302 



THE AGRICULTURAL NEWS. 



September 21, 191fe. 



PLANT DISEASES. 



COCO-NUT BUD-ROT. 



In the last number of this Journal, in giving an account 

 c( the type of bud-rot commencing in the heart of the tree, 

 now suspected to be comparable with the fungoid bud rot of 

 the East, brief allusion was made to the alternative type of 

 disease occurring on the outer limbs or fruit-stalks. To 

 complete the account of bud-rot as at present understood, 

 some particulars will now be given, also druwn in the main 

 from the .Tamaica descriptions of this form. The affection 

 is believed on good grounds to be of bacterial origin, but the 

 characters of the particular species, believed to be causative 

 by different workers, exhibit somewhat wide diversity. 



The attack may begin eithei on the bases of the leaves 

 or flower spikes, or the tissues between them. It never 

 extends far on the leaf-stalk, nor does it affect the woody part 

 of the stem. 



When infection is of this nature, the first sign is commonly 

 the falling of unripe nuts owing to the infestation of the base 

 of the fruit stalk. The dropping of young nuts is not in 

 itself evidence of bud-rot. It occurs quite commonly when 

 trees are suffering from drought, water-;logging, or any cause 

 which affects the ability of the tree to nourish the full number 

 of fruits set. Injury to the base of the spike, such as may be 

 caused by insects or by careless picking, vill also cause 

 dropping. 



Another early sign of the disease is the discoloration 

 of the flowering spikes, which turn chocolate-brown, and 

 eventually blacken and wither. Investigation at this time 

 reveals a dark-coloured wet rot about the base of the affected 

 parts. The rot works its way through or under the moist 

 strainer, affecting the various organs as it reaches their points 

 of atuchrnent. Water-soaked areas appear on the leaf stalks, 

 and as the rot progresses the leaves involved turn yellow and 

 hang down. Eventually, though it may be the work of 

 months, the rot reaches to the central column, and the tree is 

 killed. 



The usual method by which treatment is attempted to 

 arrest the development of this disease in an infected tree, is 

 the firing of the dry matter in the top, using kerosene if 

 necessary to start a blaze. It is said to be a good 

 plan after firing to spray the whole top with Bordeaux mix- 

 ture, adding 2 B). of lead arsenate to each .50 gallons 

 of spray, iu order to prevent weevil damage to the scorched 

 ti'.-^ues. 



W.N 



At various times writers on the subject have classed the- 

 manaca and coquito as the Attalea cohioie, but a very cursory 

 examination of the habits and fruits of these trees shows 

 such differences that the writers are inclined to consider 

 them of a different species rather than simply a variant of 

 the same species. 



THE COHUNK NUT. 



A NEW SOURCE OF VEGETABLE OIL. 



fe. H. (^arsons and K. K. Heron have described in the 

 Oil, Paint, and Drug Repnrhr, for March Is. whit they 

 designate 'a new ;<ource of vegetable oil close to I nited State;. 

 ports.' The following interesting information concerning this 

 b abstracted from a summary appearing in the Pirfumen and 

 E!.f<n/ia/ Oil Pe,ord, July 23, 191.>. 



The suddenly increased demand. for vegetable oils 

 ha> drawn attention to the immense forests of oi'.-seed 

 tearing palms in Central and South America. For over 

 fifty years the fruits of several of the nut-bearing palms 

 have been exploited a.s a source of oil in a sporadic and 

 desultory manner. Chief among these are the Atl.ti.a cohun,:, 

 of Hritisli Honduras, the manaca and coyol of Guatemala 

 »nd Spanish Monflivrus. and the coquito of Southern Mexico 



The Attalea cohune of British Honduras, and the neigh- 

 bouring territory of Yucatan on the north and (Guatemala on 

 the south, does not entirely confine itself to the coast lands, 

 but it is seldom found at a greater altitude than a very few 

 feet above sea-level. The tree grows in dense clumps, 

 usually following along the slight ridges which mark the 

 ancient beach lines. 



The cohune, coquito, and manaca trees are very similar 

 in general appearance. The first two have a smoth, greyish 

 trunk, paler where the trunk is exposed to direct sunlight. 

 The manaca. has a somewhat more persistently clinging leaf- 

 stalk. Very often the entire trunk of mature trees is hidden 

 by the dead stalks. The coyol differs considerably in its 

 appearance, both in leaf and trunk. The trunk of this tree 

 seldom, if ever, is found clean and smooth. 



While the cohune. manaca, and coquito leaves are [jer- 

 fectly regular, having equal and opposite leaflets, the coyol is 

 easily distinguished by its somewhat more ragged and irregu- 

 lar leaf, the leaflets being uneiiual, and irregularly plated on 

 opposite sides of the midrib. The fruit of the coyol is 

 smaller and less elongated, being almost round. It is borne 

 in bunches of from 30 to 50 ft), each. Underneath a thin 

 outer husk which covers each nut is found a sweet, oily pulp, 

 somewhat prized by the natives as an edible fruit. 



Fruit of Manaca. — ^The fruit of the manaca is borne in 

 bunches similar to those of the coyol, though usually large in 

 size. These bunches will average from -50 to 60 ft), each, and 

 in some cases will weigh as high as 100 B). The individual 

 fruits are elongated, measuring from 1 '\ to 2 inches in length,, 

 and about 1 inch through the short diameter. The pericarp 

 of this nut, which is very thin and fragile, is underlaid by a 

 pulp considerably thicker and much softer than is the case 

 with the coyol. Considerable oil is contained iu the pericarp 

 and in the pulp. The oil extracted from this pulp approxi- 

 mates very closely the African paint oil of commerce. 



The coquito and cohune have considerably less of the 

 fleshy pulp surrounding the shell of the nut, but both of these 

 nuts contain a fair percentage of oil in the husk. Extract- 

 able oil to the amount 1 5 per cent, by weight has been found 

 in both cases. On account of the bulk, and the tough 

 fibrous nature of the outer layer of these nuts, there would 

 be some difficulty in extracting the oil except by 

 solvents. Certain experiments are being made, however, 

 which promise an inexpensive method of recovering this oil. 



The present value of the palm nuts !.■< in the kernels. 

 Of the Attalea cvliinc, the kernel is from .'-' li to l.'V.'i pet cent, 

 of the total weight of the dried nut. The usual number of 

 kernels is one to each nut. I'robably ."iO per c-eut of the 

 nuts contain two and sometimes three kernel-. 



From it comparativejjinalysis of coco-nut oil and cohune 

 oil, it api)ears that, physically both oils have the same colour 

 and apparent solidity. The faint odour of the unbleached 

 cohune kernel oil greatly resembles that of oil from coco-nuts. 

 Almost no odour can be noted after treatment with animal 

 charcoal. Unless care is taken in the preparation of the oil, 

 especially oil prepared in warm climates, a tendency to 

 rancidity is noticed. This, however, is avoided by the 

 experienced manufacturers. 



The greater part of ,the kernel-- are extracted by the 

 natives. An industrious native gathers about one half ton 



