POTATO (Solanum tuberosum) Russet Burbank Blight; Alternaria solani Late Blight; Phytophthora infestans W. R. Stevenson and R. V. James Department of Plant Pathology University of Wisconsin-Madison Madison, WI 53706 Evaluation of fungicides to control early blight and late blight of potato - Hancock, 2002 A field trial was established 29 Apr at the Hancock Agricultural Research Station in central WI to evaluate selected fungicides for early blight and late blight control. US#1 Russet Burbank tubers were mechanically cut into approximately 2 oz seedpieces 24 Apr and allowed to heal before planting. A randomized complete block design with four replications was used for the experiment, with each plot consisting of four 24-ft-long rows spaced 36 in. apart with tubers 15 in. apart in the row. To avoid soil compaction in treatment rows, drive rows for pesticide application equipment were placed adjacent to plots. The soil type was Plainfield loamy sand, ph 6.7. Fertilizer applied was: 0-0-60, 300 lb/a, broadcast 10 Apr, before planting, 6-24-24, 522 lb/a, banded in the row at planting, sidedress applications on 28 May (21-0-0, 350 lb/a) and 10 Jun (34-0-0, 375 lb/a), Cal-Sul, 500 lb/a, 31 May, and 28% UAN, applied through irrigation water 27 Jun (50 lb/a) and 30 Jul (30 lb/a). Insects were controlled with Admire 2F incorporated in the fertilizer at planting (16 fl oz/500 lb) and foliar application of Baythroid 2E (2.8 fl oz/a, 12 Jul), Actara (1.5 oz, 19 Jul) and Spintor 2SC (4.0 fl oz/a, 9 Aug). Lorox DF was applied for weed control (1.0 lb/a, 6 May). Fungicide treatments were applied to all four rows of each plot at weekly intervals from 26 Jun to 21 Aug, according to treatment protocol, for a total of nine weeks. Some treatments required an application a week ahead of our standard program and this was done 19 Jun. All treatments were applied with a plot sprayer consisting of a tractor-mounted boom pressurized with an air compressor. The majority of treatments were applied using Tee Jet Hollow Disc Cone D3-23 nozzles at a rate equivalent to 35 gal water/a at 40 psi (15 nozzles at 8-in. spacing). Five additional types of nozzles were also tested: Extended Range Flat Fan XR110 03VS, Lurmark Venturi ULD 120-03, TwinJet TJ60-11003VS, Air Induction AI11003VS, and 110-06 Agrotop. s with these nozzles were applied at a rate equivalent to 31 gal water/a at 40 psi (8 nozzles at 16-in. spacing). Plots were not inoculated but relied on natural dispersal of both Phytophthora infestans and Alternaria solani for disease establishment (the P. infestans isolate was identified as US-8 in Dr. J. P. Helgeson's lab at the UW). Disease severity was rated 18 and 24 Jun, 1, 9, 16, and 22 Jul, and 2, 6, 12, 19, and 26 Aug using the Horsfall-Barratt rating scale. Reglone (1.0 pt/a) plus Peptoil (1.0 qt/a) was applied on 28 Aug and 11 Sep to kill vines prior to harvest. The two center rows of each plot (a total of 48 ft of row) were machine harvested and graded 23-26 Sep. Tubers were graded into US#1, undersize, and cull categories, and all potatoes in the US#1 category from each treatment plot were sorted using an optical size grader into six categories: < 4 oz, 4-6 oz, 6-10 oz, 10-13 oz, 13-16 oz and >16 oz. Specific gravity was determined for a tuber sample from each plot and 25-40 pound samples from selected treatments were placed in storage. These will be evaluated for tuber decay, silver scurf, and black scurf after several months in storage. Rainfall recorded during the growing season (in.) was May, 2.89; Jun, 16.54; Jul, 3.16; Aug, 3.99; and 1-22 Sep, 2.53). An additional 16 in. of water was applied as overhead sprinkler irrigation in 24 applications (18 Jun 13 Sep). The 2002 growing season provided environmental extremes of excessive moisture early in the season and moisture stress at other times combined with high temperatures during the tuber bulking period. Even though the trial site was fumigated with metam sodium the previous fall, symptoms of early dying were prevalent by early August throughout the trial area. blight was first detected in this trial on 18 Jun and the first lesion of late blight was observed on 19 Jul. However, a prolonged period of unusually hot and dry weather continuing from early Jul to mid-aug, restricted both early blight and late blight movement for the middle part of the growing season. By late Aug, significant defoliation due to late blight was observed only in untreated plots. At the 12 Aug evaluation, approximately 25% of the foliage in untreated control plots exhibited symptoms of early blight. Control of early blight in all plots was considered good to excellent at this time with early blight severity less than 10% in many plots and less than 5% in a few plots. By 19 Aug, plants in the untreated control plots exhibited symptoms of early blight and late blight on over 40% of the foliage, respectively, while early blight severity was less than 25% in plots treated with Quadris 2.08F (3 sprays) alternated with TD 2409-01 (6 sprays), Quadris 2.08F, 0.36 pt, plus (2 sprays) alternated with alone (8 sprays), and Quadris 2.08F (3 sprays) alternated with Bravo Zn 4.17F (6 sprays). The lowest level of early blight was observed on this rating date in plots treated with Quadris 2.08F (3 sprays) alternated with Bravo Zn 4.17F (6 sprays) and applied with either the Tee Jet Hollow Disc Cone D3-23, the Lurmark Venturi ULD 120-03, Agrotop 110-06, or the TwinJet TJ60-11003VS nozzles. Given the widespread distribution of early dying symptoms in the trial, it is noteworthy that none of the treatments applied weekly to the plant foliage appeared to reduce the severity of early dying symptoms. At harvest, symptoms of advanced pinkeye, appearing as severe decay at the bud ends of tubers, were noted in most plots. The fungicide treatments applied in this trial did not affect the incidence of this disease. Total yields were lowest in the untreated control plots. Some of the highest total yields were recorded in plots treated with Quadris 2.08F (3 sprays) Page 1
