2 Countermeasures for the Utilization of Hybrid Maize Varieties in Dry-hot Valley of Jinsha River in Lijiang City
Due to the unique agricultural production conditions in the dry and hot valley area of ​​Jinsha River, rice, sugarcane, cotton, vegetables and other high-efficiency grain and food crops are planted in water-rich and irrigated areas and can be cooked or cooked three times a year. The production conditions are poor, and the drought-dehydrated plots are planted with hybrid corn or other dry crops and can only produce one season a year.
2.1 Selection and Utilization of Hybrid Maize Varieties
The general rainy season begins in the middle and late June, and even late in the year to mid-July and late. The rainy season ends in late August to early September and the latest to early October. The rainy season is only 90 to 110 days, and the rainy season accumulated temperature is 2300 to 2600 degrees. Therefore, if the hybrid corn varieties with too short growth period (around 75 days in the local area) are used, the yield will be low. If the varieties with excessive growth period (above 130 days in the local area) are used, the hybrid corn cannot be fully mature after rainfall stops. This area is suitable for use in The early-middle-maturing hybrid corn varieties with a 90- to 120-day growth period in the local area are matched with the corresponding cultivation techniques to obtain higher yields.
2.2 Hybrid corn planting density
The growing period of hybrid corn in this area is in the high temperature season, and the daily difference is relatively large. The special geographical location makes it belong to the valley in the terrain. Combined with the regulation of the Jinsha River and its tributaries, the valley winds slide quickly and the wind speed is high, which is conducive to field ventilation. . Therefore, hybrid corn cultivation is suitable for higher density. According to the variety characteristics, the local plant height of about 250 cm can be controlled at about 67,500 plants/hm2, and the plant height at 180-230 cm can be controlled at 82,500 plants. /hm2 or so. Due to the high temperature season, the growth rate is fast, and each growth period is short. Hybrid maize plants grown in this region can be reduced in height by 30 to 50 cm compared with other varieties planted in other regions, and should be based on local conditions.
2.3 Fertilizer application
In the region with high temperatures, rain and heat in the same season, the organic matter in the soil converts quickly. Therefore, a large amount of farmyard manure input, straw return, etc. can stably provide nutrients needed for the whole growth period of the corn during the whole growth period. Topdressing requires timely and timely application of nutrients for the key growth period of maize. Should be administered in manure 30000 ~ 37500 kg / hm2 as base fertilizer, to NPK 600 ~ 750kg / hm2 (N10, P10, K10) as a kind of fat, large bell topdressing urea 450 ~ 600kg / hm2.
2.4 Cultivated and weed control
In the same season, rain and heat in the same region, while corn grows rapidly, the growth of weeds is also rapid. If not timely cultivating and weeding, it will easily affect the normal growth and development of corn, ultimately affecting the yield of corn. Therefore, the use of chemical control measures and timely cultivation and weeding are particularly important.