Allelopathic Effect of Weeds on Crops

(1) Maize

• Leaves & inflorescence of Parthenium sp. affect the germination and seedling growth
• Tubers of Cyperus esculentus affect the dry matter production

(2) Sorghum

• Stem of Solanum affects germination and seedling growth
• Leaves and inflorescence of Parthenium affect germination and seedling growth

(3) Wheat

• Seeds of wild oat affect germination and early seedling growth
• Leaves of Parthenium affects general growth
• Tubers of rotundus affect dry matter production
• Green and dried leaves of Argemone mexicana affect germination & seedling growth

(4) Sunflower

• Seeds of Datura affect germination & growth.

Allelopathic Effect of crop plants on weeds

• Root exudation of maize inhibits the growth of Chenopodium album
• The cold water extracts of wheat straw when applied to weeds reduce germination and growth of Abutilon sp.

Allelopathic effect of weeds on weeds

• Extract of leaf leachate of decaying leaves of Polygonum contains flavonoides which are toxic to germination, root and hypocotyls growth of weeds like Amaranthus spinosus
• Inhibitor secreted by decaying rhizomes of Sorghum halepense affect the growth of Digitaria sanguinalis and Amaranthus sp.