What is the cause of the problem with lack of uniformity in 

 some plantings of Macspur in British Columbia? Is it due to bud 

 selection? Is it due to a mixing of standard and spur-type trees? 

 Is it due to bud mutation? To date no one has come up with the 

 answer. It may take several years before an answer can be found. 

 However, it can be stated that it is thought that the variability 

 exhibited by Macspur in B.C. is related to bud selection rather 

 than reversion since the problem has been limited to whole trees, 

 not individual limbs. 



1979 DISEASE RESULTS FOR THE MASSACHUSETTS 

 APPLE PEST MANAGEMENT PROGRAM 



T. R. Bardinelli, C. W. McCarthy, and W. J. Manning 



1 



The 1979 growing season marked the completion of the first full 

 year of operation of the disease component of the Massachusetts 

 Apple Pest Management Program. The objectives of this part of the 

 program include using and developing predictive tools to time fungi 

 cide applications to achieve more effective management of apple 

 diseases . 



Seven growers participated in the 1979 disease management pro- 

 gram. Disease management blocks (10 acres) and control blocks were 

 established in each orchard. This allowed direct comparison of 

 results from control and disease management blocks located in the 

 same orchards. 



Apple scab is the ma 

 was focused on it. Seve 

 apple scab. The best kn 

 periods for primary appl 

 length of wetting period 

 during the wetting perio 

 whether or not an infect 

 thermograph was modified 

 orchard temperatures. U 

 devised that was used by 

 decide whether an infect 

 an eradicant kickback sp 



jor disease to be managed and most attention 

 ral predictive tools are available to manage 

 own is the Mill's Table (Table 1). Infection 

 e scab can be determined by measuring the 

 s and relating it to average temperatures 

 ds . The table can then be used to determine 

 ion period has occurred, A recording hygro- 



to continuously monitor leaf wetness and 

 sing this information, a predictive table was 



participating growers to allow them to 

 ion period had occurred and whether to apply 

 ray. 



Extension Technician, Scout, and Associate Professor, Department 

 of Plant Pathology, University of Massachusetts at Amherst. 



