A weed is any plant growing in a wrong place, usually considered undesirable.
Uncontrolled weeds compete with the crop of interest for nutrients, moisture and space, and may completely suppress the crop if uncontrolled. They also harbour pests and diseases.
Young maize seedlings can easily be overwhelmed by weeds.
Weeds take full advantage of the wide rows and upright growth of maize, colonizing the bare soil beneath.
TYPES OF WEED
They are majorly broadleaf and grass weeds and include the following;
|Broadleaf weeds||Grass weeds|
|· Blackjack (Bidens pilosa)||· Love grass (Setaria spp)|
|· Wandering Jew (Commelina benghalensis)||· Star grass (Cynodon spp)|
|· Witch weed/ Striga (Striga asiatica)||· Couch grass (Digitaria spp)|
|· Mexican marigold (Tagetes minuta)||· Wild oats (Avena spp)|
|· Cocklebur (Xanthium strumarium)||· Bermuda grass (Cynodon dactylon)|
|· Thorn apple (Datura stramonium)||· Yellow nutsedge (Cyperus esculentus)|
|· Pig weed (Amaranthus spp)||· Purple nutsedge (Cyperus rotundus)|
|· Oxalis (Oxalis spp)||· Guinea fowl grass (Rottboellia cochinchinensis)|
BENEFITS OF EARLY/TIMELY WEED CONTROL
- It eliminates competition for light, nutrients and moisture, giving the crop the opportunity to establish well.
- It protects the palatability and nutritional potential of the crop.
- It substantially curtails opportunities for pests’ establishment in the crop.
MANAGEMENT & CONTROL
Early weed control is very crucial in maximizing maize yields.
There are several ways which can be employed to control weeds in a maize plantation.
This method involves the use of herbicides.
Herbicides can be selective or nonselective, post or pre-emergence, contact or systemic, etc.
The following herbicides are recommended for use in controlling maize weeds;
- CLAMPDOWN 480SL 200ml/20l
This is a broad spectrum non-selective systemic herbicide which kills both broadleaved and grass weeds.
It is used before planting, usually in land preparation.
- CATAPULT 480SL 200ml/20l
This is a broad spectrum non-selective systemic herbicide which controls post emergence broadleaved and grass weeds.
It should be applied before the maize seeds germinate.
- AGROMINE 860SL 150ml/20l
This is a broad spectrum selective systemic herbicide which controls post-emergence broadleaved weeds.
It should be applied when the maize crop is about 30cm high (knee-high)
- HURRICANE 200SL 200ml/20l
This is a broad spectrum non-selective contact herbicide which controls both broadleaved and grass weeds. Its action is very fast.
It should be applied at later stages of crop growth, usually between the crop rows.
NOTE; While spraying any herbicide, it is advisable to mix it with INTEGRA 3ml/20l. This is a sticker, spreader and penetrant which improves the efficacy of the chemical.
This involves the removal of weeds using tools and implements like jembes, hoes, among others.
They include the following;
- Planting fast growing varieties of maize
- Pull out weeds before seed setting.
- Use clean maize seed that is free from weed seeds
IMPORTANCE OF WEED CONTROL
Weeds greatly reduce crop yield as well as its general performance.
They harbor pests and diseases.
They compete with plants for sunlight, water, nutrients, space. This makes the plants weak and susceptible to attack by pathogens.
Some are parasitic, others are harmful when eaten by livestock.
Generally, plants in wrong places look ugly.