CN107409706B - A method for improving the transplanting survival rate of cassava seedlings - Google Patents

Abstract

The invention discloses a method for improving the transplanting survival rate of cassava seedlings, which comprises the following steps: (1) preparing a seedling substrate; (2) cultivating seedlings in bags: after germinating the seedlings, transplanting them into a nutrient bag, Sprinkle with water, cultivate at room temperature, keep the substrate humidity at 50-60% by spraying water in the future, spray 0.8-1.0% urea solution every other week after 7 days, and spray 2-3 times; after 10 days, use 3000-5000 times of 1.8 % Abamectin EC and 200-300 times of Bacillus thuringiensis insecticide are sprayed, and then sprayed again after 20 days; (3) refining seedlings; (4) transplanting field. The invention reduces the lesions of the seedlings, improves the ability to resist pests, and lays a foundation for improving the transplanting survival rate of the seedlings by adding pesticides when the seedling substrate is prepared, and spraying fungicides during the seedlings' culturing.

Description

A method for improving the transplanting survival rate of cassava seedlings

technical field

The invention belongs to the technical field of plant sexual reproduction, in particular to a method for cultivating cassava seedlings.

Background technique

Cassava is a plant of the Euphorbiaceae cassava genus, native to the Amazon River Basin of South America. It is a perennial shrub with starch-rich roots that grow underground and can obtain high biomass. It is called "pioneer crop" and "reclamation crop". Sweet potato and potato are the three major potato crops in the world. Cassava is rough and easy to grow. It is a typical tropical crop. It has outstanding biological characteristics such as high starch accumulation, drought resistance and barren resistance. It has fewer pests and diseases. Above ℃, frost-free period of 240 days, and annual rainfall of 400mm or more are distributed in vast areas. Cassava stems are composed of nodes and internodes. , palmately lobed into 5, 7, 9 leaflets; the flowers are panicles, and the flower spikes are drawn from the branches at the stem end, the male flowers are attached to the upper part, and the female flowers are attached to the lower part, and the fruit can be obtained 2 to 3 months after flowering , The fruit is a capsule, the seeds are kidney-shaped, and the seed coat is hard, gray or black.

With the rapid growth of my country's energy demand, cassava has become an important resource for the development of my country's biomass energy industry. The cassava industry has gradually transformed from a primary stage to a rapid development stage, the trend of industrialization has accelerated, and the demand for raw materials in the processing industry is strong. However, the average yield and quality of fresh cassava in Guangxi are still at a low level, which is difficult to meet the needs of the further development of the current cassava industry. Obviously, through cassava cross-breeding, it is the core problem to be solved in the current Guangxi cassava system to select new varieties with high yield, strong stress resistance and wide adaptability suitable for local environmental and climatic conditions. Among them, the cultivation of cassava seedlings is also extremely important. How to improve the germination rate of cassava seeds and the survival rate of transplanted seedlings and provide more and more robust seedlings for variety breeding is also one of the key technologies.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a kind of method that improves the transplanting survival rate of cassava seedlings, reduces the pathological changes of seedlings by adding insecticides, spraying fungicides etc. The ability to resist insect pests lays the foundation for improving the survival rate of seedling transplanting.

A method for improving the transplanting survival rate of cassava seedlings, comprising the steps:

(1) Preparation of seedling substrate: Mix the pond mud, topsoil, organic fertilizer and river sand in a ratio of 3 to 5:1:1:1 to prepare moisturizing and transparent nutrient soil, stir well, and mix the soil per square meter. 1～2g of 50% wettable carbendazim powder, sealed for 5 to 7 days, opened for ventilation for 3 to 5 days before use, and put into a nutrition bag;

(2) Cultivate seedlings by bagging: after germinating the seedlings, when the true leaves of the seedlings are fully unfolded, they are transplanted into nutrient bags, and the roots of the seedlings are buried to a depth of 2 to 3 cm. Cultivated at room temperature, spray water to keep the substrate humidity at 50-60% in the future, spray 0.8-1.0% urea solution after 7 days for top dressing of seedling leaves, and spray once every 7 days, spray 2-3 times until transplanting Field; after cultivating for 10 days, spray with 3000-5000 times of 1.8% Abamectin EC and 200-300 times of Bacillus thuringiensis insecticide, and spray again after 20 days;

