88 NEW YORK STATE ^FUSEUM 



application of a miscible oil, find their counterpart in the case of 

 certain fruit trees. The early history of the use of miscible oils in 

 New York State contains several instances of severe, though some- 

 what restricted injury following treatment. In one instance young 

 trees were dipped when the temperature was below 40° F. The 

 buds were killed and the stock ruined. In another case a number 

 of trees died after a fall application followed by a heavy, wet snow 

 which remained on the trees for a day or two and undoubtedly 

 promoted penetration by the oil. 



The most extended injury following spraying with a miscible 

 oil came to our attention last June. An apple orchard at Athens, 

 set twelve years ago, was sprayed Thanksgiving week or the one 

 following in 191 1 with a miscible oil used at the rate of 4 gallons 

 to 50 gallons of water, and about 160 trees, mostly Baldwins, were 

 dead or in a dying condition at the time of our examination (plate 3, 

 figure 2). There was severe and general injury to a considerable pro- 

 portion of the orchard thus treated. Nine-tenths of the apple trees 

 in one representative section were dead or nearly so. One tree said 

 to have been sprayed with the wind from the north had most of its 

 branches on that side killed. The restriction of the injury on other 

 badly affected trees was such as might be expected if the damage 

 were caused by spraying. Furthermore, dying limbs were girdled 

 by dead inner bark near the middle or at the base, the affected 

 tissues being dark brown, sappy and with a sour or acid odor. 

 Many of the twigs had a reddish brown bark with some discolora- 

 tion of the wood. The buds on some of the limbs failed to start, 

 while many had only sufficient vigor to develop leaves about one- 

 quarter the normal size. Later in the summer, with the approach 

 of drought conditions, some of the badly affected trees and most 

 severely injured branches succumbed. About the middle of July 

 there w^as an abundant development on the dead wood of a fungus 

 identified by State Botanist Peck as Naemospora croceola 

 Sacc, a species which subsists only on dead bark. Numerous 

 vigorous shoots appeared on the trunk and the larger limbs of the 

 badly affected trees in early summer, and by fall had made a fair 

 to extremely good growth, thus eliminating the probability of root 

 injury. Trees most severely affected were practically free from 

 San Jose scale or other insect pests which might have been a pos- 

 sible cause of the trouble. A number of smaller trees just to the 

 west of one part of the badly affected area were sprayed at the 

 same time, the insecticide being used at the rate of 3 gallons to 50 



