What are the main diseases of rice seedling by mechanical transplanting?

1. Types and quantity of seedling trays: The rice bowl-shaped blanket seedling tray can cultivate the upper and lower bow

What are the main diseases of rice seedling by mechanical transplanting?

1. Types and quantity of seedling trays: The rice bowl-shaped blanket seedling tray can cultivate the upper and lower bowl-shaped blanket machine transplanting, realize the machine transplanting in the bowl and improve the effect of machine transplanting. 2. Sowing date: Generally, early rice is sowed in mid-March, and the seedling age is 20-30 days. 3. Sowing amount: the general sowing amount is1.20-1.50g/plate, the sowing amount of single-season conventional rice machine transplanting is1.000-1.20g/plate, and that of hybrid rice is 70-1plate.

1.

1, type and quantity of seedling trays

(1) First of all, choose the appropriate seedling tray according to the season of rice and the type of transplanter. The traditional seedling tray is generally a flat-bottomed blanket transplanter. This kind of seedling tray has a disadvantage, that is, it does serious damage to seedlings and roots, and it takes a long time for seedlings to turn green.

(2) The rice bowl-shaped blanket seedling tray can be used to cultivate the bowl-shaped blanket machine for transplanting rice seedlings. The advantage of bowl-shaped blanket seedling tray is that it can transplant seedlings by machine and improve the effect of transplanting seedlings by machine.

2. Sowing date

(1) Early rice is usually sown in mid-March, and the seedling age is about 20-30 days. The sowing date of single-season rice should be flexible, and the suitable sowing date of single-season rice in Jiangsu, Zhejiang and other provinces is from late May to early June.

(2) The sowing date must be reasonably arranged according to the early rice harvest period. The sowing date is about 10-20 days later than that of conventional hand transplanting, usually from the end of June to the middle of July, and the seedling age is about 15- 18 days.

(3) According to the actual situation (the number of rice transplanters, planting area, proficiency of manipulator, working efficiency, etc.). ), determine the appropriate transplanting date, arrange the planting progress, soak the seeds in stages to prevent the seedlings from being transplanted over age.

3. Sowing amount

(1) At present, most early rice transplanters in China are conventional rice, and the general sowing amount is about 120- 150g/ plate. The sowing amount of single-season conventional transplanter is generally100-120g/plate, and that of hybrid rice is 70-100g/plate. Continuous cropping of late rice, conventional rice120-150g/plate, hybrid rice 80-100g/plate.

(2) The sowing amount should be adjusted according to the germination rate and 1000-grain weight of varieties. For varieties with high germination rate and light 1000-grain weight, the sowing amount should be reduced appropriately, and for varieties with poor germination rate and large 1000-grain weight, the sowing amount should be increased appropriately.

2. What are the main diseases at seedling stage?

1, bakanae

(1) bakanae disease occurs in rice seedling stage. The diseased plants are thinner and taller than the healthy plants, with slender leaf sheaths and leaves, yellow leaves and poor root development.

(2) Some diseased plants died before transplanting, and white or reddish mildew appeared.

2. Bacterial wilt disease

(1) Bacterial wilt is mainly caused by physiological water loss of rice, which is not conducive to seedling growth, poor root development, and decreased ability to absorb nutrients at low temperature.

(2) If it suddenly clears up after being exposed to continuous low temperature or rainy days, it will lead to physiological disorder of seedlings and cause diseases.

3. Rhizoctonia solani

(1) Rhizoctonia solani is a pythium belonging to Flagellaceae. Bacteria can overwinter in the soil, and after rice is sown, the bacteria will begin to invade the seedlings.

(2) Rice seedlings suffer from serious diseases under the condition of water shortage, which generally occurs in dry seedling fields, and is a common major disease in dry seedling fields.

(3) After the second leaf stage of dry-raised rice seedlings, the seedling tips will wither and shrink, and the root hairs will be scarce, which will appear in clusters on the seedbed in the early stage.

4. Rice blast

(1) Rice blast occurred before the three-leaf stage. The stem base of the seedling is gray-black, the leaf sheath and leaves are reddish brown, and there is no obvious lesion and it dies.

(2) Rice blast is a fungal disease of rice, which can occur in the whole growth period of rice and is one of the important diseases of rice. It can greatly reduce the yield of rice, even 40-50% in severe cases, or even no grain harvest.