Effects of sowing date on the incidence of sorghum midge, stenodiplosis sorghicola (coq.),(cecidomyiidae: diptera) in sorghum (sorghum bicolor (l.) moench) at Damazin rainfed area, Sudan
2009
Fadl-Elmula, A.A., Agricultural Research Corporation, Damazin (Sudan). Damazin Agricultural Research Station
Trials were conducted during July - December rainy seasons of 1998-2001 at Damazin Research Station Farm. Six sowing dates were tested for their effects on midge density and midge damage. The results showed that the sorghum midge density and midge damage were low (0.9 - 2.7 adults and 0.8 - 2.3% per five sorghum panicles, respectively) in early sowings of the first to the 3rd week of July. Beyond this limit, both the density and damage of the pest increased rapidly depending on the onset of the effective rains. The average number of midge adults, the percentage of damage and the grain yield ranged between 0.9 adults, 0.8% and 689 kg/ fed in the first sowing date (5-9/7) and 76.3 adults, 76.5% and 37 kg/fed in the sixth sowing date (30/8-1/9), respectively. There was a high and positive correlation between the sowing date, midge density and midge damage (r = 0.8) and the correlation was high and negative between the sowing date and the grain yield (r = - 0.7)
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