RICE EXPERIMENTS IN CALIFORNIA. 53 
early and the water held continuously the rate of seeding should be 
heavier than when it is grown in the usual way. 
To kill young water-grass plants they must be kept under 4 to 6 
inches of water continuously. Fields, therefore, should be as level 
as possible, so that the water can be held at a uniform depth over 
the entire check. 
JAPANESE OR WHITE WATER GRASS. 
The late, vigorous water grass locally known as Japanese or white 
water grass does not appear to be materially reduced by early, deep, 
continuous submergence; in fact, this variety seems to increase from 
year to year under the continuous submergence method of irrigation. 
When this grass is thick it is one of the worst types in the rice fields. 
It has an extensive root system, stools abundantly, and where thick 
materially reduces the yield of rice. Good cultivation preceding 
fallow and dry farming help to control this grass. 
SCALE-GRASS. 
Scale-grass (Leptochloa fascicularis) , locally known as ray-grass, is 
spreading quite rapidly in the California rice fields. This grass stools 
abundantly and matures from June 20 to October. The slender, 
weak stalk when young makes it practically impossible to pull this 
grass economically. Scale-grass will stretch through water just as 
quick as, if not quicker than, rice, so it can not be suffocated after 
it has started growth. When mature the seeds drop to the ground 
or water and are seldom, if ever, present in the threshed grain. The 
seeds of scale-grass are much smaller than those of rice. As they 
will germinate as soon as mature, the grass may be reduced by con- 
tinuous submergence. The seed which falls to the water will ger- 
minate and the plants may then be destroyed by natural agencies be- 
fore they reach maturity in the fall. On one plat continuously sub- 
merged last year there was considerable scale-grass, but the same plat 
continuously submerged this year has practically none. Improved 
drainage and good cultivation should aid in the control of this grass. 
SPIKE RUSH. 
Spike rush (Eleocharis palustris), locally known as wire-grass, is 
abundant in the shallow irrigation ditches, on levees, and particularly 
on the low, poorly drained rice land. It spreads by means of under- 
ground rootstocks. The spike rush usually gets started in a field 
near the levees or corners, where it is difficult to do a good job of 
plowing. It then continues to spread by means of the underground 
rootstocks. Rice can not grow where the spike rush is thick. Im- 
proved drainage and thorough cultivation will eradicate this weed 
The spike-rush sod should be plowed with a moldboard plow, each 
layer of sod being well turned and thoroughly dried. 
CAT-TAILS. 
The cat-tail (Typlta Jatifolia) finds conditions ideal for its growth 
in the rice fields. It is also present in canals, lateral supply ditches, 
shallow drainage ditches, and on poorly drained marshy land. The 
cat-tail is a perennial ranging in height from 3 to 9 feet. On the end 
of the stalk is a cylindrical flower head, which is 4 to 8 inches long 
and produces thousands of small seeds that are readily spread by 
wind and water. 
