FIREBLIGHT.

Press, Volume LXVII, Issue 20184, 12 March 1931, Page 11

FIREBLIGHT.

TO TED EDITOR 07 THE -PBBSB.. . Sir, —With reference to the- various accounts* about' firoblight, I notice all' the accounts appearing in Tot Press ; .are'from'laymen. Personally," I would lika'to hearwliatDjr. Ouninghasa sad ; ' V ' '< J' 'v.- 'v-<

J ; 1 'yi. , \ r \ A A Dr. Curtis have to say about, one report, 1 Mr Pope-is made to that in 6ne orchard the treesloojfced.as though ring-barked. The »\Die?back fungus (Cytaspora Cucostoma)-; would make fruit trees look something'like that, "and as" I)r. ; H. "WormaldJ Agricultural College,'lfent, whofis, or rather' was, the world's best authority on the various 'Die-backs, gays/it is v quite possible that much that is thought fireblight is caused by/one ; of, the Die-back-diseases- ' I have various articles, on, the subject of fireblight from different. Horticultural Colleges in the United.States of America. The latest one. came in' December, 1930, and is by J.-A. McClm-; tock, University of Tennessee.- The following are some extracts from- this article:— „ ) 4 "It i has been established that tho Wight bacteria live all winter both in the larger limb cankers and to a lesser degree in the smaller- blighted twigs,- From this knowledge . we- recommend careful pruning out'of'both limb cankers and, blighted twigs; The importance of this recomimendation is seen - when viewed in the light of our findings in Tennessee*' ana those of workers' in other States,;' to the effect that rain is an important factor in spreading, the blight bacteria. Rain drops ..falling 011 bacteria oozing from the base of a blighted 'twig, in-'the top of a "tree may spread the organisms to both blossoms and twigs, and. cause infection without the assistance of insects." . . * "While there is no denying the fact that bees'" are secondary agents in spreading blight from flower to flower, -evidence is accumulating thiat primary blossom infections are more often v caused by r'aih than by bees. We must have bees' to ensure cross-pollination and friut set. Therefore, keep these innocont carriers of blight- bacteria free. > from such contamination by pruning out all, blight cankers and twigs .before the .blossom opens...Carefullv executed, experiments by several workers in other States have. proved that blight bacteria get into the tender growing shoots through the leaves. 'lt has been found that in' grown leaves the stomata,' or breath' mg pores, of the leaves cpn be readil> entered by tho lilight' l bacteria., spread from cankers by drops of- rain. At the tips of the leaf serrations; where the vascular-strands- or waterrconduoting tubes'terminate, there are generally several large stomata - whiph al certain immature stages .are susceptible'to entrance by any blight /bacteria that ' comes > into contact- with these openings once inside the leaf. The . bacteria multiply, rapidly -■ and I' spread through the lea! 'and ita petidh \ ' t', , r

- ".'typical twig blight A' r v.,>fAWJien -cutting off: twigs . out cankers the tools mtfalSTbe dMafe* |> fected "Withw thq> l > rl-lflQO mercuri chloride.'' . >' :\ "Remember thut" rain ?* r s in! primary «pread /! :'of • f "blighted twigs, Jiihba,- and cankers., j Removethose centres from which theap' f 'rain 'drops become* jsontmipwtM;' ' yori 'will -' tion."—Yours, etc.-, ■--*'!» ' ' , i; t-p.*., MglS 1 ?!; 1 .- J ' k - 1 - » «■* i*