222 



THE GARDENERS* MAGAZINE. 



March 16, 1912. 



trees are liable to diseases and ailments 

 which either affect them constitutionally or 

 reduce the commercial value of the crops. 

 These diseases are a varied quantity, and 

 while some may be prevented or checked, in 

 the case of others no effective remedies are 

 as yet forthcoming, and scientists are in 

 the same position in respect of them as 



APPLE AM> PEAR SCAB DISEASE. 



Afi illustrated by the Board of AgricitUiire ; the spots 

 on tihe apple and 1-eaf are caused by Kiisicladium. 

 dentdritioam, and tiho&e on the pear by F. pirinum. 



edical men are in reference to several of 

 the diseases to which human flesh is heir. 

 Further, there is a similarity between the 

 two, and just as a healthy man is more 

 proof against an epidemic than a sickly 

 one, so does a dirty and weakly fruit tree 

 fall a readier prey to di»sease sooner than 

 a vigorous one. The obvious lesson from 

 this is — keep fruit trees clean and in sound 

 health by good cultivation, use preventive 

 measures so far as possible to ward off 

 diseases, and if remedies are necessary, 

 apply them promptly before much damage 

 is done. Spring spraying is not a cure for 

 diseases, but in some cases a means of pre- 

 vention, and several instances of this are 

 described below. 



Apple Canker. 



The real cause of canker is unknown, 

 and it appears under many different cir- 

 cumstances, some varieties, like Lord Suf- 

 field and Ribston Pippin, are more liable 

 to it than others, and frequently it does its 

 worst in injuring trees where the conditions 

 of subsoil are unfavourable to apples. 

 When canker gets all round a branch there 

 is no hope for it, and the limb may as well 

 be severed, but in the case of wounds, par- 

 ticularly on young trees, the fungus may be 

 checked by cutting the cankered part away 

 to clean wood and painting with Stockholm 

 tar. This is an old remedy, and a better 

 one, to my mind, is to secure a small bottle 

 of Lysol from a chemist, dilute it to one 

 part of Lysol to three parts of water, and 

 apply it to the cankered parts with a stiff 

 paint brush. A few years ago I treated a 

 number of young standard trees with this 

 remedy that were cankered at the point of 

 working, and the results were so satisfac- 

 tory that I have every confidence in recom- 

 mending it. 



Apple and Pear Scab. 



Most of us are painfully acquainted with 

 the apple scab (Fusicladium dendriticum) 

 and its relative Fusicladium pirinum, 

 which attacks i>ears, and is perhaps the 



worst trouble of the two^ because whereas 

 the former is responsible for corky scabs on 

 the fruit, the latter makes pears crack, 

 and^ prevents their development. In the 

 bright sunny summer of last year lioth 

 apples and pears came very clean, and there 

 was little scab, which leads one to the con- 

 clusion that climatic conditions are largely 

 responsible for it, but in any average sea- 

 son it is a common cause of trouble. Spra}'- 

 ing in the spring for scab must be viewed 

 in the light of a preventive measure, and 

 lime-sulphur wash is recommended. Two 

 years ago I had evidence of the value of 

 ordinary limewash, applied warm, being 

 good for scab, and this was in connection 

 with some Wellington apples, which were 

 always so scabby as to be unmarketable, 

 but the season following the spraying the 

 fruit was w^onderfully clean and free from 

 scab. Lime-sulphur wash may also be ap- 

 plied in the summer, and some prefer it to 

 Bordeaux mixture. A recipe for making 

 a self-l>oiled lime-sulphur spray was given 

 in the " Journar' of the Royal Horticul- 

 tural Society, March, 1909, and is as fol- 

 lows : Flowers of sulphur, 101b. ; quicklime, 

 151b. ; w^ater, 50 gallons. The lime is 

 placed in a wooden vessel, and a few gal- 

 lons of boiling water poured over it. The 

 sulphur is then added with a few more gal- 

 Ions of hot water. The mixture should be 

 covqfred with a cloth, and the solution 

 boiled by the heat of the slaking lime for 

 twenty minutes. AVhen boiling has ceased 

 the remainder of the water to make 50 

 grUlons is added^ and in straining care 

 should be taken that all the sulphur is 

 worked through. Bordeaux mixture is 

 also recommended for scab, and the Board 

 of Agriculture formula is a half-strength 

 solution formed of Gib. copper sulphate and 

 31b. quicklime to 100 gallons of water. 

