Abstract: The aim of this study was to explore the effects of prolonged overcast and rainy days duration during flowering on maize yield. Here, Xundan 29, a widely used maize variety in Huang-Huai-Hai region was used. Six shading treatments since tasselling which lasts 0 days (CK), 3 days (S3), 6 days (S6), 9 days (S9), 12 days (S12) and 15 days (S15)were set to explore different low light stress duration during flowering stage on maize ear development and yield. The result indicated that accompany low light stress duration elongation since tasselling, low light stress lasts 3-15 days result a 1-7 days delay of silking dates, and 1-2 days delay of pollen shedding ending dates. All treatments finished pollen shedding at 11 days after tasselling, and silking rate at the end of pollen shedding dates decreased 3%-43%. Compared with CK, ear elongation rate and ear dry matter (DM) accumulation rate at the end of each treatments of S3-S15 decreased 71%-79%and 83%-100%, respectively.There was little influence on the final husk length. Fertilizing rate and kernel setting rate decreased 22-58 and 16-71 percentage under 3-15 days shading treatment (P<0.05). Low light stress since tasselling stage reduced plant DM accumulation rate. DM accumulation rate exhibit recovery growth after shading removed, but the DM accumulation rate was still lower than CK. Ear length and kernel setting length were reduced significantly, ear barren length was increased significantly, and kernel number per ear and grain yield decreased significantly in accordance with low light stress duration elongation (P<0.05). There was no significant variation of 100 kernel weight between each treatment.

Key words: Maize, Flowering stage, Shade, Duration, Kernel setting rate

CLC Number: 

• S513.01