Commercial uses of antitranspirants in crop production: A review

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.