Maize reproductive development and kernel set under limited plant growth environments.

Area of Science:

• Agricultural Science
• Plant Physiology
• Genetics

Background:

• Maize grain yield is critically dependent on kernel number established during flowering.
• Kernel number is determined by ear biomass accumulation and the efficiency of its conversion into kernels.
• Biomass allocation to the ear in maize is highly plastic, unlike other crops, and diminishes significantly under stress.

Purpose of the Study:

• To describe mechanistic plant and canopy traits for understanding maize yield determination.
• To identify ideal genotypic traits for maximizing kernel set and yield under limited plant growth conditions.
• To highlight the implications of genetic variability in biomass partitioning for crop management and breeding.

Main Methods:

• Characterization of mechanistic plant and canopy traits influencing yield.
• Phenotyping for stress susceptibility using silk appearance delay relative to male anthesis.
• Utilizing ear biomass accumulation for predicting silk extrusion and kernel set.

Main Results:

• Conditions inhibiting plant growth commonly delay silking, impacting kernel set.
• Wide native genetic variability exists for biomass partitioning to the ear, crucial under stress.
• Ear biomass accumulation and silk extrusion timing are key indicators of yield potential under stress.

Conclusions:

• Ideal maize genotypes sustain growth under limited resources, exhibit uniform canopies, and prioritize ear biomass allocation.
• Rapid silk extrusion and minimal ear biomass at silking are desirable for maximizing kernel set.
• These traits, often indirectly selected, are vital for improving maize yield in challenging environments.