(3) Seedling refinement: remove the shade net after 20 days, and continue to refine and cultivate the seedlings for 5 to 7 days. When the seedlings grow to 25 to 30 cm in height, they can be taken out of the nursery and planted in the field; gradually training the seedlings before planting can not only improve the seedlings’ ability to cope with adverse environments The resistance ability of the seedlings is enhanced, and the cold resistance and drought resistance of the seedlings are enhanced, and the trained seedlings are planted slowly and quickly, and the trees grow early;

(4) Transplanting the field: with the row spacing of 80 to 100 cm and the plant spacing of 40 to 50 cm, transplant the seedlings to the field with both irrigation conditions and drainage. After transplanting, pour enough water to fix the roots and keep the humidity at 70 to 80%. , 5 to 7 days later, according to conventional field management, strengthen water and fertilizer management and pest control.

As a preferred technical solution, after 7 days of bagging and cultivating seedlings, spray 0.8% urea solution to carry out top dressing on seedling foliage, then spray once every 7 days, and spray 2 to 3 times until the field is transplanted; after 10 days, use 5000 times of 1.8% Abamectin EC and 200 times of Bacillus thuringiensis insecticide were sprayed, and then sprayed again after 20 days.

In the present invention, 0.8% urea solution is used as foliar topdressing. First, the low concentration of urea can promote leaf growth, make the root system strong, and improve the survival rate of transplanting.

In the present invention, the 1.8% abamectin EC of 5000 times liquid can not only have stomach poisoning and contact killing effects on Tetranychus cinnabarinus, which harms cassava, the pests appear paralyzed, do not move, do not take food, and die after 2 to 4 days. To achieve the effect of insect control, reduce the impact of pests, improve the survival rate of transplanting, and at the same time this concentration of pesticides does not harm the seedlings themselves. The Bacillus thuringiensis is a kind of microbial insecticide, using 200 times of liquid, the toxins it produces can make the pests stop feeding, and finally the pests are starved and die to achieve the pest control effect, preventing the pests from gnawing the seedlings and affecting the transplanting survival rate. , and this concentration of pesticides does not harm the seedlings themselves.

As a preferred technical solution, the pond mud used in the present invention is the old pond mud that is crushed by a pulverizer after being naturally dried for 6-8 months. The topsoil is an area of 15-20 cm at the top of the soil, which contains a lot of organic matter and microorganisms. The average particle size of river sand is 0.35 to 0.50 mm.

As a preferred technical solution, the pH value of the organic fertilizer is between 6.5 and 7.5, and the nutrient content is 10% to 15% of organic matter, 0.6% to 0.9% of total nitrogen, 0.3% to 0.6% of phosphoric acid, and 1.0% to 1.0% of potassium oxide. 1.5%, available nitrogen 280-300ppm, available phosphorus 80-100ppm, available potassium 300-320ppm.

As a preferred technical solution, before the field is planted, 20-25 kg of nitrogen, phosphorus and potassium compound fertilizer per mu of field is used as the base fertilizer, and then mixed with the planting mud and then used as the planting condition. The weight ratio of nitrogen, phosphorus and potassium in the nitrogen-phosphorus-potassium compound fertilizer used is 15:15:15.

As a preferred technical solution, seed selection, soaking in warm soup and seed germination are carried out before allocating seedling substrates.

Seed selection, harvest mature and full fruits, put them in a cool place to dry, the seeds will pop out after the fruits burst naturally, and choose the seeds with full particles. Soak the seeds in water at a ratio of seed:water=1:5 and stir evenly. After ten minutes, most of the seeds still floating on the water surface are hollow and discarded, and the bottomed seeds are selected for breeding materials.

For soaking seeds in warm soup, put the bottomed cassava seeds into a mesh bag and tie the bag tightly, and soak them in a 30°C constant temperature water bath for 7 hours for warm soup treatment.

