THE RICE WATER-WEEVIL. 



17 



speedily overcome owing to flooding rains. The crop eventually 

 produced an excellent yield. 



USE OF FERTILIZERS AND APPLICATION OF LIME. 



In an experiment to determine whether the use of fertilizers and 

 application of lime would serve as a check on weevil infestation, plats 

 for growing rice were prepared at Crowley, La., as shown by the 

 accompanying diagram, which also gives the results of examinations 

 on July 8. The whole field was flooded equally to an average depth 

 of 6 inches. The arrangement and treatment of the plats and status 

 of infestation are outlined as follows: 



Unlimed. 



Limed, 2,000 

 pounds per 

 Unlimed. acre. 



Checks. 



Acid phosphate, 400 pounds, 16 per 

 cent, per acre 1 



Acid phosphate as above plus muriate 

 of potash, 50 pounds per acre 



5 larvae per 25 stalks. 



larva- per '.'5 stalks. 



1 1 larvae per 25 stalks. 



1 larva. 



G larvae. 



9 larvae. 



11 lame. 



Total proportionate number of larvae : 



For the check plat 17, or 22§ per cent infestation. 



For the phosphate plat 19, or 25£ per cent infestation. 



For the phosphate and potash plat 30, or 40 per cent infestation. 



Calculating another way from the foregoing outline, the limed 

 areas were found to have 24 larva? compared with 1G larvae in the 

 unlimed areas of the same plat, while in the opposite plat 26 larva? 

 were taken on the roots of the same number of stalks. 



No advantage in reducing or retarding infestation appeared to be 

 shown through the application of fertilizers or lime to the soil, but 

 rather the contrary effects are indicated, as the strip with double 

 fertilization contained the most larva?. Since the plant growth had 

 responded in proportion to the degree of fertilization, the stimulated 

 plants exhibited no signs of injury resulting in yellow appearance of 

 leaves except in the limed areas, which as a whole included the 

 poorest growth on account of the severer pruning of the small root 

 systems. 



Further observations made at Midland, La., have led to the con- 

 clusion that fertilization does not prevent nor even hinder the pro- 

 pagation of larva 1 , but the extra nourishment may assist the plants 

 to overcome attacks. 



