New Relationships between Light Interception, Ear Growth and Kernel Set in Maize

OTEGUI, M.E.; ANDRADE, F.H.

Physiology and Modeling of Kernel Set in Maize

ASA-CSSA

Lugar: Baltimore; Año: 2000; p. 89 - 102

Maize grain yield is the product of kernel number at harvest and kernel weight. In most cases, however, maize grain yield is more closely associated with kernel number than with kernel weight. Moreover, for a given genotype, the number of fertilized spikelets that survive and form mature kernels is more critical and more affected by environmental conditions than the total number of differentiated spikelets. Spikelet survival is correlated with the physiological condition of the crop during the period bracketing flowering. Therefore, understanding the mechanisms of kernel number determination is of great importance to maize physiologists, modelers, and breeders. In the work presented here we analyze several aspects related to kernel set in maize. First, the importance of the number of kernels set as a determinant of yield in maize is defined. Next we describe the morphogenic processes leading to potential kernel number  and the abortion of reproductive structures as the main mechanisms that determine final kernel set. Third we define the most critical stage for grain number determination in relation to ear elongation.  Finally, we examine the processes and mechanisms that determine kernel number during the critical stage. We will focus on duration of the critical period, radiation interception, plant and crop growth, dry matter partitioning, and spikelet fertility as determinants of final kernel number in maize.