190 STATE HORTICULTURAL SOCIETY. 



July 22, 1891, i, e., 3 years from the beginning of the experiment. They 

 were still entirely free from yellows, or any symptoms suggestive of that 

 disease, and were more vigorous than in 1890, owing to the turning under 

 of a crop of scarlet clover. 



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 constitu- 

 tions 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 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 ninety 

 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 destructive 3s yellows and appar- 

 ently of a totally different character. The orchards of the north island of 

 New Zealand have been almost completely 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. Yel- 

 lows 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 fifteen or twenty 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. 



One of the most striking examples which has come under observation is 

 a tree on the home farm of James S. Harris, near Still Pond, Maryland. 



