APS_Jan2023

J ournal of the A merican P omological S ociety

20

Table 5. Cause of tree death (2015-19, no.) of Modi® apple trees at individual planting locations in the 2015 NC-140 Organic Apple Rootstock Trial. Tab 5. Cause of tree death (2015-19, no.) of Modi® apple trees at individual planting locations in the 2015 NC-140 Organic Apple Rootstock Trial.

Causes of tree death (tree no.)

Initial tree count (no.)

Tree death (no.)

Tree death (%)

Weed competition Breakage

Vole s Voles

Fire blight

Dogwood borer

Winter injury

Unknown cause

Loc CA CA CA CA CA CA CA CA CA CA CO CO

Root

G.011 G.030 G.041 G.202 G.214 G.222 G.890 G.935 G.969 G.890 G.935 G.016 G.041 G.214 G.935 G.011 G.041 G.214 G.935 G.011 G.016 G.214 G.222 G.935 G.969 G.969 G.030 G.041 G.202 G.214 G.890 G.030 G.890

12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 7 6

5 4 2 1 8 3 2 3 4 9 1 2 1 1 1 1 2 1 1 1 1 1 1 3 2 1 1 1 1 1 1 1 5 1 1 1 1

42 33 17 67 43 17 25 33 75 8

1 3

4 1 2 1 6 3 1 3 1 7

2

1

1 2

2

M.9T337

8

1 2

17 17

ID ID ID ID

1

8 8 8 8 8 8

1

1

1 2 1 1 1 1

MA MA MA MA MA NM NM NM

17

M.9T337

9

11

12 12

8 8

1 1 3 2 1

M.9T337 M.9T337

9 9

33 22

NS

NYG NYG NYG NYG NYG NYG

12

8

5

20

1 1

12

8

7

14

1

12 12 12 11 11 12 12 12

8 8 8 9 8 8 8

1

1

NYI

1

VT VT VT VT VT

45

1

2 1

2

1 1 1

yields were from trees on G.222 and G.214 (Table 3). For the main effect of location, the highest yields were harvested in Idaho, and the lowest were from California, Colo rado, and Massachusetts (Table 3). Cumula tive yields were mostly consistent across site (Table 7). Trees on G.890 and G.935 were

among the highest yielding rootstocks, and trees on G.222 and G.16 (where planted) were among the lowest yielding rootstocks. The effect of rootstock on yield efficiency in 2019 was consistent across sites (Table 3), but trees in Idaho were most yield efficient and those in California, Colorado, and Mas