Potential of glyphosate as a sprout suppressant for potato (Solanum tuberosum L.) tubers during storage

Abstract

Storage of potato (Solanum tuberosum L.) tubers at 8–12 °C (depending on the countries either 8–10 or 10–12 °C) with 85–90 % RH in cold stores is common practice because at this storage temperature the accumulation of sugars is minimum and potatoes remain suitable for processing. This temperature is however, also suitable for sprout growth and therefore, use of a sprout suppressant becomes essential. Isopropyl N-(3-chlorophenyl) carbamate (CIPC) is the most commonly used sprout suppressant used in potatoes. It is applied in the form of aerosol on the stored potatoes as a Post-harvest application. The possibility of using glyphosate as a pre-harvest foliar application on the potato crop to check the sprout growth of potatoes during subsequent storage has been reviewed in this article. Relative comparison between CIPC and glyphosate showed that glyphosate is safer in terms of lower mammalian toxicity with respect to oral LD50, contaminant level for human toxicity (long-term), acceptable daily intake limit (for human body) and acceptable residue limit (for human consumption). Comparatively, CIPC is more harmful to birds, fishes and other aquatic animals, worms and the environment. There are growing concerns regarding degradation products/metabolites of CIPC as they are more toxic and cytolytic in nature. Practical aspects such as cost of the chemical, application cost and ease of application also favor the glyphosate. Higher water solubility of glyphosate over the CIPC and its metabolites is also a point, as this can assist in minimizing the residue levels of glyphosate either in processed or cooked potato tubers. It is proposed that outcome of the further research work, especially on the suggested lines, may help in developing glyphosate as an alternative/supplementary to CIPC for its use as sprout suppressant on potatoes stored at 8–12 °C.