Critical period for yield determination across grain crops

Area of Science:

• Agricultural Science
• Crop Physiology
• Plant Breeding

Background:

• Grain or seed number per unit area (GN m^-2) is a primary determinant of crop yield across diverse species.
• The critical period for determining GN m^-2 varies significantly among major grain crops, occurring either pre-flowering or post-flowering.

Purpose of the Study:

• To investigate the reasons for the observed variation in the timing of the critical period for GN m^-2 determination across different crops.
• To propose a unified framework for understanding the critical period for GN m^-2 determination, irrespective of crop type.

Main Methods:

• Comparative analysis of crop development phases, focusing on flowering duration and pre-flowering development allocation.
• Re-evaluation of the critical period's timing by considering grain abortion stages in addition to flowering.

Main Results:

• Discrepancies in critical period timing correlate with variations in flowering phase duration and the proportion of the crop cycle dedicated to pre-flowering development.
• Shifting the focus to the grain abortion phase, rather than flowering, reveals a consistent timing for the critical period across contrasting grain crops.

Conclusions:

• The apparent variation in critical period timing for GN m^-2 is an artifact of crop-specific developmental phase durations.
• A unified understanding of the critical period for GN m^-2 determination is achieved by considering the grain abortion phase, unifying observations across diverse grain crops.