Studies on the salt tolerance of trees and shrubs

Abstract

In this investigations, the deposit and invasion of salt in various leaves were studied in relation to the leaf form, size, maturation influencing the salt injury pattern of trees and shrubs. The results obtained are as follows:
1. There is different amount of salt deposited on leaf between the outside surface and the backside one, and the salt amount in the mesophyll depends deeply on the salt amount deposited on backside surface of leaf.
2. From the experiments of salt injury of Camellia japonica var.hortensis f.incarnata Lodd., salt injury appears at the leaf tip or the margin with lgihtbrown or brown inverse V-shape injury, in the order of appearance, first at the wounded leaves, then the worm-eaten leaves and last the sound leaves which limiting Cl amount in mesophyll injured is 0. 06mg/cm².
3. Water spray effect to reduce the salt injury can be seen until 10hours after water was sprayed and in the amount of water corresponding to more than 6mm precipitation, and its effect is promoted by spraying twice the half of the given amount of water.
4. Salt injury obtained in various trees depends on following cases:
(i) Cl amount deposited on leaf surface
(ii) Cl amount in the mesophyll
(iii) Duplicate action both (i) and (ii)
5. Generally the new leaves are more sensitive to salt injury than the old ones, for the easiness of salt deposit and the unmaturation of leaves.