140 



apple are snch that they afford a suitable food for the fungus 

 to grow in. Not perhaps the best of food, but, at any rate, 

 such that the fungus can live. Now, if that is the case, it *s 

 evident that any top planted out in an infested field stands a 

 chance of contracting the disease. In just such proportion as 

 its tissues are suitable food for the fugus, in that proportion 

 it will be liable to become diseased if it is exposed to the 

 fungus. Ill is sJiozi's honh important it is to keep the soil of the 

 pineapple plantation as free as possible from this fungus. 



It will be noted that the iungus does not penetrate beyond a 

 certain distance into the top. From this it is evident that at 

 a certain point the tissues become less suitable to the fungus 

 than they are lower down. From this we may correctly argue 

 that, when planting, the removal of the tissues from the 

 lower part of the pineapple top is a wise precaution, as the 

 lowermost tissues of the new plant will then for some time 

 oft'er some resistance to the attacks of the fungus should it be 

 present in the soil. 



THIELAVIOPSIS AND BORDEAUX MIXTURE. 



Experiment has shown that cane cuttings can be protected 

 from the bad effects of pineapple fungus, that is Thielaviopsis, 

 for weeks, or, it may be, months, in some cases, by the appli- 

 cation to their ends of fungicides such as Bordeaux mixture 

 or tar. The facts of the case are presented in Bulletin No. 5 

 of the Hawaiian Sugar Planters' Association, Division of 

 Pathology and Physiology, to which the reader is referred 



Field inoculation showed the power of the Thielaviopsis of 

 the pineapple to infect cane cuttings, so that there is no prob- 

 ability that the two sorts of Thielaviopsis, that is, that from the 

 pineapple and tliat from the cane, are two different races. 

 They are one and the same, and hence it follows that in all 

 ])robability the experiments carried out at the Planters' Ex- 

 periment Station are directly applicable to the pineapple. This 

 means that the rot can be prevented from entering the pine- 

 apple "set" for some time by simply smearing the cut end with 

 Bordeaux mJxture or tar. It is probable that in time, even if 

 not at present, this is an operation that will pay well, for the 

 reason that it will enable the "set" to establish itself to better 

 advantage. The pineapple tops need not be dipped — only 

 smeared at the cut end. 