alternated with Bravo Zn 4.17F (6 sprays) using the nozzle types listed above. In general tuber size was smaller than normal across all treatments. The proportion of tubers in the 6-10 oz size category was somewhat higher in plots where early blight progress was slowed by fungicide sprays. Significant differences in undersize and cull (misshapen and green) potatoes were not observed between treatments. Likewise, fungicide treatment did not appear to affect specific gravity. There was no evidence of treatment phytotoxicity in this trial. Efficacy, yield, and yield quality are important ways to evaluate fungicide performance. For the past several years we ve also used the market cost of fungicide sprays, a typical 2002 processing contract to compute crop value, and a typical 2002 return on fresh market sales to compute the economic return a grower might expect after treating the crop throughout the growing season. The value of treating the crop with fungicide varied widely in the 2002 trial depending on product efficacy and material cost that ranged from $55 to $190 for the season. While there were significant (P = 0.10) differences in values between treatments, the LSD was large. Using the fresh market value of harvested tubers for the value calculation, we find treatment values that range from +$957 (Quadris plus Bravo [3 sprays] and [6 sprays]) to negative values for several treatment protocols. When the processing contract values were used, the highest treatment value was +378 (same Quadris/ program) and there were many treatment values in the negative category. Table 1. treatment on foliar disease severity (percent foliage infection, early blight and late blight combined). Foliar Disease Severity (%) Rate/Acre Blight and Late Blight 2 Total Application 18 24 1 9 16 22 2 6 12 19 26 Product AI Schedule 1 Jun Jun Jul Jul Jul Jul Aug Aug Aug Aug Aug 3 1 Untreated 0.0 0.0 1.2 1.3 1.6 2.0 5.3 10.8 45.3 81.3 97.4 2 Bravo Ultrex 82.5 WDG Reason + Bond Previcur N 0.7 lb 0.52 pt 0.25 pt 1.2 pt 0.58 lb Appl 1-3 0.27 lb Appl 4-7 0.13 lb 0.90 lb Appl 8-9 + Bravo Ultrex 82.5WDG 0.91 lb 0.75 lb 0.0 0.0 1.0 1.6 2.0 1.9 3.9 4.4 9.8 48.0 90.6 3 Bravo Ultrex 82.5 WDG Reason + Previcur N Bravo Ultrex 82.5 WDG 4 Bravo Ultrex 82.5 WDG Reason + Scala 5 BAS 510F 70WG + Ranman 400SC + Silwet L-77 Bravo Zn 4.17F 6 BAS 510F 70WG + Bravo Zn 4.17F Bravo Zn 4.17F 7 Headline (BAS500)2.08EC BAS 510F 70WG + Ranman 400SC + Silwet L-77 Acrobat 50WP + Polyram 80DF Bravo Zn 4.17F Page 2 0.7 lb 0.35 pt 0.7 pt 1.4 lb 0.7 lb 0.35 pt 0.64 pt 0.14 lb 0.17 pt 0.125 pt 0.14 lb 1.44 pt 0.39pt 0.14 lb 0.17 pt 0.125 pt 0.4 lb 1.6 lb 0.58 lb 0.18 lb 0.53 lb 1.16 lb 0.58 lb 0.18 lb 0.27 lb 0.07 lb Appl 1-3 Appl 4-7 Appl 8-9 0.0 0.0 1.9 1.8 1.8 2.3 4.7 4.2 13.6 54.3 91.1 Appl 1-3 Appl 4-9 Appl 1-6 0.0 0.0 0.9 0.9 1.3 2.2 3.2 3.8 7.9 43.0 86.7 1.11 lb Appl 7-9 0.0 0.0 2.0 0.6 1.5 1.9 3.1 2.9 10.1 53.1 90.5 Appl 1,3,5 0.75 lb 1.11 lb Appl 2,4,6-9 0.0 0.1 1.6 1.5 1.5 2.0 2.8 2.6 7.0 36.6 86.4 Appl 1,4 Appl 2,5 0.07 lb 0.2 lb 1.3 lb 1.11 lb Appl 3,6 Appl 7-9 0.0 0.0 0.9 1.5 1.2 1.6 2.8 2.3 6.4 36.7 81.7 8 BAS 536F 18.7WG 1.66 lb 0.31 lb Weekly 0.0 0.3 0.9 0.9 1.2 2.0 3.8 4.5 12.0 57.0 89.3 9 BAS 536F 18.7WG 1.66 lb 0.31 lb Weekly + Silwet L-77 0.125 pt 0.0 0.4 0.9 1.2 1.6 1.6 3.1 4.4 12.6 62.1 92.1 10 BAS 536F 18.7WG 1.66 lb 0.31 lb Appl 1,3,5,7,9 BAS 510F 70WG + Ranman 400SC 0.14 lb 0.17 pt 0.07 lb Appl 2,4,6,8 + Silwet L-77 0.125 pt 0.0 0.0 0.9 1.2 1.9 1.9 3.7 3.2 9.4 62.5 91.5 11 BAS 536F 18.7WG Bravo Zn 4.17F 12 Quadris Bravo Zn 4.17F 13 Gem 25 WG + Echo Zn Echo Zn 1.66 lb 0.39pt 0.78 pt 8 oz 1.6 pt 2.13 pt 0.31 lb Appl 1,3,5 1.11 lb Appl 2,4,6-9 0.0 0.0 1.2 1.3 1.9 2.2 3.2 4.7 11.1 55.9 91.5 Appl 1 0.2 lb Appl 3,5 1.11 lb Appl 2,4,6-9 0.0 0.0 1.2 1.3 1.9 2.2 3.7 4.1 9.7 62.5 90.2 2 oz 0.84 lb 1.11 lb Appl 1,3,5,7,9 Appl 2,4,6,8 0.0 0.0 1.0 1.5 1.6 1.9 3.1 4.2 10.8 38.3 90.0
Foliar Disease Severity (%) Rate/Acre Blight and Late Blight 2 Application 18 24 1 9 16 22 2 6 12 Schedule 1 Jun Jun Jul Jul Jul Jul Aug Aug Aug 19 Aug Total 26 Aug 3 Product AI 14 Quadris 2.08 F 0.39pt Appl 1,3,5 Penncozeb 75WP Appl 2,4,6-9 0.0 0.0 1.0 1.2 1.6 2.2 3.7 4.2 8.1 44.1 89.7 15 Quadris 2.08 F 0.39pt Appl 1,3,5 TD 2409-01 2.34 pt Appl 2,4,6-9 0.0 0.0 0.9 0.9 1.3 1.8 2.8 3.2 5.3 23.2 82.4 16 Quadris 2.08 F 0.39pt Appl 1,3,5 TD 2457-01 2.56 pt Appl 2,4,6-9 0.1 0.0 1.3 1.2 1.6 1.6 3.2 3.5 9.7 41.0 84.2 17 Quadris 2.08 F 0.39pt Appl 1,3,5 Dithane 75DF Appl 2 Gavel 75DF Appl 4, 6-9 0.0 0.0 1.2 1.3 2.2 2.6 3.5 4.5 9.5 56.2 91.1 18 Quadris 2.08 F Gavel 75DF 19 Quadris 2.08 F Dithane 75DF + Curzate 60 DF Gavel 75DF 20 KQ667 68.75 WG 21 KQ667 68.75 WG 22 KQ667 68.75 WG 23 KQ667 68.75 WG Manzate 200DF 75WG 24 KP 481 50 WG + Manzate 200DF 75WG 25 Manzate 200DF 75WG Curzate 60 DF + Quadris 2.08 F 26 Manzate 200DF 75WG Manzate 200DF 75WG + Super Tin + Curzate 60 DF 27 Manzate 200DF 75WG Quadris 2.08 F. + Curzate 60 DF 0.39pt 0.39pt 1 lb 0.5 lb 1.0 lb 0.38 pt 0.188lb 0.38 pt 5.0 oz 5.0 oz 1.1 lb 0.69 lb 1.03 lb 1.38 lb 1.03 lb 0.25 lb 0.75 lb 0.15 lb 0.19 lb 1.12 lb 0.19 lb Appl 1,3,5 Appl 2, 4, 6-9 0.0 0.1 0.7 0.9 1.2 2.0 4.2 4.8 9.1 45.5 87.1 Appl 1,3 Appl 2 Appl 4 Appl 5-9 0.0 0.3 1.3 1.3 1.0 1.9 2.6 3.4 8.2 44.1 86.4 Appl 1,3,5,7,9 Appl 3, 5, 7, 9 Appl 2, 4, 6, 8 Appl 2, 4, 8 0.0 0.0 1.3 0.7 1.5 2.3 3.5 3.8 11.3 54.4 91.4 Appl 1,3,5,7,9 Appl 3, 5, 7, 9 Appl 2, 4, 6, 8 Appl 2, 4, 8 0.0 0.0 1.6 0.7 2.0 1.9 3.2 2.9 8.2 55.1 86.8 Appl 1,3,5,7,9 Appl 3, 5, 7, 9 Appl 2, 4, 6, 8 Appl 2, 4, 8 0.0 0.0 1.5 1.6 1.8 1.3 3.1 3.4 8.1 35.3 83.5 Appl 1, 3, 5 Appl 3, 5 Appl 2, 4, 6-9 Appl 2, 4, 7-9 0.0 0.0 1.2 1.5 1.9 2.0 3.4 3.2 8.9 45.5 87.0 Appl 1, 3, 5 Appl 2, 4, 6-9 Appl 2, 4, 7-9 0.0 0.1 1.2 0.7 0.9 2.0 3.7 3.8 8.5 37.8 88.3 Appl 1 3 Appl 4, 6, 8, 9 Appl 5, 7 0.0 0.1 0.7 0.6 1.5 1.9 2.8 3.2 6.7 33.0 80.3 Appl 1 4 Appl 5 9 Appl 1, 2 Appl 3,5 Appl 3 Appl 5 Appl 4, 6-9 0.0 0.0 1.0 1.0 1.2 2.6 4.4 3.1 8.2 45.9 87.1 + Curzate 60 DF 0.0 0.0 1.2 1.6 1.9 1.8 3.4 3.8 9.1 51.6 83.9 28 KQ667 68.75 WG 1.03 lb Weekly + Curzate 60 DF Appl 2-5, 7-9 0.0 0.0 1.5 1.2 1.5 2.5 3.7 3.4 9.7 59.4 90.3 29 Messenger (20 ppm=2.5g/gal) Appl 0, 3, 8 Quadris 2.08 F 0.38 pt Appl 1, 3, 5 1.12 lb Appl 2,4,6-9 0.0 0.0 0.6 1.3 1.8 1.6 2.8 3.4 6.1 31.1 85.1 30 Equus 720 1.12 lb Appl 1,4,7 Quadris 2.08 F 0.38 pt Appl 2, 5, 8 + Manzate 200DF 75WG Equus 720 1.12 lb Appl 3, 6, 9 + Super Tin 2.5 oz 0.13 lb 0.0 0.1 1.3 0.7 1.3 2.2 2.5 3.2 6.1 28.2 81.7 31 Equus 500 Zn 2.1 pt 0.57 lb Weekly 0.0 0.0 1.3 1.5 1.0 2.0 3.5 3.9 9.1 48.4 88.9 32 Equus 720 1.12 lb Appl 1, 4, 7 Headline (BAS500)2.08EC 0.39 pt Appl 2, 5, 8 + Manzate 200DF 75WG Equus 720 1.12 lb Appl 3, 6, 9 + Super Tin 2.5 oz 0.13 lb 0.0 0.0 1.5 1.5 1.0 1.9 2.9 3.1 6.0 40.6 86.5 Page 3
