Trametes nivosa (Berk) ]\riirrill. — La Romana, Higiiral. 

 Tuhcrcnlaria fsarcharicola Speg. — Santo Domingo City. 



CONTROL OF CANE FUNGI. 



It is impracticable, in fact impossible, to entirely eliminate fungi 

 from the cane fields. It is, rather, the aim of the good agriculturist, 

 to produce as vigorous cane as possible and so reduce the fungi to 

 a minimum. There are very few cane diseases that will not yield to 

 proper agricultural methods combined with certain principles of con- 

 trol to be outlined here. 



Space will not permit a consideration of the various points in- 

 cluded under "proper agricultural methods," such as good drainage, 

 irrigation when necessary, selection of seed, proper planting and cul- 

 tivating. They are fully covered in other publications of this Station. 



Among the control principles may be mentioned the following, a 

 brief exposition of each being given. 



1. Healthy seed only should be used for planting, since normal 

 cane can hardly be expected from diseased seed. This means that 

 all seed should undergo a careful selection to eliminate any that show 

 borer or other insect injury, tlic presence of the mycelium of Odontia 

 or other fungi, internal discolorations or rot due to Melanconiuni, Col- 

 letofrichum, Diplodia, or other cane-destroying agent. Seed selection 

 should be carried out in the field where the cane is cut and not where 

 it is to be planted. 



2. Certain varieties of cane are more resistent to a given disease 

 or diseases than others. An efifort should be made to discover these 

 liy comparative tests and to use those that give the best results. The 

 root disease often yields to a change in variety as do other diseases. 

 Care should be exercised not to mix different varieties in the same 

 field. 



3. Certain diseases, particularly TJtielaviopsis, are prevented by 

 disinfection of the seed or by providing a protective covering. Bor- 

 deaux mixture is the only practicable substance for this purpose 

 and gives good results where conditions are not favorable for quick 

 germination or where the seed can not be planted at once. 



4. Various oilier plants which harbor cane fungi should not be 

 grown in rotation with cane or in the case of weeds they sliould be 

 kept down as tlioroughly as possible. This will apply especiall.y to 

 pineapples, wliicli are very suljject to Thielaviopsis and to various 

 grasses attacked by Odontia, some of them of econonuc value. Per- 

 mitting the land to revert to pasture after the cane is abandoned does 

 not serve to kill out tliose fungi that attaclc the cane i-oots. It will 



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