The seeds are germinated. The seeds soaked in the warm soup are sown in a sand bed, and the clean pure river sand is placed in a 45*35*7cm tray. ℃, 70% humidity artificial climate incubator, keep the sand bed moist during the period, after the seeds are treated with warm soup to absorb enough water, artificially controlling suitable conditions for germination can promote the rapid decomposition and operation of nutrients in the seeds for the growth of young embryos required to speed up the germination of the seeds. The average particle size of the pure fine river sand is 0.25-0.35 mm; the length of the tray is 40-45 cm, the width is 30-35 cm, and the height is 7-10 cm.

The sunshade used in the present invention is supported by cement uprights, and the skeleton is made of special steel-plastic composite pipes for greenhouses. The surrounding area is naturally ventilated and covered with a layer of six-pin shading net, with a shading rate of 85% to 90%. Because the cassava seedlings are not resistant to moisture, if the first five days after bagging and cultivating encounter cloudy and rainy weather, the shading net needs to be covered. A layer of plastic film to prevent the seedlings from waterlogging.

In the present invention, carbendazim is mixed with carbendazim when the seedling raising substrate is prepared. It can effectively prevent and control diseases at the seedling stage, improve the disease resistance effect at the seedling stage, and improve the survival rate of subsequent transplanting.

Cassava seeds are natural hybrids. Seeds are brown or gray-brown with tan, gray-banded macular or black tabby.

Beneficial effects of the present invention:

1. the present invention adds carbendazim in the process of seedling matrix preparation and mixes, and plays a bactericidal effect on microorganisms, fungal diseases, etc. in the matrix, and avoids pathologies such as root rot and leaf blight in the process of seedling bagging and cultivating. . At the same time, the nutrient elements required for the growth of seedlings in the seedling matrix can promote the development of the root system of the seedlings and improve the survival rate of transplanting.

2. the present invention, in order to promote the growth of seedlings and the control of seedling diseases and insect pests, during the cultivation period of transplanting the seedlings into the nutrient bag, spray low-concentration urea as foliar fertilizer at regular intervals to accelerate the growth of leaves, and the root system is robust; Apply low concentrations of 1.8% Abamectin EC and Bacillus thuringiensis for insecticide and sterilization to avoid the impact of pests and diseases, and at the same time improve the resistance of seedlings, lay the foundation for subsequent transplanting in the field, improve the emergence rate and improve the survival rate of transplanting .

3. The method of the invention is simple, easy to master and operate, and the survival rate of bagged culture reaches more than 95%, and the survival rate of planting field reaches 100%.

Detailed ways

The present invention is further described below through specific examples, so as to make the advantages and characteristics of the present invention easier to understand. It should be understood that the following examples are only preferred solutions of the present invention, rather than limitations of the present invention.

Example 1

In this experiment, cassava Huanan No. 5, Guire No. 4, Guangxi cassava, Thai species, and glutinous rice species are selected as the test varieties. The specific test includes the following steps:

(1) Seed selection: Select the seeds with full particles, soak the seeds in water according to the ratio of seeds: water = 1:5 and stir them evenly. After ten minutes, most of the seeds still floating on the water surface are hollow, discard them, and select The bottomed seeds are used as breeding material. 50 seeds were selected for each group.

(2) Soaking seeds in warm soup: Put the 5 groups of seeds screened into mesh bags and fasten the bag mouths respectively, and put them into a 30°C constant temperature water bath for 7 hours for warm soup treatment.

(3) Sand sowing germination: The seeds soaked in the warm soup are sown in a sand bed, and the clean pure fine river sand is placed in a 45*35*7cm tray, and the seeds are sown in the sand bed on demand, about 1.0cm away from the sand surface. Seed germination experiments were carried out in an artificial climate incubator at 30°C and 70% humidity, during which the sand bed was kept moist.

