This study evaluated the effects of polyethylene glycol concentrations in enhancing the physiological performance of the rice varieties and their recovery ability after drought stress. The experiment comprised of IR64, NIL-SUB1DRO1, and NIL-DRO1. Seed priming was conducted by submerging 5 g of samples in petri dishes containing 100 mL of 5% and 10% PEG solutions. Drought stress significantly reduced all the growth traits, with the susceptible genotypes IR64 recorded highest reduction of shoot length 36%, tiller number 41.3%, shoot dry weight 77%, and root dry weight 72% compared to non-primed NIL-DRO1 and NIL-SUB1DRO1 with reduction in shoot length 34–35%, tiller number 34–45%, root dry weight 60–66%, and shoot dry weight (70–71%). Similar results were recorded for IR64, Pn, 63%, gs 78% E 66%, and RWC 66%, respectively, compared with NIL-DRO1 (55%, 60%, and 58%), while NIL-SUB1DRO1 showed reductions of 55%, 50%, and 54%. PEG 5% and 10% significantly enhanced primed IR64 Pn (29–57%), gs (70%), E (56–64%), and RWC 65%. During the recovery phase, primed seedlings showed a more rapid restoration of growth and photosynthetic efficiency than the non-primed seedlings. PEG 5% and 10% were effective in mitigating drought stress and enhanced recovery ability of rice.

In sub-Saharan Africa, projected climate change is expected to reduce rice productivity as a result of excessive light exposure and prolonged flooded conditions that favor soil iron reduction and accumulation. Excess iron (Fe), which commonly accumulates in poorly drained rain-fed fields across the region, hinders rice growth. Conversely, excess light causes photoinhibition. While Fe toxicity disrupts plant growth, its interaction with light intensity remains poorly understood. NERICA4, an interspecific rice hybrid between Oryza sativa and Oryza glaberrima , a widely cultivated upland rice variety, is recognized for its tolerance to Fe; however, its response to the combined effects of Fe toxicity and varying light intensity has not been thoroughly investigated. This study aimed to assess the responses of agricultural traits of NERICA4 under simultaneous Fe toxicity and different light intensities. A controlled hydroponic experiment was carried out using a completely randomized design with three replications. Seedlings of NERICA4 and IR64 were exposed to either control or excess Fe (750 mg L ⁻¹ ) under both low (450 μmol m ⁻² s ⁻¹ ) and high (700 μmol m ⁻² s ⁻¹ ) light conditions for 12 days. Results revealed that NERICA4 maintained higher biomass, restricted Fe translocation, and showed reduced oxidative damage, as evidenced by lower hydrogen peroxide (H ₂ O ₂ ) accumulation. Furthermore, the variety preserved greater chlorophyll and carotenoid content, supporting enhanced photoprotection and antioxidative defense. Despite stress conditions, NERICA4 sustained photosynthetic efficiency (Fv/Fm), reflecting robust adaptive mechanisms against photoinhibition. These findings demonstrate that NERICA4 exhibits superior tolerance to combined excess iron and high light stress compared to IR64, maintaining photosynthetic and antioxidant defense. This highlights NERICA4’s potential as a resilient rice variety for cultivation under challenging agro-environments.

Cassava plants’ response to waterlogging must be monitored in an accurate and timely manner to mitigate the adverse effects of waterlogging stress. Under waterlogging conditions, root hypoxia reduces water uptake and stomatal closure limits transpiration, which often results in increased leaf temperature due to reduced evaporative cooling. However, how this relationship changes in cassava leaves under waterlogged conditions remains poorly known. This study hypothesized that a cooler canopy is more critical for better performance under waterlogging stress in various cassava genotypes. Two cassava cultivars were subjected to twelve days of waterlogging. Results revealed a significant decrease in photosynthetic rate, stomatal conductance, and transpiration, and an increase in leaf temperature and ΔT, reflecting impaired stomatal regulation and reduced evaporative cooling. Strong negative correlations between ΔT and photosynthetic parameters were observed presenting ΔT as a reliable, nondestructive indicator of cassava’s physiological responses under hypoxic conditions. Findings indicate that maintaining cooler canopies may contribute to enhanced tolerance and survival under waterlogging. ΔT can be used as a practical screening tool for identifying and selecting waterlogging-tolerant cassava genotypes. However, further studies involving contrasting cultivars and additional parameters such as leaf relative water content, and leaf anatomy are recommended to validate and strengthen reported findings.

Cassava plants’ response to waterlogging must be monitored in an accurate and timely manner to mitigate the adverse effects of waterlogging stress. Under waterlogging conditions, root hypoxia reduces water uptake and stomatal closure limits transpiration, which often results in increased leaf temperature due to reduced evaporative cooling. However, how this relationship changes in cassava leaves under waterlogged conditions remains poorly understood. This study hypothesized that more negative ΔT values reflect enhanced transpirational cooling, which is a key determinant of superior physiological performance under waterlogging stress among cassava genotypes. Two cassava cultivars were subjected to twelve days of waterlogging. Results revealed a significant decrease in photosynthetic rate (p < 0.001), stomatal conductance (p < 0.001), and transpiration rate (p < 0.001), as well as an increase in leaf temperature (p < 0.001) and ΔT (p < 0.001), reflecting impaired stomatal regulation and reduced evaporative cooling. Strong negative correlations between ΔT and photosynthetic parameters (Pn (p < 0.001, r = −0.91), gs (p < 0.001, r = −0.91), and E (p < 0.001, r = −0.87)) were observed, presenting ΔT as a reliable, nondestructive indicator of cassava’s physiological responses under hypoxic conditions. Findings indicate that maintaining cooler canopies may contribute to waterlogging-tolerant cassava genotypes, and that ΔT can act as a screening parameter for waterlogging-tolerant genotypes. However, further studies with contrasting genotypes and additional parameters are recommended for validation.