May 2i f 1898. 



GARDENERS' 



MAGAZINE. 



Strawberry Leaf Spot 



The strawberry leaf spot (Spharella Fragaritr> Tul.) is a very destruc- 

 tive and widespread disease, occurring wherever the strawberry is 

 cultivated ; it is also met with on the leaves of wild strawberries, and 

 from thence probably often passes on to the cultivated varieties. The 

 leaves are the parts attacked by the fungus, the earliest sign of its pre- 

 sence being indicated by the appearance of scattered minute dark-red 

 spots on the upper surface of the leaf. These spots as a rule rapidly 

 increase in number, and also in size, adjoining spots often growing into 

 each other, and forming larger, irregularly shaped blotches. As the 

 spots increase in size, the central portion of each becomes grey or 

 whitish, and is surrounded by a narrow dark-red ring. When the fungus 

 has reached this stage of development, examination with a pocket lens 

 shows the pale central portion of the spot to be sprinkled with very 

 minute white tufts. Each of these tufts is composed of a bundle of very 

 delicate white threads, or hypha y each of which bears an exceedingly 

 minute reproductive body, or conidium, at its tip. When quite ripe the 

 conidia become free, and are then carried by wind, rain, insects, or very 

 frequently by watering or spraying, on to other strawberry leaves, 

 where, if the surface of the leaf is damp with dew or rain, they germi- 

 nate at once, enter the tissues of the leaf, and soon give origin to a 



w^l aP J ear ter the fruitin S season > is in j ur ed, afterwards remain 

 veaK, and as a rule are not worth preserving. Repeated experiments, 



that the di S C ° Untry ^ • — Ul?itC ^ ^ tateS ' W dearly proved 

 mixture. 



can be held 



extent on the amount of 



™ in check by the use of Bordeaux 



, * he . Plants should be sprayed with a dilute solution when the 



tc if S a r? . be S inni . n S t0 expand, and again at intervals if the fungus shows 

 jiseir. it is most important that the plants should be sprayed after the 



flh S ^ athered > so as t0 protect the second crop of leaves, as the vigour 

 fu r n ntS, « and cons equently the quantity and quality of fruit produced 

 on tne following season, depends to a very great 



material accumulated by these leaves. 



All diseased and dead leaves should be raked together and burned, so 

 as to guard against infection the following spring ; for although the leaves, 

 it allowed to remain on the ground, would probably decay and disappear 

 during the winter, yet the fungus fruit and sclerotia present in their 

 tissues would not decay, but remain on the ground, and germinate in the 

 spring, when some of the conidea produced would almost certainly find 



their way on to the surface of the young leaves, and thus commence the 

 disease. 



G. Massee. 



Th 



Au 



V 



6 



Diseased Strawberry Leaf. 



Fig. i. 



f ig. 2. One of the 

 r ig. 



diseased strawberry 



The genus primula may be said to have held a levee of its admirers on 

 the occasion of the recent exhibition of the National Auricula Society 

 Though the improved modern forms of P. auricula were mainly repre- 

 sented, other species and sub-varieties were well to the fore, and found 

 their admirers. It is well such an exhibition be held annually, and 

 the Royal Horticultural Society is to be congratulated on encouraging 

 the holding of such a display. Some of the best-known species and 

 varieties of primula were seen in P. intermedia, unusually fine in 

 character as shown by Mr. J. Douglas ; the delightful P. verticillata, 

 P. obconica ; the charming ever-blooming P. floribunda ; some varieties 

 of P. Sieboldi; a fine form of P. pubescens, in the liookham collection ; 

 P. japonica, &c, also the primrose, both double and single, with the 

 bolder polyanthus. It was a liberal feast of spring flowers, relished by 

 a large company. It was the florist's auricula, however, which held the 

 field ; his green, grey, and white edges, and striking selfs, with brilliant 

 alpines of many shades and pleasing combinations of colours, and the 

 grotesque and striking nondescripts, conveniently denominated 44 fancies." 

