Results 



The annual incidence of each fruit and foUar pest 

 in the Conway orchard across the 20 years of orchard 

 operation is depicted in Figures 1 and 2 in the form of 

 regression lines that express pest incidence as a 

 function of time. If a line shows an upward slope from 

 1981-2000, it means there was a positive relation 

 between pest incidence and time. That is, the pest 

 tended to increase in incidence over time. If a line 

 shows a downward slope from 1981-2000, it means 

 there was a negative relation between pest incidence 

 and time. That is, the pest tended to decrease in 

 incidence over time. 



Among insect pests of fruit in the Conway orchard, 

 only lesser appleworm showed a tendency to increase 

 in incidence from 1981-2000, but the increase was 

 slight and not significantly different from zero. All 

 other insect pests of fruit, including tarnished plant bug, 

 European apple sawfly, plum curculio, green 

 fruitworm, codling moth, leafroUers and apple maggot 

 showed a tendency to remain about the same or 

 decrease in incidence from 1 98 1 -2000. Decreases were 

 significantly different from zero only m the cases of 

 tarnished plant bug and green fruitworm. There was 

 no incidence whatsoever of San Jose scale during the 

 entire 20 years. 



Among disease pests of fruit in the Conway 

 orchard, both sooty blotch and flyspeck showed a 

 significant tendency to decrease in incidence from 

 1986-1990 (when incidence of these diseases was first 

 sampled and when no management measures were 

 used) to 1991-1995 (when three types of wild hosts 

 within 100 yards of the orchard were removed) and 

 thence to 1996-2000 (when two summer fungicide 

 sprays were applied annually). There was no incidence 

 of apple scab during any of these years. 



Injury by birds in the Conway orchard showed a 

 significant tendency to decrease from 1986-1988 (when 

 no balloons were used as repellents) to 1989-2000, 

 when balloons were employed throughout (data not 

 shown). 



Among arthropod pests of foliage in the Conway 

 orchard, three pests (mites, woolly apple aphids and 

 leafminers) showed a tendency to increase in incidence 

 from 1986 (when first sampled) to 2000, but the 

 increase was significantly different from zero only in 

 the case of leafminers. White apple leafhoppers 

 showed a tendency to decrease (but not significantly) 



from 1986-2000. In no year did populafions of any 

 foliar pest exceed levels considered potentially 

 injurious. 



Compared with annual pest incidence (across the 

 two decades) on fruit of unmanaged trees 200-250 m 

 from the Conway orchard, annual pest incidence on 

 Conway orchard fruit (across the two decades) was 

 significantly less (at least eight-fold less) for seven of 

 the nine insect pests and apple scab, with especially 

 dramatic reduction in incidence of the four most 

 damaging pests: plum curculio (30-fold), codling moth 

 (150-fold), apple maggot (150-fold) and apple scab 

 (zero injury of orchard fruit) (Table 1). The only 

 exceptions were tarnished plant bug (against which no 

 protective measures were taken in the Conway orchard 

 and injury was not significantly different from that on 

 the unmanaged trees) and San Jose scale (whose level 

 of injury was ml in the Conway orchard and very low 

 on the unmanaged trees). 



Discussion 



Even though almost all of the elements that 

 comprised the bottom-up, ecological approach to pest 

 management adopted at (or shortly after) the outset 

 remained in place across the entire two decades of 

 Conway orchard operation reported here, there were 

 four exceptions. First, the applicafion of hay mulch 

 beneath orchard trees, instituted for the second quartile 

 (1986-90), had to be abandoned for the third and fourth 

 quartiles (1991-00) because of buildup of damaging 

 voles beneath the cover of mulch. Second, it was 

 necessary to introduce use of Scare-Eye balloons 

 during the second and for succeeding quartiles to deter 

 wounding of fruit by birds. Third, the encouragement 

 of growth and proliferation of all rosaceous plants in 

 areas bordering the orchard (except for unmanaged 

 apple, pear, hawthorn, and quince trees) had to be 

 abandoned at the beginning of the third quartile for 

 blackberry, whose canes supported progressive buildup 

 of summer disease inoculum during the first two 

 quartiles. Many large commercial orchards are 

 equipped to remove or diminish evidence of flyspeck 

 and sooty blotch on fruit by water-dipping and brushing 

 fruit before sorting. Lacking such equipment, I was 

 obliged during the second quartile to remove evidence 

 of these diseases by wiping fruit with a damp cloth, a 

 process that became uneconomical as yields increased 

 with tree maturity. Hence, during the third quartile, 



Fruit Notes, Volume 66, 2001 



