The northern sorghum can be sown in May and ripened in September-65438+10. However, due to different sowing areas and other factors, the specific sowing maturity time needs to be determined according to the actual situation. Sorghum belongs to C4 crop, which needs sufficient light and high temperature resistance during the whole growth period. The suitable temperature for the whole growth period is 20-30℃, which has the characteristics of drought resistance, saline-alkali resistance and barren resistance.

First, the northern sorghum is sown and matured in a few months.

1. Generally, northern sorghum can be sown in May and ripened in September-June. 10. However, the sowing area, variety and other factors are different, and the specific sowing maturity time needs to be determined according to the actual situation.

2. Sorghum likes warm and light, and is relatively resistant to high temperature. The suitable temperature for the whole growth period is 20-30℃. Too high or too low temperature will affect the growth of plants. For example, when the temperature reaches 44-50℃, the germination rate of sorghum will slow down or stop, so the germination temperature must be kept at 25-30℃.

3. Sorghum belongs to C4 crop, and it needs sufficient light during the whole growth period. It has developed root system, high osmotic pressure of root cells, strong ability to absorb water from soil, and has the characteristics of drought resistance, waterlogging resistance, saline-alkali resistance and barren resistance.

Sorghum can usually be harvested at the end of wax ripening. When harvesting, first cut off the stalks, then tie them up, every 20-30 plants 1 bundle, and then pile them into sorghum piles to dry. Sorghum ears can also be pinched off and transported back to the threshing floor.

Second, the northern sorghum planting technology

1, select improved varieties.

According to local climatic conditions, soil characteristics and other factors, select high-quality sorghum varieties with strong drought resistance, strong insect resistance and high yield.

2. Land selection and preparation

(1) Sorghum has strong adaptability and stronger drought resistance than other crops. It is more tolerant to saline-alkali soil in northern China, and has low requirements on soil fertility and water conditions, but it is suitable for planting in land with convenient irrigation and drainage and PH value between 6.2 and 8.

(2) The climate in northern China is characterized by more droughts in spring and less precipitation in winter. Therefore, it is suitable for autumn soil preparation, first weeding, then stubble cleaning, fertilization, ploughing and harrowing. Keep the soil loose and improve the water storage capacity.

(3) When the soil begins to thaw in spring, the ground should be raked in time to make the soil sufficiently fine and flat.

3, processing seeds

(1) seed selection and drying

① Eliminate the seeds that are not full, and choose the mature seeds with healthy color, no damage and full seeds.

② Then spread the seeds in the sun to improve the germination rate of the seeds.

(2) Germination detection

Before sowing, the seeds were germinated, and the appropriate sowing amount was determined by combining the germination rate. Usually, the germination rate needs to exceed 90% to be used as seeds.

(3) accelerating germination

Soak the seeds in warm water at about 40℃, take them out after 2-3 hours, put them in a wet cloth bag, and then put them on a heatable adobe sleeping platform for 10- 12 hours, and then sow the treated seeds on wet soil. Note: if you choose coated seeds, you generally don't need to accelerate germination in advance.

(4) chemical seed dressing

Before sowing, seeds can be evenly mixed with a proper amount of carbendazim wettable powder to reduce pests and diseases.

4, timely sowing

(1) Generally, when the ground temperature reaches 10- 12℃ at 5cm of soil, sowing time is too early, which will prolong the time of seed emergence, and sowing time is too late, which will lead to high temperature in the late growth stage of sorghum and aggravate pests. Therefore, it is necessary to master the sowing time.

(2) The suitable sowing depth is 3cm. Sowing too deep and too late will affect the sowing effect.

(3) Different sorghum varieties have different planting densities. In the northern region, the suitable planting density of dwarf varieties is 200,000-300,000 plants/hectare, and the high-yield sweet sorghum varieties are 865,438+/kloc-0,000 plants/hectare.

5. Water management

(1) According to the different growth stages of sorghum, choose the appropriate fertilizer. As seed fertilizer, compound fertilizer with high phosphorus content can generally be selected, and the dosage is 250-300kg/ ha.

(2) Topdressing urea120-150kg/ha at jointing stage can be combined with intertillage.

(3) Although sorghum is cold-resistant, there is little precipitation in the northern area, which requires reasonable irrigation. Irrigation is usually needed for 3-4 times in the whole growth period, and irrigation can be done in furrow fertilization, heading, flowering and filling 1 time.

6. Tian Tuan management

(1) When the seedlings have just emerged, it is necessary to solve the problem of lack of seedlings or weak growth by replanting or replanting to ensure that the seedlings are neat.

(2) If the planting density in the field is too high, the density can be appropriately reduced by thinning seedlings, and the seedlings with poor growth can be eliminated and the strong seedlings can be kept.

(3) Usually, sorghum needs to be cultivated twice in the growing period, when the seedlings are ridged and waist-high. The depth of the first intertillage is shallow, and the depth of the second intertillage is easy to be deep.

7. Prevention and control of pests and diseases

(1) disease

① Species: Common sorghum diseases include smut, leaf spot and rust.

② Control method: Before sowing, 35g of 50% Weixiuling powder mixed with 5kg seeds can effectively control head smut; In the early stage of leaf spot disease, 50% captan can be sprayed 500 times; At the beginning of the disease, spraying 3,000 times of 5% dipyridamole EC or1500-2,000 times of 25% triadimefon wettable powder can prevent rust.

(2) Insect pests

① Species: The common pests of sorghum are aphids, borers and flies.

② Control method: spraying 2.5% mirex emulsion 3000 times or 50% chlorpyrifos emulsion 1000 times can control aphids. Before heading, 3% dimehypo large granule snacks can be used to control stem borers; At the peak of adult oviposition, 40% dimethoate EC 700- 1000 times can be sprayed to control mango flies.