Page 4 Foliar Disease Severity (%) Rate/Acre Blight and Late Blight 2 Application 18 24 1 9 16 22 2 6 12 Schedule 1 Jun Jun Jul Jul Jul Jul Aug Aug Aug 19 Aug Total 26 Aug 3 Product AI 33 Ranman 400 SC 0.17 pt 0.07 lb Appl 1,3,5,7,9 BAS 536F 18.7WG 1.6 lb 0.3 lb Appl 2, 4, 6, 8 0.0 0.0 1.0 1.5 2.0 2.5 3.9 5.3 10.0 64.5 94.1 34 Ranman 400 SC 0.17 pt 0.07 lb Appl 1,3,5,7,9 BAS 500 2.08F (Headline) 0.77 pt 0.2 lb Appl 2, 4, 6, 8 0.0 0.0 1.3 1.5 1.6 1.8 2.8 3.8 10.0 36.6 84.5 35 Ranman 400 SC 0.17 pt 0.07 lb Appl 1, 4, 7 BAS 500 2.08F (Headline) 0.77 pt 0.2 lb Appl 2, 5, 8 Acrobat 50WP 0.4 lb 0.2 lb Appl 3, 6, 9 + Polyram 80 DF 1.6 lb 0.0 0.0 1.5 1.3 1.8 1.8 2.5 3.7 6.6 28.2 82.1 36 Ranman 400 SC BAS 536F 18.7WG 37 Champ DF + Bravo Zn 0.13 pt 1.6 lb 2 lb 1 pt 1.56 pt 2.13 pt 0.05 lb 0.3 lb 0.52 lb 0.81 lb 1.11 lb Appl 1,3,5,7,9 Appl 2, 4, 6, 8 0.0 0.0 1.0 0.4 1.6 1.8 3.4 3.9 11.3 44.0 87.0 Weekly Appl 1-3 Appl 4-6 Appl 7-9 0.0 0.0 0.9 1.5 1.6 2.2 3.5 3.9 10.0 58.6 91.2 38 Fluoronil Bravo Zn 2 lb 1 pt 1.56 pt Appl 3,5,7 0.52 lb Appl 1-2 0.81 lb Appl 4,6 2.13 pt 1.11 lb Appl 8,9 0.0 0.0 1.9 1.2 1.9 2.2 3.4 4.8 11.1 55.1 91.2 39 Echo Zn 1.11 lb Weekly 0.0 0.1 1.2 1.3 0.9 1.8 2.9 4.1 6.9 34.0 83.0 40 Echo Zn + Quadris 2.08 F Echo Zn Polyram 80 WP + Super Tin 80 WP Echo Zn + Polyram 80 WP 41 Gem 25 WG + Echo Zn Echo Zn 42 YF11959 43 YF11959 44 YF11959 45 Quadris 2.08 F + 46 Quadris 2.08 F + 0.38 pt 2.13 pt 0.23 lb 1.25 pt 0.375lb 1.6 pt 2.13 pt 1.19 pt 2.25 pt 0.36 pt 1.25 pt 0.54 pt 1.88 pt 0.78 lb 1.11 lb 1.6 lb 0.18 lb 0.65 lb 1.2 lb 1.5 oz 0.84 lb 1.11 lb Appl 1, 3 Appl 2, 4, 5 Appl 6, 8 Appl 7,9 Appl 1,3,5,7,9 0.0 0.0 1.0 1.3 1.8 2.3 3.2 3.7 8.6 37.9 85.6 Appl 2, 4, 6, 8 0.0 0.1 1.3 0.9 2.0 2.0 3.8 4.1 10.2 50.8 90.8 0.82 lb Appl 1, 3, 5 Appl 2, 4, 6-9 0.0 0.0 1.5 0.9 0.9 1.3 2.9 3.8 6.9 44.3 86.1 1.03 lb Appl 1, 3, 5 Appl 2, 4, 6-9 0.0 0.0 1.0 1.8 0.6 1.6 3.4 3.8 7.9 41.0 85.6 1.55 lb Appl 1, 3, 5 Appl 2, 4, 6-9 0.0 0.0 1.5 0.9 1.8 1.9 3.1 4.1 10.5 58.6 92.5 0.09 lb Appl 1, 3, 5 0.94 lb Appl 2, 4, 6-9 0.0 0.0 1.3 0.3 2.0 1.8 2.6 3.1 5.6 13.8 72.7 0.14 lb 1.41 lb Appl 1, 3, 5 Appl 2, 4, 6-9 0.0 0.0 0.9 1.3 0.9 2.5 3.9 3.7 9.5 53.1 91.8 47 Quadris 2.08 F 0.39 pt Appl 1, 3, 5 Appl 2, 4, 6-9 0.0 0.0 0.7 0.6 1.3 2.0 2.9 4.2 10.0 40.0 85.8 48 Weekly 0.0 0.0 1.2 0.6 1.3 1.9 3.4 4.1 12.3 53.1 88.3 49 Headline (BAS500)2.08EC 0.38 pt Appl 1, 3 Bravo Ultrex 82.5 WDG 1.0 lb 0.83 lb Appl 2 Polyram 80DF + Super Tin 0.156lb 1.6 lb 0.13 lb Appl 4-8 Bravo Ultrex 82.5 WDG 1.0 lb 0.83 lb Appl 9 0.0 0.1 0.9 1.2 1.6 2.2 3.4 4.1 8.1 42.9 86.5 50 Headline (BAS500)2.08EC Bravo Ultrex 82.5 WDG Polyram + Acrobat 50 WP Headline (BAS500)2.08EC + Bravo Ultrex Bravo Ultrex 82.5 WDG 51 Bravo Zn 4.17 F + Curzate 60 DF 52 Quadris 2.08 F + Curzate 60 DF Bravo Zn 4.17 F + Curzate 60 DF 53 Quadris 2.08 F Bravo Zn 4.17 F 0.38 pt 1.0 lb 0.4 lb 0.38 pt 0.5 lb 1.0 lb 0.39 pt 0.39 pt 0.83 lb 1.6 lb 0.2 lb 0.41 lb 0.83 lb Appl 1, 3 Appl 2 Appl 4, 6-8 Appl 5 Appl 9 0.0 0.0 1.5 1.2 1.2 2.3 4.4 4.8 10.5 39.5 84.2 1.11 lb Weekly Appl 1-4, 6-8 0.0 0.0 1.8 1.6 1.6 1.9 3.4 3.2 8.5 61.9 92.7 Appl 1,3,5 Appl 1,3 1.11 lb Appl 2,4 6-9 Appl 2,4 6-8 0.0 0.3 1.2 0.3 1.6 2.2 3.5 4.2 13.2 55.5 91.7 1.11 lb Appl 1 Appl 0,2-9 0.0 0.0 0.7 0.7 0.9 1.6 2.6 2.6 8.5 35.8 81.0
Foliar Disease Severity (%) Rate/Acre Blight and Late Blight 2 Total Application 18 24 1 9 16 22 2 6 12 19 26 Product AI Schedule 1 Jun Jun Jul Jul Jul Jul Aug Aug Aug Aug Aug 3 54 Quadris 2.08 F 0.39 pt Appl 1,3 Bravo Zn 4.17 F 1.11 lb Appl 0,2,4-9 0.0 0.3 1.2 0.6 1.2 1.8 2.5 2.3 4.8 23.2 80.1 55 Quadris 2.08 F 0.39 pt Appl 1,3,5,7 Bravo Zn 4.17 F 1.11 lb Appl 0,2,4,6,8,9 0.0 0.1 1.6 1.0 2.0 2.2 3.5 4.7 9.5 53.0 86.7 56 Quadris 2.08 F 0.39 pt Appl 0,2,4,6,7 Bravo Zn 4.17 F 1.11 lb Appl 1,3,5,8,9 0.0 0.0 1.2 1.6 1.5 1.6 2.3 3.4 6.6 37.6 79.4 57 Quadris 2.08 F 0.39 pt Appl 0,2,4-7 Bravo Zn 4.17 F 1.11 lb Appl 1,3,8,9 0.0 0.0 0.4 0.9 1.3 2.2 2.3 3.4 5.7 25.5 68.9 58 Bravo Zn 4.17 F 1.11 lb Weekly 0.0 0.0 0.6 1.8 1.8 1.8 2.8 3.5 7.5 29.1 77.5 59 Quadris 2.08 F 0.39 pt Appl 1, 3, 5 Bravo Zn 4.17 F 1.11 lb Appl 0,2,4,6-9 0.0 0.0 0.4 0.7 1.6 1.6 2.8 3.8 7.9 31.4 83.3 s 60-64 all received the same fungicide treatment but with different nozzle types. All were applied at 40 psi, using 8 nozzles with 16" spacing, at 31 GPA Quadris 0.39pt 0.78 pt 0.2 lb 1.11 lb Appl 1 Appl 3,5 Appl 2,4,6-9 Bravo Zn 4.17F 60 110-06 Agrotop (Venturi body w/ Ext. Range Flat Fan nozzle XR110 03VS) 0.0 0.0 1.2 1.3 1.5 1.6 2.6 3.4 5.7 20.7 75.7 61 XR110 03VS Ext. Range Flat Fan nozzle 0.0 0.0 1.2 1.2 1.5 2.5 2.9 3.5 8.9 36.9 81.0 62 ULD 120-03 Lurmark Venturi nozzle 0.0 0.0 0.4 1.0 1.8 2.2 2.8 3.5 5.0 14.4 74.8 63 TJ60-11003VS TwinJet nozzle 0.0 0.1 0.6 1.5 1.5 2.0 2.9 2.9 5.1 18.8 80.1 64 A111003VS Air induction nozzle 0.0 0.0 1.5 0.7 1.9 2.0 3.2 3.7 4.7 26.1 80.4 Pr > F 4 0.49 0.60 0.31 0.53 0.14 0.52 0.03 <0.01 <0.01 0.02 0.03 LSD 4 NS NS NS NS NS NS 0.3 1.5 5.9 31.0 12.6 1 Application dates for our standard spray program: 1 = 26 Jun, 2 = 3 Jul, 3 = 10 Jul, 4 = 17 Jul, 5 = 24 Jul, 6 = 31 Jul, 7 = 7 Aug, 8 = 14 Aug, 9 = 21 Aug. Some treatments required an application a week ahead of our standard program. This was done 19 Jun and is designated application 0. 2 Severity rated on a Horsfall-Barratt scale of 0 (no infection) to 11 (all foliage and stems dead). Ratings were converted to percentages. disease severity (early blight and late blight, attempting to exclude damage from early dying) was assessed first. Then amount of early and late blight were estimated separately (the separate estimates do not necessarily add up to the combined defoliation figure as they were done independently). 3 For the final rating the Total severity evaluation includes defoliation due to early blight, late blight and early dying. Severity of early blight and late blight was then estimated separately for each plot. 4 Analysis of variance was performed on data, and Fisher s protected least significant difference (LSD) was calculated. NS = not significant at P = 0.10 (* indicates differences between pairs of treatments were significant at P = 0.10, but not at P = 0.05). Table 2. treatment on early blight and late blight severity (percent foliage infection). ( numbers correspond to those listed in Table 1). # 18 Jun 24 Jun 1 Jul 9 Jul Foliar Disease Severity (%) 1 Blight Alone 16 22 2 6 12 19 26 Jul Jul Aug Aug Aug Aug Aug 1 0.0 0.0 1.2 1.3 1.6 2.0 5.0 7.6 24.6 43.8 --- 0.0 0.0 0.6 2.6 8.8 49.6 --- 2 0.0 0.0 1.0 1.6 2.0 1.9 3.9 4.4 9.8 48.0 78.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3 0.0 0.0 1.9 1.8 1.8 2.3 4.7 4.2 13.6 54.3 81.