ANALYSIS OF REPLIES TO QUESTIONS BY FRUIT-GROWERS. 56 



number of theories have been propounded by growers to account for it. Some of the principal 

 theories and opinions are here given: — 



(a) Excess of sap is the most common reason given. Heavy rains after a dry spell 



cause a sudden flow of sap, and this abundant supply of sap may receive a sudden 

 check. ^ Excess of sap will produce overgrowth in the fruit, and in nearly every 

 case it is the large overgrown apples which are affected. Uneven and irregular 

 flow of sap is also mentioned, as in those cases where Pit occurs during dry seasons 

 with occasional thunderstorms.—" I feel sure it is caused by too free a flow of 

 sap, which, of course, may be caused in many ways, such as heavy pruning, 

 strong growth of young trees, a wet spring, or heavy showers at long intervals 

 during the end of the ripening season— anything, in fact, which causes a sudden 

 or exceptional flow of sap." " My idea of Bitter Pit has been where trees have 

 suffered in the summer with drought, then heavy rain falling has caused a rush 

 of sap. I have irrigation for my orchard, and never let a tree suffer from want 

 of moisture, then when rain comes there is no excessive rush of sap, and I suffer 

 less than my neighbours, who trust to the natural rains. In fact, my loss is not 

 worth mentioning." " Young trees are more subject to it than old. I find it 

 less prevalent as the trees become mature." " After a close study for many years 

 I have thought that it is caused through an irregular flow of sap. My reason 

 for advancing this theory is, that one season part of an orchard that had a strong 

 vigorous growth was left out in the early watering. After a spell of dry weather 

 the trees showed signs of dryness, the water was put on, and the trees on that 

 part had the worst attack of Bitter Pit I have known." 



(b) Severe pruning.— " Trees bearing fruit on well-ripened wood are not affected, but 



if pruned heavily and a light crop of fruit on a vigorous growing tree, it is most 

 likely to occur." " T think severe priming causes a vigorous flow of sap 

 which helps to develop Bitter Pit." " Extreme variations of temperature and 

 excessive moisture are important factors in producing the disease. In pruning, 

 great judgment is necessary. T consider that the modern method of training 

 the trees to a very limited number of branches is responsible for a great deal of 

 the disease, as the sap, being concentrated in a few channels, becomes too strong 

 for the regular development of the fruit." "I am fully convinced that pruning 

 has nothing to do with it, as six Cleopatra trees, twenty years old, I have growing 

 in a gully have never been pruned, and they were as bad or worse than any tree 

 I have got — as bad as the young Cleopatra trees five years old, which have been 

 pruned." " We can only say that we know that hard cutting back of the leaders 

 will produce apples badly affected. Our treatment is to cut the leaders very 

 little, and, by a judicious thinning every year, we keep our orchard practically 

 free of the disease." In this orchard there is a red sandy soil over red clay 

 subsoil. 11 Less pit on apples grown on left laterals." 14 Slight benefit effected 

 by leaving lateral growths." " Tf vou prune" hard you are liable to intensify 

 it." 



('*) Want of drainage and excess of moisture. " Where the land is wettest the Pit is 

 worst." 



(d) Unsuitable stocks.—" I think that if a change in the stock were tried it might be 

 an advantage. The principal stock used is Northern Spy, and it is the worst 

 affected with us." " I consider if the Winter Majetin stock was more in use 

 there would be loss Bitter Pit." Meier Brothers, of Kilsyth, Victoria, have a 

 number <»f trees worked on seedling stocks, viz., Jonathan, Five Crown, Yates, 



