448 



JOURNAL OF HORTICUIiTUEE AND COTTAGE GARDENER. 



[ Jime 27, 188T. 



There is not only some difference of opinion as to the time, 

 bnt also as to the amount of summer pruning. The time is 

 solely dependant on the season, and the vigour of the trees. 

 The amount of pruning depends on the growth of the trees 

 operated on, for tliat of some trees is so weak that it may be 

 necessary to encourage it ; others are not weak in growth, but 

 are vigorous enough to produce fine fruit ; whilst some are so 

 vigorous that the spurs are not nearly so jdentiful as the shoots, 

 and the fruit fewer in number than the spurs. Now, to fix any 

 time as the most suitable for summer pruning, and to limit 

 the extent of the pruning to any one rule is impraoticablc, as 

 it is evident that different trees require different treatment. 



All shoots and laterals not required for the extension of the 

 tree, or to fill up vacant space, must be summer-pruned or 

 pinched, whether they spring from the young or old wood ; but 

 the leading shoots, or those shoots required for the extension of 

 the tree, should not be pruned, except in the case of pyramidal 

 or bush trees, in which, when the leading shoots make a greater 

 gi'owth than 12 inches, these should have their points lunched 

 at that length. It the trees have covered as much space as is 

 allotted to them, then the leading shoot, and, in fact, all the 

 shoots, should be stopped or pruned in the same manner as 

 the laterals. 



Very few trees are so tractable as to produce good crops and 

 require no pruning, or if there are such (as I have had a few 

 instances), the fruit is generally small, and iudifferent in qua- 

 lity. In such rare cases, no shortening of the summer shoots 

 being practicable, or at least desirable, any that show them- 

 selves should be allowed to grow, and not be stopped until the 

 second week in July, when they may have their points taken 

 off immediately above the sixth leaf, and that is all the pinch- 

 ing they will need. 



Trees that are moderately vigorous, or those with shoots not 

 exceeding from il to 12 inches in length, should not be pruned 

 until the fourth week in .lune or first week in July, according 

 to the season, when they should have the points of all the laterals 

 taken out at the sixth leaf, and when they push again, as in all 

 probability they will, take out their points at the third joint 

 above the last stopping, or from the base of the last growth. 



Trees that are vigorous, and make shoots when unrestrained 

 of 15 or 18 inches in length, should have the points of the 

 shoots taken off above the fifth leaf, and all growths after the 

 first stopping should be pinched off at the third leaf until the 

 beginning of September, when pinching should cease. 



Trees of very strong and rampant growth should be stopped 

 as soon as they have made four leaves, and repeatedly through- 

 out the summer up to September at the third leaf, after the 

 first stopping. 



Trees upon the Quince stock may be stopped in all cases one 

 or two joints closer than those on the Pear. The most vigorous 

 shoots will be those at the top of the wall, or where the greatest 

 amount of winter pruning is practised ; but, wherever they are, 

 the strongest shoots will of course attain a length fit for pinch- 

 ing sooner, and they ought to be the first stopped or pinched, 

 and in the course of a few days the remaining shoots should 

 be stopped. In all cases, in calculating the number of leaves 

 for stopping, do not count the latent or undeveloped buds at 

 the base of the shoots, of which there are always two or more ; 

 OJily the leaves should be counted, and not the joints or buds. 



Any trees with the branches weaker in one part than in 

 another may have the laterals upon the strong branches closely 

 pinched, whilst those upon the weak branches are allowed to 

 grow without stopping until September, when a few inches 

 may be cut from the extremity of each, and these in winter 

 should be cut back to within an inch of their base. In spring 

 a number of shoots will spring from the short stub left. All 

 of them except one should be pinched, that one being left to 

 grow unrestrained until September, when a few inches of its 

 point may be removed, and cut close away at the winter prun- 

 ing. The shoots pinched throughout the summer should be cut 

 in winter to within 1 inch of their base. We have now a stub 

 two years old, on which fruit-buds are usually produced. It 

 is hardly necessary to add that the short stubby shoots (spurs), 

 with a bunch of leaves, are not to be stopped, for on them 

 fruit-buds form. — G. Abbey. 



GYPSUM AS A FERTILISER. 



