19, 4 Reinking and Groff: Siamese Seedless Pummelo 429 
complete history of ‘this tree could not be obtained, but it is 
reported as being a seedless pummelo from the Ban Mai district. 
The tree in its new locality had been producing fruits that were 
seedless but not juicy, having woody juice sacs. Raw salt was 
scattered around the base of the tree. The salt application was 
reported to have produced a better-flavored and juicier fruit. 
There was no effect upon the seedy character. Other trials 
about Bangkok produced the same result. People in the north- 
ern part of Siam, at Chieng Mai, also practiced the salting of 
trees and reported an improvement in juiciness and flavor. The 
seedy character in these cases was not changed, as the fruits 
always remained seedy. 
The application of salt along with rice-paddy ash is practiced. 
This method was reported in every case, after the first year’s 
application, to decrease the bitterness of the fruits and to increase 
their juiciness. Some reported that the treatment had the 
effect of producing seedlessness, but no direct evidence on this 
point could be given. Two systems of application are practiced. 
The first method consists in applying the salt and rice-paddy 
ash directly to the trunk of the tree by digging the soil away 
from its base. In the second one the salt and paddy ash are 
scattered about the base of the tree, away from the trunk. Or- 
dinary sea salt is used. It is recognized that too much salt will 
kill a tree. Usually only one application is made each year. 
These methods have not been practiced on a large scale; only 
a few trees, here and there, were so treated. Without a doubt 
the salt treatment produces fruit of better quality as to flavor 
and juiciness, but there is no effect, so far as any evidence 
shows, upon its seediness. 
It has long been known that common salt, sodium chloride, has 
a marked effect on certain soils. The cause of this is not clearly 
understood. The addition of sodium and chlorine as soil con- 
stituents undoubtedly has no effect, as there is usually an excess 
of these elements in available form in soils. It is known that 
the addition of sodium chloride, especially to clay soil, liberates 
certain plant nutrients such as calcium, magnesium, potassium, 
and phosphorus. It may be that such action is responsible for 
some of the beneficial effects observed in the regions under dis- 
cussion, as the soil in those regions is primarily clayey. Soil 
structure also is improved by the addition of salt, and salt has 
the effect of conserving and distributing the soil moisture. 
Transpiration is retarded and the film movement increased by 