 Those interested in the fascinating flower saw it in numbers, but not at 

 its best There was little of that superb finish sometimes seen. Nature 

 had not been in a benignant mood ; cold winds, frost, and drought 

 induced roughness ; the incidence of the weather was too powerful for 

 the best endeavours of the florist, and he was beaten in the conflict. He did 

 his best against unequal odds, and it was gratifying that he did so well. A 

 genial season is required to impart finish to the flowers ; it was uncongenial, 

 hence comparative failure. Yet the exhibition was full of interest, as 

 reported in these columns, notwithstanding. The auricula is a perennial, 

 but its life is one of limited duration. "An individual plant may maintain 

 its vigour and blooming powers for a few years, and it is found in experi- 

 ence that plants of some varieties are slower in coming to maturity, and 

 longer lived than those of others. In a dozen plants of any one variety 

 no two may live for exactly the same time, or during their life be in cor- 

 responding health. It is impossible to define the life-term of this plant 

 by the duration of a single individual. It may eventually so break into 

 several heads that which of them is the real original no one can say. It 

 may give off increase, and in favour of strong young plants, the parents 

 may have been thrown aside when comparatively worn out ; or in its 

 evident old age the plant may have been cut over, and the much reduced 

 and narrowed head induced to go on afresh in restored strength for a 

 time. Some varieties die young ; our leading raisers have had experi- 

 ence of young seedling beauties that were short-lived, sometimes to the 

 dying of the seed plant without issue." Such is the testimony of one who 

 knows the auricula well. 



* IOO. 



si One e 0 °f the S K^ffi f^*^^^ 1 ; ^ ^ „ \ Some varieties ofshow auriculas are longer lived than others, and all 



raisea point, forming the second, or ascigerous form of fruit; therare everriserl in the culture of the latter rannnt L-een th*m In „;„„„.. 



and in^anTd 8 ?^.^- 5 th * Cor V. dia are Produced in immense numbers, 



of plantsTrowinJ neT', Spna ^ ^ ^ ickl y in the case 



adopted g ° Cach ° ther ' Unless P re ventive measures are 



i^fiSSflSS of the disease> which continues in v 



dependent w n S f a Z° n > was at one time considered to be 



wcnaent lungus. ca eH P,y,i,„ r,^r, t„7„<.~„: , , 7 



Ih^wS con , dition of the disease, which continues in vigorous 



an in- 



season, numeroi^^7ArvC. /l TTrT *™™7**\ Towards the end of the 



each piiSI S£ P rS ^ SeC ° n , d f ° rm ° f fruit P roduced ^ th * fan*™, 

 numerous spore! or llr ^ om P'^. struc ^, containing in its inteno^ 



Ranged b ° dieS ' These s P ores remain in "> an- 



nate ?h f vo„nT hC K ll0WI i g Sprmg .' ^ hen the y terminate and 

 c °nid>al form^ g,v r in S ori ? in to the first or 



th * spores,Tls 0 £l£* 8U ? A pother form of reproduction, which, like 

 of minute black Z • C the / ul ?S us over th * winter season, consists 

 xlerotia, wh ich : [ e ^ 1 ? n \ of . the niycelium of the fungus, called 



f° WaiS o* nhelrnu^ 2 ? C £ £ € deca y in * ^ These 



the V produce a c^n? ™ d ™ chan S ed ^til the succeeding spring, when 

 ^rface of Th! vmm? c ? nidl £ som f of whlch fi nd their way on to the 

 afresh. youn 8 strawberry leaves and commence the disease 



of M^JS& ° { the str awberry are badly 



!i 5 P ro P er ly matured ; furthermoj 

 racked bv thp A\*^ c * *»er^;oii„ \t *i 



diseased, a good crop 



the care exercised in the culture of the latter cannot keep them in vigour 

 beyond a limited time Probably a variety cannot be expected to last 

 longer than six years at the outside, hence, then, the necessity for obtain- 

 ing young stock, so that existence may be secured This is the way 

 Nature suggests for maintaining a collection in all possible completeness. 

 Some sorts give off increase much more freely than others, while others 

 will form an offset quite at lengthened intervals. Occasionally it is 

 necessary to behead a plant to obtain increases, making a cutting of the 

 top and causing the beheaded stem to break into growth. It may happen 

 that all the care bestowed upon a particular variety will not induce it to 

 make vigorous development, but change has been known to conduce to 

 this result, either by sending the plant to some brother florist to nurse to 

 convalescence, or by exchange of the same variety from a distant part. 

 Further, to maintain the auricula in the characteristic attributes which 

 commend it to the enthusiastic florist, the raising of fresh varieties from 

 seed is vital to its existence. Yet some varieties have been in cultivation 

 for half a century or more, and among them a few of the best Yet it is 

 a fact that in the course of years they surely, if slowly, wear out, not 

 coming in character so constant or so grai|l as they used to do. They 

 become more difficult to keep, and pass out of cultivation. There are 

 always growers who cherish the favourites of bygone times, and when the 

 evening of a long day comes at last for those which have become sacred 

 by long association parting brings sore regret. Old varieties will no more 

 live for ever than human beings ; and, on the other hand, no new variety 

 has been raised which cannot be surpassed. It is as sure as possible 

 that flowers more fixed and richer in qualities of recognised excellence than 

 the former ones can be raised ; and that our improvements will be improved 

 upon, if only men follow who will care to give the love, and thought, and 

 time required to the work. R. D. 



