Under certain natural conditions, cultivation conditions and people's choices, a variety of soybean varieties are formed. Each species has its own characteristics and adaptability. For example: hi-fat water, limited or sub-constrained habits of thick stalks, large grains with developed main stems, and medium and small grain species with high plant height and strong luxuriance, should be planted under excellent cultivation conditions with high fat and sufficient water; The glutinous cultivars are suitable for planting in arid and arid lands. Both cropping practices will result in a decline in yield, which will be limited to their respective production conditions in order to exert their high yield performance. It can be seen that there is no uniform standard model for the fine varieties of soybeans. In cultivated areas, varieties that can give full play to their high yield performance are called superior varieties.
For the specific selection of varieties, firstly, the ecological characteristics of soybean such as growth period, knot habit, grain size, seed coat color and velvet coat color, and resistance to pests and diseases should be considered.
1, growth period
The growth period of soybean varieties is determined by the light and temperature response characteristics. It is related to whether the variety of a soybean field in a ripe spring can adapt to the frost-free period in an area and whether it can normally mature before frost. For summer and autumn soybeans, the requirements for multiple cropping must be considered when selecting the growth period.
In the southern soybean area, the frost-free period lasts for more than 300 days. Sowing soybeans in spring, summer, autumn and winter can be planted according to the need of replanting. Summer soybeans are planted from late May to early June, and harvested from late September to early October. Middle-early-maturing or mid-late-maturing varieties can be selected between 110-125 days of fertility. Spring soybeans are planted from the end of March to the beginning of April, and harvested from mid-July to early August. Mid-maturing varieties with 100-110 days of fertility or precocious varieties with 95-100 days are selected. Autumn soybeans are mostly planted at the end of July after the harvest of early rice. It is advisable to use medium-early-maturing or late-maturing varieties with 90-115 days of fertility. In short, according to the arranging schedule, suitable varieties for the growth period should be selected.
2, guilty habits
Soybean varieties with different pod habits have different adaptability to soil fertility and other cultivation conditions. The cultivars with limited knot habits have thick stems, short internodes and medium plant heights. Under conditions of sufficient fertilizer and water, they have more pods, full grain, and high yield performance, and are suitable for planting in areas with high rainfall and fertile soil; The requirements for fertilizer and water are not very strict, and even if they are planted in infertile areas, they can still obtain a certain amount of production. The requirements for the water and fertilizer conditions of the sub-contracted and deficient breeds are between the first two. Among the sub-contracted breeding habits, the moderately high plant heights and the developed main stem varieties are suitable for fertility cultivation. Plants with tall plants and strong luxuriant plants are suitable for planting in barren soil.
In rainy and fertile areas, or in paddy fields, or in soybeans intercropped with corn, high yield performance, thick stalks, and limited pod habits of medium and large grains should be used. Insufficient rain, low-growth regions with short growing seasons, and cold mountainous regions should use indeterminate varieties.
3, shape and size
The soybean grain shape and grain size have different adaptability to soil fertility and cultivation conditions. Large seeds require fertile soil and adequate moisture. Ovals, flat ellipses, and small seed varieties are more adaptable to adverse environmental conditions. The closer the traits are to wild soybean, the stronger the resistance of the varieties.
The size of the selected grain size is also dependent on the application requirements. Vegetable soybeans, 100-grain weight 38-40 grams; varieties of raw bean sprouts, 100-grain weight is only 4-5 grams; for the feed of autumn soybeans mud beans, horse beans, 100-grain weight 6-10 grams.
4. Seed coat, umbilicus color and hair color
Seed coat, umbilicus color, and velvet coat color represent an indicator of the evolution of soybeans. Seed coat, umbilicus color and deep fur color are the more primitive types of soybean. The seed coat color is yellow, blue, black, brown and gray.
5, pests and diseases
It is advisable to use soybean varieties that are resistant to pests and diseases. Soybean varieties are used in addition to considering the above ecological characteristics, but also to adapt to farming conditions. For example, in soybean mechanized cultivation areas, varieties with tall plants, strong culms, strong main stems, compact plant types, high scab locations, and no easy to rot or fall should be selected to facilitate mechanical harvesting and threshing.