Effects of shading on growth， development， and yield of different peanut varieties

【Objective】This study aimed to explore the effects of shading on growth， development， and yield of diffe-rent peanut varieties， and to provide theoretical basis for screening shade-tolerant peanut varieties and optimizing high light efficiency cultivation technologies.【Method】Four varieties （Yuhua 22， Yuhua 23， Huayu 20， and Yuanza 9102 ） of small-seeded pearl pod type peanut were used as experimental materials. Shading treatment （cultivation inside a wire mesh greenhouse） and conventional light treatment （field cultivation） were set up. The flower number was recorded every day after the beginning of flowering until the end of flowering. The branch number per plant， main stem diameter， length of each main stem internode， and the number of nodes within 10 cm of the first pair of lateral branches were recorded before harvest. The peg rate and pod rate were measured at harvest， and the yield， full pod rate， and kernel rate were counted.【Result】Shading could reduce the branch number and main stem diameter of peanut plants. Compared with conventional light treatment， the average branch number and average main stem diameter of four peanut varieties under shading treatment decreased by 17.97% and 10.55%， respectively. Shading increased the main stem internode length of peanut plants and decreased the number of nodes within 10 cm of the first pair of lateral branches， especially the 5^th-9^th nodes of the main stem were greatly affected by shading. Compared with the conventional light treatment， the average blooming period of the four peanut varieties under shading treatment was shortened by 3.25 d， the average total flower number was reduced by 32.16%， the average flower number during blooming period was reduced by 43.13%， the average peg rate was reduced by 46.88%， and the average pod rate was reduced by 35.70%， resulting in an average yield reduction of about 45.76%. Effects of shading on growth and yield of different peanut varieties were different： Yuhua 22 and Yuhua 23 showed good shade tolerance under shading conditions； under shading conditions， the morphological changes of plants were relatively small； relatively high flower number and pod rate could be maintained under insufficient light； while Yuanza 9102 and Huayu 20 were more sensitive to shading.【Conclusion】Under shading conditions， peanuts adapt to the low light environment by adjusting their morphological traits and physiological processes， but this adaptive attempt has a negative impact on their reproduction， growth， and yield. Different peanuts show obviously different shade tole-rance， as Yuhua 22 and Yuhua 23 show good shade tolerance under shading conditions and can be prioritized for intercropping systems or environments with overcast， rainy， and insufficient sunlight.