Theory question 105
Weeds and Weed Control(a) Describe briefly four methods of weed dispersal.
(b) Describe three mechanical and three cultural methods of weed control.
Show the model answer
(a) Any four: wind – light seeds with hairs or wings (e.g. Tridax); water – floating seeds carried by run-off and irrigation; animals – hooked/sticky seeds on fur and clothes, or seeds eaten and passed in dung; man – in impure crop seed, on tools, machines and vehicles; explosive pods that burst and throw seeds (self-dispersal); vegetative spread by rhizomes and stolons
(b) Mechanical (any three): hand pulling; hoeing; slashing/mowing with cutlass or mower; tillage (ploughing, harrowing); burning; flooding
Cultural (any three): crop rotation; mulching; cover cropping; close spacing/high plant population; timely planting; use of clean seed; fallowing
Explain how each method works.