How frustrated do you feel when you have an attack on your maize farming without knowing how to control them? Let’s talk about it.
Maize is among the world’s three most important cereal crops, the other two being rice and wheat. It is a cereal grain which was first grown by people in ancient Central America and mostly used to make corn, animal feed and other maize products, such as corn starch and corn syrup.
There are several factors that limit maize production diversely, and some of the most important being insects and closely related organism such as mites. These pests can infest maize at any stage of crop development and in storage and attack any part of the plant, often causing severe damage.
In this article, we’ll be looking at different pests and ways to control their attack on maize farming.
1. Wireworms and leatherjacket
These are the biggest threats to a young maize plant. The wireworms are golden brown larvae of click beetles while the fat, grey and legless crane fly larvae are known as leather jackets. These have an annual lifecycle while wireworm larvae exist in the soil for four to five years. They feed on the plant root and cause them to die or make the maize unmarketable. The moth group (which includes cutworms, armyworms, wireworms, earworms, borers, and grain moths) is the most damaging to maize worldwide.
There is no spray chemical control, but an insecticide seed dressing of Sonido (thiacloprid) should be applied if there are any larvae visible.
By introducing larvae to pick up birds, some cultivation techniques may reduce populations.
Later drilling is the most effective non-chemical control as the temperature of the soil allows the plant to grow through the damage.
Some farmers encourage the use of birds to tackle insects as a means of pest control which can be a risky business because some birds, particularly members of the crow family, are pests themselves. They can cause damages to the maize crops by pulling up the young plant to get to the seed for two to three weeks post-emergence.
It is essential to control birds through the high-risk period by using scarers such as gas guns and kites.
Insecticide such as Mesurol which is commonly used to treat seed also has some effects as a bird deterrent.
Eyespot appears as a very small circular spot on the lower leaves. The central part of the spot dies, leaving a brownish centre, surrounded by a purple-brown border and an outer yellow halo in the shape of an eye. Eyespot appears during long periods of cool, wet weather. The disease can also survive on crop residue.
Crop rotation, ploughing and selecting a more resistant variety can reduce the reservoir of disease.
Chemical control: Fungicide mixes such as Comet or Quilt Xcel have been shown to give six weeks of protection and delay the eyespot infection. This protects the plant long enough for starch to be laid down but will require a high-clearance sprayer.
This appears as a white mould but it can lead to ear rot – a reddish, purple mould. Infection begins through the silk so the disease works its way down the ear from the plant.
The crop is most susceptible if the weather is wet two to 10 days after silk initiation. The disease is important because it produces a toxin called deoxynivalenol. It is potentially harmful to livestock causing poor feed conversion, lower fertility and a weakened immune system.
Choose varieties with a good resistance rating and carefully remove debris from previous crops by plugging into the trash.
Weed populations are competing for nutrients from maize, sunlight, water and soil. Silage yields can be decreased by up to 50%.
Weeds can be controlled effectively with herbicides but when maize is at the adult stage herbicide resistance can cause additional problems.
For broadleaved weeds, growers should assess the species on their farm and find the best solution.
Spray regimes usually comprise two applications of either one pre-emergence spray and one post-emergence spray (Pendimethalin), depending on the conditions, two sprays after the crop are growing.
However, if it is very dry, wait for a post-rainfall flush of weeds, assess the species and tackle them with a targeted herbicide soon after the crop has emerged.
Optimal spray timing is before the four-leaf stage in the maize plant to reduce herbicide damage to the crop as the young plant will take up less herbicide through its smaller leaves.
Learn something? I hope this helps better.