Influence of kaolin application on most important fruit and leaf characteristics of two apple cultivars under sustained deficit irrigation

Abstract

Background Apple is one of the oldest and most valuable fruits. Water restriction is one of the major problems in the production of this fruit in some planting areas. Methods Effects of kaolin spray treatments were studied on two early apple cultivars of Golab and Shafi-Abadi under sustained deficit irrigation (SDI) in Alborz province, Iran during 2017 and 2018. Irrigation treatments were 100%, 85%, and 70% ETc and kaolin application were concentrations of 0, 3 and 6% in 2017 and 0, 1.5 and 3% in 2018. Results Results showed that 85% ETc treatment compared to other irrigation treatments improved apple tree crown volume in 2017. Deficit irrigation treatments significantly reduced fruit weight in both years. Application with 6% kaolin resulted in 33.3% increase in apple fruit weight compared to non-kaolin treatment at 100% ETc irrigation in the first year. Severe deficit irrigation (70% ETc) significantly reduced apple fruit length in both years, but 6% kaolin increased fruit length in both apple cultivars in 2017. Severe deficit irrigation treatment increased the firmness of apple fruit compared to control and mild deficit irrigation (85% ETc) in the first year of experiment. There was no significant difference between irrigation treatments for apple fruit firmness in the second year of experiment. Kaolin treatments of 1.5% and 3% at full irrigation increased the soluble solids content of apple fruit by 36.6% and 44.1% in 2018, respectively. Deficit irrigation treatments significantly increased leaf proline content compared to control in both years. In the first year, kaolin treatments increased leaf proline but in the second year, leaf proline was not significant. Deficit irrigation treatment of 70% ETc and 6% kaolin had the highest amount of glycine betaine content, malondialdehyde and hydrogen peroxide in apple leaf in the first year of experiment. Conclusions Severe deficit irrigation stress (70% ETc) increased the activity of nonenzymatic defense systems of apple trees. Kaolin as a drought stress reducing agent can be recommended in apple orchards of Golab and Shafi-Abadi cultivars as an effective and inexpensive method to improve tolerance to drought stress conditions.

Deficit Irrigation Strategies on Tree Physiological and Chemical Properties: Treatment Effects, Prediction Based Model Analyses and Inter-Correlations

“…This study showed that DI treatments and cultivars had significant effects on leaf proline contents (Table 7 and Figure 7). Treatments with increasing water deficit resulted in a significant increase in the leaf proline content for both apricot cultivars compared to the fully irrigated control treatment (Figure 7), which were in agreement with the study of Faghih et al [94] on apple and Laajimi et al [16] on apricot. Previous studies showed that proline accumulation in plants plays a protective role against the environ-mental stresses [95][96][97], such as limited availability of water due to soil water depletion or high temperature stress inducing an increased transpiration rates [98,99].…”

Demethylzeylasteral (T-96) initiates extrinsic apoptosis against prostate cancer cells by inducing ROS-mediated ER stress and suppressing autophagic flux

“…The flow cytometry analysis was performed as previously described [ 28 ]. Briefly, PI/RNase staining buffer [Becton Dickinson (BD)] was used to assess the cell cycle progression, while AnnexinV-fluoresceine isothiocyanate/PI apoptosis assay kit (C1062S, Beyotime, China) was used to assess apoptosis, according to the manufacturer’s guidelines.…”

Characterization of cape gooseberry (Physalis peruviana L.) fruits from plants irrigated with different regimens and calcium doses

“…The water level and the frequency of the irrigation did not present significant differences in the firmness of the cape gooseberry fruits (Tab. 1), which had an average value of 9.91 N and a standard deviation of 0.55, lower than that found by Amézquita et al (2008) Some authors have confirmed that reducing irrigation increases fruit firmness in the pear (Bayona-Penagos, 2017), blueberry (Almutairi et al, 2017), apple (Faghih et al, 2021), and peach (Zhou et al, 2017;Rufat et al, 2010). This decrease is attributed to the fact that water stress reduces the size of fruits, and smaller fruits tend to be more compact and firmer than large fruits (Faghih et al, 2021).…”