Field management techniques of high-quality broccoli and mastering the prevention and control methods of orchid mosaic disease

I. Management of slow seedling stage

This period of management is mainly cooling and moisturizing, in order to promote early slow seedling. In addition to using a sunshade net to build a shed to cool down the sun, it is also necessary to drench water once in the morning and evening. In order to prevent underground pests from biting off the seedlings, Milol was scattered evenly on the soil surface during planting. About 7 days after planting, human feces and urine or 2%-3% urea aqueous solution were applied thinly to promote plant growth. In order to prevent and reduce the occurrence of diseases, 75% chlorothalonil 600 times or 50% carbendazim 600 times was sprayed once about 10 days after planting.

II. Management of the rosette period

This period is the peak period of vegetative growth of broccoli, so it is necessary to provide sufficient fertilizer and water to make stems and leaves grow faster and lay a good nutritional foundation for high yield. Topdressing was needed twice in this period. When the plant began to grow rapidly (about 15 days after planting), urea was applied with a small hoe in the plant, about 15 kg per mu; the second topdressing was carried out before the plant was sealed. When the heart leaves of the plant began to show a twisted shape (about 30 days after planting), fertilizer was applied in shallow trenches between rows combined with weeding to cultivate the soil, applying compound fertilizer 20kg / mu or peanut bran 25kg / mu. Where there are conditions, it is best to apply human feces and urine every 7 to 10 days. Watering should be sufficient in the early stage of rosette stage to meet the needs of rapid growth and development of plants; when plants grow in clusters, watering should be properly controlled to promote the development of underground roots. The lateral branches occurred in this period should be removed in time to promote the formation of the main bouquet. At the same time, pay attention to the prevention and control of diseases and insect pests, especially pay attention to the harm of Plutella xylostella (commonly known as hanging filaria), Pieris rapae (commonly known as Pieris rapae), black rot and soft rot. Plutella xylostella can be sprayed with 3000 times of 5% fipronil or 3000 times of 1% insecticidal from the peak of egg hatching to the 2nd instar larvae. Pieris rapae can be sprayed with 1000 times of Bt emulsion or 1500000 times of chlorhexidine. At the initial stage of the onset of black rot and soft rot, 200 mg / L agricultural streptomycin, or 200 mg / L chloramphenicol, or 75% chlorothalonil 600 times solution, or 77% chlorothalonil 600 times solution, or 77% chlorothalonil 500 times 800 times solution can be sprayed alternately.

III. Management of the closing period

In order to promote the transformation from vegetative growth to reproductive growth and be beneficial to the formation of flower heads, it is necessary to properly control nitrogen fertilizer and apply phosphorus, potassium, boron, molybdenum and other fertilizers. Heavy fertilization was applied once in the initial period of flower head formation (40-50 days after planting), 15 kg of potassium chloride and 15 kg of compound fertilizer per mu. In order to reduce the yellowing of the corm surface and the cavities of the flower stem, and delay the senescence of the plant, the leaf surface was sprayed with 0.5% borax and 0.5% ammonium molybdate solution during the formation of the corm, about once a week, 2 times in a row. During the whole period of flower ball formation, the soil in the field should be kept moist, diseased leaves and old leaves should be removed in time, and diseases and insect pests should be controlled. There are 3 or 4 strong lateral flower branches per plant cultivated in the lateral flower bulb, and the rest of the lateral flower branches should be removed.

IV. Management of the harvest period

During this period, we should not only pay attention to timely removal of diseased leaves and old leaves, so as to facilitate ventilation and light transmission, promote the accumulation of nutrients to the flower bulb, but also pay attention to controlling moisture to prevent excessive humidity, causing disease and corm mildew. In case of acid rain or foggy weather, sprinkle water in time to wash away foggy water and acid rain to reduce flower ball rot. The suitable harvest time of broccoli is short. if the harvest is too late, the flower bulb will be loose, the bud will turn yellow and the quality will decline, but the flower head will be small and the yield will be low if it is harvested too early. Generally, the flower bud particles in the hand feel are loose or the flower bud particles at the edge of the flower ball are slightly loose, the surface of the flower ball is tight and flat, and the harvest time is not concave or convex. Broccoli should be harvested in the early morning or evening on a sunny day. When harvesting, cut the bouquet together with fat and tender stems about 10 centimeters long, put them in a cool place away from light, pack them and list them as soon as possible, and store them at a low temperature quickly if they fail to appear on the market in time. Those cultivated with side heads should also be fertilized once after the main heads are harvested, applying about 15 kg compound fertilizer per mu, and then harvest when the side heads grow to about 5 cm in diameter.