THE BOLL-WEEVIL PROBLEIM 27 



certainly prevent the maturity of the hiter fruit and, moreover, will 

 be forced to attack bolls which otherwise would not be injured. 



Effect of late cultivation. — There are many conspicuous illustrations 

 of the disastrous effects of careless late cultivation. One of these 

 occurred in Louisiana, where some planters in the Red River Valley 

 below Shreveport were making fair crops (in one case 600 bales 

 on 900 acres), while others were making very small yields, as, for 

 instance, m one case 200 bales on 800 acres. Upon investigation it 

 was found that all the planters in the neighborhood were compelled 

 to put all their hands on levee work for five weeks to save their 

 places. During that time the cotton remained uncultivated. After 

 the subsidence of the flood the fields were plowed. Where this work 

 was done carefully, good crops were being produced. In cases where 

 the plows were run too deeply and too close to the plants excessive 

 sheddmg had taken place, and the weevils prevented the putting on 

 of any more fruit. Careful investigation on several places where the 

 essential conditions were identical left no doubt that the cause of the 

 difference in yields was primarily the difference in summer cultivation. 



Occasionally a farmer is found who has obtained better yields on 

 fields where cultivation has been discontinued early. In fact, the 

 writer has seen fields full of grass that were outyielding perfectly 

 clean ones on the same plantation. Such situations have caused 

 erroneous conclusions. As a matter of fact, the explanation is that 

 the late, careless cultivations had done more harm than good. The 

 importance of careful shallow summer cultivations can not be too 

 strongly emphasized. 



SPECIAL DEVICES FOR DESTROYING WEEVILS. 



The use of an arm oi projection that wiU agitate the cotton plants 

 has been suggested frequently. It was assumed that the knocking 

 of the squares to the ground earlier than they would fall naturally 

 would mcrease the effect of heat in destroying the immature stages 

 of the weevil. It has been ascertained, however, that throughout 

 much of the territory occupied by the weevil the destruction of the 

 stages in hangmg squares is much greater than in those that fall to 

 the ground. For this reason it is evident that the best practice is to 

 allow the squares to hang on the plants as long as they will. In 

 addition to the effect of heat on the immature stages it is important 

 to note that the attack of parasites is much greater m the case of 

 hanging squares. On these accounts our advice is that cross arms 

 or projections on cultivators should not be used except in central 

 and western Texas, where the dryness of the climate brings about a 

 very heavy mortality in fallen squares. In eastern Texas, Arkansas, 

 Louisiana, Mississippi, and Alabama the mortaUty is greater in the 

 hanging squares, and the planter who causes these sc^uares to fall 

 early merely assists the weevil. 



