GARDENERS' MAGAZINE 



B 



in Apples 



This general and very destructive disease is caused by a minute 

 fungus called Glceosporium fructigenum, Berk. 



most conspicuous "on the ripe fruit, nevertheless the apples are usually 



" * The earliest 



diseased. But more man this, the mycelium of ti, t 

 every part of the fallen apple, and the latter does not gUS 



s causeu uy a muiuic — ---- — ~ " ^* i y> icamery ■ 



Although the disease is condition the mycelhum passes the winter 



b all, and 



ls . a PP* 



conidia of the glceosporium, which are produced bv thl 2.. ,. m **s* 



n A/Mi #% iirmtflr'c? VQpf 1 -v% 4-1* ~ J • 1 / LUC 



first attacked by the fungus when about half grown, 

 external indication of the disease consists in the presence of one or more 

 discoloured spots ; these gradually increase in size, still retaining a more 

 or less circular outline. Not unfrequently two or more of these spots 

 increase in size until they run into each other, and thus form large, 

 irregular disease patches, which continue in most instances to extend 

 until the entire surface of the apple is covered. As the disease progresses 

 the patches become dark brown in colour and sink a little below the level 

 of the healthy portion of the surface. This sinking of the surface is 

 caused by the mycelium or vegetative portion of the fungus breaking up 

 the tissue of the apple, which serves as food for the fungus. The brown, 

 disease portion of the apple has a very bitter, disagreeable taste, hence 

 the popular name of the disease. 



Development of the Fungus. 



After the brown spots have been present for some time, their surface 

 will be seen to be covered with minute black points, which are often 



and burned ; do not throw it on the manure heap nor intn th 

 under the microscope, are seen to consist of numerous upright branches — • --- J i • • H ur imo tne 



of mycelium, compacted into a bundle, and further examination shows 

 that each upright branch bears a minute reproductive body or conidium 

 at its tip. The conidia are produced in immense numbers, and ooze to the 



/ 



r w m s 



< t 



* »\. £ ^ 



I"- * 



\ 



\ 



v 



2. 



3. 



H r* L* *C 



Apple infected with Gmeosporium fructigenum. 



surface of the disease spots under the form of very fine hairs or tendrils 

 being s uck together by a viscid substance. On reaching the surface 0 f 

 the apple, the strings of conidia are dissolved by dew or rain, each coni 

 d.um being capable of .noculating a young, healthy apple, and thus start- 

 ing a new centre of disease. Bearing in mind the rapid and continuous 

 Production of such immense numbers of conidia or reproductive bodied 

 of the fungus, . can be readily understood by what means the disease 

 2 ds so rapidly when it has once gained a foothold in an orchard Se 

 conidia being washed from diseased on to healthy fruit by rain or carried 

 by insects, birds, wind &c, and if the surface of the fruit is damp he 

 comda germinate, and enter the tissue of the apple within a few hours 

 and under favourable conditions, within a week a disease patch bffi 



the uZ^featon it't meth ° d by which the fun * us spreads 'during 



time to infect the wwnJ ftS" 1 ?, pUt 2 a PP e f aranc e again just in 

 attacked, and that there fs no LI ? i the frU,t 1S - the onl y 



the apple tree to fa^sh Se^"S^ t? 3 !^ llUin i Prese I? t in an y P^ of 

 hence the germs must be furnish 1 ?2 m0C ^ Iate the ?° un Z frui < I 

 the tree itself. Diseased annl, fr ° m - ? ther ^° UrCe than th * of 

 before they are attacked fl£P£n \ eS P ec,a,1 y " hen of considerable size 

 the fungus continu e rTrr : ; Tl^ the ^ ound ' and if flowed to remain 



which find their wav to the Sacenf r Cr - PS $ F?®** m ^ o{ 



j » me surface of healthy fruit, which in turn becomer 



becoming active again the following 



June its su^V^f &Hai 



to the n 



fungus after a winter's rest in the dried-up tissues oft? m / Celium ^ 

 and produced just at the season when the young- anr^c yeda Pfc 

 inoculation, when the activity of the fungus commence £ are read v* 

 the fruit is attacked quite young it usually remains firS""* 1 ^ 

 the tree in the mummified state, and produces conidia hf?^ * 

 year, as already explained in the case of the fallen aoi. i S 

 fruit great care should be taken to pick out all apples shot- n , st0ri < 

 indication of the disease, otherwise healthy fruit will bern i- lea * 

 especially if allowed to remain for any length of time in a heaL ^ 

 dition. An American observer has stated that the disease ?i Pc * 

 pears, peaches, grapes, &c, in the United States. atu * 



Methods for Preventing the Disease. 