(4) Preparation of seedling matrix: Mix pond mud, topsoil, organic fertilizer, and river sand in a ratio of 3:1:1:1 to prepare moisturizing and transparent nutrient soil, stir well, and mix 1.2g per square meter of soil 50% wettable carbendazim powder, sealed for 5 to 7 days, open for ventilation for 3 to 5 days before use, and put into a nutrition bag;

(5) Cultivate seedlings by bagging: after the seedlings are germinated, when the true leaves of the seedlings are fully expanded, they are transplanted into nutrient bags, and the roots of the seedlings are buried to a depth of 2 to 3 cm. Cultivate at room temperature, keep the substrate humidity at 50-60% by spraying water in the future, spray 0.8% urea solution after 7 days for seedling foliar topdressing, and spray once every 7 days until transplanting the field; after cultivating 10 days, use 5000 times 1.8% Abamectin EC and 200 times of Bacillus thuringiensis insecticide were sprayed, and then sprayed again after 20 days;

(6) Seedling refinement: remove the shade net after 20 days, and continue to refine and cultivate the seedlings for 7 days. When the seedlings grow to 25-30cm, they can be taken out of the garden and planted in the field.

(7) Transplanting the field: The seedlings were transplanted to the field with both irrigation conditions and drainage with the row spacing of 80cm and the plant spacing of 40cm, and different varieties were planted in groups. After transplanting, drench the feet with root-fixing water, keep the humidity at 70-80%, and follow the routine field management after 7 days, and strengthen the management of water and fertilizer and the control of diseases and insect pests. Statistics were performed one month later, and the germination rate of cassava seeds and the transplanting survival rate of seedlings were shown in Table 1.

Table 1 The germination rate of cassava seeds and the survival rate of transplanted seedlings

Remarks: Germination rate = (germination number / sowing number) × 100%;

Survival rate = (the actual number of surviving plants/the actual number of plants) × 100%;

The actual number of plants cultivated by bagging in the shade is the number of germinations, and the actual number of plants in the field planting is the number of survivors cultivated in bags in the shade.

As can be seen from Table 1, the seedlings that grew true leaves after germination were bagged and cultivated in a shade shed, and the survival rate reached more than 95%. The cassava seedlings grew to about 25 cm and were transplanted into the field after 7 to 10 days of hardening, and all the plants survived. , the survival rate is 100%. It shows that the method of the present invention is practical and effective.

Example 2

In this experiment, five natural hybrids of cassava Huanan No. 5, Guire No. 4, Guangxi cassava, Thai species and glutinous rice species were selected as test varieties. Seed selection, soaking, and germination were carried out using conventional methods. After the germination has grown out of true leaves and fully expanded, a transplant culture test is carried out. The specific test includes the following steps:

(1) Preparation of seedling matrix: Mix pond mud, topsoil, organic fertilizer, and river sand in a ratio of 3:1:1:1 to prepare moisturizing and transparent nutrient soil, stir thoroughly, and mix 1.2g per square meter of soil 50% wettable carbendazim powder, sealed for 5 to 7 days, open for ventilation for 3 to 5 days before use, put into a nutrition bag, and set aside;

(5) Cultivate seedlings by bagging: after the seedlings of five varieties of cassava Huanan No. 5, Guire No. 4, Guangxi cassava, Thai seed and glutinous rice are germinated, wait until the true leaves of the seedlings are fully expanded, according to 50 plants of each variety Transplant into a nutrient bag, bury the roots of the seedlings to a depth of 2 to 3 cm in the matrix, one bag per plant, drenched with water, and placed under a awning for cultivation at room temperature. Each group is marked. In the future, spray water to keep the substrate humidity at 50-60%, spray 0.8% urea solution after 7 days for top dressing of seedling leaves, and then spray once every 7 days until transplanting the field; after cultivating for 10 days, use 1.8% of 5000 times the solution. % Abamectin EC and 200 times Bacillus thuringiensis insecticide were sprayed, and then sprayed again after 20 days.

(6) Seedling refinement: remove the shade net after 20 days, and continue to refine and cultivate the seedlings for 7 days. When the seedlings grow to 25-30cm, they can be taken out of the garden and planted in the field.

(7) Transplanting the field: The seedlings were transplanted to the field with both irrigation conditions and drainage with the row spacing of 80cm and the plant spacing of 40cm, and different varieties were planted in groups. After transplanting, drench the feet with root-fixing water, keep the humidity at 70-80%, and follow the conventional field management after 7 days, and strengthen the management of water and fertilizer and the control of pests and diseases. Statistics were carried out after one month, and the transplanted survival rate of cassava seedlings was shown in Table 2.

