Ecophysiological study of SiK impact on Castanea sativa Mill. tolerance to drought stress

Abstract

Drought is an abiotic stress that may be aggravated by climate changes with increasingly warmer and drier summers. This is a severe problem in the chestnut crop in Portugal due to its need for water during this time, which is essential for good formation and development of the fruit. Si fertilization is referenced by several authors as important in the tolerance of plants under drought. The experiments were carried out in the field trial and chestnuts were fertilized with 0, 5, 7.5, and 10 mM potassium silicate (SiK), which was applied to the soil and to the leaves and exposed to a non-irrigation and an irrigation phase during the summer. Results indicate that Si fertilization increased the relative water content and water potential, while the transpiration rate, stomatal conductance, and stomatal density were reduced under deficit irrigation in Si-treated plants (10 mM SiK). Moreover, the Si induces a higher photosynthetic activity and vessel frequency with a smaller diameter, promoting a higher relative hydraulic conductivity and a lower vulnerability to cavitation. This work suggests that Si can be used as a potential source to induce drought tolerance in chestnuts.

The potential of SiK® fertilization in the resilience of chestnut plants to drought - a biochemical study

“…Relative to the membrane injury, the present study also showed a significant decrease in ROS in Si-treated chestnut plants under abiotic stress conditions similar to previous studies ( Carneiro-Carvalho et al., 2020 ; Carneiro-Carvalho et al., 2021 ). In this study, oxidative damage was significantly reduced in C. sativa plants under water stress.…”

“…The data show that Si fertilization significantly increased the accumulation of SS concentration in plants exposed to NIP by approximately 120% in 2015 (Figure 3A) and by 180% in 2016 (Figure 3B), between the 0-and 10-mM SiK ® treatments, as previously observed by other authors in chestnut plants (Carneiro-Carvalho et al, 2020;Carneiro-Carvalho et al, 2021). When examining the IP, a similar tendency was observed.…”

“…In the present study, the plants were submitted to annual SiK ® applications between 2014 and 2016. The concentrations of SiK ® were selected from the results obtained in previous studies of chestnut plants ( Carneiro-Carvalho et al., 2020 ; Carneiro-Carvalho et al., 2021 ). Each treatment containing 30 plants and was set 12 replicates per treatment; in the study, a total of 120 plants were used.…”

“…Previous studies carried out about the application of Si in chestnut trees demonstrated that Si-treated plants at concentrations of 7.5 and 10 mM of SiK promote higher resilience in adverse conditions ( Navarro, 2020 ). Taking into account the existence of few studies about the role of Si in the resistance of the chestnut tree to drought, it was decided to carry out the present study to evaluate the potential of Si fertilization in promoting the resistance of the chestnut tree to water stress, namely, in the biochemical and enzymatic mechanisms, in order to help chestnut producers during the increasingly frequent drought periods ( Carneiro-Carvalho et al., 2020 ; Carneiro-Carvalho et al., 2021 ).…”

Influence of Silicon on Tolerance to Water Deficit of Peach Trees

“…Although there have been some studies on the use of foliar applications of Si to fruit trees, their focus was on yield and fruit quality (Artyszak 2018), and there is very limited research on the role of foliarly applied Si on water relations and gas exchange. A study on water-stressed chestnut trees fertilized with Si (Carneiro-Carvalho et al 2020) suggested that foliarly applied Si can reduce cuticular transpiration and permeability to water vapor, limiting the loss of water and, thus, promoting better tree water status, although they used a combination of soil-applied and foliarly applied Si.…”