Forecast of pests and diseases of winter vegetables

(Baonghean) - Winter weather conditions are complex and unpredictable, the rainy and stormy season in early September and October will cause many difficulties in production. Based on the results of monitoring the occurrence of pests in recent years, it is possible to predict some major pests that will cause damage to corn and vegetables in the 2013 winter crop.

1. Fruit flies damage bitter melon

- Flies begin to damage bitter melon fruit when it is formed, causing the fruit to curl up, not develop and fall off, affecting quality and yield.

- Prevention measures: Collect fallen fruits and destroy them or bury them deep in the ground. Use traps to attract fruit flies: use drugs with attractants and fruit fly killers such as: VIZUBON-D active ingredient Eugenol 75% + Dibrom 25%. How to use: Use 1-2ml of drug/trap; the trap is made of a plastic bottle and hangs bait soaked in the drug in the bottle, holes are drilled on both sides of the bottle for flies to enter and eat the bait, hang 20-30 traps/ha; weekly investigate and collect fly samples in the trap; after 14 days of applying new drug, continue to hang the trap on the tree; combine spraying protein bait (Ento-protein) when seeing about 10 flies entering the trap/trap.

Note: When using traps, bait must be applied over a large area to be effective in eliminating fruit flies in the entire field. Do not spray protein bait on the squash fruit, but only spray on the leaves of the bitter melon plant.

2. Silkworms, green worms, armyworms that harm vegetables

- All three types of worms cause damage throughout the growing process of vegetables such as cabbage, broccoli, and mustard greens, eating away the leaves, leaving the main veins. The older worms eat away the leaves, affecting the yield and quality of the vegetables. Silkworms are highly resistant to pesticides, so it is necessary to rotate pesticides to avoid the worms becoming accustomed to the pesticides.

When using drugs, the following requirements must be followed: Low-toxic drugs must be on the list of drugs allowed for use on vegetable plants, priority must be given to biological products and herbal drugs, and quarantine time must be ensured, and only spraying must be done when pests arise and cause damage to the control threshold. In addition, some pheromone sex traps, sweet and sour baits, etc. can be used to attract adult pests and destroy them.

3. Soybean stem borers and leaf rollers

* Body borer:

- Causes damage from when the plant has two single leaves to the end of the season, mainly from the stage when the plant has two single leaves to 2-3 compound leaves, causing mass death of the plant. When the plant grows, stem borers only kill the tops. In the winter, the maggots can kill 40-50% of the seedlings, greatly affecting productivity.

- Prevention measures: Sow on schedule, take good care of seedlings for healthy growth. Sow seeds evenly, pull up and destroy plants with dead tops to kill pests. Detect the appearance and damage of maggots in time to organize spraying with specific pesticides. Spraying time starts when the bean plant has 2 single leaves, and ends when the plant has 3 compound leaves. When the maggots are severely damaged, spraying can be done 2-3 times.

* Leaf roller:

- The worm causes damage from when the plant has 2-3 compound leaves until the end of the season, starting to cause serious damage 28 days after planting, especially in soybean fields with excess nitrogen. The worm rolls the edges of the leaves together and eats the leaf flesh, leaving the main vein.

- Prevention measures: Manual measures: Organize to catch worms when they still appear at low density. Chemical measures: When worms appear at high density, organize to spray when the worms are still young, choose low-toxic pesticides in the list of pesticides allowed for use on vegetables such as active ingredients: Abamectin, Alpha - Cypermethrin..., when spraying, ensure the isolation time and follow the instructions on the packaging.

4. Vegetable diseases

* Root rot disease:

- The disease is most harmful in the seedling stage, especially in wet weather conditions with high humidity.

- Prevention measures: Clean the field and treat the soil if the previous crop was severely affected. Treat seeds before sowing with fungicides. When the disease occurs at a high rate, use: Anvil 5SC, Score 250EC, Cavil 50SC...

* Downy mildew: Causes damage to tomatoes and potatoes. The disease is severe when the weather changes to cold, drizzly, and foggy. The disease damages leaves and can kill the entire garden.

* Anthracnose: Causes damage to many types of vegetable plants but is most harmful to chili plants. The disease kills seedlings, causes leaves to fall off and fruit to rot, seriously affecting yield and quality.

- Prevention measures: Clean the fields, collect diseased plant residues. Make high beds with good drainage. Balanced fertilization creates conditions for healthy plant growth and development, increases resistance to pests and diseases. Ash and potassium can be added to poor soil and where the disease often occurs. When the disease has developed and the weather is favorable for the disease to develop, use drugs such as: Rhidomil MZ 72BTN, Zinep 80WP, Aliette 80WP...

Nguyen Huy Khanh