 Spraying should be commenceil as soon as 

 the fungus appears on the foliage, and be 

 continued, if necessary, at intervals until 

 the apples are the size of a nut. Still 

 another preventive remedy is to spray trees 

 on which scab has been prevalent, just 

 before the buds commence to swell, with a 

 solution of sulphate of copper, at the rate 

 of lib. of sulphate to 75 gallons of water. 



Apple Mildew. 



The development of trees is sometimes 

 checked in the spring and early summer 

 by the powdery mould of the above mildew, 

 and for this the same remedies as sug- 

 gested for the scab are applicable. If it 

 is only a case of a few shoots being affected 

 by the mildew, and this is by no means in- 

 frequent, the best plan is to cut off the 

 twigs and burn them. 



■ 



Brown Rot. 



This fungus (Selerotinia fructigena) not 

 only affects apples and peais, biit stone 

 fruits as well, and it appears on the foliage 

 before attacking the fruit. The effect of 

 the disease is that the fruits become hard 



and remain on the t 



to the 



in a inuinmified 



These 



state, even to the next season, 

 specimens are holders of the fungus germs, 

 and should be picked off and burnt, b\it in 

 other respects the remedies for brown rot 

 arc the same as for apple scab. 



Pea.ch Leaf Curl, 



This disease (Exoascus deformans), also 

 known as the ''leaf bi ster," is the bane of 

 all gardeners who grow peaches and nec- 

 tarines out of doors, and it is so well known 

 that no description of it is necessary. There 

 is no doubt w^hatever that climatic condi- 

 tions have a great influence on leaf curl, 

 and when these are particularly favourable 

 for the disease it is doubtful whether there 



is any known remedy that will effectually 

 prevent or check it. Cold, damp weather 

 in the spring, with biting winds or quick 

 changes of atmosphere, are very favourable 

 for the disease, which gives much less 

 trouble if the conditions are genial at the 

 critical period. Last spring leaf blister was 

 very prevalent, and dozens of trees have 

 not recovered from the effects of it. 

 Lime and sulphur sprays and Bordeaux 

 mixture are both effective as preventives 

 if applied when the buds first show signs of 

 swelling, but before the leaf buds expand, 

 and the latter solution is then used at the 

 strength of 101b. copper sulphate, 51b. of 

 lime, and 50 gallons of water, the copper 

 sulphate being dissolved in one wooden 

 vessel, and the lime slaked in another 



before they are brought 



in 



"together. In 



America the self-boiled lime and sulphur 

 wash is also used as a check to the disease 

 when the trees are in leaf, without injury 

 to the latter. 



America.!! Gooseberry Mildew. 



This notable diseai>e, which is costing the 

 countrj- so much money in attempts to 

 eradicate it, has been illustrated and de- 

 scribed so many times that most people 

 must be acquainted with its symptoms^ and 

 if one is unfortiuiate enough to have bushes 

 affected with the mildew the best thing to 

 do is to obey the law^ by reporting the case 

 to the Board of Agriculture or a local in- 

 spector, and instructions will be given as to 

 the compulsory pruning and spraying of 



AIMERICAN GOOSEBKKHY MILDEW 



(Sphiprothoca mors-uvae). Diseased leaves 

 «^ imistrated by the Irish Board of Agricui 



the bushes. 



American Gooseberry Mijd^ 

 caused a great scare when it was first 

 covered " several years ago, and the 

 appears to have arrived when growers in.^^^ 

 reasonably ask whether it is such ^^^^^ 

 thing as it was at first declarecl to be, ^^^^ 

 also what effect the compulsory mea^. 

 have had in eradicating the disease. 



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