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4 0.0 0.0 0.9 0.9 1.3 2.2 3.2 3.8 7.9 41.2 71.2 0.0 0.0 0.0 0.0 0.0 0.7 2.6 5 0.0 0.0 2.0 0.6 1.5 1.9 3.1 2.9 10.1 53.1 77.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6 0.0 0.1 1.6 1.5 1.5 2.0 2.8 2.6 7.0 36.6 66.2 0.0 0.0 0.0 0.0 0.0 0.0 0.1 7 0.0 0.0 0.9 1.5 1.2 1.6 2.8 2.3 6.4 36.7 60.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 8 0.0 0.3 0.9 0.9 1.2 2.0 3.8 4.5 12.0 57.0 73.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 9 0.0 0.4 0.9 1.2 1.6 1.6 3.1 4.4 12.6 62.1 83.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10 0.0 0.0 0.9 1.2 1.8 1.9 3.7 3.2 9.4 62.5 79.5 0.0 0.1 0.0 0.0 0.0 0.0 0.0 11 0.0 0.0 1.2 1.3 1.9 2.2 3.2 4.7 11.1 55.9 80.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 12 0.0 0.0 1.2 1.3 1.9 2.2 3.7 4.1 9.7 62.5 79.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 13 0.0 0.0 1.0 1.5 1.6 1.9 3.1 4.2 10.8 38.3 77.7 0.1 0.0 0.0 0.0 0.0 0.0 0.0 14 0.0 0.0 1.0 1.2 1.6 2.2 3.7 4.2 8.1 44.1 76.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 15 0.0 0.0 0.9 0.9 1.3 1.8 2.8 3.2 5.3 23.2 58.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 16 0.1 0.0 1.3 1.2 1.6 1.6 3.2 3.5 9.7 36.0 65.4 0.0 0.0 0.0 0.1 0.0 1.2 0.6 17 0.0 0.0 1.2 1.3 2.2 2.6 3.5 4.5 9.5 56.2 82.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 18 0.0 0.1 0.7 0.9 1.2 2.0 4.2 4.8 9.1 45.5 73.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Page 5 9 Jul 16 Jul Late Blight Alone 2 6 12 Aug Aug Aug 19 Aug 26 Aug
Foliar Disease Severity (%) 1 Blight Alone Late Blight Alone 18 24 1 9 16 22 2 6 12 19 26 9 16 2 6 12 19 26 # Jun Jun Jul Jul Jul Jul Aug Aug Aug Aug Aug Jul Jul Aug Aug Aug Aug Aug 19 0.0 0.3 1.3 1.3 1.0 1.9 2.6 3.4 8.2 44.1 61.4 0.0 0.0 0.0 0.1 0.0 0.0 0.0 20 0.0 0.0 1.3 0.7 1.5 2.3 3.5 3.8 11.3 54.4 76.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 21 0.0 0.0 1.6 0.7 2.0 1.9 3.2 2.9 8.2 55.1 74.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 22 0.0 0.0 1.5 1.6 1.8 1.3 3.1 3.4 8.1 35.3 65.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 23 0.0 0.0 1.2 1.5 1.9 2.0 3.4 3.2 8.9 45.5 74.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 24 0.0 0.1 1.2 0.7 0.9 2.0 3.7 3.8 8.5 37.8 74.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25 0.0 0.1 0.7 0.6 1.5 1.9 2.8 3.2 6.7 33.0 56.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 26 0.0 0.0 1.0 1.0 1.2 2.6 4.4 3.1 8.2 45.9 65.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 27 0.0 0.0 1.2 1.6 1.9 1.8 3.4 3.8 9.1 51.6 74.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 28 0.0 0.0 1.5 1.2 1.5 2.5 3.7 3.4 9.7 59.4 77.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 29 0.0 0.0 0.6 1.3 1.8 1.6 2.8 3.4 6.1 31.1 63.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 30 0.0 0.1 1.3 0.7 1.3 2.2 2.5 3.2 6.1 28.2 59.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 31 0.0 0.0 1.3 1.5 1.0 2.0 3.5 3.9 9.1 48.4 77.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 32 0.0 0.0 1.5 1.5 1.0 1.9 2.9 3.1 6.0 40.6 69.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 33 0.0 0.0 1.0 1.5 2.0 2.5 3.9 5.3 10.0 64.5 87.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 34 0.0 0.0 1.3 1.5 1.6 1.8 2.8 3.8 10.0 36.6 63.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 35 0.0 0.0 1.5 1.3 1.8 1.8 2.5 3.7 6.6 28.2 62.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 36 0.0 0.0 1.0 0.4 1.6 1.8 3.4 3.9 11.3 44.0 65.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 37 0.0 0.0 0.9 1.5 1.6 2.2 3.5 3.9 10.0 58.6 75.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 38 0.0 0.0 1.9 1.2 1.9 2.2 3.4 4.8 11.1 55.1 81.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 39 0.0 0.1 1.2 1.3 0.9 1.8 2.9 4.1 6.9 34.0 68.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 40 0.0 0.0 1.0 1.3 1.8 2.3 3.2 3.7 8.6 37.9 60.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 41 0.0 0.1 1.3 0.9 2.0 2.0 3.8 4.1 10.2 50.8 78.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 42 0.0 0.0 1.5 0.9 0.9 1.3 2.9 3.8 6.9 41.2 68.6 0.0 0.0 0.0 0.0 0.0 0.9 1.2 43 0.0 0.0 1.0 1.8 0.6 1.6 3.4 3.8 7.9 41.0 76.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 44 0.0 0.0 1.5 0.9 1.8 1.9 3.1 4.1 10.5 58.6 85.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 45 0.0 0.0 1.3 0.3 2.0 1.8 2.6 3.1 5.6 13.8 49.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 46 0.0 0.0 0.9 1.3 0.9 2.5 3.9 3.7 9.5 53.1 84.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 47 0.0 0.0 0.7 0.6 1.3 2.0 2.9 4.2 10.0 37.1 67.4 0.0 0.0 0.0 0.4 0.3 0.7 1.2 48 0.0 0.0 1.2 0.6 1.3 1.9 3.4 4.1 12.3 53.1 76.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 49 0.0 0.1 0.9 1.2 1.6 2.2 3.4 4.1 8.1 42.9 69.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 50 0.0 0.0 1.5 1.2 1.2 2.3 4.4 4.8 10.5 39.5 67.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 51 0.0 0.0 1.8 1.6 1.6 1.9 3.4 3.2 8.5 61.9 84.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 52 0.0 0.3 1.2 0.3 1.6 2.2 3.5 4.2 13.2 55.5 78.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 53 0.0 0.0 0.7 0.7 0.9 1.6 2.6 2.6 8.5 35.8 57.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 54 0.0 0.3 1.2 0.6 1.2 1.8 2.5 2.3 4.8 23.2 51.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 55 0.0 0.1 1.6 1.0 2.0 2.2 3.5 4.7 9.5 53.0 75.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 56 0.0 0.0 1.2 1.6 1.5 1.6 2.3 3.4 6.6 37.6 62.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 57 0.0 0.0 0.4 0.9 1.3 2.2 2.3 3.4 5.7 25.5 47.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 58 0.0 0.0 0.6 1.8 1.8 1.8 2.8 3.5 7.5 29.1 55.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 59 0.0 0.0 0.4 0.7 1.6 1.6 2.8 3.8 7.9 31.4 54.3 0.0 0.0 0.0 0.0 0.0 0.0 0.3 60 0.0 0.0 1.2 1.3 1.5 1.6 2.6 3.4 5.7 20.7 47.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 61 0.0 0.0 1.2 1.2 1.5 2.5 2.9 3.5 8.9 36.9 65.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 62 0.0 0.0 0.4 1.0 1.8 2.2 2.8 3.5 5.0 14.4 39.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 63 0.0 0.1 0.6 1.5 1.5 2.0 2.9 2.9 5.1 18.8 50.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 64 0.0 0.0 1.5 0.7 1.9 2.0 3.2 3.7 4.7 26.1 54.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Pr >F 3 0.49 0.60 0.31 0.53 0.14 0.52 0.03 <0.01 <0.01 0.09 0.04 2 0.49 0.49 0.49 <0.01 <0.01 <0.01 0.22 2 LSD 3 NS NS NS NS NS NS 0.3 1.5 5.7 31.3 25.8 NS NS NS 0.4 0.2 3.9 NS 1 Severity rated on a Horsfall-Barratt scale of 0 (no infection) to 11 (all foliage and stems dead). Ratings were converted to percentages. foliage infection was assessed first. Then amount of early and late blight were estimated separately (the separate estimates do not necessarily add up to the combined defoliation figure as they were done independently). 2 Disease had progressed sufficiently that early and late blight could not be evaluated separately on 26 Aug for the untreated control plots thus analysis for early and late blight for 26 Aug is for differences AMONG treatments, excluding the untreated control. 3 Analysis of variance was performed on data, and Fisher s protected least significant difference (LSD) was calculated. NS = not significant at P = 0.10 (* indicates differences between pairs of treatments were significant at P = 0.10, but not at P = 0.05). Page 6
