Effect of cover crops on maize-velvet leaf competition: leaf area density and light interception

Abstract

Cover crops influence on canopy structure and light interception of maize (Zea mays L.) and velvetleaf (Abutilon theophrasti Medik), was studied in a field experiment. Treatments included planting of bean (Phaseolus vulgaris L.), soybean (Glycine max (L.) Merr.) and berseem clover (Trifolium alexandrium L.) as cover crops at the same date and 21 days after maize. Sole cropping of maize under weed- free and weedy conditions were also included in this experiment. All tested cover crops significantly reduced leaf area density and height of velvetleaf up to 50 %, while maize leaf area density increased in the presence of cover crops. Among cover crops, bean and soybean were the most effective in reducing velvetleaf leaf area density and height. Bean and soybean also strongly reduced absorbed light by velvetleaf by up to 80 % compared to clover. Maize grain yields were significantly influenced by cover crops planting in the inter row space. Compared to weeds free plots, only treatment with soybean as a cover crop resulted in similar maize grain yields, while maize intercropping with bean and clover significantly reduced maize yields. Delayed planting of cover crops, 21 day after maize, increased maize grain yield compared to cover crops and maize planting at the same time.

Keywords

• canopy structure
• leaf area density
• light interception
• leaf area index
• maize
• velvetleaf