June, 1909 



THE CANADIAN HORTICULTURIST 



123 



Peach YcIIow^s* 



M. B. Waite, Pathologist in Charge, Investigation ol Diseases of Fruits, 

 U.S. Departn\ent of Agriculture 



WE have always considered that 

 three annual inspections, when 

 properly made at the right time, 

 were sufficient for finding trees affected 

 with yellows. It need hardly be men- 

 tioned that the important thing about 

 this work, when it is really undertaken, 

 is to find the diseased trees. Their 

 prompt removal, after being found, is a 

 secondary matter, which is to be taken 

 for granted. Ordinarily three inspec- 

 tions are sufficient. 



In Ontario, the first one should be 

 made in July or perhaps about August 

 1st; the second one should be made the 

 latter part of August or about September 

 1st, and the third late in September or 

 even running over into October. If a 

 previous eradication has never been car- 

 ried out, all plainly diseased trees should 

 be removed as soon as they can be noted 

 in the spring. It is always a good thing 

 to inspect a block or row of peaches 

 when they are ripening or about to ripen 

 their fruit. Then the symptoms of pre- 

 mature fruits can be utilized. It is al- 

 ways a good plan to have the pickers in- 

 structed to call attention to every tree 

 with suspiciously large or premature 

 red-spotted fruit. Orchards should be 

 inspected tree by tree, row by row, thor- 

 oughly, regardless as to whether they are 

 supposed to have the disease or not. In 

 1^ this way, unsuspected cases will often be 

 found. 



It seems to me that where a severe 

 outbreak occurs, doubling the number of 

 inspections may well be advised. That 

 would mean pretty nearly an inspection 

 about every two weeks from the first of 

 August. It certainly is advisable to 

 make a very late inspection in October 

 so as to prevent, if possible, the disease 

 carrying over another year. 



The orchardist or inspector is often 

 puzzled over a doubtful case. He dis- 

 likes to condemn a tree for removal un- 

 less certain that it is diseased. To my 

 mind, however, the real doubtful cases 

 which are not plainly caused by some 

 other disease or injury should invariably 

 be removed. One is certainly taking 

 chances of leaving infection behind when 

 he leaves these uncertain cases. It should 

 always be borne in . mind that the re- 

 moval is done for the benefit of the 

 healthy trees left behind. 



INSPECTION LAWS 



The best results are to be secured in 



districts where every orchardist will be 



his own inspector. No outside man can 



more quickly and accurately detect this 



disease than a peach grower in his own 



orchard. He knows the appearance of 



the trees on every different piece of land, 



soif, tjpe and exposure, and keenly re- 



•Seventh and concluding instalment of a paper 

 read at the conTention of the Ontario Fruit 

 urowera' Assooiation held in Toronto last Norem- 

 ber. 



cognizes and watches any change of" 

 symptoms which could be attributed to 

 the yellows. 



On the other hand, it is absolutely 

 necessary, to secure good work in a com- 

 munity, to have official inspectors. The 

 reason for this is that many growers, al- 

 though constantly in the presence of this 

 disease do not learn to recognize it in its 

 early stages, especially when the trees 

 are not in fruit. Furthermore, there are 

 a good many trees in gardens or by the 

 roadsides or otherwise out of commercial 

 peach orchards, that would receive no 

 attention. To secure proper uniformity, 

 therefore, some sort of an official inspec- 

 tor, no matter by whom paid, should be 

 employed. The smaller the unit, the bet- 

 ter. The less territory an official inspec- 

 tor must cover, the more thoroughly he 

 can be expected to accomplish his work. 



As a matter of fact, only a few or- 

 chardists in my experience have ever 

 done strictly first-class work in eradi- 

 cating the yellows. Many orchards oth- 

 erwise well cared for by progressive and 

 enterprising growers are still somewhat 

 neglected in this regard, and it is a ques- 



are found, with our present lack of 

 knowledge about the disease, we feel 

 that the only safe way is to dig the tree 

 up or pull it up with horses and destroy 

 it by burning. Perhaps the very safest 

 way of all is to bring dry wood into the 

 orchard and burn the tree on the spot or 

 in the centre of the colony, if there are 

 several trees, without dragging it out. 

 •As a matter of fact, however, there has 

 been so little unsatisfactory experience as 

 to make this seem an extra precaution. 

 Possibly it might be advisable to pull the 

 trees up and let them wilt or dry out 

 before removing from the orchard. At 

 any rate, there seems to be abundant 

 evidence that a dead peach tree, though 

 it may have had the yellows, is not dan- 

 gerous in transmitting the disease. 

 Never cut the tops off yellows trees 

 and leave them standing. Such trees 

 may still sprout out new growth and 

 from the yellows standpoint are still in 

 action. Kill the tree, root and branch, 

 at any rate. Many orchardists wish to 

 use their yellows peach trees for fuel, 

 and, while this is not supposed to be ab- 

 solutely safe, I have seen good results in 

 many cases where this was done. 



Summing up, therefore, I should say 

 that if you wish to be extra careful con- 

 cerning infection, burn the tree at once. 



An Orchard That is Kept Well Coltivited and in Good Condition 



Orchard of Mr. A. K. Sherrington, Walkcrton, Ontario, who may be seen in the illustration 



mind whether 



tion in my mmd whether the recent 

 severe outbreak in southern New York 

 and Connecticut cannot be to some extent 

 attributed to carelessness on the part of 

 the growers. I have been through these 

 states every summer for the last four 

 years and have been surprised to see the 

 yellows left so commonly scattered about. 



DISPOSAL OF DISEASED TREES 



A word in conclusion as to what to do 

 with the yellows trees after they are 

 found. The main thing, of course, is to 

 find the diseased trees, but when they 



but if the tree is promptly pulled out and 

 allowed to dry you have probably done 

 all that is possible in killing the disease. 

 Above all, the best advice I can give you 

 is to pull out and destroy every peach 

 tree in the province which shows the 

 slightest symptom of the yellows. If this 

 is carried out, especially if repeated for 

 two or three seasons in succession, all the 

 previous history and experience connect- 

 ed with this trouble points to success in 

 bringing this malady under control. New 

 orchards can then be rapidly planted out 



