Potatoes—a global food security and staple crop—is threatened by dry spells in drought-prone areas. The use of physiological thresholds to save water while maintaining a reasonable tuber yield has been proposed, but their effects on physiological performances and usefulness under different irrigation methods are yet to be evaluated. In this study, photosynthetic traits were monitored to assess the effect of water restriction and rewatering under drip (DI) and furrow (FI) irrigations. The treatments consisted of two maximum light-saturated stomatal conductance (g ${}_{s\_max}$ ) irrigation thresholds (T2: 0.15 and T3: 0.05 mol H ${}_2$ O m ${}^{-2}$ s ${}^{-1}$ ) compared with a fully irrigated control (g ${}_{s\_max}$ > 0.3 mol H ${}_2$ O m ${}^{-2}$ s ${}^{-1}$ ). DI used less water than FI but promoted early senescence and low percentage of maximum assimilation rate (PMA) at late developmental stages. FI caused no yield penalization in T2 and higher recovery of carbon isotope discrimination and PMA than DI. It is suggested that moderate water quantities of early and frequently water pulses in the irrigation, promote short-term water stress memory improvement, senescence delay and more capability of recovery at late stages.

Cadmium (Cd) contamination, primarily from anthropogenic activities, represents a major concern that threatens plant productivity and food safety by promoting bioaccumulation in edible plant tissues. Tomatoes (Solanum lycopersicum L.), a globally important horticultural crop and a model species, are notably susceptible to heavy metal uptake. Sustainable strategies to increase plant resilience in this context are urgently needed. This study evaluated the effectiveness of a seaweed-derived biostimulant, ProSoil Recover (PSR), in mitigating Cd toxicity, focusing on growth parameters, Cd uptake, the translocation factor, bioaccumulation, and the quantification of physiological responses, such as total chlorophyll content, nitrate reductase enzymatic activity, proline content and peroxidase enzymatic activity, in tomato plants grown in a soilless culture system to evaluate the consequences of Cd-induced abiotic stress at the macroscopic and biochemical levels. The tomato plants were subjected to five different Cd concentrations, with or without PSR application, under a factorial arrangement experimental design. The growth parameters were not negatively affected by Cd exposure. Cd uptake increased proportionally with increasing external Cd supply (p < 0.0001), and it was distributed at higher and similar levels in roots (44.73%) and leaves (49.12%) and much lower in fruits (6.15%). Cd uptake in all organs was significantly negatively correlated with the translocation factor (p < 0.0001). In the leaves, Cd stress significantly reduced the total chlorophyll content (˗14.75%) but promoted increases in nitrate reductase activity (+ 61.04%). Moreover, compared with the control plants, the Cd-supplemented plants presented increased proline content (+ 105.42%) and peroxidase activity (+ 58.27%), which are indicators of oxidative stress. PSR application consistently reduced average Cd uptake in roots (˗32.48%), leaves (˗30.47%) and fruits (˗34.82%), lowered the bioaccumulation index (˗35.43%), and increased the translocation factor (+ 76.43%). In most cases, the PSR-treated plants presented attenuated oxidative stress, as evidenced by a reduced proline content (˗12.7%) and peroxidase activity (˗23.96%). Seaweed-based biostimulants such as PSR offer a promising strategy to alleviate heavy metal-induced abiotic stress in horticultural crops. By reducing Cd bioaccumulation, increasing the translocation factor, modulating key physiological responses, and mitigating oxidative damage, the PSR contributes to safer food production and promotes sustainable agricultural practices under environmental stress conditions.

