The principle and control of fruit spot of bottle gourd

Bottle gourd, alias: sweet gourd, sweet gourd, gourd, Jingjie mallet, longmi melon, celadon, long gourd, flat cattail; angiosperm, a kind of gourd in the gourd family, is a variety of gourd, annual climbing herb. It is different from the gourd (original variety) in that the ovary is cylindrical; the fruit is cylindrical, straight or slightly curved, up to 60-80 cm long, green and white, and the flesh is white. The fruit is soft and juicy when it is tender and can be used as a vegetable. It is cultivated in most parts of the country, widely cultivated in the Yangtze River basin and harvested in summer and autumn.

The growth potential of bottle gourd is strong, the growth of stems and leaves is large, the fruit is more, and the water demand is larger in the whole growing period. Bottle gourd requires good permeability, rich in organic matter soil, avoid continuous cropping. It grows well on the sandy loam which is fertile and loose and convenient for drainage and irrigation. Planting bottle gourd in heavy clay and low-lying land is susceptible to disease. During the growth period, a certain amount of nitrogen fertilizer is required, and sufficient phosphorus and potassium fertilizer is preferred in the melon-bearing period. The humid environment is preferred in the early growth stage, and the soil and air humidity should not be too high during the flowering and fruiting period.

What is bottle gourd fruit spot disease?

Bottle gourd fruit spot is mainly harmful to fruit. The disease spot on the fruit is round or nearly round, 4-8 mm in size, brown to dark brown, without edges, often fuses with each other to form a large disease class, and then gives birth to many small black grains in the disease part, that is, the conidium of the pathogen. It is called submembranous stem mildew, which belongs to the subphylum fungus. Conidia accumulate, break through epidermis, spherical or oblate, wall membranous dark brown, size 144 × 220 microns; spores cylindrical, individual rectangular round, unicellular, colorless transparent, upright or slightly curved, there are 2 oil balls, size 6 ~ 8 × 2 ~ 2.5 microns. The pathogen overwintered on the diseased body and spread through wind and rain the following year, invading through wounds or lenticels, causing fruit spot disease. In production, there are poor conditions of water and fertilizer, poor management, weak growth and easy infection.

Prevention and treatment of bottle gourd fruit spot disease:

The main results are as follows: (1) apply fully mature organic fertilizer before planting, do not apply quick-acting nitrogen fertilizer during the growing period, loosen the soil and weed in time at the seedling stage, promote the development of the root system, and press the vine and disk vine in time after shedding the vine.

(2) watering should be less rather than more, and drainage should be carried out in time after rain.

(3) rotation with melons for more than 3 years, pay attention to the selection of high dry land or high border cultivation, clean the fields in time after harvest, remove the diseased melons in time, and concentrate on burying them deeply.

(4) at the initial stage of the disease, 30% Ludabao suspension 400 times or 25% complex ammonia copper solution 500 times, 47% Garinon wettable powder 800 times solution, 1 0. 5 times Bordeaux solution and chloramphenicol 4 000 times solution were sprayed at the initial stage of the disease, about once every 7 days, 2 times in a row. Stop using medicine 3 days before harvest.