Effect of drought on ear development and yield of maize

Drought is the most important limitation to maize yield. Studies have shown that drought can affect plant morphology, dry matter accumulation, physiological processes and reproductive organ development, thereby decreasing grain weight and per-ear kernel. With a specific focus on the development of male and female organs, this paper reviewed the effects of drought on the development of reproductive organs and anthesis-silking interval. Drought before anthesis delayed tassel and ear development, decreased total spikelets and increased kernel abortion, thereby lowering per-ear grain number. Drought during tasseling and silking hindered tasseling, delayed silking and prolonged anthesis-silking interval. In addition, severe drought during tasseling induced ultra-structural changes in pollens and silk, which severely affected pollination and fertilization and eventually resulted in bald- heading and grain number reduction. Moreover, drought during filling stage triggered leaf senescence, low photosynthetate accumulation, limited grain filling, induced grain weight lowering and eventually yield reduction. In terms of source-sink relationship, drought before grain-filling reduced grain number in response to weak sink, eventually reducing yield. Drought during grain-filling stunted the development of vegetative organs such as leaf senescence, which hindered the accumulation and transport of assimilates. Thus, source restricted yield increase.