X, 6,6 Rundles: Studies in Rice 371 
ber, seem to indicate that one of the principal factors governing 
poor yield is excessive planting. 
One hectare may be planted with 1,290,000 seedlings when 
transplanted 8.8 by 8.8 centimeters apart with one plant in 
the hill. Under these conditions that number may not be con- 
sidered excessive when compared with the same number trans- 
planted 25 by 25 centimeters apart with eight plants to the hill. 
The number of seedlings per given unit of area remains the same, 
yet by the latter plan overcrowding is evident as the plants 
are spaced neither to use the ground economically, nor to pro- 
vide sufficient room for growth. Thus it is very evident that 
the maximum number of seedlings per hectare requires the 
closest planting distance. More than four plants for a trans- 
planting distance of 15 by 15 centimeters or more than six for 
a distance of 20 by 20 centimeters must be regarded as over- 
crowding. Three plants for the former distance and four for 
the latter are regarded as the optimum number of seedlings 
to a hill, a rate which would limit the number of seedlings 
used on a hectare to 1,000,000 for the lesser distance and 
1,300,000 for the greater. 
These results correspond very closely with those of the Bu- 
reau of Agriculture, which advocates from three to five seedlings 
per hill as the best number to insure maximum yields. H. O. 
Jacobson comments on this subject as follows: 
Denser plantings will surely not increase the yield, but, as to how dense 
a planting can be before it affects the yield adversely, I am not prepared 
to say. On the other hand much scantier spacing than indicated above 
will affect the yield but slightly if at all. 
It should be borne in mind that the rice plant is very adaptable in some 
respects, and that the limiting factors on yield are available plant food 
and water. If a plant is given much space it will draw upon available 
plant food to its utmost capacity; but where the plants are more closely 
crowded a number will not survive and the remaining ones compete with 
each other for the available plant food and water. 
Planting too closely should be condemned because it tends to prevent 
normal development of the plants, requires more labor in planting which 
is profitless and wastes seed. 
The final hectare production depends upon the sum total of 
the yields of the individual rice plants. The data presented in 
Table V indicate that the average production of the individual 
plant is very poor when grown under the usual conditions. The 
data in Tables VI and VII point to the possibilities of rice 
when attention is given to the individual plant. 
To secure the maximum yield of rice, proper attention to 
all the important factors is demanded—that is, selecting a va- 
