Methods of promoting precocity of Zizania latifolia

Under natural conditions, due to the low temperature in early spring, the buds germinate late and grow slowly, the varieties of Zhejiang University are generally conceived in May and produced in late May. In order to advance the marketing period of Zizania latifolia, greenhouse mulching was used to promote early maturity in summer Zizania latifolia production. Popularizing early cultivation in greenhouse can improve the field growth environment of Zizania latifolia, shorten the hibernation period of Zizania latifolia, make Zizania latifolia grow ahead of time, put on the market ahead of time, increase the yield and improve the quality, thus improving the economic benefits. At the same time, water bamboo is planted in greenhouse, and basically no pesticides are used to control pests and diseases during the whole growth period, so the commodity water bamboo is safer and more hygienic. The results showed that compared with conventional cultivation in the open field, the length of Zizania latifolia increased by 3.02cm, the transverse diameter increased by 0.59cm, the shell weight increased by 28.08g, the net weight increased by 26.99g, the net rate increased by 7.56 percentage points, and the yield of 667m2 increased by 65438+.

First, site selection.

In order to promote the early cultivation of Zizania latifolia in greenhouse, there are low-lying land, fertile and loose soil, high organic matter content, deep plough layer, convenient irrigation and drainage, good water quality, no industrial "three wastes" pollution, and no fields for continuous cropping Zizania latifolia.

Second, select and retain excellent seedlings and plant them at a reasonable density.

The seedlings of Zizania latifolia should be carefully selected every year, and the seeds should be left on the pier with neat plant type, high pregnancy rate, fat meat, low node position, no male gray water, low tillering node and consistent maturity. At the end of March and the beginning of April, seeds were dug in the seed mound, with one seedling and one hole, the seedling density was 30×40cm, and the Miao Di Honda ratio was 1: 10. Sowing began in late June and ended in late July. The planting method is wide and narrow rows, and the specification is 100-80×50 cm. Density per mu 1500 clumps, each clump 1-2. If the leaves of the planted seedlings are too long, the upper leaves should be cut off in time, and the height of the stems and leaves is 30-40cm to reduce the nutrient consumption of the plants. In a 6-meter-wide greenhouse, leave 60cm at each film edge on both sides, with 6 rows of * * * species.

Third, clean up the farmland and apply sufficient base fertilizer.

Autumn harvest basically ends from mid-October of 165438+ 10, and by mid-February of 65438+, it is necessary to cut off some residual plants and dead leaves on the ground, clean up the fields and burn them centrally to reduce the overwintering base of insect population and pathogens. In the field where there are many weeds in the water bamboo field, the accumulated water in the water bamboo field is drained 5-6 days before the shed is set up, and 40 kg of 10% glyphosate water agent 1 kg water is sprayed per mu as pre-germination treatment. 2-3 days before the shed is erected, shallow water is irrigated, and 667m2 special organic fertilizer for Zizania latifolia (developed by Institute of Soil Fertilizer of Zhejiang Academy of Agricultural Sciences and produced by Cixi Zhongci Ecological Fertilizer Co., Ltd., containing 25% organic matter, 7% N, 5% P2O5 and 8% K2O8)120-16% or Russian compound fertilizer is applied.

Four, scaffolding insulation, careful management

Before the end of February, that is, from winter to around, the shed should be covered with film to prevent frost. Bamboo greenhouse is mainly used to promote the early cultivation of Zizania latifolia, with a width of 6m, a height of 1.8-2.0m, a column in the middle, and the length depends on the field. Standard steel pipe vegetable greenhouse can also be used. The film is a multifunctional non-dripping film with a thickness of 0.08 mm and a width of 8 m. The greenhouse is mainly sealed and insulated all year round. After beginning of spring, the temperature changes dramatically, so it should be sealed to keep warm at night and checked frequently during the day. Usually when the weather is mild, both ends should be ventilated; When the weather is fine and the temperature in the shed exceeds 32℃, the edge (skirt) film should be uncovered and both ends should be ventilated. In case of continuous rainy weather, it is necessary to strengthen ventilation, which is conducive to strong seedlings and reduce the pregnancy rate of seedlings. Generally, all films are uncovered in mid-April.

Five, seedling spacing, clever topdressing.

At the end of February and the beginning of March, the temperature began to rise, and the water bamboo plants grew rapidly. When the plant height is 30-40 cm, the seedlings should be deleted in the shed, and 20-30 strong seedlings should be left in each pier, so that the effective seedlings of 667m2 can reach about 40-50 thousand. When deleting seedlings, weeding can be combined with ploughing to remove weeds at the edge of fields and improve soil permeability. At the same time, mud can be pressed on the pier rhizosphere to disperse the tillers and improve the nutritional status. On the premise of deleting seedlings, apply strong stalk fertilizer in time according to seedling color, generally 30-50kg imported compound fertilizer is applied to 667m2. At the end of March, Zizania latifolia gradually became pregnant with a flat stem. When 30% plants are pregnant, the pregnant fertilizer should be applied skillfully according to the leaf color, and the imported compound fertilizer of 15-20kg can be applied to 667m2, so as to ensure the nutrients required by the water bamboo after pregnancy and the meat quality of the water bamboo is fat and white.

Six, nest mud protection, timely harvest

At the end of March and the beginning of April, Zizania latifolia was pregnant one after another, and artificial nest mud was needed to protect Zizania latifolia. The purpose of nest mud is to block the direct sunlight of Zizania latifolia, raise the soil temperature, promote the coarseness, whiteness and crispness of Zizania latifolia, and improve the commodity rate. The nest mud should be carried out in stages, with 1 pregnant nest and 1 pregnant nest on each pier, and the nest mud should grow continuously with the elongation of Zizania latifolia. Generally, the height of nest mud is 15-20cm, which should not exceed the eyes of Zizania latifolia. Because the plants are pregnant first and then bred, it is necessary to collect mud nests as high as possible to promote the individual hypertrophy of Zizania latifolia. When Zizania latifolia grows until the heart leaves contract, the left and right lateral occipitals contract evenly, and the middle swells slightly to expose the chest, it can be harvested in time.

Seven, pay attention to the problem

1. After the film is sealed, urea, urea or other volatile fertilizers and any chemical herbicides cannot be applied in the shed to prevent the fertilizers and herbicides from burning seedlings.

2. In order to prevent seedlings from being damaged by high temperature, when the temperature in the film reaches 32-33℃ on sunny days, both ends of the greenhouse should be ventilated in time. When the temperature reaches 20℃ in sunny days, some side (skirt) films should be removed in time, and the maximum temperature in the greenhouse should not exceed 35℃.

3. Prevent premature removal of the whole film from causing freezing injury of Zizania latifolia. After mid-March, the temperature changed greatly. If the whole film is removed too early, it will be frozen by cold air and the yield of Zizania latifolia will be delayed. Generally, the whole film can be uncovered after mid-April of a year. In years with frequent cold weather, the time for uncovering the whole film should be appropriately postponed.