Dispersal Or Dissemination Or Spread Of Weeds
Agencies responsible for dissemination are:
1. Wind: Seeds may be very small & light, equipped with parachute like arrangement, plumes or fuzz. They blow by wind to along distance. E.g.: Seeds of Rui/Ruchki, Striga, Gajar Gawat.
2. Water: The irrigation canals, drainage channels, surface runoff, flood water of rivers & streams carry weed seeds.
3. Animals like wild & domestic: Weeds having hooks (Gokhuru), twisted awns, spines, etc. E.g.: Ghaneri, weeds of Graminae family.
4. Man: Man disperse the weeds indirectly through compost (partially decomposed), feeding castles with hay or fodder having weed plants, using uncleaned farm machinery. E.g.: Ghaneri, weeds of Graminae family.
5. Crop weed: During harvesting, they get mixed with produce. E.g.: Jungli dhan, Bharad in rice and phallaris in wheat.