This study reports the sensitivity of simple gravimetric derived water relations in distinguishing plant stress status across distinct growth developmental phases. Resource allocation strategies in plants are linked to tradeoffs between efficiency (productivity) and safety (defense). In seasonal plants with fixed life cycle, reproductive investment at the end of the growth cycle is critical to ensure species continuity. While allocation strategies may differ at development stage, allocation demand due to environmental constraints may influence allocation strategies. To understand these dynamics, variation in leaf level responses at vegetative, flowering and podding stages was studied in Vigna unguiculata (L. Warp)(cowpea) under savanna conditions. In addition, we evaluated how N, non-hormonal(nh) biostimulant and exogenous metabolite affect leaf level responses at each stage. Stress responses were assessed based on changes in leaf level physiology: chlorophyll content Chl; maximum quantum yield, FvFm-1; leaf temperature lt ; and leaf water capacity, LWC: relative water content, RWC; leaf density, ρl ; and relative maximum water, RMAX.
Results/Conclusions
LWC parameters were relatively more sensitive to discriminating leaf responses across developmental stages than leaf physiology measurements regardless of variability in biochemical treatments. This indicates LWC as a potentially valuable utility for distinguishing the effects of intrinsic demand from abiotic induced traits when measuring plant status otherwise not detectable by the more conventional techniques in savanna field surveys.