Using Biostimulants Containing Phytohormones to Recover Hail-Damaged Essential Oil Plants

Abstract

Hail can cause significant damage to aromatic and medicinal plants; however, this has never been investigated scientifically on most of aromatic and medicinal plants. Globally, essential oil crop producers primarily make use of agricultural crop insurance and costly mitigation strategies to recover lost production costs and alleviate hail-damaged plants. However, most aromatic and medicinal plants are not covered under agricultural crop insurance, and many commercial farmers are not able to regularly employ expensive alternative strategies. Therefore, hail damage may present a challenge to essential oil growers. The use of natural and synthetic phytohormones in a form of biostimulants, as an alternative biological mitigation strategy against hail damage in essential oil crops, has not received much attention, and there is no information on this topic. Exogenous applications of natural and synthetic biostimulants have consistently demonstrated growth enhancement, nutrient acquisition, yield and quality optimization, as well as physiological efficiency in plants. Biostimulants in a form of phytohormones are involved in diverse plant physiological processes, including the regulation of gene expression for adaptive responses to biotic and abiotic stresses. Using biostimulants, this chapter will detail the potential recovery response of aromatic and medicinal plants to hail damage, and the response of plants treated with biostimulants.

Phytohormone-Based Biostimulants as an Alternative Mitigating Strategy for Horticultural Plants Grown Under Adverse Multi-Stress Conditions: Common South African Stress Factors

“…DPPH scavenging rate is measured to study the antioxidant activity of plant extracts. In the case of herbivory harm, volatile compounds are released to deter pests and draw predators and parasitoids (Khetsha et al, 2022).…”

“…Phytohormones are small organic molecules produced naturally by plants or synthesized in laboratories to induce metabolic activities and regulate local and distant plant growth processes within plant cells at low endogenous concentrations (Khetsha et al, 2022;Verma et al, 2022). Phytohormones, namely auxins, CKs, GAs, auxins, brassinosteroids (BRs), and ethylene (ET) are categorized under plant growth regulators and ABA, Jasmonic acid (JA) and SA as bio-inhibitors (Chen et al, 2016;Iqbal et al, 2020;Jiménez-Arias et al, 2022;Verma et al, 2022;Wei et al, 2023).…”

“…These mitigation strategies include several tools such as agronomical techniques (Franzoni, 2020), in-vitro selection, tissue culture, and genetic engineering (Kumar et al, 2020), biofertilizers and xenobiotic agrochemicals (Rana et al, 2022), insect pest, protected cultivation, use of compounds or substances applied on leaves to reduce moisture loss, and biostimulants or specific bioactive compounds (Franzoni, 2020). The biostimulant industry is commonly composed primarily of humic acids, fulvic acids, algal extracts, silicon, and plant growthpromoting microorganisms, bio-inhibitors, and phytohormone in South Africa (Khetsha et al, 2022).…”