Maize is one of the widely cultivated crops in the world. Maize is very important as it is of many values; its byproducts are copious and of great nutritional importance. Maize plays a prominent role in livestock nutrition as it is the best energy source for livestock. The need to cultivate maize is very relevant as it is known to be a staple crop. However, some factors impede its cultivation.
After successful pre-planting operations; which involve proper land preparation method, procurement of high yielding seeds and planting, a farmer expects optimum yield from his farm. From a hectare of land, if all agronomic practices are done judiciously, a farmer should get at least 6tons of maize after harvesting. This is quite laudable; but maize farmers face lots of problems, chiefly pest.
Weed is one of the pests that reduce the yield of a maize farm. Weeds are unwanted crops that grow sporadically with the sown crop. They are always hardy and difficult to control; most times, farmers often use pre-emergence herbicide after planting to keep the weeds at bay for about 3months. Then, the maize can outwit the weeds. When weeds invade a maize farm, the maize crops become less vigorous and several disturbing signs are seen on the crops.
Although weeds cannot be totally eliminated from the farm, weeds can be maintained below the economic threshold level. Uncontrolled weed on a maize farm can out-compete maize crops for water, nutrients, and sunlight, causing farmers economic losses.
Therefore, effective weed management practice must be adopted to sure the maize farm yield optimally. Manual weeding is undoubtedly the best form of weed control; however, the high cost of manual weeding has discouraged its usage on large maize farms, thus, chemical control is the best substitute and has become more economical as it is equally effective and at low cost.
Chemical compounds used to control weeds are called herbicides. There are two types of herbicides, namely:
Pre-emergence herbicides are applied before the emergence of the weed, that is, immediately after planting; they are targeted at the weed seeds. They prevent weed seeds from emerging. Pre-emergence herbicides used on maize farm are:
|Cycle||metolachlor + cyanazine|
Post-emergence herbicides are herbicides applied on the farm after the emergence of weeds. They are applied to control weeds; they may be selective or nonselective.
Selective herbicides control a specific type of weed, while nonselective herbicides control all kind of weeds. In the case of maize, the selective broadleaf herbicide is used because maize crop belongs to the grass family so any herbicide to be applied must be friendly to grasses but injurious to broadleaf weeds. Post-emergence herbicide for maize crops are:
These herbicides are broadleaf post-emergence herbicides; they are applied only when weeds emerge.
Important precautions on herbicide application
- Apply the right type of herbicide, either pre-emergence or post-emergence
- Do not spray in the afternoon, spray early in the morning or late in the evening.
- Mix herbicide in appropriate and prescribed concentration as directed by the manufacturer
- Do not spray to the direction of the wind
- Do not eat while spraying.
- Ensure you do not have direct contact with the herbicide, however, in case if this happens, apply fresh water to the affected part and see the physician for appropriate medication.
Weeds are pests to maize crops; they reduce the growth potential of the maize crop and conversely reduce the profit of the farmer. Endeavor to share this as wide as possible so as to get other farmers liberated.