Three peanut (Arachis hypogaea) varieties were maintained at soil water levels ranging from moderately wet to very dry. Pod yield and quality were significantly reduced in treatments receiving less than about 30 cm of water during the growing season. Although not statistically different, yield and quality tended to increase as irrigation amounts increased from 40 to about 60 cm. Average harvestable yields for 4 years were 4464, 5080 and 4543 kg/ha for Florigiant, Florunner and Tifspan, respectively, when irrigated to a profile depth of 60 cm when the soil moisture tension in the surface 30 cm reached 0.2 bar. This compares with yields of 2631, 3341 and 3125 kg/ha for Florigiant, Florunner and Tifspan, respectively, when the soil water tension in the surface 30 cm profile was allowed to reach 15.0 bars. Water extraction to a depth of 106 cm was recorded for all three varieties. Apparent plant use of water from profile depths greater than 60 cm was observed at about 75 days after planting. Evapotranspiration vs age relationships were developed from daily soil water measurements to a 1.2 m soil depth.

Summary. Thiocarbamate herbicides were applied with incorporation devices and new subsurface application equipment on loamy sand at Tifton, Georgia, U.S.A. Subsurface‐applied ethyl N,N‐dipropylthiolcarbamate (EPTC), S‐propyl bulylethylthiocarbamate (pebulate), and S‐propyl dipropylthiocarbamate (vernolate) generally gave better control of Cyperus esculentus L. and Richardia scabra St Hil, but injured peanuts more than applications made on the soil surface and then incorporated into the soil. For soil incorporation, the power‐driven rotary hoe was generally better than a disc harrow. Depth of subsurface placement critically affected herbicidal activity, especially on Cyperus esculentus; placement 1·5 in. below the soil surface gave more effective control than placement at 5·5 in. Réactions de Cyperus esculentus, de Richardia scabra et de l'arachide mix herbicides à base de thiocarbamate, en relation avec la methode de placement dans le sol

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