THE AGRICULTURAL NEWS. 



Jamauv 11. 191;*. 



PLANT DISEASES. 



SUMMARY OF NOTES ON FUNGI AND 

 PLANT DISEASES IN 1918. 



The folkiwiiig is a classitii-d summary of the informa- 

 tion given in this .fournal under the heading Plant Diseases 

 during the year 191f<: — 



si'i;ak-c.\nk. Observalifiii.s on diseases of the sugar- 

 curie in Karbrtdds, reproduced on page 78 from the Annual 

 lltport nf the Barbados l)e[jartment of Agriculture, show 

 that Jt/ii/nsM/itx Saa/iii/i, the root fungus, was \>y far the 

 anost troublesome disease in tliat island affecting the cane 

 crop. Four other fungi causing disease in cane are also 

 recorded. From the Annual Report of the Department of 

 Science and Agriculture rjf British Guiana, 1916, which is 

 noticed on page 222, it seems that fungoid diseases of sugar- 

 cane are diminishing in that colony. An account of a new 

 and serious disease of sugarcane, known as the mottling 

 disease, which has lately appeared in Porto Rico, is given on 

 page 110. A short review of an important paper on sugar- 

 cane diseases in the West Indies, which was contributed to 

 the li'tsf liiilian Hitllitin. Vol. .\VI, No. 4, will be found 

 on page InJ*. 



ciTKii-* TKKKs. An account of citrus scab, as affecting 

 grape fruit and other citrus in Porto Rico, as well as of wood 

 rot of citrus trees in that island, is given on page 62. C)n 

 the same page tliere are some notes on the water and mois- 

 ture conditions most favourable or otherwise to disease- 

 resistance of citrus trees. How to protect citrus fruits from 

 rots in transit i.-- the .>ub.ject of an article on page 94, and 

 the occurrence of a disease found nn citrus fruits on sale in 

 the market is noted on page 254, while on page 1 12 it is 

 noticed that orange fruit may be infected with the same 

 fungi which cause in'.ernal boll di.sease of cotton, in the same 

 manner as the cotton boll.s an-, namely by jmnctures of some 

 plant-feeding bug. A seri(>iis disease affecting orange trees 

 in California, and knuwn is citrus, blast, is described 

 On page 1 1 0. 



i.ACAo. Diseases atfectinj.' i;a(;ao in I ganda are noticed 

 On page 30, and a description 'if the algal disea.ie known as 

 red rust of cacao, will be found on page 190. 



• oiT.iN. A siiiiiinary of the record of ob.servations 

 made on the internal disease of cotton bolls in the AVest 

 Indies, which forms the .subject of papers in the West 

 Jiidimt Jiulkltn, Vol. XVI, nI,. 3, and Vol. .WII. Xn. 1, 

 is to be found on page 23!<. Xotes are given (p. SO) with 

 regard to the diseases atfe(;ling cotton in 1 'ganda. 



iiicoM T-^. Diseases affecting coconut trees in .famaica 

 are described, on page 2S(i, and cm page 302 there is a further 

 note on the destructive di.sease, cocotiut bud rot, as occurring 

 in that island. C'n pages 'iW and 41 I will be fomid articles 

 dealing with tlie n suits of ;. recent investigation on diseases 

 of c 'ico nut trees in (frenad.i. A description of several 

 moulds orriirririg un copra, wliich cau.'-e great deteririralion of 

 the pr'iduct in the rhilippiiic.--, is given nn page '.W'!^. 



oTiiKi: i;icf>l's. A serii'iis 'ii.seasei'f banana.'- in (irenada. 

 ■where it i^ called 'bhick hcu'l , is Hescrified on page 2(Ki. 

 InveMtigations iiiK' the cauf e \<\ this di.sease .seem fo point t'' 

 the conclusion that iil is due to attacks of nematodes (eel- 

 ■worms). An article on grey mould of castor beans, which 

 ha» occa.sioned seriou- injury to that crop in Flortda, is 

 reprinted on pa^c .''••'U .\ t.i w disease of coffee plants in 

 J^urinani is th" subiecl of a note on page '<82, 



Other articles in connexion with plant diseases, which 

 were printed in last year's volume of this Journ;il, deal with 

 the subject in a more general way. The di.-,seminatiau of para- 

 sitic fungi (p. 14) is the subject of an anick which points out 

 themany ways in which this disseminilionmay occur, and urge.s 

 ihc necessity of vigilance in guardini,; against iinportations^ot 

 such foes. On page 174 there is a description of the measure* 

 which are in force in Cuba with respect to plant sanitation. 

 The difierect degrees of resistance or susceptibility to difeiise, 

 shawn by various strains of the same .species nf plant.'s, is thn 

 subject of an article on page 270. A useful scheme of classi- 

 fication of plant diseases with reference to the nature of the 

 parasitism involved is outlined on page Jififi. 



.Short reviews of the accounts of plant diseases given iu 

 the report of several agricultural departments will be found 

 on pages 30 (Uganda), 78 (Barbados), and 222 (British 

 Guiana). 



On page 46 an account is given of the possible damage 

 done to trees by the growth of the bracket fungus {Fomes 

 lucidiis') on their roots or collars. P.rief notes on the [low- 

 dery mildew of rose bushes, and on the treatment of seed 

 with reference to angular leaf spot, will be found on page 204. 



BAKU ADOS: KEFORT OA Till: SU(.;AR-CAi\E 

 EXPERIMENTS FOR THE SEASON ii)r6 iS. 



This is the usual joint report, recently i.ssued by Pro- 

 fessor J. P. d' Albuquerque, Island Professor of Chemistry 

 and Agricultural Science; and Mr. J. U Itovell, Superinten- 

 dent of .Agriculture, on sugar cane experiments conducted in 

 Barbados during the season 1916-ls Like previou.s reports, 

 this is divided into three parts: Part I analysing the rainfall. 

 Part II dealing with manurial experiments with sugar cane, 

 and Part III relating to experiments with varieties of sugar- 

 cane- 



The inanurial experiment.> were directed, as in former 

 years, to ascertaining the effect of the application of farm- 

 yard manure in ordinary ijuantity and in double the ordinary 

 i|Uantity; also of nitrogen, phosphate, and potash, upon the 

 industrial yield of the sugarcane. The results from most of 

 the plots, which are given in tabular form, are said to be si» 

 different from those of previous years, with the exceiition, of 

 the last three years, and so conflicting with those of some of 

 the other plots as to leave no doubt but that this year a very 

 disturbing factor was again tiresent, which has masked the true 

 results of the manuring Thi< disturbing factor is stated tn 

 be grubs of the root borer (DinhipiS ni'/iriTidfiis) and the 

 brown hard back {I'/iy/n/iis s»ii//ii\ which attacked the canes 

 in the manurial pints to such an extent as tn render it impn.ssi- 

 ble to draw any definite conclusions from the results obtained. 



As to the number of seedlings raised during the period 

 under review, it is mentioned that, in 1916. owing to the 

 suitable weather (onditions about 15,000 .«eedling sug;ir- 

 canes were growr 0\ these. 6,.'0." were potted out, and 



