What are the precautions for growing amaranth in a greenhouse?
Amaranth, also known as green fragrant amaranth, is an annual herbaceous plant. It looks green with a touch of red, and its tender stems and leaves are used for food. This vegetable sells very well in markets and is one of the main leafy green vegetables of summer that the public loves. So when carrying out greenhouse amaranth cultivation, what are the key points to note?
1. Precautions for greenhouse amaranth
Amaranth originated in southern China and is widely cultivated in the Yangtze River basin. Amaranth can be grown in rotation from spring to winter. For off-season cultivation in early spring, plastic greenhouses, small greenhouses and plastic film are used. Amaranth has extremely high nutritional value, especially containing more iron, calcium and other minerals, while also containing more carotene and vitamin C, which are of great benefit to the human body. In addition, the seeds and leaves of amaranth can both be used medicinally.
When carrying out greenhouse amaranth cultivation, the first thing to note is the choice of variety. Amaranth varieties can be divided into round-leaf types and pointed-leaf types, and generally pointed-leaf types are suitable for greenhouse cultivation. For the sowing plot, choose as far as possible a section with convenient drainage and irrigation and few weeds. After land preparation, cover with greenhouse film. To bring it to market earlier, small arched sheds can be built inside the greenhouse and covered with film for preheating. When carrying out greenhouse cultivation, sowing should be done in a timely manner, preferably from mid-February to early March.
2. Pest and disease control of amaranth
Common diseases of amaranth include powdery mildew, anthracnose and brown spot, and the common pest is the mole cricket. After pests and diseases appear, confirm the disease promptly according to the symptoms and take targeted measures for treatment.
Powdery mildew mainly harms the leaves. Irregular brown patches begin to appear on the leaf surface, and round to irregular white blister-like spore mounds form on the underside of the leaves. In severe cases, the scab spots are densely distributed or merge, the leaves become uneven, and they eventually wither and turn yellow. In the early stage of the disease, spray 58% Ridomil · mancozeb wettable powder at 500 times dilution, or 50% methyl frost copper wettable powder at 600~700 times dilution, and spraying 1~2 times is sufficient.
Anthracnose mainly harms the leaves and stems. When leaves are infected, dark green water-soaked small spots first appear, then expand to grayish brown. When stems are infected, the lesions are brown, long oval and slightly sunken. In the early stage of the disease, spray 25% carbon special spirit wettable powder at 600~800 times dilution, or 80% anthracnose · fu jia he wettable powder at 600~800 times dilution. Spray once every 7~10d, treat continuously 2~3 times, and stop using the pesticide 7d before harvest.
Brown spot mainly harms the leaves. The leaf lesions are round or irregular, yellowish brown, and in the later stage the center of the lesion fades to grayish brown to grayish white, with a clear boundary between diseased and healthy parts. In the early stage of the disease, spray 50% pu hai xiong wettable powder at 1000~1500 times dilution or 70% mancozeb wettable powder at 500~700 times dilution; 75% chlorothalonil wettable powder at 500~600 times dilution can also be used. Spraying once every 7~10d is sufficient.
When mole cricket pest damage occurs, manual capture can be carried out, or cooked grain chaff mixed with 90% trichlorfon can be sprinkled on the field ridge surface for poisoning. The conventional chemical control method is to apply 1~1.5kg of 5% phoxim granules per 667m2 on the ground, then harrow it into the soil.