October 2, 1866. ] 



JOUKNAL OP HORTICULTURE AND COTTAGE GARDENER. 



25$ 



WEEKLY CALENDAR. 



GRAPES SHANKING AND SPOTTING. 



APES shank owing to two 

 causes — viz., a deficiency of 

 Bap, and vitiated sap. 



1st, Deficiency of Sap. — 

 This may result from the 

 great disparity between the 

 temperature of the ground in wliich the roots are situated 

 and that of the house where the foliage and fruit are. In 

 the case of outside borders there is very often a difference 

 of 10° between the mean temperature of the house and 

 that of the border, and in a hot, dry day the leaves and 

 fruit will throw off moisture rapidly, but the roots fnrnish- 

 ing sap slowly, too little will be pumped up to meet the 

 requirements of the expanding fruit. The footstalks of the 

 berries will therefore shrivel, or become ulcerated, and a 

 complete stoppage of the communication between, the roots 

 and the berries will be the consequence, ending in the 

 shrivelling of the berries thus cut off from further supplies 

 of sap. Shanking may, therefore, be the effect of the roots 

 not famishing sap in sufficient quantity for the demands 

 of the expanding fruit, through the disparity between the 

 temperature of the ground and that of the air ; and yet that 

 in all cases will not cause shanking, for the condition of 

 the roots may lie such that they will supply sap fast enough, 

 or there may be enough stored up in the stems to meet 

 any sudden demand of the expanding fruit. This, how- 

 ever, can only be the case where the roots are in a medium 

 favourable to the formation and preservation of the fibres 

 and their points or spongioles. Shanking, therefore, may 

 not be the effect of too great a difference between the tem- 

 perature of the soil and atmosphere ; but the conditions 

 unfavourable to shanking are elevation, dryness, and open- 

 ness of the border, which are essential to the preservation 

 of the fibres in health until the crop is mature ; whilst 

 the predisposing causes of the disease are lowncss, wet- 

 ness, and closeness of the material of the border. In short, 

 all outside borders have a tendency to cause shanking, 

 for, however dry they may be rendered by drainage and the 

 materials of which they are formed, yet very wet and cold 

 weather when the fruit begins to colour may so retard 

 root-action as to induce shanking through an insufficiency 

 of sap. arising from inactivity of the spongioles. 



A deficiency of sap may also result from the border 

 being not only outside, but also below the level of the 

 surrounding ground, and deep, rich, and imperfectly 

 drained. This is generally the case when shanlcing is 

 most severe. Than roots situated deep beneath the sur- 

 face, and in a manner shut out from all sun and atmo- 

 spheric influences, in conjunction with excessively rich soil, 

 nothing further is required except a period of cold rainy 

 weather when the Grapes commence ripening, to cause the 



No. 283.— Vol. XI., New Series. 



speedy destruction of the fibres (never very plentiful!, 

 rendering the supply of sap insufficient for the expansion 

 of the fruit, and as a consequence the berries shank. 

 Examine at what time we may the roots of Vines situated 

 in a deep, rich, low, wet border, we shall find them little 

 better than so many bare sticks, with a few fibres at the 

 ends — in winter almost entirely rotten and dying back, 

 and what can we expect but that similar destruction of the 

 fibres will take place in summer when the same conditions 

 of coldness and wet present themselves ? Too great a 

 depth of soil, roots too deep, soil wet, too rich, and cold in 

 comparison with the temperature in which the branches 

 and fruit are situated, will destroy the fibres, and cause a 

 deficiency in the supply of sap, owing to wliich the foot- 

 stalks of the berries or parts of the bunches will become 

 ulcerated. 



An insufficiency of sap may also result from depriving 

 the Vines of too much foliage either in the current or the 

 previous season. It is not unusual to keep vineries warm 

 and moist, with no great amount of air after the fruit has 

 set, in order to secure root-action ; a great breadth of 

 foliage is produced, and when the fruit begins to colour, or 

 a little before, a great part of the leaves is suddenly re- 

 moved under pretence of getting the fruit well coloured, 

 and thus the foliage not being in proportion to the fruit 

 and to the root, it cannot assimilate the extraordinary 

 amount of sap driven into it : hence the roots are ren- 

 dered inert, and their destruction follows either when the 

 weather proves wet and cold, or a good supply of water 

 is given to help the second swelling. The roots are now 

 gone, but more air is given, the evaporation from the leaves 

 becomes excessive, the roots do not supply sap fast enough 

 for the swelling fruit, and shanking of the footstalks of the 

 berries and bunches follows. This is not so common a 

 cause of shanking as coldness and wetness of the border, 

 but it does sometimes occur with Vines planted in an in- 

 side border. 



The remedial measures are to form the border inside, 

 or have it warmed by hot- water pipes in chambers under 

 it, to protect it from heavy and cold rains, to form it 

 in all instances where practicable above the surrounding 

 ground level, and to provide the most effectual drainage 

 possible, and this more particularly where the soil is of a 

 cold, wet, clayey nature. I found that the Vines planted 

 in a border sunk so as to be level with the surround- 

 ing surface, always had a tendency to shanking in the 

 bunches which they produced, even after they had been 

 lifted and the border thoroughly drained. The following 

 course was therefore adopted : — The surface of the border 

 was concreted with lime riddlings and gravel well pounded, 

 and two-inch drain \ in w. re laid thereon, so as to form 

 one drain lengthwise 18 inches from the front lights, 

 another a like distance from the back, and one in the 

 centre. These drams extended the length of the border, 

 came out a yard beyond it at each end. and were crossed 

 by similar pipes extending from the front to the back of 

 the border, forming, where they crossed those laid longi- 

 tudinally, a four-inch opening or parting covered with a 

 tile. The cross drams were 4 feet apart. Upon the tiles 



No. 940.— Vor.. XXXVL, Old Sertes. 



