Indoor production systems with light emitting diode (LED) lamps are a feasible alternative for increasing strawberry productivity by reducing the incidence of pests and diseases and the damage caused by extreme weather events. Blue (BL) and red (RL) LED light are considered the most important light spectra for photosynthesis and crop yield; however, recent studies have demonstrated that the beneficial effects of green light (GL) have been underestimated. This information would be of particular importance for strawberry production in controlled-environments/vertical farming systems as it may lower input costs and enhance production efficiency and quality and marketability. The present study aimed to define the effect of GL in combination with BL in strawberry. A proportion of 20% GL (20% BL + 60% RL) of total photosynthetic photon flux density was beneficial for plant growth and productivity; however, a 27% GL (12% BL + 61% RL) proportion was detrimental or comparable to that with 6% GL (36% BL + 58% RF). Total dry mass increased 51% when plants were illuminated with 20% GL lamps compared to those with 6% GL; the most impacted plant part was the root as it increased by 155%. The higher yield was observed with GL at 20%, but further increasing GL to 27% resulted in reduced yield. GL at 20% and 27% exhibited higher photosynthesis but reduced transpiration, stomatic conductance, and internal CO₂, which in turn increased instantaneous and intrinsic water-use efficiency. Plants with the highest yield (20% GL) exhibited lower total soluble solids in fruits but still the values obtained were acceptable (8.25 °Brix); these fruits contained a high total sugars and phenolics concentration but a reduced antioxidant scavenging capacity. High proportions of GL were associated with a higher leaf and fruit Ca and a higher leaf P and K, which may be due to the increased allocation of biomass to the roots. In conclusion, GL at 20% and BL at 20% resulted in the best growth and yield parameters, enhanced net photosynthesis rate, water-use efficiency and fruit quality attributes. The effects of GL observed in this study may also be important for other high-value horticultural crops suitable for indoor vertical farming.

Salinity is a major threat to the productivity of agroecosystems as it affects the soil structure and the osmotic potential of the soil solution, resulting in nutritional imbalances, Na toxicity and reduction in crop growth and yield. As Silicon (Si) has been considered a beneficial element for alleviating plant stress, the present study was performed to determine if it could enhance tomato plant tolerance to NaCl-salinity in a closed-loop hydroponic system. Plants were irrigated with solutions containing 0, 20 or 60 mM NaCl combined with 0 or 1.50 mM Si. Shoot dry weight and fruit yield decreased with salinity, however, Si partially restored biomass and yield when the solutions contained 20 mM NaCl. Shoot and root K decreased with salinity, however, supplementary Si restored K in plants with 60 mM NaCl. Root and shoot Si was unaffected by NaCl or Si, however, shoot Na increased. Nonetheless, compared to non-Si plants, Si-treated plants showed a 19% and 32% lower shoot Na concnetration in 20 and 60 mM NaCl-plants, respectively. Silicon partly alleviated the K/Na imbalance caused by salinity. Increased shoot K/Na and Ca/Na balances were correlated with higher shoot biomass. Supplemental Si allowed an 80% increase in peroxidase activity and proline in plants with 60 mM NaCl. Fruit yield under moderate salinity was partially restored by Si, due to an increased root Na exclusion, lower shoot Na, and improved K, Ca and K/Na balance, which was correlated with increased shoot growth, POD activity and proline concentration.

Determinations of nitrogen (N) and chlorophyll (Chl) by destructive methods are precise but time-consuming and frequently expensive. The objective of this study was to determine the relationship between SPAD, atLEAF, and MC-100 readings with the concentrations of Chl, N, and fresh matter (FM) in basil 'Nufar'. In addition, we determined the relationship of the N concentration with fresh matter (FM). The plants were irrigated with five levels of N (0, 4, 8, 12, and 16 mEq·L-1 of NO3) based on a modified Steiner solution for 42 days after transplant. Plants were evaluated weekly with SPAD, atLEAF and MC-100 portable chlorophyll meters in the greenhouse, while fresh matter and the concentration of chlorophyll and N were determined in the laboratory using conventional techniques. The relationship between SPAD readings, Chl, N, and FM was strong, positive, linear, and significant, with correlation coefficients (R2) between 0.94 and 0.98. For atLEAF and MC-100 readings, R2 values were 0.96 to 0.99 and 0.96 to 0.99, respectively. The relationships between SPAD, atLEAF and MC-100 readings were strong, positive, and significant, with R2 values of 0.98. Similar behavior was shown by the relationship of N concentration and FM with R2 of 0.88. With these results, we conclude that SPAD, atLEAF, and MC-100 can be used to estimate the nutrient status of N in a non-destructive, rapid and reliable manner during basil production.

The accurate measurement of herbage mass is essential for feed budgeting and the management of sustainable and profitable grazing systems. There are many techniques available to estimate herbage mass in pastoral systems, and these vary in accuracy, cost, and time taken to implement. In situ and remote sensing techniques are both associated with moderate to high error, as herbage mass is affected by a number of dependent and independent factors, including sward composition, soil structure, chemical characteristics and moisture levels, climatic conditions, and grazing management, which must be considered in the development of an accurate local calibration model for precise estimation of herbage mass. This review provides an overview of commonly used herbage mass assessment techniques and describes their limitations, synergies, and trade-offs, and also covers the integration of new technologies which have the potential to monitor pastures at scale. This review highlights the need for further research and to integrate new technologies for accurate and precise measurement of herbage mass, noting the lack of calibration with in situ methods, the need for development of new protocols for assessment, variance in equipment and software compatibility, and the need to evaluate the effectiveness of methods/techniques on a variety of livestock operations for extended periods.

Grass species have a range of strategies to tolerate soil water restriction, which are linked to the environmental conditions at their site of origin. Climate change enhances the relevance of the functional role of anatomical attributes and their contribution as water stress tolerance factors. Morpho-anatomical traits and adjustments that contribute to drought resistance in Lolium perenne L. (Lp) and Bromus valdivianus Phil. (Bv), a temperate humid grass species, were analysed. The structure of the leaves and pseudostems (stems only in Lp) grown at 20–25% field capacity (FC) (water restriction) and 80–85% FC (control) were evaluated by making paraffin sections. In both species, water restriction reduced the thickness of the leaves and pseudostems, along with the size of the vasculature. Bv had long and dense leaf hairs, small and numerous stomata, and other significant adaptive traits under water stress, including thicker pseudostems (p ≤ 0.001), a greatly thickened bundle sheath wall (p ≤ 0.001) in the pseudostem to ensure water flow, and a thickened cuticle covering on leaf surfaces (p ≤ 0.01) to avoid water loss. Lp vascular bundles developed throughout the stem, and under water restriction the xylem vessel walls were strengthened and lignified. Lp leaves had individual traits of a ribbed/corrugated-shaped upper surface, and the stomata were positioned to maintain relative humidity outside the leaf surface. Water restriction significantly changed the bulliform cell depth in Lp (p ≤ 0.05) that contributed to water loss reduction via the curling leaf blade. This study demonstrated that the two grass species, through different morphological traits, were able to adjust their individual tissues and cells in aboveground parts to reach similar physiological functions to reduce water loss with increased water restriction. These attributes explain how both species enhance persistence and resilience under soil water restriction.