Inter- and Mixed Cropping of Different Varieties Improves High-Temperature Tolerance during Flowering of Summer Maize

Abstract

Global warming increases the risk of high-temperature injury to maize. Inter- and mixed-cropping of maize varieties with different genotypes is one way to effectively alleviate the high-temperature injury during the flowering period. However, the mitigation effect of different varieties and intercropping modes on high-temperature injury is still unclear. Based on previous years of field production, Denghai 605, which is more sensitive to high temperatures during the flowering period, was determined as the main test variety, and Zhengdan 958, Dedan 5, Weike 702, and Xianyu 335, which have great genotypic differences, were used as auxiliary varieties. The main test varieties and auxiliary varieties were intercropped and mixed cropped, respectively. Plant height, ear height, leaf area index, population light transmittance, ear characteristics, and yield were measured, and the land equivalent ratio (LER) was calculated. The plant height of Denghai 605 intercropped with Zhengdan 958 and Dedan 5 and mixed with Weike 702 and Xianyu 335 decreased significantly. The population light transmittance of the bottom or middle layer in Denghai 605 increased significantly when intercropped with other varieties. The grain number per ear increased significantly under inter- and mixed cropping with Zhengdan 958 and Weike 702. Except under intercropping with Dedan 5, the yield of Denghai 605 increased significantly, by 8.8–28.0%, under inter- and mixed cropping. Under intercropping with Zhengdan 958 and inter- and mixed cropping with Weike 702 and Xianyu 335, respectively, the group land equivalent ratio was greater than 1.1, indicating that under the combination of these varieties, inter- and mixed cropping effectively reduced the impact of high temperatures during flowering.

Maize (Zea mays L.) responses to heat stress: Mechanisms that disrupt the development and hormone balance of tassels and pollen

“…The effects of heat stress on the growth and development of maize have been studied extensively, but most research focuses on exposure during the flowering and silking stages (Li et al, 2022). While less research has been done on the stress that occurs during the 12‐leaf stage (V12).…”

Intercropping of two maize varieties shifts the bacterial community and enhances nutrient uptake and grain yield under different fertilization managements

“…Intercropping of rice varieties decreased rice blast disease and increased grain yield than monoculture (Zhu et al, 2000;Han et al, 2016). Intercropping of maize varieties enhanced resistance to southern corn rust disease (Liu et al, 2013)., Intercropping of maize varieties improved tolerance to high-temperature stress, pollination synchrony and cross-fertilization during owering, which increased grain yield (Li et al, 2022a;Li et al, 2022b). Intraspeci c intercropping of reasonable varieties of the same crop species under high planting density increasednet photosynthetic rate, improved the dry matter, and increased grain yield under the same nutrient supply (Hu et al, 2019).…”