Weed control in irrigated groundnuts (Arachis hypogaeaL.) in the Sudan Gezira

Abstract

SummaryExperiments were conducted at Gezira Research Station during the 1964 and 1965 seasons to determine the effect of time and number of weedings on pod yield of Ashford groundnuts.Natural stands of annual weeds, mainlyIpomoea cordofanaandRhynchosia memnonia, reduced the pod yield by an average of 80%. Results showed that groundnuts must be weeded at least once after the first 30 days from sowing. Groundnut pod yield was increased from 986 kg/ha in the unweeded plots to 4690 kg/ha in the plots weeded 30 and 60 days after sowing. Three weedings, i. e. 15, 30 and 45 days from sowing, yielded less than 30 and 60 days from sowing because weeding stopped too soon. For practical purposes weeding at 30 and 60 days only was adequate.Number of pods per plant was the most important factor determining yield. Maximum pod yield was obtained from 15–20 pods per plant, and the earlier the 20 flowers produced, the higher was the pod yield.Weeds decreased number of branches per plant and consequently number of pods per plant. Weight of 1000 seeds, shelling percentage and harvest index was also affected by weeds.Ipomoea cordofanawas the most noxious weed because it emerged about the same time as the groundnut plants and also the seeds germinated throughout the growing season.