Table 3. fungicide treatment on relative area under the disease progress curve, yield, proportion of US#1, undersize and cull potatoes, specific gravity, and size grades of US#1 potatoes ( numbers correspond to those listed in Table 1). Relative AUDPC 1 Yield No. of Size Grades of US # 1 Potatoes - % Late TOTAL US#1 Undersize 2 Culls Specific Rotted Blight Blight cwt/a cwt/a % cwt/a % cwt/a % Gravity tubers 3 < 4 oz 4-6 oz 6-10 oz 10-13 oz 6-13 oz 13-16 oz > 16 oz 1 0.070 0.040 0.195 357.4 202.3 56.1 94.5 26.8 60.7 17.1 1.074 10.5 34.9 40.0 22.1 2.9 25.0 0.0 0.0 2 0.054 0.000 0.119 394.7 197.0 49.7 118.8 30.3 78.9 20.0 1.069 13.8 40.5 41.1 16.1 2.3 18.4 0.0 0.0 3 0.063 0.000 0.131 383.7 201.2 52.7 117.5 30.6 65.0 16.7 1.074 13.3 42.1 36.7 18.4 2.8 21.2 0.0 0.0 4 0.045 0.000 0.107 384.9 191.2 49.8 123.6 31.9 70.1 18.3 1.071 14.5 37.9 40.3 20.1 1.8 21.8 0.0 0.0 5 0.054 0.000 0.121 388.2 211.5 53.9 111.4 29.3 65.3 16.8 1.068 16.3 39.3 40.5 18.9 1.3 20.3 0.0 0.0 6 0.042 0.000 0.100 367.6 177.2 47.5 119.4 33.1 71.0 19.4 1.071 22.5 34.9 42.2 19.6 3.3 22.8 0.0 0.0 7 0.039 0.000 0.095 390.1 203.8 52.1 111.7 28.7 74.6 19.2 1.074 17.5 31.9 36.8 28.3 2.3 30.6 0.6 0.0 8 0.060 0.000 0.128 376.1 225.7 59.7 99.8 26.8 50.6 13.5 1.073 11.8 33.3 40.5 24.3 1.0 25.2 1.0 0.0 9 0.062 0.000 0.134 389.0 216.7 55.4 106.3 27.4 66.1 17.2 1.072 18.0 39.1 36.8 20.5 3.1 23.6 0.4 0.0 10 0.059 0.000 0.131 373.0 211.1 56.4 105.6 28.4 56.4 15.2 1.071 20.3 40.7 39.5 18.5 1.3 19.7 0.0 0.0 11 0.059 0.000 0.128 392.6 205.0 51.8 119.0 30.9 68.7 17.3 1.073 13.0 39.7 38.5 20.5 1.3 21.8 0.0 0.0 12 0.061 0.000 0.132 362.9 177.9 48.8 118.6 33.1 66.4 18.1 1.070 26.3 33.6 42.9 21.3 2.2 23.5 0.0 0.0 13 0.047 0.000 0.108 391.6 195.1 49.7 116.7 29.8 79.8 20.5 1.074 14.3 36.6 40.0 21.2 2.2 23.4 0.0 0.0 14 0.049 0.000 0.112 390.6 196.0 49.6 121.5 31.4 73.1 19.0 1.070 15.3 37.9 40.7 19.6 1.8 21.4 0.0 0.0 15 0.031 0.000 0.081 439.9 232.7 52.6 106.9 24.5 100.3 23.0 1.074 12.0 33.0 34.8 30.8 1.0 31.8 0.4 0.0 16 0.044 0.001 0.106 430.9 222.6 51.2 119.1 28.2 89.2 20.6 1.077 13.0 34.1 35.6 28.0 1.8 29.8 0.5 0.0 17 0.059 0.000 0.127 352.5 184.0 50.7 114.6 34.0 53.9 15.3 1.075 18.3 38.6 41.8 17.9 1.7 19.6 0.0 0.0 18 0.050 0.000 0.113 401.6 210.6 52.5 116.0 28.9 74.9 18.6 1.072 16.0 31.5 40.6 24.1 2.7 26.9 1.0 0.0 19 0.047 0.000 0.108 398.7 215.3 53.0 108.9 28.3 74.5 18.7 1.076 9.5 31.8 38.5 26.8 2.9 29.7 0.0 0.0 20 0.057 0.000 0.125 363.3 173.5 47.9 110.6 30.3 79.2 21.9 1.071 20.8 36.4 40.0 22.5 0.6 23.2 0.5 0.0 21 0.054 0.000 0.120 373.0 197.0 52.3 106.7 29.3 69.3 18.4 1.071 17.3 28.4 41.2 27.4 2.7 30.1 0.0 0.3 22 0.042 0.000 0.098 381.0 201.1 52.0 110.1 29.3 69.8 18.7 1.072 11.3 33.2 37.6 26.2 2.2 28.4 0.8 0.0 23 0.050 0.000 0.112 383.6 189.0 49.4 116.9 30.5 77.7 20.1 1.070 17.8 39.5 37.9 21.9 0.7 22.6 0.0 0.0 24 0.044 0.000 0.103 366.9 188.5 51.0 113.4 31.1 65.0 17.9 1.071 15.3 36.8 39.9 22.8 0.6 23.4 0.0 0.0 25 0.038 0.000 0.091 407.5 229.7 55.9 99.6 25.1 78.2 19.0 1.073 9.5 33.3 38.5 26.4 1.5 27.9 0.3 0.0 26 0.050 0.000 0.112 359.3 193.9 53.7 102.8 28.9 62.6 17.4 1.076 13.0 34.9 37.6 27.0 0.5 27.5 0.0 0.0 27 0.054 0.000 0.117 376.8 201.2 53.3 104.3 27.7 71.3 18.9 1.072 14.8 35.6 41.8 21.1 1.5 22.6 0.0 0.0 28 0.059 0.000 0.129 359.9 175.6 49.0 105.8 29.6 78.6 21.4 1.073 20.8 38.1 41.0 19.3 1.6 20.9 0.0 0.0 29 0.036 0.000 0.092 401.4 232.8 58.1 101.8 25.4 66.9 16.5 1.075 12.5 35.0 40.1 23.1 1.4 24.5 0.3 0.0 30 0.035 0.000 0.087 396.2 225.4 55.5 101.6 26.7 69.2 17.8 1.073 7.8 33.6 38.2 26.3 1.4 27.7 0.5 0.0 31 0.052 0.000 0.116 392.4 213.3 54.5 111.2 29.0 67.9 16.6 1.072 11.8 37.9 39.2 21.4 1.5 22.9 0.0 0.0 32 0.042 0.000 0.103 401.1 209.7 52.3 117.9 29.3 73.5 18.4 1.074 13.5 35.5 37.5 24.1 1.6 25.7 1.3 0.0 33 0.064 0.000 0.138 372.1 201.3 53.7 102.6 27.8 68.2 18.5 1.070 13.3 35.5 43.4 20.5 Page 7
Page 8 Relative AUDPC 1 Yield No. of Size Grades of US # 1 Potatoes - % Late cwt/a cwt/a % cwt/a % cwt/a % Gravity tubers 3 < 4 oz 4-6 oz 6-10 oz 10-13 oz 6-13 oz 13-16 oz > 16 TOTAL US#1 Undersize 2 Culls Specific Rotted Blight Blight oz 37 0.058 0.000 0.129 372.7 182.7 48.9 131.6 35.3 58.3 15.8 1.070 19.0 37.9 42.2 19.2 0.7 19.9 0.0 0.0 38 0.059 0.000 0.128 364.5 188.8 51.7 109.2 30.1 66.4 18.2 1.069 16.8 33.5 40.2 24.0 2.4 26.4 0.0 0.0 39 0.040 0.000 0.095 415.8 232.1 55.7 110.5 27.1 73.2 17.2 1.073 7.8 33.6 35.0 28.8 2.3 31.1 0.0 0.3 40 0.045 0.000 0.103 386.0 184.7 47.8 119.1 30.9 82.2 21.3 1.072 13.3 32.7 36.1 28.2 2.2 30.3 0.0 0.9 41 0.055 0.000 0.121 379.8 186.3 48.7 126.1 33.4 67.4 18.0 1.071 20.8 39.9 41.5 16.4 2.2 18.6 0.0 0.0 42 0.043 0.000 0.106 406.5 224.5 54.9 110.0 27.6 72.1 17.5 1.073 10.3 34.2 39.2 23.7 3.0 26.6 0.0 0.0 43 0.045 0.000 0.104 394.1 228.0 57.5 101.0 25.8 65.1 16.6 1.073 14.5 40.8 34.3 22.0 2.4 24.5 0.0 0.5 44 0.058 0.000 0.129 406.7 253.3 62.3 99.0 24.3 54.4 13.4 1.075 14.0 40.8 36.2 21.3 1.2 22.5 0.6 0.0 45 0.026 0.000 0.067 472.2 299.3 63.7 90.4 19.3 82.4 17.0 1.075 8.0 32.8 34.0 29.9 3.0 32.9 0.3 0.0 46 0.055 0.000 0.123 396.0 225.8 56.4 104.2 26.8 66.0 16.7 1.071 16.5 34.8 40.3 23.7 1.0 24.6 0.0 0.3 47 0.044 0.001 0.105 399.8 221.8 55.4 106.5 26.7 71.5 17.9 1.073 16.3 32.3 38.7 24.4 4.3 28.8 0.3 0.0 48 0.056 0.000 0.122 434.7 255.3 58.0 110.0 25.9 69.3 16.1 1.070 10.8 35.7 38.4 23.9 2.0 25.9 0.0 0.0 49 0.047 0.000 0.108 374.3 169.6 44.9 126.2 33.9 78.6 21.2 1.077 14.5 32.1 42.0 23.3 2.3 25.6 0.3 0.0 50 0.050 0.000 0.108 387.7 211.4 54.5 106.6 28.0 69.6 17.5 1.073 14.0 35.4 37.4 25.1 2.0 27.1 0.0 0.0 51 0.059 0.000 0.131 340.0 159.6 45.9 121.3 36.5 59.0 17.6 1.068 19.8 34.5 41.8 23.3 0.3 23.7 0.0 0.0 52 0.060 0.000 0.128 369.4 204.8 55.0 103.3 28.2 61.3 16.8 1.071 17.0 34.0 39.7 25.4 1.0 26.3 0.0 0.0 53 0.039 0.000 0.095 438.6 232.4 52.8 125.8 29.3 80.4 17.8 