Field Crop 2025, Vol.8, No.3, 126-138 http://cropscipublisher.com/index.php/fc 129 were commonly used, but nowadays, AMMI and GGE double-label plots are more popular. AMMI separates genotype, environment and interaction effects, and then uses principal component analysis to reveal the patterns among them. GGE is even more straightforward, presenting the average output and stability in a single chart (Thangavel et al., 2011; Rao et al., 2023). Take the Huang-Huai-Hai region as an example. When conducting GGE analysis on 11 summer soybean varieties, the results showed that the pilot could be divided into two "super environments", and in each environment, there were relatively better varieties. It should be noted that the performance of drought-resistant varieties cannot be judged solely by the years of drought. Some can maintain high yields under extreme drought conditions, but their advantages are not significant in bumper years. There are also some that remain relatively stable in different years and are more suitable for promotion (Sharma et al., 2022). This research will conduct G×E analysis using multi-year and multi-point data in order to screen out drought-tolerant varieties with wide adaptability and specific adaptability. Considering the trend of climate change, the "yield resilience" of varieties is becoming increasingly crucial. 3 Experimental Design and Material Methods 3.1 Selection of test sites and description of environmental characteristics This study selected three rain-cultured sites in northern China, but the climatic conditions varied greatly. Tongliao is located in the Horqin Sandy Land, with an annual rainfall of approximately 350 mm. The soil is sandy loam and it often suffers from spring drought and summer drought (Wang et al., 2015). Wuwei is located on the edge of the Hexi Corridor. With an annual rainfall of only 200mm, it is accompanied by an evaporation of over 1500mm, making it a typical dry farming area. Although Anyang has an average annual rainfall of 600 millimeters, most of the rainfall is concentrated in summer, and short-term droughts occur frequently (Shi et al., 2017). All the test sites rely on natural precipitation and no irrigation is carried out. To ensure representativeness, the experiment was conducted for two consecutive years: the rainfall in the first year was lower than the average of the years, while in the second year it was relatively higher, but there were still periods of drought. Rainfall, temperature and soil moisture content were recorded in detail at each point. The results show that drought often occurs during the flowering and podding stage: In Wuwei, there was only 20 mm of rainfall within 45 days from the beginning of flowering to the grain filling stage, with severe water deficiency. Tongliao experienced nearly 30 days without rain from the seedling stage to the initial flowering stage. Although Anyang has abundant precipitation, there is also an intermittent drought of about 20 days in July. Overall, these points are covered from semi-humid and slightly dry to typical arid areas, providing a suitable platform for drought resistance evaluation. 3.2 Field design and control setup methods The layout of this experiment is quite conventional yet a bit special. Random blocks were used in the design, with each point repeated three times, mainly to reduce the errors caused by environmental differences. The selection of the comparison was quite thoughtful: Zhonghuang 13 was used for soybeans, Longwan 3 for peas, Yinchuan Dalu for mung beans, and a variety of peanuts from the Luhua series with relatively weak drought resistance was chosen. In each district group, a control is repeatedly installed to facilitate subsequent comparisons. The division of the community is determined by the crops. For soybeans and peanuts, it is 4 rows ×5 meters, approximately 15 square meters. Peas and mung beans are 6 rows by 4 meters, approximately 10 square meters. The row spacing and density are kept consistent with the conventional practice. The blocks are randomly arranged inside, with a 1-meter isolation belt and protective rows added. One rather special point is that initially, there was no control of "adequate irrigation", and water stress was entirely formed by the differences in precipitation at different years and points. However, in the following year, at Henan Point, an additional irrigation area was added to see what level the potential output could reach. The sowing time varies from place to place according to local customs. In Henan, soybeans are sown in summer, while in Inner Mongolia, they are sown in spring. The planting density is carried out in accordance with the recommended values. Apply only one base fertilizer, no top dressing, and carry out regular pest and disease control. Throughout the entire growth period, water is basically not given. Only when it is extremely dry will "life-saving water" be applied, but this has not happened in the past few years of the experiment. In this way, when the water conditions are basically the same, the differences in drought tolerance among varieties become clearer.
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