What is Weed Management?
Weed management is defined as the management and control of weeds in such an integrated way so that their harmful and determinantal effects can be cured on crop plants and livestock before reaching the plants reach maturity. It is an approach in which weed prevention and weed control have a companion and helping roles. It can also be understood as the integrated approach to control weeds with the most economic and effective methods. Weed management covers all the methods of weed control i.e.cultural, chemical, economical, physical & biological methods in a combined way so that there is no harmful effect on crop plants & cost of economical. But all the management practices which are used depends on the severity of weeds & conditions in the field where the weeds are to be managed.
Why is Weed Management important?
There are many factors due to which Weed Management is an important topic for us. Those factors are stated below:
1. To produce quality seed (or for quality seed production)
As weeds pose a great menace in producing good and quality seed under breeder seed production programs, controlling weeds is necessary. So, weed management is important. For example, Loranthus sp. leaves impair the quality of tea.
2. To improve yields and production efficiency
As weeds cause losses up to 30-35 % in foodgrain crops. Normally weed cause more losses in Kharif crops (35%) compared to losses caused in Rabi crops (22% ), that is why controlling weeds can improve yields and production efficiency.
3. To prevent health diseases in humans and animals
Weeds cause allergy of certain kinds to humans.
For example, Parthenium hysterophorous causes dermatitis, asthma and certain fevers like yellow fever, malaria etc.
4. To increase the aesthetic value of tourist and natural places
As weeds are a menace to the aesthetic value of the attractive places. Weeds can also destory asthetic view of a beautifully organized garden. For example cyperus rotundus, cynodon dactylon, sorghum halepence etc.
5. To reduce the menace of weeds to the forest and pasture lands
As weeds occupy the area meant for woody plants like chir, pine etc. and result in land space loss.
6. To reduce the contamination of water bodies
As certain aquatic weeds change the color of water of river waters and ponds, lakes etc. and they also pose a hindrance to the swimming, river rafting, boating etc. For example Water hyacinth, Ecornia crassipes.
7. To cure the fire hazard
As weeds are very light in weight and dry in nature so there are very high chances that the weeds catch fire, which can lead to the fire hazards in forests & grasslands.
8. To cure the palatability of hay and silage
As weeds enter into the hay and silage with the fodder crops and their seeds and leaves are get mixed into the stored hay and silage, which results in the reduction in the paltability and storage life of hay and silage. For exmaple. Striga sp. and Motha sp. reduces the quality of sugarcane leaves.
9. To reduce the competition of weeds with crop plants
As weeds compete for nutrients , space , sunlight & moisture with crop plants growing with them. Normally, weeds are more powerful than the crop plants and surpass crop plants in the early growth stages of the crop plant.
10. To reduce the allelopathic effects of weeds on crop plants
As certain weed roots relese toxic chemicals into the soil which reduces the crop yield of subsequent season . For example. Dodder, Sorghum halepance etc.
11. To reduce the home of insect – pests
As weeds are a host plants for many harmful insect pests which cause deteriorating looses in crop yields .For example. Chenopodium album is host for maize and tomato borer and also of gram caterpillar.
PRE-REQUISITES FOR EFFECTIVE WEED MANGEMENT:
- See life cycle of weeds growing in controlling area i.e. weeds is annual, biennial or perennial.
- Characteristics of weeds i.e. nature & growing habits of weed plants
- Mode of reproduction of weeds, dormancy type, dispersal methods & their ability to survive in adverse conditions.
- The condition of soil i.e. light or heavy & organic matter content in the soil.
- Habitat & location of the area to be controlled i.e. cropped or not -cropped area.
- season of weed control.
- Farm practices adopted in the field i.e. pure or mixed cropping.