Abstract
The content and distribution of potassium (K) and calcium (Ca) in the leaves of broad bean during the snow cover period were investigated to clarify the role of snow melt water in snow damage. The experiments were carried out under the conditions where air temperature was usually above 0°C and snow had been melting during the snow cover period. The melt water with an average pH of 4.4 contained CL-, SO42- and NO3-. The plants were cultivated in open fields or inside tunnels covered with non-woven fabric to decrease the quantity of melting water. Most of the plants in the open fields were damaged after 52 days of snow cover, but the plants inside the tunnel were hardly damaged. The K content in the leaves decreased under snow cover in both plots and the decrease in open field plots was greater than that in the tunnel plots. On the other hand, Ca content decreased only in the open field plots. The observations of leaves after snow melting with an Electron Prove Micro X-ray Analyzer revealed that the content of K in the necrotized part of the leaf was lower than that in the healthy part. From these results, we concluded that the minerals i leaves were leached out by continuous out by continuous snow melt water and the melt water is one of the factors enhancing the snow damage.
