Effects of some integrated management options on parthenium interference in sorghum

Parthenium is widely distributed across the uncropped areas of the tropics. It has slowly encroached into many crops and causes considerable yield loss. It heavily infests sorghum, which is widely cultivated by the resource‐poor farmers in Africa and Asia. Its interference and management in sorghum in these cropping systems is not well understood. Therefore, this experiment was undertaken to determine the appropriate parthenium management techniques to use in sorghum crops. All the studied weeds, in combination with parthenium, offered greater competition to sorghum than parthenium alone. Similarly, under a composite stand of weeds, parthenium was inferior in competitiveness to the other weeds until 60 days after sowing (DAS); by 90 DAS, it could accumulate a higher dry weight due to its consistent growth. A pre‐emergence treatment of atrazine (0.75 kg ha^‐1) with wheat straw mulch (5.0 t ha^?1) brought about a consistent and significant reduction in the parthenium growth and, consequently, increased the sorghum yield by 90.8%. Cowpea intercropping with and without pendimethalin (1.0 kg ha^?1) as a pre‐emergence treatment could not control parthenium between 0 and 60 DAS, but could reduce the parthenium growth during the later period of 60–90 DAS, which resulted in a significant increase in sorghum growth. These intercropping treatments increased the sorghum grain yield by 156.2% and 142.4%, respectively, over the unweeded control and by 18.5% and 12.1%, respectively, over the weed‐free control. These treatments also promoted a higher uptake of N, P, and K by the sorghum crop. Thus, cowpea intercropping was the most effective method for parthenium management vis‐à‐vis sorghum yield improvement, followed by cowpea intercropping with pendimethalin and then by atrazine as a pre‐emergence treatment with wheat straw mulch.