Six common diseases and control methods of green beans in greenhouses (一)

1. Carob rust

Main symptoms: The disease mainly affects leaves, and in severe cases, it also damages petioles and pods. The pathogen is Basidiomycotina and Puccinia spp. At the initial stage of the disease, there were dots of chlorotic yellow and white spots under the leaves, and the spots gradually increased until the whole leaf was densely covered. A yellowish-brown slightly protruding spot is formed on the corresponding back of the lesion. After the epidermis is broken, a reddish-brown powder is emitted. The leaves are yellow and fall off, the plants are short, the pods are few and small, the growth period is shortened, and finally they become thin and die. Carob beans can be infected with pathogens during the whole growth period. During the period from flowering to fruiting, the resistance is weakened, the susceptibility is increased, and the source of infection is reduced.

Prevention Methods

①Strengthen the management of soil, seed, fertilizer and water, choose well-drained sandy loam soil for planting, select high-yield disease-resistant varieties, adopt high-border deep furrows, rational topdressing, enhance plant immunity, and comprehensive control measures supplemented by timely spraying.

②Clean the countryside. After harvest, the diseased bodies in the field should be removed and burned collectively. Choose the field where the previous crop is planted with gramineous family, and do not choose the field where the previous crop is planted with legumes or peanuts.

③Select disease-resistant varieties.

④Chemical control: timely application of pesticides in the early stage of disease. The medicament can choose 25% difenoconazole 1500 times liquid, or 75% thiophanate methyl wettable powder 1000 times liquid, or 50% carbendazim wettable powder 1000 times liquid alternately. Spray once every 8-10 days.

2. Carob blight

Main symptoms: Mainly damage stems, leaves and pods, mostly at or near the stem nodes, especially near the ground. The diseased part was water-stained at first, then it was wet rot and constricted around the stem, and the leaf vines above the diseased part died. When the humidity is high, the skin layer rots and white mold is formed on the surface. The infected leaves showed dark green water-stain-like spots at first, and then expanded into round hazel spots with white mold on the surface. The diseased part of the pod also grew white mold and rotted.

Prevention Methods

①Select disease-resistant varieties.

②Implement crop rotation.

③Choose well-drained sandy loam soil for planting, adopt high borders and deep ditch, and plant reasonably densely to make it ventilated and light, and pay attention to timely drainage after rain.

④Pharmaceutical control, timely spray protection at the initial stage of the disease, you can choose 64% oxadixyl.mancozeb wettable powder 500 times liquid, or 72.2% propionamide water 800 times liquid, you can spray 1 every 7-10 days Times, 2-3 times in a row.

3. Carob fusarium wilt

Main symptoms: When a plant becomes ill, it first starts from the lower leaves. Irregular water-stained lesions appeared on the edge of the leaf, especially the tip of the leaf, the later leaf turned yellow and died, and gradually developed to the upper leaf, and finally the whole plant wilted and died. The cortex of the rhizome of the diseased plant often cracks, and the vascular bundle tissue becomes brown. When the humidity is high, a pink mold layer appears on the surface of the diseased part.

Pharmaceutical control: In the early stage of the disease, you can use 50% carbendazim wettable powder 1000 times liquid, or 99% hymexazol liquid 3000 times liquid, 75% thiophanate methyl wettable powder 1000 times liquid, and each plant can be filled with 200 times -300 grams, once every 7-10 days, 2-3 times in a row; you can also mix 500 grams of 50% carbendazim wettable powder with 200 kilograms of dry soil, and apply 200 kilograms per mu in furrow to the seeding row.

Zhengzhou Delong Chemical CO., Ltd. is the production base of plant growth regulators in China, which established in 2009, specializing in offering plant protection products. If you have any question, contact us any time.