1.073 9.5 36.1 33.7 26.9 2.5 29.4 0.5 0.3 54 0.029 0.000 0.079 435.4 221.7 50.8 126.1 28.9 87.6 20.3 1.073 11.3 31.4 39.5 26.9 2.1 29.0 0.0 0.0 55 0.056 0.000 0.122 404.5 195.9 48.1 128.2 32.5 80.4 19.3 1.074 13.8 35.5 41.4 21.4 1.4 22.8 0.0 0.3 56 0.041 0.000 0.096 418.4 235.1 56.2 113.1 27.0 70.2 16.8 1.076 9.8 33.7 40.4 22.9 2.3 25.3 0.3 0.4 57 0.032 0.000 0.077 452.1 252.5 56.2 124.1 27.5 75.5 16.3 1.073 9.3 27.3 40.5 28.6 3.0 31.6 0.6 0.0 58 0.038 0.000 0.088 406.4 208.7 51.2 113.1 27.9 84.5 20.9 1.074 8.3 28.8 36.9 29.9 4.4 34.3 0.0 0.0 59 0.038 0.000 0.092 379.4 215.8 56.5 108.1 28.8 55.6 14.7 1.073 13.0 34.7 36.8 26.7 1.5 28.2 0.3 0.0 60 0.030 0.000 0.076 413.2 221.4 53.4 100.6 24.5 91.2 22.2 1.075 10.3 29.3 36.6 31.2 2.5 33.7 0.4 0.0 61 0.044 0.000 0.100 427.2 235.9 54.7 103.8 24.8 87.4 20.5 1.074 15.8 28.2 38.3 28.9 3.4 32.4 0.8 0.3 62 0.026 0.000 0.069 458.7 260.7 57.0 104.4 22.7 93.6 20.3 1.075 8.3 33.8 35.9 26.4 3.9 30.3 0.0 0.0 63 0.029 0.000 0.076 423.9 245.0 57.8 100.7 23.7 78.2 18.5 1.077 10.5 28.7 40.4 25.8 4.2 29.9 0.3 0.7 64 0.034 0.000 0.084 449.5 251.6 54.9 112.8 26.1 85.1 19.0 1.072 11.5 36.3 38.4 23.6 1.6 25.2 0.2 0.0 Pr>F 4 0.05 < 0.01 < 0.01 0.10 0.10 0.16 0.32 0.17 0.48 0.71 0.90 0.63 0.25 0.28 0.10 0.12 0.14 0.14 0.03 LSD 4 0.025 0.003 0.043 68.1* 62.6* NS NS NS NS NS NS NS NS NS 8.9* NS NS NS 0.4 1. Relative area under the disease progress curve. Data for each observation date were plotted on a graph and the area under the line was calculated for each treatment providing a measure of the relative severity of disease throughout the season. A disease rating of 100% severity for the entire season would produce a value of 1.0. All relative AUDPC values are expressed as a proportion of this value. Either decreased disease severity or later disease development will contribute to lower relative AUDPC. and late blight AUDPC values were calculated from 18 Jun - 19 Aug. Disease had progressed sufficiently that early and late blight could not be evaluated separately on 26 Aug for the untreated control plots. The combined AUDPC was calculated from combined blight rating data (total defoliation of the plot, combining both early and late blight) from 19 Jun - 26 Aug (if only early blight was seen in a plot, total disease was equal to early blight). 2. Undersize indicates potatoes < 1 7/8 in diameter. 3. The average number of tubers per treatment with any kind of rot observed during grading. 4. Analysis of variance was performed on data, and Fisher s protected least significant difference (LSD) was calculated. NS = not significant at P = 0.10 (* indicates differences between pairs of treatments were significant at P = 0.10, but not at P = 0.05).
Table 4. No. experimental treatment on value per acre of Russet Burbank tubers. ( numbers correspond to those listed in Table 1) Cost of Chemicals/Acre ($) 1 Fresh Market 2 Processing 3 Fresh Market 2 Processing 3 Fresh Market 2 Processing of Yield ($/A) Net of Yield ($/A) 4 on ($/A) 5 3 1 0 2498 984 2498 984 0 0 2 --- 2499 947 --- --- --- --- 3 --- 2464 974 --- --- --- --- 4 --- 2482 924 --- --- --- --- 5 --- 2580 1006 --- --- --- --- 6 --- 2382 866 --- --- --- --- 7 --- 2705 1008 --- --- --- --- 8 --- 2724 1087 --- --- --- --- 9 --- 2617 1043 --- --- --- --- 10 --- 2478 997 --- --- --- --- 11 --- 2565 990 --- --- --- --- 12 112 2400 863 2288 751-209 -234 13 190 2550 956 2360 766-137 -219 14 55 2528 939 2473 885-25 -100 15 --- 3048 1145 --- --- --- --- 16 --- 2930 1117 --- --- --- --- 17 87 2317 904 2230 817-267 -167 18 91 2783 1027 2692 937 194-48 19 88 2823 1084 2735 996 237 11 20 --- 2331 843 --- --- --- --- 21 --- 2662 965 --- --- --- --- 22 --- 2619 982 --- --- --- --- 23 --- 2438 903 --- --- --- --- 24 --- 2421 910 --- --- --- --- 25 88 2897 1125 2809 1037 312 53 26 84 2461 943 2377 859-121 -125 27 118 2540 975 2423 857-75 -127 28 --- 2316 863 --- --- --- --- 29 125 2813 1131 2688 1005 190 21 30 101 2773 1097 2672 996 174 11 31 76 2628 1023 2553 947 55-37 32 --- 2701 1030 --- --- --- --- 33 --- 2508 967 --- --- --- --- 34 --- 2496 912 --- --- --- --- 35 --- 2854 1043 --- --- --- --- 36 --- 2375 897 --- --- --- --- 37 112 2387 877 2275 765-223 -219 38 121 2480 911 2359 790-138 -194 39 77 2943 1128 2866 1051 368 67 40 100 2563 908 2463 808-34 -176 41 72 2395 892 2323 820-175 -165 42 --- 2821 1087 --- --- --- --- 43 --- 2685 1101 --- --- --- --- 44 --- 2832 1211 --- --- --- --- 45 101 3556 1464 3455 1363 957 378 46 128 2779 1078 2651 949 153-35 47 84 2830 1089 2746 1005 248 21 48 72 3068 1222 2997 1150 499 166 49 --- 2440 856 --- --- --- --- 50 --- 2671 1029 --- --- --- --- 51 105 2192 767 2087 661-411 -323 52 128 2576 990 2447 862-50 -123 53 89 2998 1121 2910 1033 412 48 54 92 2972 1088 2879 995 382 11 Page 9
No. Cost of Chemicals/Acre ($) 1 Fresh Market 2 Processing 3 Fresh Market 2 Processing 3 Fresh Market 2 Processing of Yield ($/A) Net of Yield ($/A) 4 on ($/A) 5 3 55 100 2622 961 2522 861 24-123 56 103 2949 1169 2845 1065 348 81 57 107 3312 1235 3205 1128 707 144 58 85 2853 1038 2768 953 270-31 59 96 2669 1050 2572 954 75-30 60 112 2953 1097 2842 985 344 0 61 112 3119 1168 3007 1056 509 72 62 112 3258 1288 3146 1176 648 192 63 112 3125 1218 3013 1106 515 122 64 112 3103 1216 2991 1104 494 120 Pr > F 6 --- 0.11 0.15 0.08 0.10 0.08 0.10 LSD 6 --- NS NS 719* 339* 719* 339* 1 2002 Season-long cost of chemicals/acre (rate, number of applications and retail cost are included in calculation). Application costs are not included. Typical retail prices used: Acrobat 50WP - $ 19.25/lb Curzate 60DF - $ 29.00/lb Gavel 75DF - $4.50/lb Previcur Flex - $ 62/gal Bond - $28.95/gal Dithane DF Rainshield - $ 2.50/lb Gem 25 WG- $ 3.10/oz Quadris 2.08 F - $ 250/gal 6F - $ 42.50/gal Echo Zn - $ 32.00/gal Manzate - $ 2.00/lb Silwet L77 - $159/gal Bravo Zn 4.17F - $ 32.00/gal Equus 500 Zn - $ 32.00/gal Messenger - $4.50/oz Super Tin 80WP- $ 30/lb Bravo Ultrex - $ 6.50/lb Equus 720-38.00/gal Penncozeb - $ 2.00/lb Champ DF - $3.08/lb Fluoronil - $13.85/lb Polyram 80DF - $ 2.10/lb If ANY component of the treatment was an experimental product with no retail price, the cost of chemicals was not calculated. 