432 The Philippine Journal of Science 1021 
Some growers contend that the quality of the Nakorn Chaisri 
pummelo is due to the method of curing and storing. While 
this undoubtedly is a factor in producing a better flavor and 
aroma in all varieties of pummelos, it cannot account for the 
superiority of the Kao Pan over the other varieties. 
SUMMARY AND CONCLUSIONS 
The Siam seedless pummelo, sometimes called the Nakorn 
Chaisri or Kao Pan pummelo, appears to be a distinct variety 
developed in a restricted region of the delta area in Ban Mai, 
Sarm Prarm, Nakorn Chaisri, Siam. Through the main part 
of the year it produces seedless fruits, but during November the 
fruit is reported to incline to seediness. 
The temperature in this region ranges between 24.4 and 32.1° 
C., the coolest months being December and January, and the hot- 
test about April. The mean daily range is about 9.3° C. The 
total rainfall for the district varies between 1,154.7 and 1,690 
millimeters during the year. A distinct dry season is present, 
usually starting in November and continuing through December, 
January, February, March, and April. 
The water used for irrigation in the Ban Mai orchards is taken 
directly from Tachin River. This water is extremely salty dur- 
ing at least six months of the year. In June analyses showed 
the presence of 2 per cent of salt, which approaches the salt 
content of sea water, with approximately 2.7 per cent of sodium 
chloride. 
The water used for irrigation in the Bang Bakok fruit section 
near Bangkok is obtained from the Menam Chao Phaya. The 
fruit produced in this section is seedy and its quality is inferior 
to that produced in the Ban Mai region. Analyses of this water 
showed that in June it contained only 0.04 per cent of salt, which 
is normal for ordinary river water. The water is reported to 
be less salty throughout the year than that of Tachin River at 
Ban Mai. 
The surface soil in all of the orchard sections in the delta re- 
gion is heavy, clayey, and entirely of an alluvial formation. The 
subsoil is a heavy, gray, brick clay, which is rather impervious 
to water. 
Analyses of the salt content of the soils in Ban Mai show that 
the surface soil, subsoil, and canal mud used for fertilization, 
are extremely salty in June, containing between 0.8 and 2.5 per 
