-14- 



2) Quince Rust : 



Quince rust was unusually prevalent on Red Delicious fruits. 

 We feel that this is due to late application of the first rust 

 spray. The first application should be made when the pink stage 

 is just beginning. Use of a broad- spectrum fungicide for both 

 scab and rust might be a good idea in problem orchards. 



3) Frog Eye Leaf Spot : 



Frog eye leaf spot (foliar stage of black rot) was unusually 

 prevalent on early-season leaves, especially on Cortland. Be- 

 cause of extensive early infections, most of these leaves fell 

 off and little fruit or later leaf injury was noted. 



4) Black Rot: 



Black rot was not severe on fruit. In older, poorly pruned 

 orchards, however, many major tree limbs were heavily cankered 

 or killed back by the black rot fungus. A "Yellow Bark" syndrome 

 was noted on the trunks of some apparently healthy trees in 

 several parts of the state. The black rot fungus was isolated 

 from "Yellow Bark" areas. We are currently investigating the 

 relationship of the black rot fungus to "Yellow Bark" and the 

 significance of "Yellow Bark" to tree health and vigor. 



Poor Apple Growth Disease (PAGD) : 



We investigated six cases of PAGD in 1978. The problem with 

 newly-planted trees either on old or new orchard sites that grow 

 poorly and unevenly and when severely affected they may die. The 

 cause of PAGD is unknown and we are examining possible causes under 

 controlled conditions. 



Cedar Apple Rust and Powdery Mildew : 



Neither of these diseases was a problem this past season. 



Fire Blight : 



Scattered pockets of fire blight were noted, principally in 

 Western Massachusetts. Mutsu and the Wayne were particularly sus- 

 ceptible. 



Summer Fruit Problems : 



Low level incidence of black rot, bitter rot, fly speck, and 

 white rot were noted late in the season and at harvest. 



The IPM survey involved 20 orchards in central and western 

 Massachusetts. These were surveyed routinely throughout the season. 

 Results for the full-season survey are given on the next page. 



