Technical problems and overcoming methods of "two nothing" cultivation of Cotton

The "two nothing" cultivation of cotton is the technique of raising seedlings with soilless substrate and transplanting bare seedlings without carrier. After demonstration in more than 80 counties throughout the country from 2004 to 2005, some technical problems have been found, and the solutions are put forward as follows:

1. The density of seedbed is too high.

The main reasons are: first, it is not rowed according to the row spacing of 10 cm and 3 cm; second, the amount of sowing is large, and the number of grains is large; third, there is no timely thinning of seedlings after emergence, resulting in the formation of tall seedlings or line seedlings.

The ways to overcome it are as follows: one is to row according to the row spacing of 10 cm and 3 cm; the second is to sow seeds according to the plant spacing, one grain at a hole; the third is to sparse the seedlings in time according to the plant spacing.

Second, weak seedlings, thin seedlings, not strong seedlings.

The main reasons are: first, in some places, the matrix is excessive in Gaza in order to reduce costs; second, the matrix and sand are not evenly mixed.

The ways to overcome it are as follows: first, the matrix should add river sand in proportion, with a volume ratio of 1 ∶ 1 and a weight ratio of 1 ∶ 8 to 1 ∶ 9; second, the matrix and sand should be mixed evenly; third, the water content of sand should not exceed 5%, and there is no industrial pollution and domestic pollution.

3. What are the characteristics of the matrix

First, the soilless substrate seedling bed has the characteristics of fast emergence and fast growth. For seedlings of the same age, the time should be 4 murals and 5 days earlier.

Second, the suitable seedling age for transplanting naked seedlings is 2 true leaves per plant, and the seedlings will not die of seedling disease in the field at this time. At the same time, the seedling rate of transplanting is high, growing fast and obviously early.

Fourth, how to sow seeds at the right time and accurately grasp the appropriate seedling age

Timely sowing is a key to ensure the high survival rate of naked seedlings transplanting. The methods of timely sowing and grasping the appropriate seedling age are as follows: first, the seedling sowing time should be pushed back according to the transplanting date. According to 2 true leaves of seedling age, it takes 25 days for early sowing and 20 days for late sowing. If transplanting at the end of April, sowing in early April; if transplanting in early May, sowing in mid-April. Rape in the middle reaches of the Yangtze River was transplanted in the middle of May after harvest, and the sowing date was in late April, while the short-season cotton of the Yellow River was transplanted in the first and middle of June, and the sowing time was in late May. Second, large-scale seedling cultivation emphasizes continuous sowing, or in stages and batches, centralized seedling cultivation requires continuous sowing for 2mi for 3 days. Third, the transplanting of naked seedlings emphasizes "unequal time of seedlings". The technical regulations require that the age of transplanted seedlings should not exceed 3 true leaves, and the seedlings should be transplanted when they grow to 2 true leaves per plant.

5. How to control the older seedlings

The method of "squatting seedlings" was adopted. If you cannot transplant on time in case of special climate and other reasons, there are two ways to "squat seedlings": one is to take seedlings from the seedbed and then plant them in the seedbed (also known as "pseudo-planting"), which can prevent growth. Second, the seedling bed was sprayed with low concentration of meth (0.1g / 1000 kg), and the control time was 7Mel for 8 days.

6. How to ensure the survival rate of transplanting naked seedlings

The key to the high survival rate of transplanting naked seedlings is water. "planting cotton is like growing vegetables" also requires enough water, and water is one of the elements of early growth. First, the bottom pick should be sufficient. Water before transplanting to make sure the soil moisture is sufficient. Second, the mouth moisture is good, while transplanting while watering "Angen (home) water". The third is to control the use of areas without irrigation conditions. "planting cotton is like growing vegetables" requires that water is the basic guarantee condition, and large-scale demonstration will not be carried out in areas without irrigation conditions.

7. How to promote the growth of cotton transplanting naked seedlings

In addition to adequate soil moisture, temperature is one of the factors of naked seedling transplanting and growth, and plastic film mulching is advocated. First, cover the plastic film first, and then transplant. Second, while transplanting, while pouring "Angen water", while covering with plastic film. It needs to be emphasized that the "two nothing" technology is a succession technology of seedling raising and transplanting in a nutrition bowl, and it can not replace plastic film mulching.