Maize diseases and pests: description and treatment, measures to combat them, photo

Corn diseases can be caused by viruses, bacteria and very often fungi. The quality and quantity of the harvest is sharply reduced. If timely measures are not taken to combat them, then diseases can lead to a complete loss of the crop. Knowing the first signs of a problem, you can stop the further spread of the infection.

Corn diseases, photo, their signs, control measures

Corn is a cereal crop. If corn crops are susceptible to diseases and pests, then you will not be able to get a good harvest. To prevent the occurrence of infection, as well as its spread, you need to be able to recognize the first signs of a problem and take action in time.

Infection with diseases occurs due to poor-quality planting material, improper care of the crop, untimely pest control. Therefore, it is so important to establish an irrigation regime, apply fertilizers on time in order to form good immunity and observe other agricultural practices.

Loose smut

Fungal disease loose smut affects panicle and ear of corn. This is a common disease in humid areas of the southern regions (Kuban, Transcaucasia). Affected plants look weak, grow poorly, bush strongly, cobs are poorly formed. Gradually, the affected cobs turn black, become covered with spores and turn into a dusty mass.

The cause of the disease is contaminated soil, poorly processed seeds, high air temperature.The main measure to combat loose smut and blister mold is seed dressing before sowing, observing the annual crop rotation. Choose varieties and hybrids of corn that are resistant to these fungal diseases.

In case of detection of diseased plants in the garden, they must be destroyed (it is better to burn or bury to a depth of about 50 cm). It is recommended to plant corn on a new plot of land every three years.

Bubble Smut

The causative agent of corn bunt is a fungus that affects the entire above-ground part of the plant. In the affected areas, small swellings of a pink or greenish color appear. Over time, the swelling grows and becomes black in color. Soon, the shell of the bubble bursts, and the spores, with the help of wind and insects, fall on other, he althy plants.

Infected plants, untreated, infected seeds become the source of infection.The bubbling smut is especially harmful when the stem and cob appear on the internodes. The grain yield in this case is reduced to 50%. The disease is provoked by drought and late sowing of plant grains.

The main preventive measures are the selection of varieties and hybrids of corn that are resistant to blister smut, the dressing of planting material, the removal of plant residues from the site after harvest, and the observance of crop rotation. Seeds are collected only from he althy plants.

Effective drugs for blister smut, as well as for root and stem rot, are: Protravitel Alpha, Delit Pro, Vincet, Lanta, Pioneer, Maxim XL.

Fusariosis

Fusariosis corn can appear at any stage of plant development. The causative agents of the disease are fungal spores that are in swellings. The disease leads to rot of seeds, roots and stems, as well as cobs. Accordingly, the symptoms will be different.

Rotting of seeds and seedlings occurs as a result of sowing infected planting material. Most seeds rot already in the soil, without forming the first shoots. A light or pinkish coating forms on their surface. Growing young plants from infected seeds on the surface of the earth look weak, lag behind in growth and form cobs poorly.

In the phase of milky-wax maturity, rot of the stem and roots appears more often. The leaves of the plant wither, turn yellow, dry out. The roots turn black, dry out and the affected corn is easy to pull out of the ground. The cobs themselves gradually dry and wither.

Cob rot can appear even during the storage of the harvested crop. First, a white-pink coating appears on the grains, the entire cob is gradually affected. The color of the plaque darkens and becomes brown-gray.

The source of infection is infected seeds or uncleaned plant residues on the land. Wet, cold weather, high air temperature during the ripening of the cobs, damage to the cobs and grains by pests can provoke the disease.

Before planting, be sure to treat the seeds, choose corn varieties and hybrids resistant to Fusarium, detect and remove diseased plants in time. Autumn plowing of the land and cleaning of plant residues, timely control of insect pests are shown.

Stem rot

A fungal disease stem rot appears at the end of the growing season in the stage of milk maturity of corn. The description of this disease of maize is as follows: the leaves become gray-green in color and become covered with a matte coating, dry out, fade. A pinkish coating can be observed on the stem, with time it softens and breaks.

The source of infection is the persistence of spores in plant debris after harvest. The fungus actively multiplies in hot, dry weather. The provoking factor is improper watering and too thick sowing of corn.

To increase the resistance of plants to rot, it is necessary to observe the optimal sowing dates, planting density and seeding depth, after harvesting, you need to dig up the site and remove all plant debris, it is imperative to pickle the planting material with fungicides.

Southern Helminthosporiasis

Most often, the leaves of the plant suffer from the southern helminthosporiasis of corn, less often the roots and cob. The first signs of the disease are the appearance of brown oblong spots on the leaves. Gradually, the affected area dries up. The spots grow and occupy the entire area of the leaf.

Spotting or Helminthosporiasis of corn appears in the middle of summer. The provoking factor is high humidity and low air temperature. The source of infection is untreated seeds and plant debris.

Before planting, be sure to sort and pickle the seeds. If infected seeds are planted, the seedlings are weak and often unable to reach the soil surface. To increase immunity, fertilizers are applied to the soil several times a season. It is undesirable to plant corn three years in a row on the same site.

Maize pests, their signs and control measures

Insect pests are considered one of the reasons for the spread of diseases among crops. To combat them, you can use both folk remedies and ready-made preparations.

Stem Moth

Maize pests eat the above and below ground parts of the plant, as a result, it weakens and becomes prone to diseases. In addition, the pests themselves can transfer pathogenic bacteria from a diseased plant to a he althy plant.

Moth caterpillars do not bring more harm to the plant, but moth caterpillars. Gray-yellow caterpillars (25 mm long) are especially active in July-August, when the weather is dry and warm. Caterpillars of the corn stem borer live on the surface of plants, burrow into the petioles of stems, leaves and panicle flowers.

Plant nutrition is disturbed, sometimes the stems can break. The plant begins to bloom later, the size of the leaves decreases, pollination worsens.

In order to prevent the spread of the meadow borer on corn, it is necessary to fight weeds, mow them around the plantings, and not leave tops after harvesting.

Root Aphid

Root aphids most often attack corn in hot, dry weather. The plant slows down in growth, the leaves turn yellow and dry, it is easily affected by fungal diseases. If the infection spread area is small, then diseased plants can be cut off.

Insecticides and fungicides (Confidor, Actellik, Fitoverm, Fas) are used as plant protection against pests. Since insects can overwinter on the remains of the stems, after harvesting, you need to clear the area of \u200b\u200ball vegetation. It is best to choose early-ripening varieties of corn.

Swedish Fly

Swedish fly most often infects corn during seedling germination. The larvae damage young seedlings, and they begin to lag behind in growth and development. The leaves of the affected corn become dark green in color, the stem thickens. Corn pests reduce not only the quantity of the crop, but also its quality.

During the mass summer of flies and egg laying, it is recommended to treat plants with such preparations as Karate, Decis, Tsiperon. As a preventive measure, it is useful to carry out fertilizing with nitrogen fertilizers, observe the optimal sowing dates and select resistant varieties of corn.

Preventive measures

Prevention should begin from the moment the seeds are selected and end with the cleansing of the field from plant residues. Preventive measures:

It is better to choose early-maturing varieties of corn.
Seeds should preferably be treated.
When planting, it is recommended to add potash-phosphorus fertilizers to the soil.
It is important to know the first signs of diseases and pests.
Remove damaged plants from the site in time.
Dig deep in the field in autumn.

Another common disease in corn is bacterial wilt or wilt. The bacterium infects all organs of the plant. Light green and yellow stripes appear on the leaves.

The main measure to combat the disease is the refusal to sow infected seeds. In addition, the grains need to be dressed before planting, get rid of pests in time and fight weeds.