Mitigating Wheat Lodging Through Varietal Selection and Nitrogen Management

Abstract

For greater crop yields, farmers frequently use high-yielding varieties and apply more nitrogen, both enhancing the risk of crop lodging. To better understand the tradeoff between high yield and lodging, a diverse set of 15 wheat varieties was tested under two nitrogen application rates (75 and 225 kg N ha⁻¹). Significant variations ranging from 2.60 to 6.90 t ha⁻¹ were observed in grain yield. The lodging index also varied tremendously from 118% to 537% during the two growing seasons. The higher nitrogen application rate increased grain yield, spike number per m⁻², grain number per spike, and grain weight by 17.2%, 8.0%, 5%, and 3.2%, respectively, than the lower rate. Meanwhile, it also increased the lodging index (8.60%), breaking resistance (11.1%), and bending moment (20.5%). The grain yield showed a positive correlation with the lodging index and bending moment and a negative correlation with breaking resistance. The study concludes that remarkable variations exist among the currently grown wheat varieties regarding grain yield and resistance to lodging. Moreover, a higher grain yield, whether due to the genetic superiority of the cultivar or a higher rate of nitrogen fertilizer, was mostly accompanied by an increased susceptibility to lodging. Nevertheless, genotypes with shorter plants, minimum length and dry weight of the third internode, and greater breaking resistance exhibited higher lodging resistance. Meanwhile, the percent increase in grain yield under higher nitrogen levels compared to lower was more than the percent increase in lodging index and can be thus recommended to growers after assessing its environmental implications.