SuiiBHATE of lime, popularly called gypsum, or plaster of 

 Paris, is, in many portions of America, the mineral manure in 

 most general use. As found in the refuse of salt-works, it 



acquired a local celebrity in some parts of Europe seveial 

 centuries ago, but the employment of the pulverised rock for- 

 agricultural purposes only dates back to about the period of the 

 American Revolution. 



Gypsum is a compound of 41.5 parts lime with 58.5 parts- 

 sulphuric acid ; in its natural state it also contains about: 

 twenty per cent, of water. 



It is very sparingly soluble in water, requiring 460 grains ol 

 water to dissolve a grain of gypsum. This lack of ready solubility 

 would at first thought be considered as objectionable to its use, 

 but really it is a most beneficial property ; for if it were, 

 dissolved as easily as salt, its benefit to the plant would not be 

 so lasting, and it would require frequent applications to make 

 it productive of much good. Besides this, any mineral salt,- 

 although it may be absolutely essential to the growth of thei 

 plant, if furnished in too great abundance acts as a poison 

 rather than as food. Now as plants only take in earthy matter- 

 when in a state of solution, it is evident that a substance which> 

 will allord a lasting rather than an extensive supply will be 

 most advantageous. 



The manner in which gypsum acts to increase the produc- 

 tiveness of our fields is a subject on which there have been 

 more discussion and controversy than any other connected with 

 agricultural chemistry ; indeed, there have hardly been two 

 writers who have advocated the same theory respecting it. 

 Davy regarded it simply as an essential constituent of the 

 plant, and held that it was not decomposed, but that it entered 

 the plant as gypsum. Liebig holds that its chief use is to fix 

 the ammonia of the air. According to his theory, a double 

 decomposition is effected in the sulphate of lime and the 

 carbonate of ammonia, sulphate of ammonia and carbonate of 

 lime being the result of this decomposition. Hedwig compares 

 the action of gypsum on the food of the plant to the action of 

 the saliva and gastric juice on the food of the animal. That 

 gypsum thrown into stagnant water that contains vegetable 

 .and animal substances in a state of decomposition, will cause 

 the production of sulphureted hydrogen, and will also produce 

 a more rapid decay of the vegetable and animal tissues, has 

 often been noticed. To effect this result, it is evident that the 

 sulphuric acid must be decomposed ; the oxygen uniting with 

 the carbon of the organic matter to form carbonic acid, and the 

 sulphate combining with the hydrogen. 



To apply gypsum with a oerlainty of producing the best 

 results, requires ruore theoretical and practical knowledge than 

 does the employment of most manures. Composts, and the 

 solid and liquid excrements of animals, can seldom be used 

 without benefit, whatever be the soil in which they are placed, 

 or the crop it is intended to produce. They are, in a m.inner, 

 universal fertilisers, from the fact that they contain the 

 essential food of almost every plant. But with gypsum the 

 case is very different. Indeed experience has proved that 

 gypsum of itself is quite inadequate to produce fertility, and 

 that it is only when it acts in conjunction with vegetable 

 manures that its value is most apparent. It is also true that 

 the longer it is used the smaller are the number of crops 

 which are deemed benefited by its apjilication. 



It is now well settled that it promotes the formation of woody 

 fibre .and adds to the luxuriance of foliage, and that it protracts 

 the period of the growth of the plant, or in other words, delays 

 the time of its maturity. Dust gypsum on half the area of S 

 clover field and the following distinctive results will ordinarily 

 be observed : The leaves will be longer and of darker colour, 

 the stalks more hardy and consequently less liable to lodge, 

 and the period of blossoming will be delayed several days ; the 

 number of flowers being comparatively smaller than in that 

 part of the field not so treated. 



Now all these results are desirable in the production of clover ; 

 particularly are they so when sheep-growers bear testimony to 

 the statement that sheep manifest a preference for, and eat with 

 greater avidity, the clover raised under such circumstances. 



On other crops, however, when the object is to produce seeds 

 or fruits, rather than stalks and foliage, the use of this substance 

 would not be desirable ; particularly would this be the case 

 where an early harvest is desired. Thus, the use of gypsum 

 has becu objected to in the cultivation of Strawberries, for the 

 reason that it tended to the production of Strawberry hay rather 

 than berries. 



Too large an amotmt of it applied to Potatoes, either in the 

 hill or as a top-dressing, has been found to produce a luxuriant 

 growth of tops and comparatively small tubers ; but a small 

 quantity placed in the hill or on the sprouts when they are 

 first breaking through the soil, has been found to be highly 



