Conserving Water Through the Use of Antitranspirants in Potato (Solanum tuberosum L.): Effects On Gas Exchange, Yield, and Quality in a Production Field Environment.

Nearly fifty years ago, antitranspirants (AT) were considered a promising agronomic tool to conserve water for wheat, corn, potato, and other crops.  But further research into the influence of AT on crop physiology indicated that their use often caused a blockage of stomata and a resulting loss of gas exchange and photosynthesis; concomitantly leading to detrimental effects on yield.  Continued research and the commercial use of AT began to wane and further investigations were nearly abandoned.  Recently, however, there has been increased interest in the directed application of low levels of AT timed to crop developmental stages that would be less sensitive to small decreases in gas exchange.  To examine the possible water conservation effects of this modified application of AT, we investigated their use in a commercial potato production field in north Florida.  A two factor experiment was established testing fully irrigated and deficit irrigated plots that were either treated with AT or left as non-treated controls.  Low levels of AT (1.2 l/ha during vegetative and tuber initiation; 2.4 l/ha during tuber bulking) were applied five times during the early to mid-growing season, spaced roughly 7-14 days apart.  Starting at the point when plants reached mature size and had received three AT applications, stomatal conductance, NDVI, leaf canopy temperature, and relative water content were measured three times up to crop harvest.  Results will be discussed regarding the impact of AT in adequate and deficit irrigated potato production and the potential for AT to economically conserve water in this system.