222 



THE AGRICULTURAL NEWS. 



July 4, 19U. 



FUNGUS NOTES. 



COCO-NUT ROT IN MEXICO. 



Under the heading Fungus Notes in the issue of this 

 jouioal dated July 20, 1912 (Vol. XI, No. 267) page 238, 

 ap[.iei>ied a repiint from the Review oj Tropical Ac/rirulture, 

 Yol. II, No. 4, pp. 295-6 of an article on 'A Coco-nut Disease 

 in Mexico', by Kunar Olssen-Seffer, described as Editor of 

 T,he Iteview and late Chief of the Botanical Section of the 

 Department of Agriculture. Mexico. The article as it appears 

 in the Agricidtw-al JVors is a reprint of the article in 

 the Neriev.' of Tropical Agriculture save for a paragraph 

 and a half of introductory generalities and the concluding 

 seritence of the article reproduced. The latter expresses the 

 author's intention of putting forward the results of further 

 investigation in a later issue. 



AVe are indebted to Mr. S. F. Ashby, Microbiologist on 

 the staff of the Jamaica Agricultural Department, for calling 

 our attention to the real nature of this production. With 

 the exception of the unreproduced matter above-mentioned, 

 the .source of which has not yet been traced, the article is 

 compounded of ingeniously blended extracts from accounts 

 of (a) Pytkiam pialmivorum in India and (b) Bud rot in 

 the West Indies, both reprinted in Fergusson's Coco-nut 

 Planters' Manual (Ith Edition 1907, Appendix, pp. 52- 4) from 

 a supplement or supplements to the Tropical Agrundturist. 



The original sources of the information are (a) a special 

 report to the Madras Government by Dr. E. J. Butler, 

 Imperial Mycologist of the Agricultural Department of 

 •jf India, and (b) a letter from Mr. L. A. Wates, at that time 

 a planter in Jamaica, to the Secretary of the Jamaica 

 Agricultural Society. 



Written in the first person singular, the article is put 

 forward by Olssen-Seffer without the slightest acknowledg- 

 ment, and without verbal alteration save for the omission 

 of a word or two and the .substitution of 'Eastern Coast' 

 (,of Mexico) for 'Southern India'. 



Apart from this article, which is obviously worthless 

 as evidence, there appears to be no record of the occurrence 

 of the fungus in question in the Western Hemisphere. 



DECAY OF PINE- APPLES. 



In continuation of the notes published on page 190 

 dealing with Thielaviopsis paradoxo. as the cause of base 

 rot of pine-apple plants, it may be well to summarize here 

 the available information respecting another disease, the 

 principal of all pine-apple troubles, which is connected with 

 the same fungus 



It should oe first noted that there is considerable con- 

 fusion in the use of popular names applied to pine-apple 

 diseases. So far as the West Indies are concerned it is 

 necessary to di .;inguish clearly between two type.^ of disease 

 affecting the fruit. The one is an affection of growing 

 piue-apples, visible only when the fruit is cut, and indicated 

 by dark-brown spots or streaks extending some distance 

 inward from the base of one or more of the eyes. This has 

 been most commonly designated 'black heart' by writers in 

 :;be West Indies, and it has been suggested, but not proved, 

 tihat it is due to a species of Penicillium. A disease very 

 similar in appearance occurs in Hawaii. It is described 

 "lader the name of brown rot by L. D Larsen, and is 

 regarded by him, on experimental evidence, as most com- 

 monly due to a sjiecies of Fusarium. 



The other type of disease is of the nature of a storage 

 rot, though it also occurs to some extent in the field, and is 

 due to Thielaciopsis paradaxa. It is of very general 

 occurrence. Frequently the fungus enters through the cut 

 end of the stem and passes with great rapidity up through 

 the core. Its subsequent spread through the softer tissues 

 produces a distinct water-soaked appearance. Later the 

 affected tissues turn black owing to the profuse formation 

 of spores. Wounds or bruises in any situation afford easy 

 means of access for the fungus, and Larsen and others have 

 shown that in a moist atmosphere it is capable of penetrat- 

 ing the fruit surface without the help of wounds of any 

 kind. 



The measures to be adopted for the prevention of this 

 tiouble are largely matters of handling and packing, arising 

 principally in connexion with export; though it must be 

 remembered that the fungus develops so rapidly in a tropical 

 climate that fruit intended for local consumption is liable 

 to be quickly spoiled. 



In dealing with the fruit it should be taken for granted 

 — it is indeed usually a fact — that the spores of the fungus 

 are present on the fruit and only await suitable conditions for 

 their development. These conditions are supplied by the 

 presence of a certain degree of heat, and moisture. Unless 

 the fruit is artificially cooled the former may be taken as in 

 all cases sufficient, and it is on the control of the latter that 

 success \'. ill depend. The requisite moisture may be supplied 

 by the juices of the fruit on cut or bruised surfaces, or by 

 the water given off by the fruit accumulating either on the 

 packing material or in surrounding air enclosed or allowed to 

 remain still. 



It folloA\s that the pine-apples must throughout be 

 handled with the greatest care to avoid bruising or scratch- 

 ing. They must not be broken off from the stem, but cut 

 with a stalk 3 or 4 inches long, which itself must not be 

 stripped. It would probably be of advantage to cut off 

 an inch of the stalk when the fruit is brought in from the 

 field and then sear the freshly cut end or dip it in melted 

 adhesive wax. The fruit should be laid out for twenty-four 

 hours to cool and dry before packing. It is obvious that the 

 method of packing should be such as to prevent contact 

 between, or movement of, the fruit, while permitting free 

 circulation of air, and that storage and stowage should be in 

 well-ventilated places. 



J. E. Higgins in Hawaii, and Vera H. Charles in Wash- 

 ington have experimented with the use of formaldehyde gas 

 for fumigating pine-apples previous to storage, the object 

 being to kill the spores adhei ing to the outside of the fruit. 

 Both report very considerable improvement in the keeping 

 qualities of fruit so treated. 



The fumigation is carried out in an air-tight chamber; 

 the gas is liberated by the action of permanganate of potash 

 on commercial (40 per cent.) formalin. Two and a quarter 

 imperial pints (4-5 fluid oz.) of formalin must be used for 

 each thousand cubic feet of space, and for each pint of 

 formalin 10 oz. of permanganate crystals are required. 

 A large receptacle must be used for the mixture, as very 

 considerable foaming takes place: an 8 quart tin pail may 

 be used for a quantity of about 2 pints. The permanga- 

 nate is placed in the pail, the formalin poured upon it, 

 and the door of the chamber quickly closed. Exposures of 

 thirty minutes O'- more are effective. The fumes are des- 

 tructive to iron. 



