Breeding aims at the change of Maize identity

Editor's note: in this round of structural adjustment of the planting industry, the structural adjustment of corn is an absolute priority. As the largest food crop in China, corn was a "granary" in the past. In the future, we can continuously develop high-quality special varieties, promote the adjustment of the structure of corn varieties, and change the "granary" into "granary" + "milk bottle" + "vegetable basket" + "oil bottle", so as to create new economic growth points for farmers.

So, whether it is grain corn, silage corn, fresh corn, or high-oil corn, what advantages should be exerted and which variety defects should be improved from the point of view of breeding?

Grain corn-- "precipitation": only dry goods can be harvested mechanically.

As early as 2011, Shandong Academy of Agricultural Sciences successfully selected "Ludan 9066", the first new grain maize variety suitable for mechanical harvest, and began to popularize and apply it in Shandong in 2014. What are the main points of grain maize breeding? What are the advantages of selecting grain corn? How is the promotion of this variety at present? What are the difficulties faced by large-scale promotion? With these questions, the reporter interviewed relevant experts from the Maize Institute of Shandong Academy of Agricultural Sciences.

According to researcher Meng Zhaodong, breeding adult variety "Ludan 9066", secretary of the party committee of the Maize Institute of Shandong Academy of Agricultural Sciences, and post scientist of the national corn industrial technology system, rapid dehydration and resistance to lodging are the necessary conditions and the most important elements suitable for mechanical harvesting of grains. Meng Zhaodong said: "in order to achieve grain harvest, the lower the water content of the variety, the better, otherwise it will cause too high grain damage rate." Moreover, the later the harvest time is, the lower the grain water content is, the more suitable for mechanical harvest, so the lodging resistance of varieties is required. "

Based on the above reasons, Meng Zhaodong's research group defined the breeding direction of new grain maize varieties as "two low and one high", that is, reducing water content, reducing biological yield per plant and increasing planting density. "to reduce the biological yield per plant is to meet the requirements of reducing water content and improving lodging resistance, while increasing planting density is the need of high yield. In order to make grain corn varieties competitive, it is necessary to achieve high yield under mechanized harvesting conditions before farmers will accept it. " Meng Zhaodong said.

As one of the main grain corn varieties in Huang-Huai-Hai region, the minimum water content of "Ludan 9066" in the 100-mu demonstration side of Liaocheng is only about 26%, which is lower than that of other similar varieties. At the same time, the performance of high yield was outstanding, with an average yield of 638.5 kg per mu in the two-year regional test, an increase of 3.7% over the control "Zhengdan958", and a production trial of 557.6 kg per mu, 1.9% higher than that of the control "Zhengdan958".

"Ludan 9066" is constantly being promoted, and it is also faced with the practical difficulty of "precipitation" speed.

In 2014, the reporter participated in the "Ludan 9066" mechanized grain harvest on-the-spot meeting held in Yanglankou Village, Taiping Town, Jiyang County. When the harvester goes by, a whole corn kernel is poured out with a crushed corncob.

"in this way, the processes of ear picking, peeling, threshing, cleaning, straw crushing and returning to the field are all completed at one time. After harvest, the corn grain is clean, non-broken, and the loss rate is very low. Farmers can sell it in one day, so that the autumn harvest can be completed in two days. For traditional corn varieties, it takes two or three days to dry the sticks before threshing, and it takes about a week to dry the seeds after threshing, which is time-consuming and laborious, and it is difficult to find a drying ground. " Li Wencai, an associate researcher at the Corn Institute of the hospital, said.

There are many benefits of grain corn, how about the promotion? Meng Zhaodong said frankly: "at present, the promotion of summer corn in Huang-Huai-Hai producing areas is still faced with practical difficulties, mainly due to crop rotation with wheat. The sowing time of wheat is certain, and it is very difficult for farmers to harvest seeds in 110 days when planting corn, most of which are harvested in about 100 days. In this way, the grain water content is still on the high side, and the grain damage rate of mechanical harvest is high. The moisture content of mechanically harvested grains is less than 25%, while at present it is generally more than 30% at harvest. "

In the past three years, "Ludan 9066" has been popularized in summer corn producing areas of Shandong Province, with an annual extension area of about 1 million mu, which has failed to make a major breakthrough. Meng Zhaodong said: the next step is to continue to make efforts in the direction of "precipitation" and increase the intensity of variety breeding. The second is to make a combination, select seed enterprises with strong strength and strong promotion ability, and undertake the task of promoting improved varieties. Third, actively docking cooperatives, family farms and other new business entities, the construction of grain corn planting and mechanized harvest demonstration base.