Wheat root growth and seasonal water use as affected by irrigation under shallow water table conditions

Summary Irrigation experiments with wheat (Triticum aestivum L.) in clay loam, silty clay loam and the silty clay loam. Contrary to this, irrigation at late jointing, and late jointing and milk stages produced deepest root system in the loam. Roots followed the receding water table. was greatest in the loam. Avoiding irrigation at late jointing stage caused shifting of the zone of peak root density downwards and concentration of roots near water table both in the clay loam and the silty clay loam. Contrary to this, irrigation at late jointing, and late jointing and milk stages produced deepest root system in the loam. Roots followed the receding water table. Seasonal evapotranspiration (E) was affected by number of irrigations and water table depths. Water table contribution ranged from 61.6–64.5% of the total E in clay loam, from 39.0–46.8% of the total E in silty clay loam and from 4.0–8.1% of the total E in loam. Irrigations after late jointing contributed largely to the drainage. Yield was significantly higher in the treatments with scheduled irrigations at crown root initiation and late jointing stages in the clay loam and silty clay loam and at crown root initiation, late jointing and milk stages in the loam. This research has been financed in part by a grant made by USDA, ARS, authorized by Public Law-480