2 Typical 2002 fresh market pricing: 4-6 oz $11.00/cwt, 6-10 oz $13.50/cwt, 10-13 oz $14.50, >13 oz $15, < 4 oz and culls $4.00/cwt. 3 Typical 2002 processing contract pricing: Base price is $4.92/cwt for 69% US#1 (4 oz minimum) with specific gravity of 1.078. A premium is paid for > 18% 10 oz or greater. For each 1% above 18% (to a maximum of 32%) > 10 oz the price increases $0.01/cwt. The price decreases $0.01/cwt for each 1% below 19%. There is an increase or decrease in price per hundred weight depending on specific gravity: >1.085 +$.17; 1.084 +$.14; 1.083 +$.11; 1.082 +$.08; 1.081 +$.06; 1.080 +$.04; 1.079 +$.02; 1.078 $.00; for each 0.001 decrease in specific gravity below 1.078, there is a $0.02 penalty (1.077 -$.02, 1.076 -$.04, 1.075 -$.06, etc). There is a payment of $2.00/cwt for processing culls (up to a maximum of 15% of the total by weight). 4 value minus cost of chemicals applied. 5 Net value for the treatment minus net value of the untreated control. 6 Analysis of variance was performed on data, and Fisher s protected least significant difference (LSD) was calculated. NS = not significant at P = 0.10 (* indicates differences between pairs of treatments were significant at P = 0.10, but not at P = 0.05). Table 5. Data ranked according to several disease and yield measurements ( numbers correspond to those listed in Table 1. Footnotes for all sections of this table appear on page 14). Sorted by Relative AUDPC ( Blight) (increasing) Relative AUDPC 1 Yield Processing 3 Late 45 0.026 0.000 0.067 472.2 299.3 1464 378 62 0.026 0.000 0.069 458.7 260.7 1288 192 54 0.029 0.000 0.079 435.4 221.7 1088 11 63 0.029 0.000 0.076 423.9 245.0 1218 122 60 0.030 0.000 0.076 413.2 221.4 1097 0 15 0.031 0.000 0.081 439.9 232.7 1145 --- 57 0.032 0.000 0.077 452.1 252.5 1235 144 64 0.034 0.000 0.084 449.5 251.6 1216 120 30 0.035 0.000 0.087 396.2 225.4 1097 11 29 0.036 0.000 0.092 401.4 232.8 1131 21 35 0.036 0.000 0.089 409.9 208.6 1043 --- 25 0.038 0.000 0.091 407.5 229.7 1125 53 58 0.038 0.000 0.088 406.4 208.7 1038-31 59 0.038 0.000 0.092 379.4 215.8 1050-30 7 0.039 0.000 0.095 390.1 203.8 1008 --- 53 0.039 0.000 0.095 438.6 232.4 1121 48 39 0.040 0.000 0.095 415.8 232.1 1128 67 56 0.041 0.000 0.096 418.4 235.1 1169 81 6 0.042 0.000 0.100 367.6 177.2 866 --- 22 0.042 0.000 0.098 381.0 201.1 982 --- 32 0.042 0.000 0.103 401.1 209.7 1030 --- 42 0.043 0.000 0.106 406.5 224.5 1087 --- 16 0.044 0.001 0.106 430.9 222.6 1117 --- 24 0.044 0.000 0.103 366.9 188.5 910 --- 47 0.044 0.001 0.105 399.8 221.8 1089 21 Page 10 Relative AUDPC 1 Yield Processing 3 Late 61 0.044 0.000 0.100 427.2 235.9 1168 72 4 0.045 0.000 0.107 384.9 191.2 924 --- 34 0.045 0.000 0.102 371.7 186.4 912 --- 40 0.045 0.000 0.103 386.0 184.7 908-176 43 0.045 0.000 0.104 394.1 228.0 1101 --- 13 0.047 0.000 0.108 391.6 195.1 956-219 19 0.047 0.000 0.108 398.7 215.3 1084 11 49 0.047 0.000 0.108 374.3 169.6 856 --- 14 0.049 0.000 0.112 390.6 196.0 939-100 18 0.050 0.000 0.113 401.6 210.6 1027-48 23 0.050 0.000 0.112 383.6 189.0 903 --- 26 0.050 0.000 0.112 359.3 193.9 943-125 36 0.050 0.000 0.111 365.9 180.7 897 --- 50 0.050 0.000 0.108 387.7 211.4 1029 --- 31 0.052 0.000 0.116 392.4 213.3 1023-37 2 0.054 0.000 0.119 394.7 197.0 947 --- 5 0.054 0.000 0.121 388.2 211.5 1006 --- 21 0.054 0.000 0.120 373.0 197.0 965 --- 27 0.054 0.000 0.117 376.8 201.2 975-127 41 0.055 0.000 0.121 379.8 186.3 892-165 46 0.055 0.000 0.123 396.0 225.8 1078-35 48 0.056 0.000 0.122 434.7 255.3 1222 166 55 0.056 0.000 0.122 404.5 195.9 961-123 20 0.057 0.000 0.125 363.3 173.5 843 --- 37 0.058 0.000 0.129 372.7 182.7 877-219
Relative AUDPC 1 Yield Processing 3 Late 44 0.058 0.000 0.129 406.7 253.3 1211 --- 10 0.059 0.000 0.131 373.0 211.1 997 --- 11 0.059 0.000 0.128 392.6 205.0 990 --- 17 0.059 0.000 0.127 352.5 184.0 904-167 28 0.059 0.000 0.129 359.9 175.6 863 --- 38 0.059 0.000 0.128 364.5 188.8 911-194 51 0.059 0.000 0.131 340.0 159.6 767-323 8 0.060 0.000 0.128 376.1 225.7 1087 --- Relative AUDPC 1 Yield Processing 3 Late 52 0.060 0.000 0.128 369.4 204.8 990-123 12 0.061 0.000 0.132 362.9 177.9 863-234 9 0.062 0.000 0.134 389.0 216.7 1043 --- 3 0.063 0.000 0.131 383.7 201.2 974 --- 33 0.064 0.000 0.138 372.1 201.3 967 --- 1 0.070 0.040 0.195 357.4 202.3 984 0 Pr>F 4 0.05 < 0.01 < 0.01 0.10 0.10 0.15 0.08 LSD 4 0.025 0.003 0.043 68.1* 62.6* NS 339* Sorted by Relative AUDPC (Late Blight) (increasing) Relative AUDPC 1 Yield Processing 3 45 0.026 0.000 0.067 472.2 299.3 1464 378 62 0.026 0.000 0.069 458.7 260.7 1288 192 54 0.029 0.000 0.079 435.4 221.7 1088 11 63 0.029 0.000 0.076 423.9 245.0 1218 122 60 0.030 0.000 0.076 413.2 221.4 1097 0 15 0.031 0.000 0.081 439.9 232.7 1145 --- 57 0.032 0.000 0.077 452.1 252.5 1235 144 64 0.034 0.000 0.084 449.5 251.6 1216 120 30 0.035 0.000 0.087 396.2 225.4 1097 11 29 0.036 0.000 0.092 401.4 232.8 1131 21 35 0.036 0.000 0.089 409.9 208.6 1043 --- 25 0.038 0.000 0.091 407.5 229.7 1125 53 58 0.038 0.000 0.088 406.4 208.7 1038-31 59 0.038 0.000 0.092 379.4 215.8 1050-30 7 0.039 0.000 0.095 390.1 203.8 1008 --- 53 0.039 0.000 0.095 438.6 232.4 1121 48 39 0.040 0.000 0.095 415.8 232.1 1128 67 56 0.041 0.000 0.096 418.4 235.1 1169 81 6 0.042 0.000 0.100 367.6 177.2 866 --- 22 0.042 0.000 0.098 381.0 201.1 982 --- 32 0.042 0.000 0.103 401.1 209.7 1030 --- 42 0.043 0.000 0.106 406.5 224.5 1087 --- 24 0.044 0.000 0.103 366.9 188.5 910 --- 61 0.044 0.000 0.100 427.2 235.9 1168 72 16 0.044 0.001 0.106 430.9 222.6 1117 --- 47 0.044 0.001 0.105 399.8 221.8 1089 21 4 0.045 0.000 0.107 384.9 191.2 924 --- 34 0.045 0.000 0.102 371.7 186.4 912 --- 40 0.045 0.000 0.103 386.0 184.7 908-176 43 0.045 0.000 0.104 394.1 228.0 1101 --- 13 0.047 0.000 0.108 391.6 195.1 956-219 19 0.047 0.000 0.108 398.7 215.3 1084 11 49 0.047 0.000 0.108 374.3 169.6 856 --- Relative AUDPC 1 Yield Processing 3 14 0.049 0.000 0.112 390.6 196.0 939-100 18 0.050 0.000 0.113 401.6 210.6 1027-48 23 0.050 0.000 0.112 383.6 189.0 903 --- 26 0.050 0.000 0.112 359.3 193.9 943-125 36 0.050 0.000 0.111 365.9 180.7 897 --- 50 0.050 0.000 0.108 387.7 211.4 1029 --- 31 0.052 0.000 0.116 392.4 213.3 1023-37 2 0.054 0.000 0.119 394.7 197.0 947 --- 5 0.054 0.000 0.121 388.2 211.5 1006 --- 21 0.054 0.000 0.120 373.0 197.0 965 --- 27 0.054 0.000 0.117 376.8 201.2 975-127 41 0.055 0.000 0.121 379.8 186.3 892-165 46 0.055 0.000 0.123 396.0 225.8 1078-35 48 0.056 0.000 0.122 434.7 255.3 1222 166 55 0.056 0.000 0.122 404.5 195.9 961-123 20 0.057 0.000 0.125 363.3 173.5 843 --- 37 0.058 0.000 0.129 372.7 182.7 877-219 44 0.058 0.000 0.129 406.7 253.3 1211 --- 10 0.059 0.000 0.131 373.0 211.1 997 --- 11 0.059 0.000 0.128 392.6 205.0 990 --- 17 0.059 0.000 0.127 352.5 184.0 904-167 28 0.059 0.000 0.129 359.9 175.6 863 --- 38 0.059 0.000 0.128 364.5 188.8 911-194 51 0.059 0.000 0.131 340.0 159.6 767-323 8 