256 



THE GARDENERS' MAGAZINE. march 30, 1912. 



tlirough the orchards of a West Country 

 grower, who some years ago planted a few 

 Victorias, and, finding that they did well, 

 he put in more and more. For a time 

 ev^erything was smooth sailing^ for the Vic- 

 torias flourished and cropped heavily, but 

 the trouble began when a tree here and 

 there became affected with silver leaf. At 



first the grower thought little of it^ but put 

 it down to lightning, which is a common 



thing in the West of England when a fruit 



tree dies without there being any apparent 



reason for it. The man knows better now, 



LIME, 



Much misconception exists 

 action of lime in soils. 



FATALITY AMONGST PLUMS. 



In spite of seasons of scarcity and years 

 of glut, witli the consequent low prices in 

 the latter case, and the shortage of fruit 

 in the former, the plum growing industry 

 is an important one in this country, and, 

 taking one year with another, there is pro- 

 bably no other fruit crop that pays better. 

 A characteristic about plum culture from . 

 a commercial point of view is the extent 

 to which it is localise<l and dotted about 

 the country in different parts, and on 

 varied classes (rf soil are areas w^iich in for, a few at a time^ his once profitable and acid in consequence, w^ith the result 

 *>ome peculiar way are adapted to plums, Victorias are being killed by silver leaf, that plants sicken and die in them. Here 



as to the 

 or its effects o„ 

 plant growth, and it is clearly evident that 

 many old kitchen garden soils have been 

 sadly neglected as regards suitable appl> 

 cations of this most essential constituent. 

 A great many of these soils are highly 

 charged with liumus, due to repeated dress- 

 ings of garden refuse, farmyard manure 

 cow and horse manure^ and many other 

 forms of organic matter ; they become sour 



and Jiaving found this out men have de- 

 veloped the cult of the fruit until it has 

 become an important commercial industry. 



Local Varieties. 



It may also be observe<l that in nearly 

 every one of these plum districts there is 

 a Iwal variety peculiar to the neighbour- 

 1io(k1, which originated in a natural way, 

 and needs no working on a stock, for it 

 propagateti itself from su<»kers and grows 

 on its own roots in a natural manner. 

 Speaking generally, in every plum-growing 

 district it is the local variety that pre- 

 dominates, and one reason for this may 

 be because it is so easily propagated, but 

 another is that, taking an average of years, 

 the local plums are the most profitable to 

 growers, because they are produced in 

 quantity, are sold wholesale, and svipply the 

 needs of the juin maker. 



Even in that favoured fruit-growing 

 tjounty of Kent there are many less profit- 

 ttble varieties grown than the native round 

 purple Bush plum that belongs to Kent, 

 and is rarely st-eii outside its borders. If 

 you stand in tlie vale of Ev^csham by the 

 meandering Avon, in the < arly .spring you 

 may look over sloping liillsidt^^ for miles 

 that are white as snow with jx^arly plum 

 blossoms, and most of these are on trees 

 of the famous Pershore or the native yellow 

 egg plfem of Worcestershire. It is not a 

 liigh-class plum ; no one ever argued that in 

 its favour, but it serves a certain purpose, 

 and^ all things considered, there is none 

 more profitable in the Evesham valley. 

 The neighbouring county of Gloucester has 

 its native plums, and one of them fiUs many 

 of the orchards that skirt tihe banks of the 

 Severn. This plum, which flourishes like 

 the proverbial bay tree in its own particu- 

 lar district, originated in the little village 

 of Blaisdon, from ivhich it takes its name 

 of the Blaisdon Red^ and if you ask any 

 grower in the locality he will tell you that 

 it -pays better than any other, and a lot of 

 the fruit is consumed in the mining valleys 

 of South Wales. Bristol is the chief corn- 



while he is helpless, and can only talk of 

 the money that the trees brought in 'before 

 the deadly disease attacked them. This 

 is only one instance, but hundreds of trees 

 of soft-wooded varieties of which Victoria 

 is the worst, are dying every year, and no 

 remedy is as yet forthcoming. From what 

 I know and have seen, I can say without 

 foar of contradiction that the fatality 

 amongst Victorias in particular owing to 

 silver leaf is becoming very serious, and in the" kiln 



some places the very existence of this popu- 

 lar variety is threat<^ned. 



The Shot Borer. 



One day last summer, I was in a district 

 where plums are an important source of 

 income to the small holcleis and farmers, 

 and I observe<;l a large number of trees that 

 had died suddenly, and some of them had 

 crops of withered fruits hanging on the 

 branches. Most of the dead trees were of 

 introdaiced varieties, but I do not remem- 

 ber the particular names at the moment, 

 and the growers thought it must be light- 

 ning or some other mysterious cause. A 

 (lose examination of the bark, however, 

 proved it to be pitted with tiny holes, and 

 the mystery was solved, for the death of 

 the trtH's was due to the ravages of the 

 Shot Borer (Xyleborus dispar), w^hich bores 

 inside the bark into the stem, and brings 

 about the death of the tree. From what 



I could see the growers were taking the 

 trouble very philosophically. They knew 

 that nothing ctmld be done in bad cases, 

 but cut down the trees, and though they 



I I a d b een a d vised to keep the stem s of 

 other specimens coated with limewash as 

 a means of prevention, few of them w^ere 

 doing it, and as another tree w^ent wrong 

 they deplored their ill luck, and enlarged 

 on tlie uncertainties of fruit aulture as a 

 means of livelihood. Tliough one might 

 blame the growers for not being more ready 

 to adopt preventive methods one cannot 

 help sympathising when losses of this kind 

 occur, because a plum tree does not gro'W 

 in a week, aiul after waiting until it comes 



is evident necessity for the application of 

 lime to correct such acidity. 



