Xue Jun, Ming Bo, Xie Ruizhi, Wang Keru, Hou Peng, Li Shaokun
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China.
Plant Methods. 2020 Nov 4;16(1):148. doi: 10.1186/s13007-020-00689-z.
The accurate evaluation of the stalk-lodging resistance during the late stage of maize growth can provide a basis for the selection of cultivars, the evaluation of cultivation techniques, and timely mechanical grain harvesting. In this study, the critical wind speed of stalk breaking, plant morphology, stalk mechanical strength, and lodging rate were investigated in 10 maize cultivars to identify the parameters evaluate lodging resistance during the later growth stage of maize. Clarify the relationship with the stalk mechanical strength, critical wind speed of stalk breaking, and natural lodging rate in the field.
The results showed that, in the late growth stage, with increasing number of days after physiological maturity, (1) the stalk lodging rate gradually increased, (2) the stalk breaking force and rind penetration strength (RPS) of the third internode above the soil gradually decreased, and (3) the critical wind speed of stalk breaking increased first and then decreased, and was highest at about 16-24 days after physiological maturity. The position of stalk lodging mostly occurred between second and fifth internodes. The torque at the base of maize plant increased as wind speed increased, and the different of torque was excited among different maize cultivars under same wind speed. Furthermore, the stalk lodging rate was significantly negatively correlated with the critical wind speed of stalk breaking. Additionally, the critical wind speed of stalk breaking was significantly positively correlated with the stalk breaking force and the RPS.
This indicates that the critical wind speed of stalk breaking is a superior way to determine the stalk lodging resistance. These results suggest that, in the late growth stage, the decrease in the stalk mechanical strength is an important reason for the decrease in the critical wind speed of stalk breaking and the increase in the lodging rate.
准确评估玉米生长后期的茎倒伏抗性可为品种选择、栽培技术评价及适时机械籽粒收获提供依据。本研究对10个玉米品种的茎折断临界风速、植株形态、茎机械强度和倒伏率进行了调查，以确定评价玉米生长后期倒伏抗性的参数。阐明其与茎机械强度、茎折断临界风速和田间自然倒伏率的关系。
结果表明，在生长后期，随着生理成熟后天数的增加，（1）茎倒伏率逐渐增加；（2）土壤以上第三节间的茎折断力和表皮穿刺强度（RPS）逐渐降低；（3）茎折断临界风速先升高后降低，在生理成熟后约16 - 24天最高。茎倒伏位置大多发生在第二至第五节间。玉米植株基部的扭矩随风速增加而增大，相同风速下不同玉米品种间扭矩差异明显。此外，茎倒伏率与茎折断临界风速呈显著负相关。另外，茎折断临界风速与茎折断力和RPS呈显著正相关。
这表明茎折断临界风速是确定茎倒伏抗性的一种较好方法。这些结果表明，在生长后期，茎机械强度的降低是茎折断临界风速降低和倒伏率增加的重要原因。
