Vol. XV. No. 379. 



THE AGKICULTURAL NEWS. 



367 



There are two broad classes of trouble with lime trees 

 in these islands, for both of which, as regards the causes 

 believed to be responsible, close comparisons may be found 

 in the account of the Queensland experience above. 



In the drier islands, of which ilpntserrat is most con- 

 spicuous in view of its definiie lime industry, it has been so 

 common as almost to amount to a rule, for lime trees once 

 they have been sucessfully established, to grow and bear 

 well for a few years, and theft to bfgin to die back. On 

 outstanding twigs and branches the leaves curl up and drop, 

 the fruit yellows prematurely and sliirivels and the branch 

 dies, usually without any attempt tg develop new foliage. 



A Colletolrichum on the twigs, and a Diplodia on the 

 branches may e.xtend the injury beyond the point it would 

 otherwise reach, the latter especially being able to get into 

 a main branch from a side shoot and cut oil' supplies to the 

 branch system above the junction, l.-;t these fungi cannot be 

 regarded as the primary cause of the die-back. During 

 a wet season recovery takes place to some extent by 

 the development of branches from below the injury, but 

 in many cases the loss is not balanced by this process, 

 and progresses year by year until the tree is killed. In 

 Montserrat a similar sequence of events has been traced upon 

 the roots, due to the infestation by weakly parasitic fungi of 

 the wood of roots which lack sufficient vigour to cover up the 

 wounds make by soil grubs of the Exopkthalnius and 

 Diaprepes type. The seasonal nature of the atiection, and 

 the fact that it does not occur in the same form in the islands 

 with no pronounced dry season, show its relation to water- 

 supply, but it cannot be legarded as a simp'e drought effect, 

 since the trees will grow well for a period of years, and then 

 fail, under* conditions not more severe, and at a time when 

 younger trees are flourishing. It niayin fact be regarded in 

 the manner suggested by Benson, as a .question of the reduc- 

 tion of longevity under conditions of irregular growth. Put- 

 ting the period of life under these circumstances at roughly ten 

 years, we find from examples ail'orded by old plantations that 

 in Dominica it may be multiplied in fertile soils at least by 

 three or four. 



The second class of trouble is one which can be seen 

 most clearly in Dominica, where it is free from complications 

 as to water supply, but, examples of which have emerged 

 from other factors in ilontserrat and elsewhere. It has to do 

 with another type of irregulaiity, that of food supply. The 

 clearest cases are exhibited wheie chemical manures have been 

 used and have stimulated rapid growth which owing to their 

 lack of residual effect has been left for a period unsupported. 

 This has resulted in a die-back very similar in its etJects to 

 that already described, and when the two are combined the 

 results are particularly fatal. Experience points to the 

 danger, in situations liable to long spells of dry weather, of 

 adopting any measures which lead to sudden accessions of 

 growth. 



As regards the effect of heavy bearing, referred to in 

 F. Smith's report above, parallels are -also to hand. In 

 August of this year Mr. W. Eobson Curator of the Botanic 

 Station, Montserrat reported that following a dry June lime 

 trees had received a marked set-back, and suggested a connex- 

 ion between this and the attempt to develop a large crop on an 

 insufficient rainfall. The writer had independently reached 

 a similar conclusion with regard to a group of lime trees under 

 observation in Barbados. In the catly months of this year 

 these trees were very healthy and vigorous, and began to 

 develop a very heavy crop. About -Tune, the weather being 

 dry for a period very many branches with half-grown fruit 

 shed their leaves and died. The branches which were bare 

 ■but not yet dead when rains ensued, revived and put out 



new foliage. This is of course only a special case of the die- 

 back already described, but the point of interest is that the 

 trees would probably not have suffered at this time had 

 they had not been bearing heavily 



In view of the considerations set out above, the 

 striking results obtained some years ago in experiments 

 conducted by this Department in Montserrat are signifi- 

 cant. Vigorous cultivation of selected plots led to very 

 active growth and the production of large crops for a 

 season or two, but these results were followed by an 

 equally striking decline, vvhich was rather accelerated than 

 checked by the application of manure, and ended in the ruin 

 of the trees. 



The statement of the trouble as arising from the 

 intolerance of citrus trees for irregular conditions does not 

 .solve the question as to its cause, and by tending to refer it 

 to the inherent constitution of the plant, seems to place it in 

 a large class of problems at present insoluble It is impor- 

 tant, however, as permitting a varied set of experiences, 

 common, as has been shown to such widely distant countries as 

 Queensland and the West Indies, to be brought into relation 

 with each other and expressed in a general formula. 



The measures which have been recommended by this 

 Department may all be regarded as tending to smooth out as 

 far as possible the irregularity of the conditions in the drier 

 islands. They comprise the conservation of soil moisture 

 by heavy coverings of vegetable mulch, the conservation 

 of atmospheric humidity by close shelter, and the use of pen 

 manure as the fertilizer with the slowest and most regular 

 action. 



W.N. 



SEA ISLAND COTTON MARKET. 



Messrs. Wolstenholine and Holland, of Liverpool, 

 write as follows, under date October 2, 1916, with 

 reference to the sales of West Indian Sea Island 

 cotton: — 



The only business done in West Indian Sea Island 

 cotton since our last report is a sale of 2.5 bales Stains at 

 l-2-ld. 



Owing to the high prices at which Sakalarides Egyptian 

 is ruling, good West Indian should be worth 20d. to 2\d. 



The Report of Messrs. Henry VV. Frost & Co., on 

 Sea Island cotton in the Southern States, for the 

 week ending September 30, 191 (i, is as follows: — 



ISLANDS. The receipts to date being only 64 bales, the 

 Factors have not sampled any of it, and will not offer any 

 cotton for sale until the stock is larger, therefore the market 

 has not opened. 



FLORlDAs AND GKORGIAS. The demand continued very 

 active throughout the week, both in Savannah and in all 

 the interior markets, taking all offerings at very full prices, 

 and at the close of the week the Factors in Savannah 

 refused to sell under J, -cent to 1 cent advance. The interior 

 was also dearer, and ^cent advance was freely paid, the 

 buying being on account of the Northern and Southern Mills. 



The general feeling is bullish, there being some specula- 

 tive demand in expectation of higher prices ruling. 



The future of prices depends upon the mills being able 

 to sell their production on a basis of current or even higher 

 prices. 



