Rice Production in Southwestern Louisiana 
17 
ing acid phosphate than on those plats which were not so treated. 
Several species of sedges in particular respond to a marked degree 
whenever acid phosphate is applied, except when lime is used. 
During all stages of their growth the rice plants growing on plats 
receiving acid phosphate were also more susceptible to< the disease 
caused by the fungus Pirlcularia oryzae than plants on plats not so 
fertilized. Rice plants so affected are crowded out by weed growth. 
In commercial fields low yields that are usually attributed to other 
causes are largely due to this disease. The effect of this disease was 
particularly marked in 1919 and 1921, when yields on the phosphate- 
fertilized plats were much reduced by this fungus. In addition, 
whenever germination was delayed good stands were not obtained 
on plats to which acid phosphate had been applied. The seed appar- 
ently was injured by this fertilizer. On the other hand, during the 
first two weeks after emergence the plants on the phosphate-fertilized 
plats were vigorous and dark green in color. As soon as irrigation 
water was applied, however, they became very unhealthy in appear- 
ance. This effect was noticeable even where the least amount of acid 
phosphate was used. On plats where other fertilizers were used this 
effect was not noted. 
Table 13. — Annual and average yields of Wataribune rice obtained in the 
fertilizer experiments and in rotation with the Biloxi soybean on duplicated 
tenth- acre plats at the Rice Experiment Station, Crowley, La., in the 5-year 
period from 1919 to 1923, inclusive 
Sources of plant food 
Fertili- 
zers 
applied 
per acre 
(pounds) 
Yields per acre (pounds) 
1919 
1920 
1921 
Average 
Acid phosphate 
No fertilizer 
Sulphate of ammonia 
Nitrate of soda 
Cottonseed meal 
Dried blood 
Sulphate of potash 
Acid phosphate 
Sulphate of ammonia 
Acid phosphate ,. 
Sulphate of potash 
No fertilizer 
Sulphate of ammonia 
Sulphate of potash 
Acid phosphate 
Sulphate of ammonia 
Sulphate of potash 
Limestone 
Do 
Do 
Do 
Acid phosphate 
Sulphate of ammonia _ 
Sulphate of potash 
No fertilizer 
Manure, horse 
Biloxi soybean plowed under after beans 
were harvested 
350 
100 
350 
100 
350 
100 
100 
100 
350 
100 
100 
2,000 
4,000 
6,000 
4,000 
350 
100 
100 
2,000 
790 
2,000 
1,780 
1,800 
1,980 
2,130 
1,850 
620 
800 
1,760 
1,780 
510 
1,850 
1,955 
1,805 
1,315 
1,515 
1,585 
2,340 
1,710 
1,420 
1,390 
1,390 
1,250 
1.515 
1,725 
1,720 
1,610 
1,645 
2,000 
1,825 
1,515 
1,410 
1,275 
1,570 
1,785 
545 
1,375 
1,200 
1,160 
1,050 
1,315 
1,485 
1,095 
1,215 
1,540 
815 
1,680 
1,675 
1,330 
1,585 
1,490 
1,605 
2,320 
1,605 
1,590 
1,370 
1,370 
1,590 
1,555 
1,605 
1,380 
1,400 
1,370 
1,660 
1,845 
1,495 
1,340 
1,205 
1,320 
1,440 
2,325 
1,050 
1,150 
1,020 
900 
1,170 
1,205 
1,125 
1,140 
1,230 
1,170 
1,020 
910 
490 
1,070 
1,170 
1,280 
1,860 
1,140 
1,507 
1,352 
1,324 
1,408 
1,544 
1,558 
1,149 
1,208 
1,394 
1,642 
1,233 
1,512 
1,458 
1,158 
1,413 
1,539 
2,353 
It is evident from the yields shown in Table 13 that dried blood 
may be advantageously applied as a source of nitrogen for rice when 
a legume is not used to supply this plant food. The dried blood used 
in these experiments contained on an average 16 per cent of nitrogen. 
A larger quantity of dried blood probably would not increase the 
yield appreciably and might stimulate the growth of the plant to 
such an extent as to cause lodging. 