From what has akeady been stated respecting the mode of life of *. 

 fungus, it is seen that the appearance of the disease depends on X 

 sence of decayed fruit which has remained over the vear eitW i • p: 



flip orronnH or hantrincr on the tro»s All a;*,^ i , ' . . cr 'yigOl 



athered 



not, above all, out of "pure "cussedness," r -~ ° " IUU ' and * 



the ground or hanging on the trees. All diseased fruit should be gath* 

 nothing in reality is gained by so doing, and a'greaTrisk is run **** 



nnt. annvp a nut nf " nni-p nicco/In«>r. n * ' 



j j u • u - tr y some otner method m 



recommended, hoping it may answer as well, or better, than the metS 



of prevention specially asked for, and then ignored. Where the diu*. 

 has previously existed it is imperative that the trees should be thoronS! 

 sprayed with a solution of potassium sulnhide— half an ounce to a J£ 

 of water— the first spraying just after the fruit is set, and aeain aft<*» 

 interval of three weeks. The spraying should be again repeated if tk 

 disease appears, as by this means it is held in check. As the funeus k 

 very abundant and widely diffused, a spraying after the fruit is set wj 

 always be a wise precaution against the possibility of infection from m 

 neighbours orchard, who does not believe that " prevention is better tha 

 cure," and consequently never sprays, but accepts what he considers a 

 the inevitable. 



Store-rooms that have contained diseased fruit should be stenlisrf 

 before they are used again. Spray the floor with a hot solution d 

 potassium sulphide, one ounce to a gallon of water ; the walls, and, ii 

 fact, every part of the interior of the building, should be treated in t 

 similar manner, not forgetting the furniture, especially the trays «4 

 shelves, where spores are most likely to lie nascent until their oppor- 

 tunity arrives. If these precautions were persistently carried out the 

 amount of bitter-rot and other ripe fruit diseases would be reduced to i 

 minimum, instead of which one enters an elaborate storehouse whk 

 feelings of awe, arising from the preliminary talk about equal tempera- 

 ture, perfect ventilation, &c, and is surprised to find a hamper of rotta 

 fruit under a shelf, and a mummified apple reposing in a corner, h 

 placed there by its owner as a warning to apples not yet mummified, and 

 emerges from the spore-laden atmosphere feeling, but not daring to say. 

 that, whether through gross ignorance or gross neglect, all concerin 

 are equally culpable. 



Description of the Figures. 



natural size ; 2, a string or tendril of conidia oozing" out of a diseased 

 spot, mag. 8o times ; 3, Branches of mycelium, each bearing a conidia 



' G. Massel 



iseast 



at its tip, mag. 400 times. 



Ripening of Late Pears. 



Frequent reference has of late been made in the pages of the G.tf- 

 DENERS' Magazine to the premature ripening of late pears this seascc 

 and so far as I have noticed, it is the southern growers that have dia* 

 attention to it ; and by them, the dry, warm summer and mild autumn i 



c St T Ca j a P Dears t0 be held as the main cause of the evil. Here, » 

 Scotland, the ripening of late fruit has been of much the same nature!! 

 described by others, and our most reliable varieties that are usaj 

 sound and of good quality until the end of February, were ripe at C»» 

 mas and had to be used shortly after. Of these Heurre Sterckmansaj 

 Ne Plus Meuris, two varieties that seldom vary much in their seas** 

 "Penjng, were as bad as others; while Plaster Beurre and Beurre KJ*e. 

 which should be the latest of any, scarcely reached maturity before deaj 

 set in. 



In our case neither much heat nor drought was sufficiently in eridg 

 here last summer to have any great effect upon the keeping of the rm 

 in tact, I had thought that the want of more sun and less moisture^ 

 the reason of the fruit keeping so badly, as with the exception of t>cw» 

 and November, in which the rainfall was below the average, all the <x=* 

 months were considerably above. The total for the year being ir 

 inches, which was the highest registered since 1883. I may state 



the pear crop of last season was very unsatisfactory throughout tnewj 

 of Scotland, as, coupled with a light 'crop, the fruit was small, even i»£ 

 grown against walls with the most favourable aspects for full .<J^J 



ment 



manner 



; and the mid-season varieties came to maturity in a morel 'y^ 

 er than I ever before remember, and mostly in advance 01 , 



us " a ' tinie of ripening. The only fruits at present that are keeping 

 and nt for dessert are those of Bergamotte D'Esperen, which werejf 

 on cordon trees. These are of excellent quailty, but very small » ^ 

 a point that is not of so much importance now as it would be ear 

 the season. - 



Galloway House, Wigtownshire, N.B. 



I a 



