BBI = 1 / (n-1) X \{|(a2 - a1)| / (a2 + a1) + |(a3 - a2)| / (a3 + a2) ... + |(a(n) - a(n-1))| / (a(n) + a(n-1))\} where n = number of years, and a1, a2, ..., a(n-1), an = yield of corresponding years.
y The Biennial bearing index (BBI) was calculated on the basis of the Pearce and Debusek-Urbank formula (14):
2A freeze event in 2003 killed all developing fruit, therefore data was not recorded in this year.
Clone 2002 2004 2005 2006 Biennial bearing index (2004-2006)y
Middletown 3.7 abc 7.1 f 3.5 ghij 6.2 hi 0.56 abcd
Mitchell 0.5 fg 8.1 def 2.9 ij 7.1 ghi 0.56 abcd
NC-1 1.4 cdefg 8.3 def 3.7 ghij 11.3 defgh 0.62 ab
Overleese 1.7 cdefg 6.6 f 4.9 defghij 10.1 efghi 0.56 abcd
PA-Golden 5.7 a 14.4 abcde 8.8 ab 17.2 ab 0.25 fg
Potomac 1.8 cdefg 12.8 bcdef 5.7 cdefghi 12.8 bcdef 0.54 abcd
Rappahannock 1.9 cdefg 14.0 abcdef 4.3 fghij 11.5 cdefgh 0.29 efg
Shenandoah 2.9 bcdef 17.0 ab 4.3 efghij 13.1 abcdef 0.49 abcde
Sunflower 3.8 abc 11.8 bcdef 3.8 ghij 16.7 abc 0.22 g
Susquehanna 1.0 defg 8.2 def 5.1 defgh 8.8 efghi 0.46 abcde
Taylor 2.0 bcdefg 9.6 cdef 3.5 ghij 7.9 fghi 0.46 abcde
Taytwo 1.5 cdefg 9.1 def 6.7 bcdef 10.2 efgh 0.43 abcdef
Wabash 2.3 bcdefg 11.0 bcdef 8.0 abc 13.4 abcde 0.40 cdefg
Wells 2.5 bcdefg 7.9 def 4.9 defghij 5.0 i 0.42 bcdefg
Wilson 1.5 cdefg 10.5 bcdef 6.0 bcdefgh 13.0 abcdef 0.58 abc
1-23 3.5 abcd 13.3 abcdef 4.1 ghij 12.0 bcdefg 0.56 abcd
1-68 3.2 abcde 14.4 abcd 5.6 cdefghi 16.6 abc 0.32 efg
2-10 1.8 cdefg 8.4 def 6.4 bcdefg 11.7 bcdefgh 0.29 efg
2-54 0.9 efg 7.5 ef 3.1 hij 12.8 bcdef 0.40 bcdefg
3-11 2.0 bcdefg 10.7 bcdef 2.5 j 15.9 abcd 0.32 efg
3-21 0.4 g 6.1 f 4.7 efghij 8.4 efghi 0.55 abcd
5-5 0.4 g 9.5 cdef 6.6 bcdefg 8.8 efghi 0.35 defg
7-90 1.2 defg 12.4 bcdef 7.8 abcd 13.6 abcde 0.63 a
8-20 3.1 bcde 16.3 abc 2.9 ij 12.5 bcdef 0.28 efg
9-47 1.0 defg 11.1 bcdef 5.8 cdefgh 9.0 efghi 0.41 bcdefg
9-58 1.6 cdefg 7.9 ef 4.7 efghij 15.9 abcd 0.35 defg
10-35 4.5 ab 19.7 a 9.6 a 18.2 a 0.25 fg
11-13 2.6 bcdefg 14.5 abcd 7.1 abcde 9.2 efghi 0.60 abc
significance**************
LSD 2.5 9.2 3.5 6.6 0.25
mean 2.2 11.0 5.2 11.8 0.44
block effect*** NS NS***
Table 3. Yield (kg per tree) of pawpaw (Asimina triloba) selections from 2002-2006 for the Frankfort, Kentucky pawpaw regional variety trial.
THE KENTUCKY PAWPAW REGIONAL VARIETY TRIAL