"Vol. XII. No. 288. 



THE AGRICULTURAL NEWS 



159 



fairly moist. No great dirterence was observed between tlie 

 inoculated and controls, except that the developing buds of 

 the inoculated cuttings were rather longer than tho.se of 

 the lontrol.s, namely, the inoculated shoots measured from 

 1 to 7 inches long, whereas the siioots of the controls were 

 -from iinch to 5 inches long. Thfre were occasionally roots 

 near the buds in the inoculated. There was practically no 

 bud development in B.147, though there were as many roots 

 (each about ^-inch long) arising chietly from the end nodes, 

 as in the cuttings of the other varieties. 



On removing the tapes, the rind was seen to be 

 discoloured purple, in the case of the inoculated plants, 

 about 1 J by ^inch around the wound In the case of the 

 Bourbon inoculated cuttings the discoloured area was accom- 

 panied by much shrinkage and wrinkling 



On splitting open the cuttings, a red discoloration was 

 seen to e.xtcnd about 2 by 'inch around the wounds in the 

 inoculated plants. The infection appeared to be spreading 

 only very .slowly, and there was no definite sign of the 

 penetration of the fungus into the bud. The controls .showed 

 no discoloration around the wounds. There was, however, 

 some secondary infection, in both inoculated and controls, 

 through the tarred ends which had somewhat split. Cultures 

 were made to determine (a) if C. falcatum was present in the 

 wound discoloration; (b) the cause of the discoloration in the 

 end internodes of the controls; (c) whether in one case the 

 fungus in an inoculated cutting had spread into the next 

 internode. The result of (a) was that C. falcatum was 

 isolated in every instance: in (b) bacteria but no fungi were 

 isolated; in (c) a green Aspergillus fungus was isolated. 



There was sufficient evidence, therefore, to prove the 

 inoculations to have been successful. 



The final series of observations concerned the effect of 

 the fungus on the development of the growing canes. In the 

 first place it may be stated again that 15.376 was the quickest 

 to germinate, the slowest was B.147, and White Transparent, 

 although somewhat late to appear, produced eventually the 

 strongest growth of shoots. At the end of three months after 

 planting, an examination of the .shoots gave the following 

 results: The number of shoots withered or dead was, for the 

 controls and inocu'ated, respectively, 1 and 1 for P).147; 1 and 

 4 for B.376; 3 and 8 for Bourbon; 2 and 2 for White Trans- 

 parent. Except in the case of the Bourbon; the inoculated 

 plants looked no worse than the controls; indeed, in many 

 instances, the inoculated plants appeared decidedly more 

 vigorous. 



An examination of the affected cuttings showed .similar 

 symptoms to those described in the St. Kitts experiments. 

 There was a red discoloration throughout, though in most 

 eases the tissue of the cutting was rotten. In several 

 instances a rotting of the growing point had taken place, but 

 although fifteen cultures were made from different diseased 

 .growing tips, it was not possible in a single case to obtain 

 a growth of C. falcatum. The green Aspergillus and the 

 pink and yellow Fusarium already referred to were isolated, 

 however, in some cases, as were also a Cephalo.sporium 

 form and bacteria. Apparently (but not necessarily) these 

 organisms are saprophytic. 



The point of greatest significance in the inoculated 

 plants was the fact that the healthy shoots had completely 

 severed their connexion with the cutting by the formation 

 ■of a woody partition at the junction of the bud and cutting; 

 these shoots had developed their own root systems, those 

 roots which had first arisen on the cutting being dead. 

 The.se features of growth were also observed earlier in the 

 • experiments. Although the same change was found to have 



occurred in the controls, it was by no means so prououncedj 

 indeed, in <3me of the contrils there appeared t3 be very 

 little thickening at the base of the young shoots, whereaw 

 in many of the inoculated plants the woody tissue was ^inch 

 thick and was bordered on the internal margin by softer red 

 tissue. This internal reddening was not often observed ia. 

 the controls. 



OENERAL rONCLUSIONS. 



Taking all circumstances into consideration, it seems 

 that the present position in regard to the parasitolozy of 

 C. talcatum in the West Indies may be summed up a» 

 follows: — 



(1) The fungus is a facultative wound parasite, of which 

 the degree of virulence varies greatly according to climatic- 

 conditions, age, and particularly with the variety of cane. Its 

 chief harm is in consequence of its invert action on cane- 

 sugar, thereby tending to increase the glucose ratio in the 

 factory, though, under certain exceptional conditions, its 

 harinfulness may be felt throagh a reduction in the yield of 

 cane per acre. 



(2) The chief mode of infection seems to be through 

 the agency of boring insects, or through wounds caused by 

 other means; though the St. Kitts experiments have not 

 definitely settled this point. (See Parts I and II, AgriculturaL 

 Neii.% Vol. XII, Nos. 28<5 and 287.) 



(3) In these experiments, the disease was not com- 

 municated by infected cuttings. The presence of the fangu.'j 

 in cuttings from mature canes seems to stimulate shoot: 

 development and the growth of roots at the base of the 

 shoots, apiiarently in order that the new plant may cut itself 

 off from the source of infection. In younger cuttings 

 of White Transparent, and in all cuttings from Bourboa 

 canes, the fungus appears to retard development, the 

 buds, in these cases, seeming to lack that vigour which is 

 characteristic of B.376 and the cuttings from mature White 

 Transparent. In the St. Kitts experiments where the 

 fungus appeared to retard development, the planted cuf.ings 

 were from younger canes and were smaller in size. 



(4) The chief danger in planting infected cuttings 

 would appear to lie in the fact '.hat the soil becomes infected, 

 thereby increasing the chance of the disease being communica- 

 ted by boring insects that come in contact with the soil. 



(.5) The behaviour of C. jalcatuni in the West Indies is 

 different to that of the organism in the Eastern Tropics, 



Agricultural Education in St. Lucia, — A copy 

 of the report of the Agricultural Superintendent, St. Lucia, 

 on the teaching of agriculture in the primary schools of that 

 Colony during 1912, has recently been received at this ofSce. 

 During the year under review it is reported that the examin- 

 ations were undertaken by the Agricultural Superintendent. 

 They were entirely oral, and the number of candidates 

 presented was on the average of twenty-one per school. The 

 results of the examination show that on the whole there has 

 been improvement, the marks obtained being in the aggregate 

 nearly 7 per cent, in advance of those of previous years. 

 The suggestion made in earlier reports to the use of 

 garden note books has with one exception been generally 

 adopted with excellent results. The plants under cultivation 

 in the school gardens have included native and European 

 vegetables and also some cotton, cacao, canes and bananas. 

 Budding work has been conducted on nianyo and orange 

 seedlings. On the whole the condition of the gardens in the 

 primary schools appears to be extremely good. 



