What are the diseases and insect pests of balsam pear and how to control them?

Balsam pear, also known as cold gourd, is a plant of the family Cucurbitaceae and is an annual climbing herb. Stems, branches, petioles and pedicels pilose, axillary tendrils. Leaves 3 to 12 cm in diameter, 5 to 7 palmately parted, lobes oval, outer margin serrated. Blossoms at the turn of spring and summer, monoecious and yellow. The fruit is long oval, with most irregular tumor-like protuberances on the surface. The seeds are hidden in fleshy fruit and are wrapped in red sacs when ripe. Balsam pear is a favorite vegetable, the origin is not clear, but it is generally believed to be native to the tropics. It is widely cultivated in South Asia, Southeast Asia, China, and the Caribbean Islands.

Balsam pear cultivation is mainly affected by powdery mildew, downy mildew, Fusarium wilt, beet armyworm, Spodoptera litura and melon fruit fly and other diseases and pests, if not early and effective control, will seriously affect the production efficiency of balsam pear, so how to control balsam pear diseases and insect pests? Now I would like to introduce the prevention and control methods to you.

1. Powdery mildew

Cause and symptom: it is caused by a kind of melon monofilament fungus, which can infect many kinds of melon plants. Recently, due to the alternation of high temperature and humidity and high temperature and drought, powdery mildew is very easy to spread. If you fail to take precautions, take it lightly or delay spraying, the melon leaves are often covered with white powder within a few days, and the leaves turn yellow and grow weak. Control methods: in addition to paying attention to the selection of resistant varieties of powdery mildew, spraying must be done in a timely manner. It is generally required to spray immediately when sporadic powder spots are found in the field, once every 5 min every 6 days. You can choose 40% methomyl 700x solution or 20% trimethoprim wettable powder 800x solution or 25% maleic acid 1000 times solution or use powder rust star or green milk copper. Spray the leaf surface and back of the leaf, especially the back of the leaf. 2. Downy mildew

Causes and symptoms: the disease spot is polygonal and light brown limited by the leaf vein. In the later stage, the disease spot is dry and easy to break. When it is wet, the gray-black mildew layer grows on the back of the disease spot. The disease gradually spread upward from the lower part of the plant, when serious, the disease spot connected into pieces, the whole leaf was yellowish brown, dry and curled, except for the top new leaf, most of the leaves of the whole plant withered and died, the diseased field was withered and yellow, the melon was lean and inferior, and the seedlings were pulled early. Prevention and control methods:

1. Strengthen the cultivation and management, increase the application of organic fertilizer and phosphorus and potassium fertilizer to enhance the disease resistance of the plant.

2. Pesticides are used to prevent and cure the disease at the beginning of the disease. You can choose the following agents, 53% Redomir 600 times solution or metalaxyl manganese zinc 500 times solution or germicidal alum 600 times solution spray or choose Kelu or frost carbon clear. As for Fusarium wilt, balsam pear old producing areas, especially the current high temperature and humidity are conducive to the occurrence and spread of the disease. Choose 10% Shuangxiaoling water agent 200x solution or 30%dt fungicide 350x solution or 50% carbendazim 300x solution to irrigate the root, each plant is infused with 05kg, once every 6 days, continuous prevention and treatment for 3 times.

Spodoptera litura and Spodoptera exigua

Recently, the harm is widespread, and it is found that the larvae are eaten into balsam pear. They have the characteristics of omnivorous, fulminant and strong fecundity, the larvae are harmed by clusters in the low instar and scattered feeding in the old age. The feeding activity increases rapidly from the first night of Jiujin, reaches its peak at 05:00 in the morning, and basically stops feeding at 09:00 the next day. Prevention and control methods:

1. Trap and kill larvae. Take the fermentation liquid of carrots, sweet potatoes and bean cakes to add a little sugar and trichlorfon to kill adults; stir-fry peanut bran or soybean powder as bait, add 90% trichlorfon to one or two for every 5 jin of bait, then mix half to 20,000 lingering powder, put the poison bait into the field in the evening, put a small pile with 2 tablespoons poison bait every other meter, and the larvae climb out to eat poisoning and die.

2. Strengthening field management, manually removing egg blocks and catching cluster larvae can get twice the result with half the effort.

3. Chemical control. Use 1500 times Yitaibao 2000 times high-efficiency metoprolol, or avermectin mixed with high-efficiency metoprolol and then mix bt, or use kung fu 5ml mixed with 10ml curon with 15kg water spray. The spraying time is chosen in the evening, and if it is cloudy and rainy, the effect of spraying in the morning is also good. Fourth, melon fruit fly

The larvae hatched and went into the melon to feed, the injured melon turned yellow at first, then the whole melon rotted and deteriorated, and there were maggots peristaltic inside, resulting in a large number of falling melons, even if they did not rot, the melons were deformed and sunken, and the quality decreased. Prevention and control methods:

1. The most effective method is to trap and kill adults. The banana peel can be soaked with trichlorfon and hung under the melon shed. It can also be boiled and fermented with sweet potatoes and hung in containers with trichlorfon and a little flavor. 20 points per mu, about half a two per point, can trap and kill adults.

2. Remove rotten melons, bury them deeply or throw them into the pond.

3. When the insect pest is serious, the paper bag should be used to protect the melon from spawning.

4. Spray the adults at noon or in the evening, choose the following chemicals, 40% Numster 2000 times or 40.5% Arebo 1500 times or Lesbon, spray once every 4 days, for 4 times in a row.