Disease and control of black spot of Dutch bean

Dutch beans belong to the genus Pea of Leguminosae, annual twining herbs with high 90~180cm. The area where Dutch beans were first cultivated was along the Thailand-Myanmar border about 12,000 years ago. Round body is also known as honey bean or honey bean (Sugar snap peas), flat body is called green bean or Dutch bean (Snow pea), there are small cold beans, Huai beans, sesame beans, green beans, remaining beans, golden beans, back beans, wheat peas, wheat beans, Bidou, Ma Lei, national beans, soft pod peas, pod peas, sweet beans, lotus beans, green spots, green peas and other names. It can be used for food. Dutch beans, also known as lotus kernel beans, cut beans, belong to the pea genus of Leguminosae. Mainly edible young pods, native to the Mediterranean coast and western Asia, Dutch beans tender pods crisp fragrance, high nutritional value.

Growth habits of Dutch beans

Lighting requirements: Holland bean long-day plants. Most varieties can blossom earlier when the light is prolonged and delayed when the light is shortened, but some early-maturing varieties are not strict with the light. General varieties require strong light and long-term sunshine during the podding period, but they are not suitable for high temperature and are suitable for planting in the alternating period of spring and summer.

High water demand: Dutch beans require more water throughout the growing period. In the process of seed germination, if the soil moisture is insufficient, the seed can not absorb water and expand, which will greatly delay the emergence of seedlings. The seedling stage can tolerate a certain dry climate. If the air humidity is too low during flowering, it will cause flowers and pods to fall. In the case of high temperature and drought during the pod growth period, the pod fiber will harden earlier and mature prematurely, thus reducing the quality and yield. Therefore, in the whole growing period of Dutch beans, there must be sufficient water supply in order to grow vigorously, with large pods and full seeds, ensuring quality and quantity. But it is not resistant to waterlogging, if the moisture is too large, the seeds are easy to rot after sowing, the roots are easy to rot in the seedling stage, and the disease is easy to occur in the growing period.

Soil conditions: although Dutch bean is not strict on soil, it can be planted on sandy soil or newly reclaimed land with good drainage, but it is suitable to grow in pH6.0-7.2soil and loose neutral soil containing organic matter. When the soil acidity is lower than pH5.5, the disease is easy to occur and the pod setting rate is reduced, so lime should be added to improve it. The root system of pea is deep, slightly tolerant to drought but not resistant to moisture, poor drainage of sowing or seedlings, poor drought and fertilization at flowering stage, and easy to form empty pods or blighted pods. Dutch bean bogey continuous cropping, generally at least 4-5 years rotation.

Nutritional value of Dutch bean

The tender shoots, pods and seeds of Dutch beans are very popular with people. Per 100g tender pods, the contents of moisture, carbohydrates, protein, fat, carotene 0.15~0.33mg and essential amino acids were 71.1-78.3 g, 14.4-29.8 g, 4.4-10.3 g, 0.1-0.6 g, and essential amino acids. Each 100g pea contains 7g protein, 12g carbohydrates, 33.4 kilojoules of calories, calcium 17mg, phosphorus 90mg, iron 0.6mg, carotene 0.15mg, thiamine 0.54 mg, riboflavin 0.09mg, nicotinic acid 2.8mg 0.6mg 14mg. Pea contains one of its unique plant lectins, statin and gibberellin A20, which play an important role in enhancing the metabolic function of human body.

Disease and control of black spot of Dutch bean

Symptoms of Dutch bean black spot:

The black spot of Dutch bean is mainly harmful to leaves, stems and pods near the ground. Leaves infected with primary round to irregular spots, the middle black brown to black, with 2-3 circles, its upper many small black grain spots, that is, the pathogen conidium; the infected stem of the stem produced stripes, the diseased part was dark brown, the stems and leaves above the stem turned yellow and withered; pod infected newborn irregular purple spots, the diseased part with secretions, brown to dark brown, scab-like after drying, invading seeds to cause spots.

The pathogen Ascochytapinodes (Berk.etBloxam) Jones. It is called leguminous crustosporium, which belongs to half-known fungi. The phenotype is Mycosphaerellapinodes (Berk.etBloxamVestergren), which belongs to ascomycetes. The ascospores are spherical in size, 100 × 140 microns in size, cylindrical to oval in shape, 58mm in size, 62 × 12 microns in size, and oval or oval in size, 17.2 × 7.9 microns in size. The conidia are colorless, bicellular, 12 ~ 17 × 3.5 ~ 5.5 microns in size, with an average of 12.3 × 4.5 microns.

The transmission route and incidence conditions of Dutch bean black spot:

Overwintering with hyphae or conidia in seeds or conidia on the surface with diseased remains, the pathogen spread through wind, rain or irrigation water in the following year, invading from stomata, water pores or wounds, causing the disease. Seed-carrying bacteria can spread over a long distance with the transportation of seeds. When the seedlings were raised with diseased seeds, the cotyledons were infected at the seedling stage, and then spread to the true leaves. After the disease occurred in the field, conidia were produced on the disease spots, which were spread by wind, rain or agricultural operations, resulting in re-infection.

Prevention and control of black spot of Dutch bean:

The main results were as follows: 1) No disease pods were selected, and the seeds were threshed and left alone. The seeds were soaked in 56 ℃ warm water for 5 minutes before sowing, and the seeds were disinfected.

2) sowing at the right time, not too early, advocating high border cultivation, reasonable fertilization, proper close planting, increasing potassium fertilizer and improving disease resistance.

3) spraying 27% copper noble suspension 600x solution or combined with prevention and control of other Dutch bean leaf spot as early as possible, spray 75% chlorothalonil wettable powder 1000 times solution, 75% chlorothalonil wettable powder 1000 times solution, 75% chlorothalonil wettable powder 1000 times solution plus 70% mancozeb wettable powder 1000 times solution, 50% methyl thiophanate sulfur suspension 1000 times, once every 10 days, 2 times in a row. Pay attention to spray your feet evenly. Stop using medicine 7 days before harvest.