THE SUGAR-CANE MOTH BORER. 59 



injure the ratoons, and at the same time to hasten decomposition of the trash. 

 The last object can be best attained by covering the tops with two furrows by 

 the turning plow, before the green material has dried out. If the labor and 

 teams are not available at the time, it is next best to do the plowing when the 

 tops are as wet as can be handled without danger of damaging the mechanical 

 condition of the soil. We find that two furrows, run as far away as possible 

 from the old ratoon, and at the same time just deep enough to cover the trash 

 lightly, are satisfactory. This practice practically allows all trash to be held 

 continuously in a moist condition with free access to air, thereby hastening 

 oxidation and decomposition. The partially decomposed vegetable matter is 

 thoroughly and deeply buried at the usual time in early spring when cane is 

 off-barred. Under average conditions of tonnage and winter rainfall we have 

 found that cane trash treated according to this method will decompose suffi- 

 ciently to allow cultivation of the middles without undue cost or inconvenience. 

 However, when a heavy crop of tops has been turned under considerable difficulty 

 may be experienced in throwing out the middles, unless the job is undertaken 

 in two operations. First, whatever implement is assigned to this task should 

 be run in such manner as to skim over the main layer of trash ; the second 

 furrow can then go deep enough to undermine any trash which has not been 

 decomposed, and divide it along the side of the two rows where the following 

 cultivation, preferably with a disc cultivator, will completely mix all this 

 organic matter, with its humus and nitrogen, into the seed bed. 



Practically the same method is used on the large plantations where 

 the trash was left in 1916 and 1917. The labor of the first cultiva- 

 tion was said by one plantation manager to be about doubled and 

 to cost about $1 more per acre than cultivation after burning. A 

 plantation owner estimates an additional cost of $1.50 per acre. 

 This is a very small amount to spend for the possible control of the 

 moth borer, and is slight as compared with a maximum loss of 

 nearly $50 per acre. Stubbs (151) calculates that for every ton of 

 cane there are left in the trash 1.9 pounds of nitrogen, equal to the 

 nitrogen in 27 pounds of cottonseed meal, while Mr. Taggart has 

 told the writers that there are 556 pounds of organic matter in the 

 trash per ton of cane. All this nitrogen and organic matter is lost 

 in the burning of the trash, but preserved when it is buried. Con- 

 sidering the chemical and mechanical benefit to the soil, the possible 

 insect control really costs nothing at all. 



On the subject of nonburning, Prof. F. S. Earle (46), formerly 

 director of the Cuba Experiment Station, writes as follows in the 

 Cuba Magazine : 



To the general burning of the trash in the fields after cutting there are, how- 

 ever, many valid objections under conditions existing in Cuba and Porto Rico. 

 On many soils this trash is badly needed to keep up the supply of humus, but 

 more particularly it is needed as a mulch to protect the soil from excessive 

 drying out during our long periods of winter drought. Aside from this, the 

 universal burning of the trash would involve an amount of summer cultivation 

 to keep down weeds and grass that would be entirely beyond the present equip- 

 ment and labor supply of most of our plantations. In other words, it is im- 

 practicable. The best we can hope in the direction of ratoon cultivation is to 

 move the trash and cultivate alternate middles. Nor is there any reason to sup- 