In order to evaluate the environmental effect on plant development and mini-tuber production of a diverse group of potato genotypes grown under an aeroponic system, a G × E interaction experiment was carried out in greenhouses located at CIP’s experimental stations in La Molina (Lima) and Huancayo (Junín). Five contrasting environments were set-up and evaluated. A combined Analysis of Variance was performed for the variables “days to tuber set”, “days to senescence” and “plant height”. An Additive Main Effects and Multiplicative Interaction (AMMI) Analysis was performed for yield variables: mini-tuber “weight” and “number of mini-tubers” per plant. There was a high variation in all the responses to the treatments. “Days to tuber set” was influenced by genetic responses, temperature and greenhouse Photosynthetically Active Radiation intensity. Considerable increases in the length of the vegetative cycle and plant height were recorded for all genotypes, and these were particularly notable in the warmer coastal environments. AMMI analysis showed that yield variables were primarily influenced by the genotypic effect followed by the genotype by environment interaction effect. The Venturana variety (T2) was the best performing genotype with a total average mini-tuber “weight” of 644 g per plant while the Chucmarina variety (T1) performed best for the variable “number of mini-tubers” with an overall average of 60.2 mini-tubers per plant. Both showed stability across different environments for these variables. The advanced clones T3 (395434.1), T5 (397077.16) and T6 (397073.16) showed stability for yield variables, but their performance was below the overall average of the trial. It is recommended that the environment and management should ideally be tailored to the genotype as this will result in significant yield gains.

En el cultivo de arúgulas vía hidroponía, la deficiencia de hierro (Fe), en comparación con las deficiencias de magnesio (Mg) y manganeso (Mn), es un factor importante que ocasiona la clorosis de sus hojas. En el presente estudio se aplicó un diseño experimental, donde se usaron bloques completos al azar con cuatro grupos conformados por seis plantas cada uno: tres grupos experimentales (GE) y un grupo control (GC). Se tomaron las precauciones para que las variables intervinientes como la oxigenación artificial y el tiempo no afectaran el resultado del experimento. Los resultados obtenidos muestran que la deficiencia de Fe, Mg y Mn en cada tratamiento influye en la aparición de clorosis en las hojas. Asimismo, se evidencia que la escasez de oxigenación y el exceso de macronutrientes influyen en la clorosis y necrosis de las arúgulas respectivamente.

La disponibilidad de agua es el factor más crítico para el crecimiento y desarrollo de las plantas. La aplicación de bioestimulantes de extractos de algas marinas pueden mejorar la resistencia al déficit de agua en los cultivos y reducir el impacto negativo que este genera en el rendimiento de los cultivos. Se realizó un experimento para evaluar el efecto de cuatro bioestimulantes: Fertimar (2.5 g·l-1), Fertimar SC (5 ml·l-1), EA 1000-13 (5 ml·l-1) y Fertikelp (5 ml·l-1), formulados a partir de algas marinas sobre el crecimiento, rendimiento y estrés oxidativo en plantas de pimiento sometidas a dos regímenes de riego: 1) riego continuo, 2) riego cada tres días (estrés hídrico). Para medir el efecto del estrés oxidativo, se evaluó la actividad de las enzimas nitrato reductasa (NR), catalasa (CAT), superóxido dismutasa (SOD) y guayacol peroxidasa (GPX). Se determinó el contenido de prolina y el contenido relativo de clorofila en hojas. Las variables de crecimiento evaluadas (peso seco de hojas, tallos y frutos) resultaron significativos (p < 0.05). Los bioestimulantes indujeron mayores valores de peso seco y longitud de tallo (p < 0.01). El contenido de clorofila unidades SPAD y prolina resultaron significativos con el factor frecuencia de riego (p < 0.01 para clorofila y p < 0.05 para prolina), indicando la presencia de estrés. La actividad de las enzimas antioxidantes GPX y SOD resultó significativa en la interacción bioestimulante y frecuencia de riego (p < 0.05), incrementando su actividad, reduciendo el estrés oxidativo. El uso de bioestimulantes demostró mejorar la tolerancia al estrés hídrico al tener efectos positivos en el crecimiento y el control del estrés oxidativo. Los resultados indican que las mejores fuentes de algas marinas para superar los daños por estrés oxidativo fueron Fertikelp y EA 1000-13.