The secrets to growing coriander in greenhouses in summer mainly include the following aspects: 1. Reasonable temperature control
Sunshade and cooling: Cilantro prefers cold and cool environments and is not resistant to high temperatures. When planting in greenhouses, shading measures should be taken to reduce temperature. You can use a sunshade net to cover the top or surroundings of the greenhouse, reducing direct sunlight and lowering the temperature inside the greenhouse.
Ventilation and air exchange: In sunny and warm weather, the ventilation openings of the greenhouse should be opened in a timely manner for ventilation and air exchange to reduce the temperature and humidity inside the greenhouse and prevent the occurrence of diseases and pests. 2、 Seed selection and germination promotion
Choose varieties that are resistant to high temperatures: When planting coriander in summer, choose varieties that are resistant to high temperatures and grow quickly, such as Thai green coriander and Thai heat-resistant large grain coriander.
Germination treatment: Before sowing, coriander seeds need to undergo germination treatment. Soak the seeds in warm water until the seed coat softens, then remove them and wrap them in wet gauze to promote germination in a cool place. Keep the gauze moist during this period. After most of the seeds have turned white, they can be sown. 3、 Handling land parcels
Soil preparation and fertilization: Choose fertile and loose sandy loam soil with good water retention and drainage as the planting site for coriander. Before sowing, it is necessary to combine soil turning and apply mature farmyard manure as base fertilizer to improve soil fertility.
Watering the beds: Make long or short beds according to the situation of the plot, and water the bottom water sufficiently in advance to ensure that the soil is moist. 4、 Fine sowing
Sowing and covering with soil: Evenly sprinkle the germinated coriander seeds on the soil surface, then cover it with a thin layer of soil (about 2 centimeters thick), and spray water appropriately to maintain soil moisture.
Moisturizing Cover: After sowing, a layer of straw or sunshade net can be used for moisturizing and sun protection treatment. The cover should be removed promptly after the seedlings are unearthed. 5、 Strengthen management
Timely watering: During the growth period of coriander, it is necessary to keep the soil moist, especially during high temperatures and droughts in summer, watering should be done frequently. Watering should be done with small amounts of water and frequently to avoid excessive flooding, which can lead to soil compaction and disease occurrence.
Inter seedling weeding: When the seedlings grow to a certain height (such as 3-4 true leaves), inter seedling treatment should be carried out to remove weak and diseased seedlings and retain strong seedlings. At the same time, it is necessary to promptly remove weeds in the fields to prevent water and fertilizer competition with coriander.
Topdressing to promote growth: During the vigorous growth period of coriander, it is necessary to apply an appropriate amount of nitrogen fertilizer to promote plant growth and lush green leaves. Watering and topdressing with quick acting nitrogen fertilizers such as urea, or foliar spraying with foliar fertilizers such as potassium dihydrogen phosphate, can be combined to improve the yield and quality of coriander. 6、 Disease and pest control
Prevention oriented: Adopt agricultural control measures such as crop rotation and soil disinfection to prevent the occurrence of pests and diseases.
Chemical control: When pests and diseases are discovered, timely chemical control measures should be taken to control the spread of the disease. Broad spectrum fungicides such as carbendazim and carbendazim can be used for prevention and control; Insecticides such as imidacloprid and imidacloprid can be used for pest control.
It is necessary to pay attention to reasonable temperature control, seed selection and germination promotion, plot treatment, fine sowing, and strengthen management and pest control when planting coriander in greenhouses in summer to ensure the normal growth, high yield and high quality of coriander.