292 



THE AGRICULTURAL NEWS. 



Septembek is, 1909. 



WEST INDIAN FRUIT. 



A COFFEE DISEASE IN DOMINICA. 



Some berries of the Arabian coffee {C'offca iiralilca) 

 which had been attacked by a fungus, StlUieUa 

 flavida, were lately received from Dominica. This 

 fungus causes brown, hardened and sunken areas on 

 the berries, which are slightly greyish in the centre, 

 and bear small, yellow, transparent pin-shaped fructifi- 

 cations scattered over their surface. The fungus also 

 attacks the leaves and twigs. 



Serious damage luis been caused in ^Mexico and several 

 of the South American States by this fungu.s, and it is also 

 reported from Trinidad and .Jamaica. 



The following preventive measures have been found 

 useful in keeping the disease in check : — 



(1) Removal of all infected portions of the cotfee plants, 

 and subsequently burning them, or burying them with lime. 



(2) Spraying tlie plants thoroughly with moderately 

 strong Bordeaux mixture, as the fungus is a .superficial 

 parasite. 



(3) Careful attention to tillage, clean weeding, and 

 manuring with lime from time to time, in addition to the 

 usual manures, as well as care that the attack of the fungus 

 is not aided by the provision of too much shade. 



Further, a careful examination of all the plants in the 

 neighbourhood is necessary, as the fungus can attack many 

 other Icinds of plants, including grasses, shrubs and trees. 

 All infected plants of this nature should be cut down and 

 burnt, after which their ashes may be used as manure. 



to perfection. It is generally considered among Trinidad 

 planters that a loose clay, or clay with an admixture of 

 a fair proportion of sand and lime i.s favourable to the 

 growth of cacao. If the soil is covered with a vegetable 

 deposit, humus, which has accunmlated from the falling 

 leaves and branches of the original forest, so much the 

 better. If land can be found on the banks of a stream or 

 river where there is considerable depth of alluvial deposit, 

 such a position, if capable of being well drained, is a sure 

 source of wealth to the cacao planter. Hard, dry, rocky 

 soils, stiff clays, mountain sides where great detrition 

 frequently takes place, shallow sands and boggy ground 

 should be carefully avoided. 'J'he aspect of the land should 

 always be carefully, considered. A site exposed to trade or 

 })revailing winds, or to strong sea-breezes, should not on any 

 account be chosen for a cacao plantation. Land which has 

 been i)reviously cultivated with other crops may be chosen 

 when it has good depth, is easily drained, and is capable of 

 being improved by the application of suitable manure.s, but 

 ' thro\\'n out ', ' ruinate ', or abandoned lands should be taken 

 up with the greatest caution. ^\'orn out sugar lands are 

 dangerous investments for the intending cacao planter as 

 a rule, but an intelligent choice even here, by men who are 

 acquainted with the local character of the soil and the cacao 

 tree and its requirements, will often result in the develop- 

 ment of a productive plantation. Salt is inimical to the 

 growth of the cacao tree, and lands liable to be inundated 

 with tidal waters should never be purchased. 



SOILS FOR CACAO. 



Information in regard to the best soils for cacao is 

 given in the third of a series of articles on cacao by 

 Mr. J. H. Hart, F.LS.,- which are appearing in the 

 West India Oiiinmliicc Cireidar. Reference to those 

 articles has already been ma(h! in the Agricidtnn'J. 

 News, Vol. VIII, p. 2m. 



The soil chosen should be one, as ^V right puts it, 

 ' having good jihysical and chemical |>roperties ', and he agrees 

 with .Jumelle in pointing out that ' the best cacao soils are 

 those which have been uncultivated for many years or not at 

 all, and that abundance of hunuis, 1 to 2 per cent, of lime, 

 0'2.") i)er cent, of phos])horic a('id,as well as abundant sujiplies 

 of other ingredient.s, are necessary before one can lio[)e to 

 obtain the best results '. A shallow soil resting upon hard 

 bed-rock is totally unsuitable, while a moderately shallow 

 soil resting upon a friable rock is often found to grow cacao 



The Black Rot of Cacao Pods. 



This disease, which is due to a fungus, I'liytophthora 

 'iiiinli'ora, is dealt with in Pamphlet No. 54 of the Depart- 

 ment, entitled Finifiua Disi'nxex of Cacao and Sanitation of 

 (Jiicao Ori-/iards, pp. .3-t-(5. According to the Bulletin de la 

 Soi'i('lr Hoi/dle de Jhtanique de Jjel;/ii/nr, \o\. Xh\, Fasc. 3, 

 this fungus has recently been found to attack the fruits of 

 pear trees in Belgium. 



The attacked pears show a rounded, brown spot, on the 

 part which is most exposed to the light. This spot increases 

 in size until it soon covers the greater part of the fruit, 

 which then falls. Such fruits after .some time become full of 

 spores, by means of which the fungus is disseminated. The 

 damage was serious ; half ot the fruits of the tree on which 

 it was found were 'destroyed, especially those on the lower 

 l)ranches, Xevertheless, pears which had been bagged did 

 not sutler at all. 



The remedies suggested are the destruction of diseased 

 fruits and preventive treatment, by means of Bordeaux 

 mixture, in the spring. 



