The cultivation period of cassava in Kagoshima, Japan, which belongs to the temperate zone, is limited by the low temperature in winter. To maximize productivity under this limited period, investigations were conducted on the gas exchange rate and production structure relating to light utilization in a plant community of cassava grown under different nitrogen fertilization conditions. Fertilization either at planting or three months after planting significantly increased stomatal conductance in the upper canopy and root dry weight compared to the control. In addition, the dry matter distribution to stem and root dry matter rate of initial fertilization treatment were significantly higher, and the dry matter distribution to root of the latter fertilization treatment tended to be higher than that of the control. However, light transmittance at 80 cm below the top of the canopy was almost the same as that at the ground surface, which was a common tendency among the treatments. In conclusion, it was revealed that the effects of fertilization on yield were mainly the increase in the gas exchange rate of individual leaves and the change of dry matter distribution rather than an improvement in light transmittance.

Tea (Camellia sinensis (L). Kuntze) cultivation by smallholder out-growers has grown significantly. Recent government initiatives have expanded production from traditional tea growing regions. This study investigated how smallholder farmers perceive and prefer different commercial tea clones. It also looked at the factors that influence their choices across major tea-growing regions of Uganda. A structured questionnaire was administered to 324 randomly selected tea out-growers from Central, Western, Kigezi, and West Nile regions. Data was analyzed using descriptive statistics, a Tea Preference Index (rating clone attributes on a 1–5 scale), and a multivariate Probit (MVP) model to evaluate farmers’ choices and preferences. Clone 303/577 is the most cultivated, accounting for 59%. Adoption rates were high in West Nile (98%), Kigezi (77%), and Central (67%) regions. Clone 6/8 ranked second at 47%, while clone 100/5 had the lowest cultivation rate at 10%. The ranking of clones by preference was 303/577, 6/8, 108/82, 31/8, and 100/5. Key attributes influencing preferences included, yield potential, canopy width, post-plucking/pruning recovery rate, shoot tenderness and cup quality. Results showed that a farmers’ choice of clone 303/577 was significantly influenced by shoot density, gender and tea farming experience. For clone 108/82, the most important factors were quick recovery after plucking/pruning, education level and household size. This information is vital for agricultural policy, extension services, tea breeding and genetic improvement programs in the tea sector.

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.

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.