57 



failed to discover any bacillus or other fungoid parasite, 

 and relinquished further enquiry as fruitless, it is probable 

 that the cause has been sought for in the wrong direction, 

 and that yellows is not a morbid condition produced by 

 parasitic interference, but something far simpler, viz., con- 

 stitutional exhaustion brought about by a long course of 

 bad cultivation, as regards soil, abuse of irrigation, 

 neglect of skilled pruning and continuous over- crop- 

 ping. To avoid lepeating here the conclusions come to and 

 published in the Agricultural Journal after a close examina- 

 tion of numerous supposed cases of yellows in the Colony, 

 Ave will subjoin, on this matter, the views of the eminent 

 pomologist from whom we have already quoted : " We 

 believe the malady to be a constitutional taint produced by 

 bad cultivation and exhaustion, and perpetuated by sowing 

 the seeds of the enfeebled trees, either to obtain new- 

 varieties or for stocks. Let us look for a moment to the 

 history of peach culture. For a hundred years after its in- 

 troduction it was largely cultivated in perfect freedom from 

 disease and with the least possible care. The natural fer- 

 tility of the soil was then unexhausted, and the land occu- 

 pied by orchards was seldom or never cropped. Most of 

 it, though at first naturally fertile, was light and sandy, 

 and inevitably in course of time became exhausted. The 

 peach, always productive to excess in this climate, was no 

 longer able in the impoverished soil, to recruit its energies 

 by annual growth, and gradually became more and more 

 enfeebled and short lived. Wheat and grain crops bore 

 high prices, and the failing fertility of the orchard land 

 was still more lowered by a system of heavy cropping 

 between the trees without returning anything to the 

 soil. Still the peach was planted, left to produce a few 

 heavy crops, till it declined from sheer feebleness and want 

 of sustenance. It was then the custom for orchardists to 

 raise their own trees from seedlings, and the nurserymen 

 collected the stones quite indiscriminately for raising stocks. 

 Hence it is evident there were present all the conditions for 

 passing on a constitutional debility of the parent trees in 

 a greater or less degree to the seedlings. Still the system 

 of allowing the tree to exhaust itself by heavy and repeated 

 crops in a light soil was continued, and generation after 



