Control methods of balsam pear blight

Balsam pear blight is harmful to stems, leaves and fruits, with the base of vines and tender vines suffering more, the pathogen is flagellate subphylum fungus parasitic Phytophthora, autumn cucumber is more common in the north, and spring cucumber in central and southern China is more common, in addition to cucumbers, it is also harmful to winter gourd, zucchini, vegetable gourd, pumpkin, watermelon and other crops. Let's take a look at the prevention and control methods of balsam pear blight.

Harmful symptoms

Balsam pear blight often appears before flowering, and stems and fruits are susceptible to the disease. The leaves lost their luster at first, and at the initial stage they were dark green water-stained spots with irregular shape and inconspicuous edge. a thin layer of white mold could be seen when the humidity was high, and it was bluish white and easy to break when dry. The petiole and vine node appear dark green water-stained soft rot, and the affected part is easy to overflow and shrink. Melon strips are damaged by dark green sunken disease spots, when the humidity is high, melon strips quickly soft rot, suffer from sparse white mold, rot and stink.

Morbidity regularity

The pathogen is mainly mycelia, oospores or chlamydospores left in the soil with the disease remains in the winter, and the seeds can also carry bacteria. The development temperature range of the pathogen was 5-37 ℃, and the optimum temperature was 28-30 ℃. In the range of suitable temperature, the length of rainy season and the amount of rainfall are the decisive factors for the occurrence and epidemic of the disease. the rainy season comes early, the rainy day is long, the rainfall is heavy, the disease is early and the disease is serious. In addition, poor drainage in the field and high soil moisture are easy to induce epidemic disease.

Agricultural prevention and control

Agricultural control of balsam pear blight can be carried out for more than 3 years, and high ridge (ridge) cultivation covered with plastic film can be used to reduce the pathogen of ground water splashing. Reasonable irrigation and control of field humidity. Proper control of watering in the rainy season, timely drainage after rain, so that the rain is dry. Timely watering in the morning, flooding is strictly prohibited when watering, and should be carried out in the afternoon or evening on a sunny day. More application of organic fertilizer can promote plant growth, deep roots and luxuriant leaves, and improve resistance. Plant adjustment should be carried out in time to prevent overdense growth and poor ventilation and light transmission. Remove the diseased leaves and burn them at any time.

Drug prevention and treatment

For the drug control of balsam pear blight, 25% Ruidu wettable powder 800 times, 80% Dysen zinc wettable powder 600 times, 64% alum wettable powder 500 times 600 times, 40% aluminum ethyl phosphate wettable powder 300 times 400 times, 80% Xinwansheng wettable powder 500 times 600 times, 72.2% Purek water agent 400 times, 50% potassium cream copper wettable powder 600 times alternately Spray once every 5 to 10 days for 3 times in a row. Spray should be thoughtful and meticulous, and all leaves, fruits and nearby ground should be sprayed.