110 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



insects, and is frank in saying that the extent to which this subject 

 lias been ignored under Texas conditions is regrettable. And, al- 

 though this problem of enabling the cotton leaf-worm, whenever pos- 

 sible, to become an ally in boll weevil destruction is almost unimpor- 

 tant when compared with the value of many predaceous and parasitic 

 species affecting other insect pests, it should be made clear to the 

 farmer that if judiciously managed he may enable the leaf -worm to 

 help him combat the boll weevil by allowing it full liberty in the 

 cotton plantation during September and October. It is evident that 

 Avhere the caterpillars are not destro} r ed in late fall they will pupate 

 and many more will successfully pass the winter. With the fall 

 destruction of stalks, however, and a thorough cleaning of the fields, 

 this obstacle could be removed. 



WHAT IS MEANT BY THOROUGH CULTIVATION. 



Frequently we are asked what is meant by thorough cultivation in 

 the cultural system of the Bureau of Entomology. Attempts have 

 been made to give as specific answers as possible, but we soon found 

 that this would become a very intricate procedure on account of the 

 varying conditions in different sections. Some seasons we must cul- 

 tivate often ; others less frequently. Again, cultivation varies with 

 localities and soils. 



The two principal results to be obtained by thorough cultivation 

 are (1) a mulch; (2) the keeping down of weeds. When a crop of 

 weeds has gained the advantage over the farmer's industry on account 

 of a prolonged wet season, it is for the farmer to conclude what kind 

 of cultivation he shall give the field to remove this stand of weeds. 

 When this is accomplished, all his attention should be given to the 

 maintenance of a mulch between the cotton rows. In bottom cotton, 

 where moisture is abundant and heavy rains may occur during the 

 growing season, the cultivation with a shovel plow may sometimes 

 be best, as it serves as a drainage system. On Upland cotton, how- 

 ever, the problem is entirely different, and when the drought begins 

 the cotton will suffer least in the well-mulched field. Thus by thor- 

 ough cultivation we mean the maintenance of a surface layer of soil 

 cultivated with sufficient frequency so as to form a blanket of dry 

 soil at the surface. This will retard the evaporation of moisture. 

 This blanket of dry soil must be the criterion for the intelligent 

 farmer to judge how many cultivations he should give his cotton. 

 This loose surface soil may be affected by light showers of rain. The 

 crust which is then formed at the surface will destroy the mulching 

 power of the soil blanket, and cultivation should therefore follow at 

 once. 



