Impact of water management on methane emission dynamics in Sri Lankan paddy ecosystems

Paddy ecosystems constitute a dominant source of greenhouse gases, particularly of methane (CH₄), due to the continuous flooding (CF) practiced under conventional paddy cultivation. A new management method, namely alternative wetting and draining (AWD) (i.e., flooding whenever surface water levels decline to 15 cm below the soil surface), is an emerging practice developed to mitigate CH₄ emissions while providing an optimal solution for freshwater scarcity. Despite extensive paddy cultivation in Sri Lanka, no systematic research study has been conducted to investigate CH₄ emissions under different water management practices. Thus, field experiments were conducted in Sri Lanka to investigate the feedback of controlled water management on seasonal and diel variation of CH₄ emission, water consumption, and crop productivity. Adopting the same rice variety, two water management methods, continuous flooding (CF) and alternative wetting and draining (AWD), were compared with plants (W/P) and without plants (N/P) present. The emission of CH₄ was measured using the static closed chamber method. The results show a 32% reduction in cumulative CH₄ emission, on average, under AWD when compared to CF. The yield under the AWD was slightly higher than that of CF. Although it was not statistically significant (p > 0.05) there was not any reduction in yield in AWD than in CF. The total water saving under AWD ranged between 27–35% when compared to CF. Thus, the results support (without considering the effect of nitrous oxide) AWD as a promising method for mitigating CH₄ emissions while preserving freshwater and maintaining grain yield in paddy systems

Plant products with antifungal activity. From field to biotechnology strategies

In this chapter, informations on the recent advances regarding antifungal activity of natural products obtained from plants collected directly from their natural habitat or from plant cell and organ, cultures have been reported. The biotechnological approaches could increase uniformity and predictability of the extracts and overcome problems associated with geographical, seasonal, and environmental variations. Human fungal pathogens are the cause of severe diseases associated with high morbidity and mortality. The major human fungal pathogens are Candida species, dermatophytes, Aspergillus species, and Cryptococcus neoformans. Side effects and resistance are frequently attributed to the current antifungal agents. Moreover, the treatments often require long-term therapy and are not resolving. Plants represent a source of antifungal agents, but up to date, the number of new phytochemicals reaching the market is very low. This review attempts to summarize the current status of botanical screening efforts, as well as in vitro and in vivo studies on antifungal activity of plant products. Despite the currently non-uniform regulatory framework in all the states, the plant-derived products are increasingly in demand for their effectiveness. The basic conclusion from these studies is that rigorous, well-designed clinical trials are needed to validate the effectiveness and safety of plant extracts for their use as antifungals