Shading under drought stress during grain filling attenuates photosynthesis, grain yield and quality of winter wheat in the Loess Plateau of China

Abstract

In the Loess Plateau region of China, winter wheat often undergoes prolonged cloudy days without rain which may affect the grain yield and quality. This study examined the impacts of shading and drought conditions during the grain‐filling period of winter wheat (Triticum aestivum L.) on photosynthesis, grain yield and quality traits in a greenhouse experiment. The imposed shading and irrigation‐deficit treatments were corresponded with naturally cloudy weather in the rainfed area. Five shading treatments, 15 days shading (SD15); 12 days shading (SD12); 9 days shading (SD9); 6 days shading (SD6); and 3 days shading (SD3), and four irrigation treatments: full irrigation (I100); 75% of full irrigation (I75); 50% of full irrigation (I50); and 25% of full irrigation (I25), were applied after completion of flowering. The results showed that shading during grain filling decreased the grain yield and individual grain weight irrespective of the dry or wet conditions of the soil. Plant height increased with a decrease in shading duration to favour the efficient capturing of light. The reduction in the rate of photosynthesis was noted with an increase in the drought intensity. Shading significantly reduced the grain protein contents and increased the grain starch contents. In conclusion, shading for a long duration (SD15, SD12 and SD9) and drought stress (I25) during the grain‐filling stage significantly decreased the yield and grain quality of winter wheat. The shading of few days without drought (I100: SD3, SD6 and SD9) improved the plant height, photosynthetic activity and increased the distribution of dry matter from vegetative organs to grains.

Nitrogen application enhances yield, yield-attributes, and physiological characteristics of dryland wheat/maize under strip intercropping

“…Similarly, during the blended growth period, increased height of wheat crop may have caused the shading effect for the companion crop. A significant reduction in chlorophyll content of maize crop due to shading has been well reported in previous study ( Naseer et al., 2022 ). Similarly, Pang et al.…”

Assessment of drought and its impact on winter wheat yield in the Chinese Loess Plateau

“…The authors explained this phenomenon in terms of the impact of water stress on the number of grains per spike, and suggested that crops can be protected from water stress during these two periods to maximize the probability of good harvests (Huang et al, 2020). Such remote sensing-based conclusions were also supported by a recent experimental study conducted at a site in the LP in which the authors observed modulations of winter wheat yield by drought stress during LG (Naseer et al, 2022). Taking all of these results together, we recommend that winter wheat should be protected from water stress mainly during MG and LG by rationally allocating the input of water and fertilizer in order to maximize the probability of a good harvest.…”

Screening of Wheat (Triticum aestivum L.) Genotypes for Drought Tolerance through Agronomic and Physiological Response

“…Under drought-induced oxidative stress, plants show abnormalities in physiological and biochemical processes leading to cell death [16]. Photosynthesis is one of the most sensitive processes to drought stress [17,18] because drought damages the photosynthetic process and causes the stomatal closure. The reduced photosynthesis due to stomatal closure is reported to limit the supply of CO 2 [18].…”