0.060 0.000 0.128 376.1 225.7 1087 --- 52 0.060 0.000 0.128 369.4 204.8 990-123 12 0.061 0.000 0.132 362.9 177.9 863-234 9 0.062 0.000 0.134 389.0 216.7 1043 --- 3 0.063 0.000 0.131 383.7 201.2 974 --- 33 0.064 0.000 0.138 372.1 201.3 967 --- 1 0.070 0.040 0.195 357.4 202.3 984 0 Pr>F 4 0.05 < 0.01 < 0.01 0.10 0.10 0.15 0.08 LSD 4 0.025 0.003 0.043 68.1* 62.6* NS 339* Sorted by Relative AUDPC ( EB & LB) (increasing) Relative AUDPC 1 Yield Processing 3 45 0.026 0.000 0.067 472.2 299.3 1464 378 62 0.026 0.000 0.069 458.7 260.7 1288 192 60 0.030 0.000 0.076 413.2 221.4 1097 0 63 0.029 0.000 0.076 423.9 245.0 1218 122 57 0.032 0.000 0.077 452.1 252.5 1235 144 54 0.029 0.000 0.079 435.4 221.7 1088 11 15 0.031 0.000 0.081 439.9 232.7 1145 --- 64 0.034 0.000 0.084 449.5 251.6 1216 120 30 0.035 0.000 0.087 396.2 225.4 1097 11 58 0.038 0.000 0.088 406.4 208.7 1038-31 35 0.036 0.000 0.089 409.9 208.6 1043 --- 25 0.038 0.000 0.091 407.5 229.7 1125 53 29 0.036 0.000 0.092 401.4 232.8 1131 21 59 0.038 0.000 0.092 379.4 215.8 1050-30 Page 11 Relative AUDPC 1 Yield Processing 3 7 0.039 0.000 0.095 390.1 203.8 1008 --- 39 0.040 0.000 0.095 415.8 232.1 1128 67 53 0.039 0.000 0.095 438.6 232.4 1121 48 56 0.041 0.000 0.096 418.4 235.1 1169 81 22 0.042 0.000 0.098 381.0 201.1 982 --- 6 0.042 0.000 0.100 367.6 177.2 866 --- 61 0.044 0.000 0.100 427.2 235.9 1168 72 34 0.045 0.000 0.102 371.7 186.4 912 --- 24 0.044 0.000 0.103 366.9 188.5 910 --- 32 0.042 0.000 0.103 401.1 209.7 1030 --- 40 0.045 0.000 0.103 386.0 184.7 908-176 43 0.045 0.000 0.104 394.1 228.0 1101 --- 47 0.044 0.001 0.105 399.8 221.8 1089 21 16 0.044 0.001 0.106 430.9 222.6 1117 ---
Relative AUDPC 1 Yield Processing 3 42 0.043 0.000 0.106 406.5 224.5 1087 --- 4 0.045 0.000 0.107 384.9 191.2 924 --- 13 0.047 0.000 0.108 391.6 195.1 956-219 19 0.047 0.000 0.108 398.7 215.3 1084 11 49 0.047 0.000 0.108 374.3 169.6 856 --- 50 0.050 0.000 0.108 387.7 211.4 1029 --- 36 0.050 0.000 0.111 365.9 180.7 897 --- 14 0.049 0.000 0.112 390.6 196.0 939-100 23 0.050 0.000 0.112 383.6 189.0 903 --- 26 0.050 0.000 0.112 359.3 193.9 943-125 18 0.050 0.000 0.113 401.6 210.6 1027-48 31 0.052 0.000 0.116 392.4 213.3 1023-37 27 0.054 0.000 0.117 376.8 201.2 975-127 2 0.054 0.000 0.119 394.7 197.0 947 --- 21 0.054 0.000 0.120 373.0 197.0 965 --- 5 0.054 0.000 0.121 388.2 211.5 1006 --- 41 0.055 0.000 0.121 379.8 186.3 892-165 48 0.056 0.000 0.122 434.7 255.3 1222 166 55 0.056 0.000 0.122 404.5 195.9 961-123 Relative AUDPC 1 Yield Processing 3 46 0.055 0.000 0.123 396.0 225.8 1078-35 20 0.057 0.000 0.125 363.3 173.5 843 --- 17 0.059 0.000 0.127 352.5 184.0 904-167 8 0.060 0.000 0.128 376.1 225.7 1087 --- 11 0.059 0.000 0.128 392.6 205.0 990 --- 38 0.059 0.000 0.128 364.5 188.8 911-194 52 0.060 0.000 0.128 369.4 204.8 990-123 28 0.059 0.000 0.129 359.9 175.6 863 --- 37 0.058 0.000 0.129 372.7 182.7 877-219 44 0.058 0.000 0.129 406.7 253.3 1211 --- 3 0.063 0.000 0.131 383.7 201.2 974 --- 10 0.059 0.000 0.131 373.0 211.1 997 --- 51 0.059 0.000 0.131 340.0 159.6 767-323 12 0.061 0.000 0.132 362.9 177.9 863-234 9 0.062 0.000 0.134 389.0 216.7 1043 --- 33 0.064 0.000 0.138 372.1 201.3 967 --- 1 0.070 0.040 0.195 357.4 202.3 984 0 Pr>F 4 0.05 < 0.01 < 0.01 0.10 0.10 0.15 0.08 LSD 4 0.025 0.003 0.043 68.1* 62.6* NS 339* Sorted by total yield (decreasing) Relative AUDPC 1 Yield Processing 3 45 0.026 0.000 0.067 472.2 299.3 1464 378 62 0.026 0.000 0.069 458.7 260.7 1288 192 57 0.032 0.000 0.077 452.1 252.5 1235 144 64 0.034 0.000 0.084 449.5 251.6 1216 120 15 0.031 0.000 0.081 439.9 232.7 1145 --- 53 0.039 0.000 0.095 438.6 232.4 1121 48 54 0.029 0.000 0.079 435.4 221.7 1088 11 48 0.056 0.000 0.122 434.7 255.3 1222 166 16 0.044 0.001 0.106 430.9 222.6 1117 --- 61 0.044 0.000 0.100 427.2 235.9 1168 72 63 0.029 0.000 0.076 423.9 245.0 1218 122 56 0.041 0.000 0.096 418.4 235.1 1169 81 39 0.040 0.000 0.095 415.8 232.1 1128 67 60 0.030 0.000 0.076 413.2 221.4 1097 0 35 0.036 0.000 0.089 409.9 208.6 1043 --- 25 0.038 0.000 0.091 407.5 229.7 1125 53 44 0.058 0.000 0.129 406.7 253.3 1211 --- 42 0.043 0.000 0.106 406.5 224.5 1087 --- 58 0.038 0.000 0.088 406.4 208.7 1038-31 55 0.056 0.000 0.122 404.5 195.9 961-123 18 0.050 0.000 0.113 401.6 210.6 1027-48 29 0.036 0.000 0.092 401.4 232.8 1131 21 32 0.042 0.000 0.103 401.1 209.7 1030 --- 47 0.044 0.001 0.105 399.8 221.8 1089 21 19 0.047 0.000 0.108 398.7 215.3 1084 11 30 0.035 0.000 0.087 396.2 225.4 1097 11 46 0.055 0.000 0.123 396.0 225.8 1078-35 2 0.054 0.000 0.119 394.7 197.0 947 --- 43 0.045 0.000 0.104 394.1 228.0 1101 --- 11 0.059 0.000 0.128 392.6 205.0 990 --- 31 0.052 0.000 0.116 392.4 213.3 1023-37 13 0.047 0.000 0.108 391.6 195.1 956-219 14 0.049 0.000 0.112 390.6 196.0 939-100 Relative AUDPC 1 Yield Processing 3 7 0.039 0.000 0.095 390.1 203.8 1008 --- 9 0.062 0.000 0.134 389.0 216.7 1043 --- 5 0.054 0.000 0.121 388.2 211.5 1006 --- 50 0.050 0.000 0.108 387.7 211.4 1029 --- 40 0.045 0.000 0.103 386.0 184.7 908-176 4 0.045 0.000 0.107 384.9 191.2 924 --- 3 0.063 0.000 0.131 383.7 201.2 974 --- 23 0.050 0.000 0.112 383.6 189.0 903 --- 22 0.042 0.000 0.098 381.0 201.1 982 --- 41 0.055 0.000 0.121 379.8 186.3 892-165 59 0.038 0.000 0.092 379.4 215.8 1050-30 27 0.054 0.000 0.117 376.8 201.2 975-127 8 0.060 0.000 0.128 376.1 225.7 1087 --- 49 0.047 0.000 0.108 374.3 169.6 856 --- 10 0.059 0.000 0.131 373.0 211.1 997 --- 21 0.054 0.000 0.120 373.0 197.0 965 --- 37 0.058 0.000 0.129 372.7 182.7 877-219 33 0.064 0.000 0.138 372.1 201.3 967 --- 34 0.045 0.000 0.102 371.7 186.4 912 --- 52 0.060 0.000 0.128 369.4 204.8 990-123 6 0.042 0.000 0.100 367.6 177.2 866 --- 24 0.044 0.000 0.103 366.9 188.5 910 --- 36 0.050 0.000 0.111 365.9 180.7 897 --- 38 0.059 0.000 0.128 364.5 188.8 911-194 20 0.057 0.000 0.125 363.3 173.5 843 --- 12 0.061 0.000 0.132 362.9 177.9 863-234 28 0.059 0.000 0.129 359.9 175.6 863 --- 26 0.050 0.000 0.112 359.3 193.9 943-125 1 0.070 0.040 0.195 357.4 202.3 984 0 17 0.059 0.000 0.127 352.5 184.0 904-167 51 0.059 0.000 0.131 340.0 159.6 767-323 Pr>F 4 0.05 < 0.01 < 0.01 0.10 0.10 0.15 0.08 LSD 4 0.025 0.003 0.043 68.1* 62.6* NS 339* Sorted by yield of US#1 potatoes (decreasing) Relative AUDPC 1 Yield Processing 3 45 0.026 0.000 0.067 472.2 299.3 1464 378 62 0.026 0.000 0.069 458.7 260.7 1288 192 48 0.056 0.000 0.122 434.7 255.3 1222 166 Page 12 Relative AUDPC 1 Yield Processing 3 44 0.058 0.000 0.129 406.7 253.3 1211 --- 57 0.032 0.000 0.077 452.1 252.5 1235 144 64 0.034 0.000 0.084 449.5 251.6 1216 120