Commercial uses of antitranspirants in crop production: A review

Abstract

Global food security is at risk due to the predicted climate change, making it imperative for agronomists to provide adaptive technologies that will sustain and improve food production. Rainfed agriculture, prone to drought, covers an estimated 80% of global cropland. One of the adaptive technologies is the use of antitranspirants – products that are applied on plants to reduce transpirational water loss and increase crop performance under drought conditions. The benefits of improving antitranspirant adoption in drought mitigation are expected to be high, especially in many drought-prone low-income countries where crop production is almost wholly dependent on rainfall. The objective of this article was to review the commercial uses of antitranspirants in food and non-food crop production. The review revealed that in horticulture, antitranspirants have several commercial uses, in addition to drought mitigation, such as transplanting shock amelioration, protection of fruit against sunburn, enhancement of nutritional quality, synchronising fruit ripening, protection of fruit and nut trees against diseases. Use of antitranspirants in arable farming has been neglected for three main reasons: first, arable crops have lower market value, for example, in Melbourne (Australia) in October 2022, a tonne of grapes was worth US$ 2694.82 compared to US$ 277/tonne of wheat. Second, molecular genetics applied to crop breeding has risen as an alternative approach to drought mitigation, shifting attention from antitranspirants. Finally, the erroneous research conclusion in the 1970s that antitranspirants could not increase yield because they reduced photosynthesis discouraged commercialisation of antitranspirants in arable farming. An antitranspirant breakthrough to either lower the cost or create a multi-purpose product is needed for the production of arable crops, especially major cereals, as has been the case for non-drought amelioration uses in horticulture.

Yield improvement with antitranspirant application in droughted wheat associated with both reduced transpiration and reduced abscisic acid

“…Antitranspirants are grouped into three classes, based on their mode of action, as metabolic antitranspirants, reflective antitranspirants and film antitranspirants (Mphande et al, 2023). Metabolic antitranspirants, also known as stomata-closing antitranspirants, for example, exogenous abscisic acid (ABA), chitosan and fulvic acid, reduce transpiration by acting on guard cells to induce stomatal closure.…”

“…For example, a study done by de Godoi and found sunflower oil to be as effective as di-1-p-methene in reducing transpiration. Antitranspirants are being used commercially in horticulture, but the high cost has limited their use in arable crops (Mphande et al, 2023).…”

Light-Emitting Diodes Modify Medicinal Quality of Mown Rabdosia rubescens, with Changes in Growth, Physiology, and Antioxidant Activity, under Drought Stress

“…Global climate change is increasing the frequency of droughts, which further modifies air CO 2 -O 3 concentrations, reduces precipitation, increases risks of water loss through transpiration, leads to the accumulation of high-temperature records, and promotes more extreme weather events [ 1 , 2 ]. Drought reduces dry mass production and limits physiological activities in medicinal plants, which, together, result in production loss and quality degradation [ 1 , 3 , 4 ].…”

“…Hence, their juvenile stocks are usually cultured in the nursery to shape high-quality stocks for transplant to quickly regenerate a destroyed population at the understory layer. As abiotic stress, drought threatens plant growth and development by impairing botanic functions in the secondary metabolism [ 8 , 9 , 10 ], photosynthetic physiology [ 9 , 10 ], nutrition [ 2 , 8 ], and antioxidation [ 8 ]. Plants can perceive these changes and adjust themselves in multiple ways, resulting in essential adaptations to drought [ 11 , 12 ].…”

Applying sunflower oil to rapeseed plants reduces water loss

“…One under‐utilised technology is the reduction of plant water loss by using sprays of hydrophobic polymers, such as terpenes, to block stomata, often referred to as film antitranspirants in this role 2 . These products are expensive, and thus currently justified mainly on high value crops or ornamental plants, but, nevertheless, they have potential to increase yield under drought of major global food crops such as wheat and rapeseed 3 . If cheaper polymers could be shown to have similar efficacy to the terpene antitranspirants, then there may be greater likelihood of their adoption for reducing drought damage to food crops, especially by smallholder farmers in low‐income countries.…”