PALAUAN TARO VARIETIES FOR LUAU TRIAL
R.T. Hamasaki
An unreplicated taro variety trial was installed to test promising varieties for luau production under wetland conditions at a cooperator's farm on July 11, 1996.  The trial included 8 Palauan taro varieties with tolerance to the taro leaf blight, one variety from the Philippines (PSBG2), and Chinese taro Cv. Bunlong which is the industry standard for luau.  Luau harvests were conducted during November through March which included some periods of extremely wet weather.  The yield (pounds and number of leaves produced) and disease incidence were recorded.  A leaf with at least one lesion caused by Phytophthora colocasiae was considered to be diseased and unmarketable.

Conditions: Wet Land (paddy)
Island: Kahaluu, Island of Oahu
Date Planted: July 11, 1996
12 plants per variety (Unreplicated)


Makai VARIETY
1 2 3 4 5 6 7 8 9 10 11 12 Bunlong
1 2 3 4 5 6 7 8 9 10 11 12 PSBG3
1 2 3 4 5 6 7 8 9 10 11 12 P1
1 2 3 4 5 6 7 8 9 10 11 12 P3
1 2 3 4 5 6 7 8 9 10 11 12 P5
1 2 3 4 5 6 7 8 9 10 11 12 P7
1 2 3 4 5 6 7 8 9 10 11 12 P13
1 2 3 4 5 6 7 8 9 10 11 12 P16
1 2 3 4 5 6 7 8 9 10 11 12 P20
1 2 3 4 5 6 7 8 9 10 11 Bunlong
1 2 3 4 5 6 7 8 9 10 Bunlong
Mauka


HARVESTING DATES
#1 #2 #3 #4 #5 #6
11/7/96 11/29/96 12/20/96 1/17/97 2/14/97 3/13/97


TOTAL (INCLUDING DISEASED) LUAU YIELD (POUNDS) FROM 12 PLANTS
Variety #1 #2 #3 #4 #5 #6 Total
Bunlong 0.50 0.44 1.5 1.75 4.63 2.81 11.63
PSBG2 0.3 0.63 1.25 2.06 2.75 2.81 9.80
P1 0.55 1.13 1.56 3.00 5.75 6.31 18.30
P3 0.5 1.31 2.19 3.00 4.69 5.31 17.00
P5 0.4 1.19 1.69 3.5 7.00 7.31 21.09
P7 0.3 0.63 1.00 1.75 4.31 5.31 13.30
P13 0.75 1.13 1.06 2.75 4.75 5.75 16.19
P16 0.6 0.94 1.56 2.19 5.00 6.63 16.92
P20 0.25 0.75 1.06 1.69 3.94 5.25 12.94


TOTAL (INCLUDING DISEASED) NUMBER OF LEAVES HARVESTED FROM 12 PLANTS
Variety #1 #2 #3 #4 #5 #6 Total
Bunlong 19 30 84 77 87 31 328
PSBG2 12 41 61 93 64 41 312
P1 10 46 46 66 83 53 292
P3 6 51 51 73 58 40 259
P5 14 39 39 62 70 48 268
P7 10 29 29 42 51 35 189
P13 11 43 43 37 41 38 190
P16 17 66 66 68 87 62 327
P20 7 24 24 30 30 34 149


AVERAGE NUMBER OF LEAVES IN ONE POUND OF FRESH LUAU
Bunlong 28.20
PSBG2 31.84
P1 15.96
P3 15.24
P5 12.71
P7 14.21
P13 11.74
P16 19.34
P20 11.52


SUMMARY OF PERCENT DISEASED LEAVES
Data Reported in Percent (%)
Variety #1 #2 #3 #4 #5 #6
Bunlong 63 83 4.8 91 75 97
PSBG2 20 83 0 72 52 90
P1 10 44 6.5 53 64 85
P3 50 90 5.9 86 76 88
P5 29 46 2.6 58 63 85
P7 10 46 0 57 67 86
P10 27
P13 0 70 0 57 73 95
P16 24 37 3.0 35 66 90
P20 29 38 0 23 60 74


MARKETABLE YIELD (POUNDS) FROM 12 PLANTS
Data Reported in Percent (%)
Variety #1 #2 #3 #4 #5 #6 Total
Bunlong 0.25 0.13 1.38 0.19 1.63 0.13 3.71
PSBG2 0.25 0.13 1.25 0.56 1.31 0.13 3.63
P1 0.50 0.69 1.5 1.63 2.19 1.13 7.64
P3 0.25 0.13 2.0 0.63 1.31 0.75 5.07
P5 0.25 0.56 1.63 1.69 3.06 1.00 8.19
P7 0.25 0.56 1.0 0.94 1.69 0.94 5.38
P13 0.75 0.69 1.06 1.38 1.25 0.19 5.32
P16 0.50 0.50 1.5 1.5 2.00 0.75 6.75
P20 0.125 0.44 1.06 1.38 2.00 1.25 6.255


STATISTICAL ANALYSIS
Mean Value: N=6
Variety Leaf Weight Total # of Leaves % Diseased Leaves Marketable Weight
BUNLONG 1.9cd 54.6a 68.9a 0.62a
P1 3.0ab 48.7ab 43.7a 1.3a
P3 2.8abc 43.2ab 66.0a 0.84a
P5 3.5a 44.7ab 47.3a 1.4a
P7 2.2cde 31.5ab 44.3a 0.9a
P13 2.7abc 31.7ab 49.2a 0.9a
P16 2.8abc 54.5a 42.5a 1.1a
P20 2.1cde 24.8b 37.3a 1.0a
PSBG2 1.6d 52.0a 52.8a 0.6a
SIGNIFICANCE LEVELS:
Cultivar ** *(10%) NS NS
Model ** ** ** **
Date ** ** ** **
Date x cv. ** NS NS** NS
NS**= not significant even after transforming the percentage points with ARCSIN.


FIELD TRIAL INTERPRETATION OF RESULTS
R.T.. Hamasaki
NOTE: THE INFORMATION BELOW IS INTENDED ONLY FOR EDUCATIONAL PURPOSES. THE RESULTS ARE NOT TO BE USED FOR PUBLISHING. REVIEWERS SHOULD BE AWARE THAT THE SUMMARY IS A PERSONAL INTERPRETATION BY THE LEAD PROJECT INVESTIGATOR. DISCRETION IS ADVISED.

  When total leaf yields (including diseased leaves) were analyzed, the varieties P5, P1, P3, P16, and P13 were the higher yielding varieties but only the yields of P5 and P1 were significantly higher than that of Bunlong.  However, there were no significant differences among varieties when "marketable yields" were analyzed.  This suggests to me that some of the Palauan varieties produced more biomass than Bunlong during high disease conditions but many leaves won't be marketable due to the presence of lesions.  Keep in mind that we went through an extremely wet winter in 1996.
 

 There were no significant differences among varieties in terms of "Percent Disease."  This suggests to me that the Palauan varieties may get just as much "leaves with at least one lesion" during high rainfall conditions.  This does make sense because the Palauan taro plants had a high percentage of leaves with blight.  However, the Palauan taro plants still looked much more vigorous and large while Bunlong was severely stunted from the effects of the disease.  The capacity for produce more biomass during high blight conditions suggest to me that the Palauan varieties would produce higher corms during high rainfall (blight) conditions than susceptible varieties and may recover faster than Bunlong for luau as soon as the weather clears.