Effects of synchronization between silk receptivity and pollen grain vigor on kernel sets of corn (Zea mays L.)

Abstract

Kernel sets in corn were affected by silk receptivity, pollen grain vigor, and the synchronization of silking and pollen shedding. Grain yield decrement was often caused by poor kernel set ability under field conditions. This study was conducted with two corn hybrids—Yedan 12 and Yedan 19— in both field and laboratory to observe silk receptivity, pollen vigor, synchronization of silking and pollen, and their effects on the kernel sets. The results showed that silk receptivity could be maintained over a relatively longer period of time after silks emerged, but both kernel set percentage and kernel weight decreased as silks aged when pollination occurred. Pollen grains that shed earlier had higher TTC-dehydrogenase activity, higher germination percentage, more rapid pollen tube growth rate, and higher percentage of kernel sets and kernel weight than those that shed later. The effect of delayed silking on kernel set ability was more significant compared with delayed pollen. Synchronization of silking and pollen shedding showed different characters in different hybrids: partial overlapped  for Yedan 12 and overlapped  for Yedan 19.