Mention of the word Lime " brings to 

 the minds of most people visions of lime 

 kilns and fine powdery slaked lime. The 

 natural form of lime^ however, is calcium 

 carbonate, and it may exist either as old 

 grey chalk, white chalk, or the Buxton and 

 North-East of England carboniferous lime- 

 stone. The crude limestone when burnt in 



chem i ca 1 ch a nges 



undergoes 



which alter its nature and composition 

 completely. From 44 to 46 per cent, of 

 carbonic acid gas is given off in the pro- 

 cess, and the original carbonate of lime is 

 changed into caustic lime or quicklime. 



Exposure of the latter material to air 

 results in a further change ; moisture and 

 carbonic acid will be absorbed, and a sub- 

 stance known as air-slaked lime is pro- 

 duced. This in time i-everts to its original 

 state, and gradually assumes the old pro- 

 perties it possessed prior to burning. When 

 chalk is burnt in the kiln^ one ton will be 

 found to yield about 11 or 12cwts. of quick- 

 lime, and the latter will vary in we ght 

 from 70 to lOOlbs. per bushel. 



Quicklime or caustic lime is of a powerful 



must be exercised 



mercial centre in the West, and to cater to a fruiting state, it is disappointing, to 



say the least of it, to watch it collapse and 



for its requirements in the way of fruit 

 orchards and plantations have been estab- 

 lished in its immediate vicinity. Bri:-tol 

 gets its earliest strawberries from the 

 Cheddar Vale in vSomerset, but some of the 

 befit come from Winterbourne in Glouces- 

 ter, where plums also flourish, and the most 

 popular local variety bears the name of the 

 Magnum Bon am. 



Silver-lea.f Disease. 



So much for local plums, but where they 

 will grow other commercial varieties w^ill 

 flourish also, and into the plum districts 

 have been introduced Victorias, Prolifics, 

 Czars, Monarchs, Pond's Seedling, Belle de 

 Liouvain, Gages, and other varieties, the 

 names of which are to be found in any 

 nurseryman's catalogoie It is not among 

 the native so much as the introduced varie- 

 ties that plum growlers in certain places are 

 perturbed and puzzled in respect of the 

 fatality amongst the trees. As an illustra- 

 tion of what I 



die, wnthout giving any w^arning 



Need for Research. 



Lastly there is a fatality about which 

 there is 



nature, and some 

 in using it on garden soils, especially where 

 it is merely required for manurial pur- 

 poses* Tomatoes, for example, are apt to 

 wilt and sicken where an excess of fresh 

 lime has been incorporated with the soil. 

 The plant roots cannot penetrate into the 

 soil freely, and sometimes the magnesia 

 contained in the lime exerts a very in- 

 jurious action on plant growth. Caustic 

 magnesia is harmful to plants, but car- 

 bonate of magnesia is a positive necessity, 

 although many gardeners do not think it 

 worth while to use this material. 



In a lecture delivered a year or two ago 

 before the Scottish Horticultural Associa- 

 tion, Mr, John Hunter, F.C.S., 

 stated that the great advantage of car- 

 bonate of magnesia is that it is capable or 

 being made soluble as required by 

 micro-organisms in the soil, and the ^^o- 

 portion in which to use ground lime and 

 carbonate of magnesia is five or six ( i 

 former to one of the latter. The small 



the 



mystery atached, and in 

 plum growino; districts there are several 

 varieties which are apt to die suddenly 

 when the trees have arrived at a state of 

 bearing. There is a reason for it, of course, 

 but it is not an easy matter to locate the 

 cause in some cases, and I have examined 

 more than one dead plum tree that be- 

 trayed no evidence of either Shot Borer or 

 other trouble that could be discerned with 

 the naked eye. Perhaps, when we get the 

 centres for research in matters of fruit cul- 

 ture, which, I suppose, are to be established 

 sometime out of the much-talked-about 



Development P\ind^ fruit growers will have than 85 per cent, o 

 places where they can send trees that die 

 mysteriously, and have them scientifically 

 examined, with the object of finding out 



n, I walked last autumn the cause. 



H. 



addition of magnesia was said to uxrease 

 nitrification twenty-fold. It is this ooti- 

 stituent of soils that gives the fine jU'^^? 

 sweetness to cultivated apples, which .s s 

 strikingly deficient in the crab apple, ano 

 it affects all fruits similarly. Both earlier 

 maturity and finer quality are ascribed 

 carbonate of magnesia. , r 



Ground lime is often recommended ru^ 

 horticultural use, the rate of usage bein^ 

 something like 7Ib. to 30 square yaru_ 

 In any case, w^here it is intended .^""P' x 

 this material in the garden, n^^^*"^. 

 the best quality lime is worth using, xn^^^ 

 being a guaranteed percentage ot 



f carbonate ot in^^ 



Moreover, this material should alwajs^^ 

 sown at the time of digging the J 

 Where the land has long been inanu 

 with farmyard manure, small appuc* 



