climatic data concept. Soil moisture at sowing, before and after each irrigation and at harvest was estimated gravimetrically in 0-15, 15-30, 30-45 and 45-60 cm soil layers. The crop Eta was maximum (410.0 mm in 1992-93 and 457.7 mm in 1993-94) when irrigations were scheduled at Eta=Etm (Eta deficit=nil) throughout the crop growth subperiod in W-W-W treatment. Eta deficit at vegetative subperiod caused Eta reduction of 2.2-11.2% relative to that of fully irrigated control. Eta deficit at tasseling-silking and pollination and kernel development subperiods decreased Eta by 61.8-65.0% and 24.8-31.7% in respective subperiods relative to Eta of respective subperiod in W-W-W treatment. Eta deficit at all crop growth subperiods, except for vegetative period, caused significant reduction in grain yield of maize. The regression of grain yield on seasonal Eta and Eta deficit showed a significant correlation with 'r', varying between 0.98 and 0.99 in both years and on pooled basis. The maximum WUE was recorded when Eta deficits were imposed at vegetative period and it was on par with the fully irrigated control. Eta deficits at tasseling-silking and pollination and kernel development periods caused a significant reduction in WUE owing to poor grain yield. Bulk of the soil moisture extraction was from soil depth increment of 0-30 cm. However, the moisture extraction from lower depth (30-60 cm) was relatively more in treatments wherein Eta deficits were imposed at 2 crop growth subperiods.
|Pages:||8 - 14|
|Journal:||Journal of Research ANGRAU|
crop growth stage, crop yield, evapotranspiration,irrigation, maize, plant water relations, soil water, water useefficiency, Andhra Pradesh, India, Zea mays, India, South Asia, Asia,Developing Countries, Commonwealth of Nations, Zea, Poaceae, Cyperales,monocotyledons, angiosperms, Spermatophyta, plants, Field Crops (FF005)(New March 2000), Plant Water Relations (FF062), Plant Production(FF100), Soil Physics (JJ300), Soil Water Management (Irrigation andDrainage) (JJ800) (Revised June 2002) [formerly Soil Water Management]