Shading effect on performances of crop growth and yield parameters of vining pea at different developmental stages

In the paper, the effect of different shading treatments (full sunlight, light shading: 40%, medium shading: 75%, and heavy shading: 90%) on yield and crop growth parameters of vining pea was investigated. The experiment was conducted at Dicle University, Faculty of Agriculture, in Diyarbakir, T?rkiye during the 2023 spring season under field conditions. The experiment was arranged Randomized Complete Blocks design with three replications. In study, some observations were investigated such as plant height, number of internodes per plant, leaf area per plant, number of leaves per plant, dry matter, SPAD value, soil moisture, number of pods per plant, fresh pod weight, pod width, pod length, number of seeds per pod and dry pod weight and some growth parameters were calculated. For this purpose, plants were harvested six times at 10-day intervals and measured for growth and yield parameters. Consequently, shading treatments increased fresh pod weight, pod width, and pod length compared to full sunlight, while heavy shading (90%) significantly reduced plant height. The crop growth rate tended downward under the shading conditions at the blooming and podding stages. However, crop growth rate was apparently higher under low light intensity (light shading; 6.46 g m-2 day-1 and heavy shading; 5.14 g m-2 day-1) than at full sunlight (3.35 g m-2 day-1) at the podding stage. Full sunlight was the most sensitive treatment to environmental conditions, therefore, the relative growth rate drastically reduced during the crop growth stages. In conclusion, the relative growth rate of crops grown under full sunlight was significantly lower than that of crops grown under other treatments. In summary, light and temperature accelerated crop development under full sunlight, while shade applications extended crop development duration. As a result, medium and low-level shading is thought to extend crop vegetation duration, especially in the arid and semi-arid climate areas exposed to water scarcity and high heat.