FIELD CROP INSECTS 265 



possible with safety from frost. A liberal use of commercial 

 fertilizers will hasten maturity. Only early maturing varie- 

 ties should be planted, and selected seed of open-growing 

 sorts is to be preferred. Chop out the plants as soon as 

 possible. Frequent light cultivation should be given so as 

 to keep the soil well stirred. Deep plowing and cultivating 

 close to the rows should be avoided, as it causes the dropping 

 of the squares. 



When infested squares fall to the ground and lie on the 

 unshaded hot soil the larvae or pupae within them are soon 

 killed by the heat. As many as 40 per cent have been 

 found killed in some fields. The rows should, therefore, be 

 planted fairly wide apart, and varieties producing a mini- 

 mum of shade are preferable, as are those which readily 

 shed their squares when injured. As most of the squares 

 drop beneath the plants where they are shaded, any means 

 of scraping them into the centers of the rows will aid in their 

 destruction. For this purpose a chain cultivator as de- 

 scribed by Hunter (I. c.) (Fig. 187), has proven very effi- 

 cient for this purpose. The chains may be attached to 

 ordinary cultivators by special attachments. An arm or 

 projection that will brush the plant should be attached to 

 whatever cultivator is used so that the squares will be 

 knocked to the ground, as the effect of the heat is greater 

 the earlier the squares drop. 



