High yield: high yield per unit area.
Methods of cultivating high-yield varieties:
1. Reasonable combination of yield factors
Grain crop yield = number of spikes per unit area * number of grains per spike * grain weight
Cotton yield = number of plants per unit area * number of bolls per plant * boll weight * lint percentage
Yield of soybean and rape = number of plants per unit area * number of pods per plant * number of pods * grain weight
Yield factor analysis
Yield =abc(a: number of spikes per unit area, b: number of grains per spike, c: grain weight)
Under the condition that other factors remain unchanged, raising one or two factors, or raising three factors at the same time, can improve the output level per unit area.
The key to high yield: the reasonable composition of yield factors and the maximum product of yield.
Ways to achieve the goal of high yield
Breeding multi-spike varieties mainly by increasing the number of spikes: breeding varieties with strong tillering ability, high tillering rate and more spikes per unit area.
Increase the number of grains per panicle and 1000-grain weight, and breed varieties with large panicle type: breed varieties with few panicles, more grains per panicle and high 1000-grain weight.
The number of spikes per unit area, the number of grains and the weight of grains are coordinated with each other, and the intermediate varieties are selected.
Application: on the basis of stable production, further increase the output.
Multi-spike varieties: mainly increase the number of spikes. Breeding varieties with strong tillering ability, high tillering rate and more panicles per unit area. (More than 500,000 plants/mu)
Application: The northern winter wheat area has a cold and dry climate, with light pests and diseases, mainly multi-spike type.
Large panicle varieties: mainly increase the number of grains per panicle and grain weight. Breeding varieties with fewer panicles, more grains per panicle and high 1000-grain weight. (about 300,000 plants/mu)
Application: The climate in the southern winter wheat area is warm and rainy, and the diseases are serious, mainly with large panicle type.
Intermediate varieties: the number of spikes per unit area, the number of grains and the grain weight are coordinated with each other. (400,000 plants/mu)
Application: on the basis of stable production, further increase the output.
2. Construct a reasonable plant type
Plant type: generally speaking, it is the appearance of the plant, including plant height, leaf shape, leaf posture, leaf color, leaf distribution, the relationship between tillers and main stems, and the appearance of ears.
Cereal crops: short or semi-short stems, compact plant type, straight, narrow and short leaves, dark leaves.
Objective: To improve the light receiving condition of crops and maximize the utilization rate of light energy, thus increasing the yield. Dwarf breeding is an important content and breakthrough of plant type breeding, which has the significance of expanding population, effectively using water and fertilizer, enhancing lodging resistance and improving harvest index. Harvest index, also known as economic coefficient, refers to the ratio of economic yield to biological yield.
Super hybrid rice is the result of the super hybrid rice cultivation plan put forward by 1996 by the Ministry of Agriculture, which is presided over by Yuan Longping, the "father of hybrid rice".
With the deepening of dwarf breeding and heterosis utilization in China, super rice is a new rice variety with high yield, high quality and strong stress resistance based on dwarf.
3. High photosynthetic efficiency breeding
Economic yield = biological yield * harvest index = net photosynthetic products * harvest index = (photosynthetic intensity * photosynthetic area * photosynthetic time-photorespiration consumption) * harvest index
Morphological and physiological characteristics of high photosynthetic efficiency varieties
Morphological characteristics: flush leaves, dark color, reasonable planting, less mutual shade, long green leaves, etc.
Physiological characteristics: high photosynthetic intensity, low light compensation point, low carbon dioxide compensation point, less photorespiration, high photosynthetic product transport rate and insensitivity to light.
Development trend of high photosynthetic efficiency breeding
The utilization rate of light energy is very low (below 1%-2%), and the improvement potential is great. It is estimated that:
Wheat and rice: 2.4-2.6%, yield per mu 1000 kg;
Corn: 5%, yield per mu 1600- 1800kg.
Prospect: Further variety improvement should focus on improving the utilization rate of light energy.