Rundles: Studies in Rice 
X, C, 6 
367 
attained. When rice is grown on a large scale, a hand seed-drill 
can be used to good advantage. 
OPTIMUM DISTANCE FOR TRANSPLANTING AND OPTIMUM NUMBER OF 
PLANTS PER HILL 
At the present time experimental evidence is not sufficient, at 
least in these Islands, to warrant a conclusive statement regard- 
ing either the proper transplanting distance for rice or the 
most desirable number of plants to set in a place. Experiments 
of this kind require a period of years to make them worthy of 
consideration. Table IV shows that there is a wide variation 
in the transplanting distances, all of which, with the possible ex- 
ception of the two extreme distances, are found in ordinary use. 
Therefore, in common practice, the area possible to transplant 
with the seedlings from 1 cavan of the ordinary-sized palay 
may vary from 0.3 hectare to 4 hectares, the smaller area being 
the most usual. The farmer should know what is considered 
the best practice. 
The optimum distance for transplanting and the number of 
plants to use is a complicated problem, since there are many 
factors to be considered. A very fertile soil of fine texture tends 
to produce rank growth and hence requires fewer plants than 
does a more porous and less fertile soil. Rank-growing and 
copious-stooling varieties naturally require fewer plants per unit 
of area than similar varieties having little or no tendency to 
stool. As the growth of vegetation is greater during the rainy 
season when the air is saturated than during the dry season 
under irrigated conditions, a greater number of plants can be 
used under the latter conditions. 
There is every reason to believe that overcrowding of plants 
results in poor yield. Overcrowding is a common practice in 
the Philippines (Plate V, fig. 2). 
Setting plants in hills 10 by 10 centimeters with one plant to 
a hill, thus equally apportioning the soil and room for growth, 
would insure each plant favorable conditions for development 
and yield. This involves too much labor in separating and 
transplanting the plants, as the number of hills required for a 
given number of seedlings is from four to ten times as great 
as that required for the greater planting distances. As long 
as transplanting is done by hand, there will be more than one 
plant in a hill. At present a distance of from 15 to 25 centi- 
meters between hills is considered most advantangeous. On 
this subject H. 0. Jacobson, Bureau of Agriculture, states: 
137624—2 
