Weed competition in sorghum under two moisture regimes
1983
Rao, A.N. | Shetty, S.V.R.
Weed occurrence and competition, and grain yield of sorghum were studied under limited and optimum irrigations. With an increase in irrigation frequency an increase in weed dry matter was observed. When the weeds were allowed to grow up to 45 days or throughout the season Dactyloctenium aegyptium (L.) Richt, Digitaria ciliaris (Ritz) Koch, Digera sp., and Echinochloa colona (L.) Link dominated the system irrespective of the moisture regime. Variation in dominance of weed species was observed under the six weed removal treatments imposed. Weeds which (i.e. after 45 days) later emerged had little effect on the sorghum grain yield. Higher reduction in sorghum grain yield due to weeds was recorded under limited irrigations than under optimum irrigation situation, thereby revealing better competitive ability of sorghum given optimum irrigations. Approximately the same sorghum grain yield could be obtained by giving five irrigations and allowing the weeds to grow as that with three irrigations and keeping the sorghum weed free. Under limited irrigations the water use efficiency of the sorghum maintained weed free was twice that of weedy check
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