Salicylic acid and kaolin effects on pomological, physiological, and phytochemical characters of hazelnut (Corylus avellana) at warm summer condition

Abstract

Climate change and population increase are two challenges for crop production in the world. Hazelnut (Corylus avellana L.) is considered an important nut regarding its nutritional and economic values. As a fact, the application of supporting materials as foliage sprays on plants will decrease biotic and abiotic stresses. In this study, the effects of salicylic acid (0, 1 mM and 2.5 mM) and kaolin (0, 3% and 6%) sprays were investigated on morphological, physiological, pomological, and biochemical characteristics of hazelnut. The results showed that 1 mM salicylic acid and 6% kaolin had the best effects on nut and kernel weight compared to control. Biochemical parameters such as chlorophyll a, b, a + b, and carotenoid contents showed that salicylic acid and kaolin improved pigment concentration. Proline and antioxidant contents such as phenolic acids, SOD, APX, and CAT enzyme activities increased by these applications. On the other hand, lipid peroxidation, protein content, and H2O2 content were decreased. Based on the tolerance index result, Merveille de Bollwiller cultivar showed the highest tolerance while 'Fertile de Coutard' had the lowest value. Therefore, hazelnut performance may be improved through exogenous application of the signaling (salicylic acid) and particle film (Kaolin) compounds in warmer climates.

Kaolin Improves Photosynthetic Pigments, and Antioxidant Content, and Decreases Sunburn of Mangoes: Field Study

“…Dinis et al [48] found that the application of kaolin spray led to an increase in photochemical reflectance and photosynthetic pigments in a grapevine plant. These results are consistent with Abdallah et al, 2019, and Khavari et al, 2021 [49,50].…”

Minor Variety of Campania Olive Germplasm (“Racioppella”): Effects of Kaolin on Production and Bioactive Components of Drupes and Oil

“…In accordance with our results ( Table 1 ), Wang et al and Brillante et al [ 30 , 31 ] showed a positive effect of kaolin treatment on the anthocyanins content of grapes and grapewines, respectively. Contrary to our results, Khavary et al [ 32 ] showed that the kaolin treatment increased the contents of carotenoids and total chlorophyll in hazelnuts, while Brito et al [ 33 ] found no significant difference between kaolin and control treatment in carotenoids and chlorophyll contents in the leaves of olive plants. Criado et al [ 25 ] showed a concentration of total chlorophyll in a range between 3.1 mg/kg to 285 mg/kg in the Arbequina cultivar and between 1.6 mg/kg to 392 mg/kg in the Farga cultivar, depending on the ripening stage.…”

Photosynthetic responses of heat-stressed apple leaves to foliar application of salicylic and ascorbic acid

“…SA is a phenolic compound that acts as a plant hormone and signalling molecule with beneficial effects on the resistance to many abiotic stressors, including salt (Nazar et al 2011), heat (Wang et al 2010), and drought (Iqbal et al 2022). During high-temperature stress, exogenous SA applications improve photosynthesis (Wang et al 2010), pigment concentration, and antioxidant systems by regulating enzymes, such as peroxidases, superoxide dismutase, and catalases, which lower the formation of reactive oxygen species and reduce oxidative stress (Khavari et al 2021). A foliar spray of AsA has been demonstrated to enhance plant growth and development.…”