42 PEACH YELLOWS. 



Of course, it is impossible to predict the results of this experiment. 

 We must wait and see. I shall continue to watch the parent trees as 

 well as their progeny. I feel reasonably confident that trees with sound 

 constitutions have been secured, and I know beyond a doubt that they 

 are in excellent locations to test their resisting power. 



(3) A twice repeated effort to introduce a sound race of peaches from 

 Turkestan has miscarried. It seemed like an easy matter to procure 

 peach stones in quantity through our consul at Teheran, but it has 

 proved very difficult. The second attempt was made in 1889 through 

 the Department of State, but with no better results. 



It appears to me safer to import stones than trees. If the latter are 

 introduced, great care should be exercised to avoid the introduction at 

 the same time of animal and vegetable parasites which might prove 

 worse than the yellows. The history of the introduction of the cottony 

 cushion scale into the orange groves of California, and of phylloxera, 

 peronospora, and black rot into the vineyards of Europe ought to be 

 sufficient warning. The danger is a very real one. 



In Mediterranean countries and also in Australasia there is a fruit fly 

 (Tephritis) which once introduced into this country would work great 

 mischief. It deposits its eggs in the fruit after it is nearly full grown, 

 and these hatch into swarms of maggots, which pupate in the ground. 

 Externally the fruit is said to be fair, but within it is disgusting corrup- 

 tion. The peach is specially subject to this fly, but apples, pears, 

 plums, and other fruits are also attacked. The -loss is great and no 

 remedy is known. In Japan there is a codlin moth which is said to 

 affect 90 per cent of the ripe fruit. This insect probably occurs also 

 in China. In the Australasian region there is also a very destructive 

 root fungus, not confined to the peach. The mycelium of this fungus 

 creeps through the soil long distances destroying almost every green 

 thing in its path. There is also an obscure peach disease fully as de- 

 structive as yellows and apparently of a totally different character. The 

 orchards of the north island of New Zealand have been almost com- 

 pletely destroyed by it, and it probably occurs elsewhere in that region. 



This enumeration by no means exhausts the list of parasites which 

 might be introduced into this country with imported peach trees. As 

 the case stands we have enough of our own without importing any. 



(4) Additional experiments will be necessary to determine what pro- 

 portion of cases are attributable to the careless selection of buds. 

 Yellows is undoubtedly communicated in this way, but it must spread 

 in other ways. I have known many orchards of budded fruit where the 

 trees flourished and bore abundantly for 15 or 20 years, or even longer, 

 before the disease appeared. In such cases, admitting the contagious 

 nature of the disease, we are driven to one of two conclusions : the 

 cause of the disease has entered the tree from without, or has been 

 dormant in it from the time it was budded. The former is reasonable; 

 the latter is absurd, especially in the light of the comparatively speedy 

 results obtained from inoculations. 



