Chloride Changes Soil–Plant Water Relations in Potato (<i>Solanum tuberosum</i> L.)

Abstract

There is evidence that chloride (Cl―) can lead to both an improved hydration and water use efficiency in plants due to its osmotic properties. The potato crop is widely assumed to be sensitive to Cl―. This is based on studies which found tuber yield or tuber starch reductions following a Cl― fertilization. However, there are also contradictory reports which could not find any detrimental effect of Cl― fertilization on potato plant development. As potato is inefficient in the use of water, we aimed to test if it is possible to improve the hydration status of potato without reducing tuber yield and dry matter by means of Cl― fertilization. We conducted a pot experiment with four different Cl― doses and investigated soil–plant water relations, biomass, tuber yield and dry matter development. Our findings deliver an indication that the potato crop is much less sensitive to Cl― than previously assumed and, more importantly, that a Cl― supply can indeed improve the potato shoot water status. This happened without impairing tuber yield and dry matter. Since potato is very sensitive to drought stress, we assume that Cl― fertilization is a promising measure to improve the drought resilience of potato.

Keywords

• potato
• chloride
• plant hydration
• soil–plant water relations
• tuber yield
• tuber dry matter