390 The Philippine Journal of Science 1921 
coming into bearing under the new conditions of growth have 
produced a fruit poor in quality and abundant in seeds. 
The present studies show that the “Siam seedless pummelo” 
reported in 1913 3 as having been successfully introduced into 
the Philippines, and later in 1917 4 as having produced fruits, 
was not the true seedless variety. The fruit described and 
illustrated in 1917 is of the best commercial type of Siamese 
pummelo, the Kao Phuang. It frequently happens that the Kao 
Phuang and other varieties produce a few fruits without seeds, 
but there is only one type that is generally recognized as being 
the seedless one. A direct result of the investigations has been 
our successful introduction of bud wood of the true Nakorn 
Chaisri seedless pummelo, into both the Philippine Islands and 
the United States. A small tree of the variety also was taken 
to the Philippines. 
The investigations were made during the months of June and 
July, 1920, through the cooperation of the Division of Crop 
Physiology and Breeding Investigations of the Bureau of Plant 
Industry, Washington, D. C., with the College of Agriculture 
of the University of the Philippines, Los Banos, Philippine Is- 
lands, and the Canton Christian College, Canton, China. The 
primary objects of the investigations were: To obtain a first- 
class series of Siamese pummelos; to make a complete study of 
the real seedless pummelo; to determine the cultural methods 
by which the proprietors of the Siamese seedless pummelo or- 
chards produce seedless fruits; to obtain varieties resistant to 
canker; to make a study of the plant diseases and insects at- 
tacking the trees ; and to look into the salting and cultural prac- 
tices in relation to quality and seedlessness. 
The low-lying region of Nakorn Chaisri is well situated for 
the production of citrus fruits, and the inhabitants of this and 
other regions have a large number of recognized varieties. 
Their pummelos can readily be classified into two main types; 
the round and the elongated. The most characteristic and best 
fruit of the first class is the so-called seedless or Kao Pan. This 
is the fruit usually referred to when residents of Siam speak 
of the delicious Nakorn Chaisri pummelo. The second class is 
represented by the Kao Phuang, a pear-shaped, elongated fruit 
produced in the Dao Kanong region. The latter is not so 
8 Wester, P. J., Citriculture in the Philippines, Bull. Philip. Bur. Agri. 
27 (1913) 1-71. 
4 Wester, P. J., New or noteworthy tropical fruits in the Philippines, 
Philip. Agri. Rev. 10 (1917) 21-22. 