Table 2 Transplanting survival rate of cassava seedlings

Remarks: Survival rate = (the actual number of surviving plants/the actual number of planted plants) × 100%; the actual number of plants in the field is the number of surviving cultivation in shaded sheds.

As can be seen from Table 2, the seedlings that grew true leaves after germination were bagged and cultivated in a shade shed, and the survival rate reached more than 96%. rate of 100%. It shows that the method of the present invention is practical and effective.

Claims (5)

1. a method for improving the transplanting survival rate of cassava seedlings, is characterized in that, comprises the steps: (1) Prepare seedling substrate: Mix pond mud, topsoil, organic fertilizer, and river sand in the ratio of 3~5:1:1:1 to prepare moisturizing and transparent nutrient soil, stir thoroughly, and mix the soil per square meter. 1~2g of 50% wettable carbendazim powder, sealed for 5 to 7 days, opened for ventilation for 3 to 5 days before use, and put into a nutrition bag; The pond mud is the old pond mud that is crushed by a pulverizer after being naturally dried for 6 to 8 months; the topsoil is an area of 15 to 20 cm on the top of the soil, which contains more organic matter and microorganisms; the average particle size of the river sand The PH value of the organic fertilizer is between 6.5 and 7.5, and the nutrient content is 10% to 15% of organic matter, 0.6% to 0.9% of total nitrogen, 0.3% to 0.6% of phosphoric acid, and 1.0% to 1.0% of potassium oxide. 1.5%, available nitrogen 280～300ppm, available phosphorus 80～100ppm, available potassium 300～320ppm; (2) Cultivate seedlings by bagging: after germinating the seedlings, when the true leaves of the seedlings are fully unfolded, transplant them to the nutrient bag, and bury the roots of the seedlings to a depth of 2 to 3 cm. Cultivated at room temperature, drenching water to keep the substrate humidity at 50-60% in the future, drenching 0.8% urea solution every other week after 7 days, and spraying 2 to 3 times; after 10 days, use 1.8% abamectin EC and 200 times of Bacillus thuringiensis insecticide was sprayed, and then sprayed again after 20 days; (3) Seedling refining: remove the shade net after 20 days, and continue to refine and cultivate the seedlings for 5 to 7 days. When the seedlings grow to 25 to 30 cm in height, they can be taken out of the garden and planted in the field; (4) Transplanting the field: The seedlings are transplanted to the field with a row spacing of 80-100cm and a plant spacing of 40-50cm to a field that has both irrigation conditions and drainage. After transplanting, drench the feet with water to fix the roots and keep the humidity at 70-80%. , 5 to 7 days later, according to conventional field management, strengthen water and fertilizer management and pest control. 2. the method for improving cassava seedling transplanting survival rate according to claim 1, it is characterized in that, carry out seed germination before allocating seedling matrix, cassava seed adopts sand bed sowing, seed is sown in sand bed on demand, leaves sand Seed germination was carried out in an artificial climate incubator with a surface of 1.0 cm at 30 °C and a humidity of 70%, and the sand bed was kept moist during the period. 3. the method for improving cassava seedling transplanting survival rate according to claim 2, is characterized in that, carry out seed selection, warm soup soaking before seed germination; By seed: the ratio of water=1:5 soaks the seed for ten minutes, The bottomed seeds were selected as breeding materials, and the seeds floating on the water were discarded; the bottomed cassava seeds were put into a mesh bag to tie the bag mouth tightly, and soaked in a 30°C constant temperature water bath for 7 hours for warm soup treatment. 4. the method for improving the transplanting survival rate of cassava seedlings according to claim 1, is characterized in that, before the field planting, in the field, 20～25 kg of nitrogen, phosphorus and potassium compound fertilizers are applied as base fertilizer in every mu of field, and 20～25 kg of compound fertilizer are applied in the field as base fertilizer. The ditch is mixed with mud and then used as a condition for planting. 5. The method for improving the transplanting survival rate of cassava seedlings according to claim 4, wherein the weight ratio of nitrogen, phosphorus and potassium in the described NPK compound fertilizer is 15:15:15.