Seeds: carefully selected for viability

Step 1: processing of improved varieties

Seeds of excellent varieties ≠ quality seeds

A good son has a good mother, a good seed and a good grain. Wang Jianhua, a professor at the School of Agronomy and Biotechnology of China Agricultural University, said that 10 high-quality corn can be sold for 80 yuan, which proves this truth. "this kind of high-quality corn is not only a fine corn variety approved by the state, but also planted by carefully selected 'high-vigor seeds'." Wang Jianhua said, "High vitality is the core competitiveness of seeds."

, the high quality seed in the fine variety = "high vigor seed". Sun Qun, associate professor of the School of Agronomy and Biotechnology of China Agricultural University, gave the definition of the image of "high vigor seed".

"improve the emergence rate of seedlings in the field; resist adverse environmental conditions; have strong cold resistance and are suitable for early sowing; enhance the competition and resistance to diseases, pests and weeds; save sowing costs, which is conducive to field management; increase crop yield; improve seed storage tolerance." Sun Qun counted the production significance of "high vigor seeds" one by one. So, how to get "high vigor seed"? "Wind selection, screening, specific gravity selection and color selection are several important means to improve seed quality in our country at present (see table for details)."

According to Sun Qun, seed cleaning and selection is the core of seed processing. Its purpose is to remove inclusions (such as immature, broken and pest-affected seeds and weed seeds) from seeds according to their physical characteristics (such as width, thickness and length, density, critical suspension speed, seed surface characteristics, etc.), and to separate seeds with high germination rate and strong vitality from general crops. It is used to reproduce offspring, so as to improve seed quality, enhance the competitiveness of seed enterprises, and ensure the safe use of seeds in agricultural production. (our reporter Miao Yi)

Step 2: variety regional test

Product positioning test brings seed quality to a higher level

People in the industry have calculated that if corn is sown according to the conventional method, the general sowing amount is 2.5kg ~ 3kg per mu; if the seed quality is improved, all the seeds are sown with a single grain, which requires 3800 ~ 4400 seeds per mu, about 1.3kg, saving about half of the seeds. In that case, about 500 million mu of corn planting area in the country, if half of the saved land for seed production is used for grain production, the problem of feeding about 4 million people a year can be solved.

However, the amount of seeds used for single seed sowing is less, how can we ensure that the seedlings are equal, the seedlings are strong, and the yield is higher? Paying close attention to seed quality and improving seed vigor is the key!

"the quality of corn seeds is the decisive factor for single-seed sowing. Seeds capable of single-seed sowing require a bud rate of more than 95%, a purity of more than 98%, and a purity of more than 99%. And the seeds are full and the buds are strong, preferably the new seeds produced in the same year. " Dr. Sun Zhanyong, deputy general manager of Beijing Denong seed Industry Co., Ltd., said, "PPT' product positioning test provides all-round technical support for the improvement of seed quality in our company."

"the breeding of new varieties is subject to regional trials (provincial or national) → production trials (provincial or national) → approval at the provincial or national level. According to the provisions of the state's "seed Law" and other relevant laws and regulations, new varieties selected and bred by scientific research institutions, seed companies, or individuals can be put on the market and sold according to the examination and approval of the province or the state, and all belong to legal operation. " Sun Zhanyong said, "however, for the legal new varieties approved and approved, we are in no hurry to put them on the market and sell them to farmers. Instead, we re-conduct the 'PPT'' variety positioning test and promote sales according to the results of the test."

Sun Zhanyong and his technical team re-subdivide the national corn, rice, sunflower and other staple crop regions every year, carry out "PPT" variety positioning experiments and provide technical services for farmers. At present, "PPT" variety positioning experiments are carried out in corn, rice, sunflower and other crops, and all "PPT" experiments are sown, investigated and harvested by technicians themselves. In order to determine a suitable test site, technicians usually observe the growth of corn or wheat in the previous year, judge whether the soil fertility is uniform and representative, and then communicate with farmers.

"at present, we have carried out 'PPT' experiments on all kinds of crops in 21 provinces across the country, achieving one point per 1 million mu in spring sowing area and one point per county or 300000 mu in summer sowing area. This year, there are as many as 362 experiments arranged throughout the country, covering 345 counties across the country, each with an area of 0.8mu ~ 2mu, with radiation coverage of 380 million mu of corn, 120 million mu of rice and 5 million mu of sunflower. " "PPT" product positioning test is probably Sun Zhanyong's most proud move at the moment.

Advantages of seed cleaning processing

The implementation of seed cleaning processing can not only improve seed evenness, purity and 1000-grain weight, significantly increase seed germination rate and germination energy, but also reduce diseases and insect pests at seedling stage and increase crop yield.

Reduce the labor intensity of workers and improve work efficiency. Manual seed selection not only has high labor intensity, but also has low efficiency, while mechanized cleaning processing seeds can not only improve the efficiency by tens of times than manual seed selection, but also stabilize the seed quality after processing.

It is beneficial to the storage and transportation of seeds. After cleaning and processing, the diseased seeds and living impurities in the seeds are reduced, the seed quality is further improved and the storage life of the seeds is prolonged. Due to the improvement of seed cleanliness and good sealing of packaging, the loss caused by long-distance transportation and variety mixing and deterioration is reduced.

It increases the convenience of post-sequence work. It is beneficial to seed coating, pelleting and precision sowing, and improves work efficiency.

It improves the competitive ability of seeds in the market. After seed cleaning and processing, it is welcomed by farmers because of its high cleanliness and good quality.

Advanced methods of seed screening in foreign countries

The principle of seed sorting by color sorter is that seed vigor is closely related to seed coat color. Generally speaking, the darker the seed coat color is, the higher the seed maturity is and the stronger the seed vigor is. At present, color selection is mainly used in rice sorting and cotton seed selection, but it is rarely used in other crop seeds. The development of color sorter is very fast, from monochrome to two-color, and then to the current full-color recognition technology. with the market demand for high-quality seeds, the application of color sorter in seed identification and separation of other crops is just around the corner.

Liquid separation is a very traditional method of seed separation, which is more accurate than mechanical specific gravity separation. In the past, Chinese people knew how to select seeds with salt water or muddy water, and select the seeds with a large proportion as sowing materials. The seeds treated by this method need to be dried in time, which is more time-consuming and laborious. The liquid separation equipment developed in the Netherlands uses a special liquid as the separation medium and the liquid as the volatile liquid, which does no harm to the seeds and does not have the problem of absorbing water. After the seed separation is over, this liquid medium can be recycled immediately.

X-ray sorting is mainly used in vegetable seeds. After priming treatment, the internal embryo structure of the seeds can be directly observed by X-ray. Combined with the computer image recognition technology, the seeds with complete embryo structure and high vigor can be separated, and the sorting effect can reach about 1000 seeds per minute.