Effect of Sowing Date and Pre-Planting Irrigation on Weed Seedling Emergenceand Yield in Maize

Field experiment was conducted to predict shoot emergence of Sorghum halepenseand Chenopodium albumL. in different planting dates of maize with stale seed bed or conventional planting. 3- parameterweibul gave a good description of cumulative shoot emergence percentage of S. halepense against GDD. Planting dates were different in emergence rates. With delaying in palnting time، the rate of emergence and the maximum cumulative emergence decreased. Irrigating the field before planting increased weed seedling emergence. There was no difference between sowing dates in the maximum seedling emergenc، except for the last sowing date i. e. T5 that indicated a lower emergence rate. The last sowing date indicated the least emergence percentage. The current study showed that applying stale seed bed method provided an opportunity for the control of S. halepenseand، Chenopodium album L. however،with delay in palnting time there was a less S. halepense and –Chenopodium album L. infested seed bed. The knowledge of the relationship between seedling emergence time and the prevailing environmental conditions could be useful to maximise the efficacy of weed control.