148 



THE AGRICULTURAL NEWS. 



May 13, 1911. 



FRUITS AND FRUIT TREES. 



OAOAO CULTIVATION AND SHADING IN 



TRINIDAD. 



It is well known that, in Trinidad as well a^ in other 

 parts of the West Indies, there is much interest in the question 

 of providing shade in cacao plantations. In order to gain 

 definite information on the subject, the Agricultural Society 

 of Trinidad and Tobago recently appointed a committee to 

 make observations on the Mont Valniont estate, and to pre- 

 sent the results of these to the Society. This has been done, 

 and the report of the committee appeared in the Port-of- 

 Spain Gazette for March 12, 1911. 



Observations showed that the gradual removal of shade 

 from cacao has been completely successful, as far as this estate 

 is concerned; the plants have fruited heavily, and present 

 a very healthy appearance, with a marked absence of squirrels, 

 insect pests and other p.arasito.^. There are, however, special 

 circumstances to be considered in regard to the good effects 

 that have accrued from the gradual removal of the shade; the 

 chief among these is the circum.stance that, although the trees 

 are fully exposed to the sun, the estate is sheltered from the 

 wind through its situation, and this favourable condition is 

 assisted by the fact that the plants have been well manured 

 with pen manure and bone meal. If the cacao had been still 

 shaded by the immortcl, it is certain tliat the shade plants 

 would have absorbed a large proportion of the manure. 



Although a large measure of .success has followed the 

 gradual removal of shade on this estate, the committee 

 recommends caution in the matter of adopting this policy. 

 Special attention must be given to the extent to which an 

 estate is exposed to tlie wand; there must be reasonable 

 provision of material for mulching, and of the labour 

 required in connexion with this; the soil must either be light 

 so that it already drains easily, or where it is heavy, there 

 must be very thorough draining for the removal of the water 

 which would be otherwise transpired by the immortel trees. 

 It is the opinion of the committee that the untoward 

 effects of overhead shade have arisen in the past thnnigh the 

 employment of e.vcess of this; so that plant food has been 

 removed from the soil to an unreasonable extent, by the 

 immortel trees. Further, cacao plants have been nmtilated 

 in order to admit light and air during the wet season, and in 

 consequence of these conditions, black pod and other diseases 

 have been very prevalent in all low lying localities, at certain 

 seasons. 



The final recommendation of the committee is that the 

 immortel .'-hould be phmted as usual on new cacao estates, 

 and that after a few years, before they become likely to do 

 damage in falling, the .shade trees should be thinned out or 

 removed entirely, according to the situation of the estate, the 

 kind of soil, and the other circumstances that are mentioned 

 particularly, above. 



METHODS OF DEPOLLINATING 

 FLOWERS. 



Bulletin Xo. 167 of theJiureau of Plant Industry of the 

 United States Department of Agriculture has been issued 

 under the title Xew Methods of Plant Breeding. The 

 publication does not, however, describe strictly any new 

 methods that might be employed for the breeding of plants, 

 but rather suggests useful practical variations in connexion 

 with tliose that are in common euipioyraent. 



The chief part of the information contained in the 

 Bulletin has more particular reference to methods for facili- 

 tating the depollinating of flowers that are to be used for 

 cro.=)sing. The work uhich is dealt with was undertaken as 

 a result of the difficulty that was found in depollinating the 

 liowers of lettuce, when it was intended to cross diti'ereut 

 varieties. The manipulation of these flowers is particularly 

 diliicult, on account of the smailness of the flower heads, and 

 the fragile natitre of the florets. The work continued to 

 present dilliculties, until it came to be suggested that a jet of 

 water might bo used for removing the pollen. The first 

 application of this means was by fitting a piece of soft rubber 

 tubing of small diameter to the end of a garden hose, turning 

 the water on to such a degree that it just trickled from the 

 tubing, and sciueezing the end of the latter so as to produce 

 a very small j(;t of water. When this jet was directed on to 

 the lettuce flowers, the pollen was removed completely after 

 a few seconds. The depoUinated florets were then dried by 

 touching them with the edges of small pieces of blotting paper, 

 and then pollinated with tlic reiiuired pollen. 



It was soon found that the method of depollinating, 

 using water from a hose, was somewhat clumsy, and uncertain 

 in its results; there was the additional objection that a hose 

 was not alwiiys available for the purpose. A fairly good sub- 

 stitute for the arrangement was found in a large rubber bulb, 

 into the mouthpiece of which a suitable piece of bamboo, or 



