Water stress poses a significant risk to achieving global food security. Plants experience water stress due to variations in environmental conditions, which have been identified as the primary factor impacting agricultural production under the current dispensation of global climate change. This review aims to combine data from multiple published research studies in the literature in order to completely analyze and assess the morphological, physio-biochemical, and metabolite responses of plants to water stress. Stress-related variables disturb the regular stability of plants, leading to changes in their structure, function, chemistry, and genetics that ultimately impact their development and productivity. Water stress often leads to reduced leaf-relative water content, loss of turgor, and closure of stomata. Plant secondary metabolites serve as distinct sources for medicines, food additives, and industrially essential biochemicals. Plants exposed to water stress, such as different elicitors or signal molecules, frequently experience the build-up of these metabolites. Secondary metabolites significantly contribute to plant ability to adapt to their environment and overcome stressful conditions. Plants exhibit diverse metabolic reactions to water stress, resulting in alterations in the composition of volatile oils in different herbs. The attempt to tackle water stress conditions by plants is inherently intricate due to the complex network of signaling. This review contributes to our understanding of plant responses to water stress conditions, to the implementation of sustainable agronomic practices, and development of varieties that can tolerate the impact of climate change.

Leafy vegetables like lettuce and spinach are prone to significant post-harvest losses during handling and storage. The pre-harvest treatment of crops with biostimulants offers a sustainable strategy for reducing post-harvest losses. Earlier studies focused on the effect of plant biostimulants applied individually. In this study, we studied the efficacy of a combined application of two commonly used plant biostimulants: Ascophyllum nodosum extract (ANE) and humic acid (HA). Interestingly, the combination of both biostimulants improved early growth of lettuce and spinach compared to ANE and HA alone. Among the combinations used in this study, 0.25% ANE + 0.2% HA produced significantly higher fresh and dry biomass in lettuce and spinach compared to the other treatments and the control. Pre-harvest treatment of combination of 0.25% ANE and 0.2% HA significantly reduced the loss of fresh biomass during post-harvest storage. The combination of 0.25% ANE and 0.2% HA reduced lipid peroxidation during storage with an increase in total ascorbate, phenolic, and antioxidant capacity of spinach and lettuce. These results suggest that a combination of ANE and HA reduces post-harvest losses of spinach and lettuce more effectively than when applied individually.

Microplastics (MPs) are plastic particles ranging from 1000 to 5000 µm in diameter, posing a growing environmental and health risk. Composting is an excellent way to add nutrient-rich humus to the soil to boost plant development, but it also pollutes agricultural soil with MPs. Previous research has shown that MPs can threaten plant development, production, and quality, hence they must be studied. This study examined how a mixture of three MP types—polyethene (PE), polystyrene (PS), and polypropene (PP)—affected greenhouse tomato plant development. MP types were spiked at 1% w/w (MPs/soil) in tomato pots, whereas non-spiked growth medium was the control. Statistical analysis was conducted using an analysis of variance (ANOVA) and Tukey’s test (95% confidence) to compare treatments and controls. Soil spiked with MPs increased chlorophyll content (SPAD), transpiration rate, photosynthetic rate, and stomata conductance by 5.16%, 16.71%, 25.81%, and 20.75%, respectively, compared to the control but decreased sub-stomata CO₂ concentration by 3.23%. However, MPs did not significantly affect tomato plant morpho-physiological features (p > 0.05). Biochemical analysis of tomato fruits showed significant (p < 0.05) reduction effects of MPs on carotenoid, total flavonoid, and sugar but increased protein, ascorbate, and peroxidase activity. However, there was no significant difference (p > 0.05) in the effects of the combined MPs on total phenolic content. These data imply that whereas MPs did not influence tomato plant physiological and morphological properties, tomato fruit biochemistry was reduced. This raise concerns that an increase in MPs in soils may reduce antioxidant content and negatively affect human health contributing to a decrease in food security.

Strawberry is an economically important crop, and its productivity is challenged due to pathogen infestation. During 2017 cropping season, leaf blight like symptom was observed in commercial fields...

Botrytis cinerea is a major fungal pathogen causing significant economic losses in grapevines worldwide. To address the environmental concerns associated with overreliance on synthetic fungicides, this study investigated the antifungal efficacy of varying concentrations of pyroligneous acid (PA) (0, 2, and 4%) compared to a commercial fungicide (Switch^®) against B. cinerea in grapevines (Vitis vinifera ‘Himrod’), as well as its physiological and biochemical responses. Our preliminary in vitro assays using the poisoned food method showed that PA significantly (p < 0.05) inhibited B. cinerea mycelial growth by approximately 0.70-, and 1-fold, respectively, compared to the 0% PA during the three weeks of observation. The results also demonstrated that the 2% PA and 4% PA treatments, as well as the Switch^® application, significantly (p < 0.05) reduced average lesion length by 0.19-, 0.52-, and 0.85-fold, respectively, compared to the untreated plants with Botrytis alone. Both the 4% PA and Switch^® significantly (p < 0.05) increased the maximum quantum efficiency of photosystems II (F_v/F_m) and potential photosynthetic capacity (F_v/F_o) by approximately 0.02-fold and 0.1-fold, respectively, compared to the untreated plants with Botrytis alone. The 2 and 4% PA treatments also increased total carotenoids and flavonoids. Further molecular studies are recommended to elucidate the mechanisms underlying the observed physiological and biochemical changes.

Nitrogen (N) fertilization at critical planting time is important to optimize productivity and reduce nitrate accumulation in edible portions of green leafy vegetable plants. A field experiment was performed to determine the effects of variations in N rate and planting time on plant growth, yield, and nutritional quality attributes of Basella alba under Atlantic maritime climatic conditions. The N rates were 0 (control), 40 (low), 80 (medium), and 120kg ha⁻¹ (high) at planting times 15 June3 August (early season), 6 July20 August (mid-season), and 4 August8 September (late season). Plant height, number of branches, and stem girth were increased after 45days after sowing in early and mid-season plantings, but leaf length decreased during the same time by 32.8 in the late planting. The average yield obtained in early, mid-, and late plantings were 171, 464, and 328g plant⁻¹, respectively. Low N gave the highest yield in early planting while medium N gave higher yields in mid- and late plantings. However, the medium N increased nitrate accumulation in B. alba by 7 compared to the high N rate. In general, there was no significant effect of N on B. alba total phenolic and total carotenoid contents. Overall, the highest yield was obtained during the warmest summer months of mid- and late plantings. Therefore, there is a potential to grow B. alba as a summer vegetable under Canadian Atlantic maritime conditions. However, it is recommended to reduce the rate of N fertilizer application during high-temperature conditions. Future studies are required to investigate phosphorus and potassium fertilization and nitrate accumulation in B. alba and potential health risks.