For more than ten years, Central Chile has faced drought conditions, which impact crop production and quality, increasing food security risk. Under this scenario, implementing management practices that allow increasing water use efficiency is urgent. The study was carried out on kiwifruit trees, located in the O’Higgins region, Chile for season 2018–2019 and 2019–2020. We evaluate the time-series of nine vegetation indices in the VNIR and SWIR regions derived from Sentinel-2 (A/B) satellites to establish how much variability in the canopy water status there was. Over the study’s site, eleven sensors were installed in five trees, which continuously measured the leaf’s turgor pressure (Yara Water-Sensor). A strong Spearman’s () correlation between turgor pressure and vegetation indices was obtained, having −0.88 with EVI and −0.81 with GVMI for season 2018–2019, and lower correlation for season 2019–2020, reaching −0.65 with Rededge1 and −0.66 with EVI. However, the NIR range’s indices were influenced by the vegetative development of the crop rather than its water status. The red-edge showed better performance as the vegetative growth did not affect it. It is necessary to expand the study to consider higher variability in kiwifruit’s water conditions and incorporate the sensitivity of different wavelengths.
1 March 2022 in Notulae Botanicae Horti Agrobotanici Cluj-Napoca
Stipa caudata is a grass native to low rainfall areas in Argentina and Chile, considered an excellent potential candidate for biofuel production or soil restoration programmes. This study aimed at analysing the effects of ammonium sulphate (AMS) and acetylsalicylic acid (ASA) on the productivity and biochemical traits of plants of this species under water scarcity conditions. The experimental work was carried out on plants grown outdoors using a randomised block plot design. Several yield and biochemical parameters related to resistance to water scarcity were analysed in plants treated with AMS or ASA. Plants in the treatments with ASA and AMS had higher total chlorophyll content than the others. Concerning ion content, water-restricted plants treated with AMS had similar values to irrigated plants. Regarding the osmoprotectants and antioxidants, treated plants had increased concentrations of proline and total flavonoids. Under water stress, plants had higher APX activity and there was an A x B interaction for CAT and SOD activity. The results obtained show that the use of ASA and AMS in some crops or in environmental restoration programmes could be a useful tool to cope with future climate scenarios of water scarcity.
Water scarcity has affected much of Chile for the past 15 years, and Amelichloa caudata, a native species adapted to arid conditions, may offer a solution. The hypothesis of this study is that both acetylsalicylic acid (ASA) and biosolids (BSs) can positively influence plant growth under water stress. This study assessed the effects of ASA and BSs on edaphic, physiological, biochemical, and productive parameters of A. caudata under water scarcity conditions. Results showed that both treatments enhanced biomass production, plant height, leaf number, and canopy weight. ASA improved water retention, mitigating water stress effects and leading to biomass levels comparable to controls. In contrast, BSs did not show significant benefits and had the lowest biomass values under all conditions. The highest root dry weight was observed in water-restricted plants, while ASA-treated plants had lower malondialdehyde (MDA) levels, indicating reduced oxidative stress. However, BS treatment increased MDA levels, suggesting more severe oxidative damage. Despite improvements in water retention, high salt concentrations in BSs may limit their effectiveness and further research is required to optimize application rates.