1. Margaret Tuttle McGrath, Dept. of Plant Pathology, LIHREC, Cornell University, Riverhead, NY mtm3@cornell.edu Managing Powdery Mildew of Cucurbits Organically

2. Powdery Mildew

3. Select resistant varieties. Availability of non-treated seed limits selection. Separate successive plantings. Apply oil, sulfur, or copper product every 7 days (14 to resistant variety). Start at threshold (1 of 50 old leaves with symptoms). Managing Cucurbit Powdery Mildew Organically

4. Gladiator Magician Harlequin Autumn Delight Bush Delicata

5. Powdery Mildew Resistant Varieties Cantaloupe: Race-specific resistance. Races 1 and 2 on Long Island. Squash + Pumpkin: 1 Major resistance gene + modifying genes. Select varieties with resistance from both parents (homozygous). ‘Resistant’. Resistance from one parent. (heterozygous). ‘Tolerant’. Resistance from one parent. (heterozygous). ‘Tolerant’.

6. NY01-605A (PMRR)98ghi91ghi Touch of Autumn (PMR)92defghi87fghi NH1755A (PMR)92defghi86fghi Gladiator (PMRR)96efghi86fghi NY01-609 (PMRR)100hi76efgh Gold Bouillon (PMR)63bc75defgh Rupp 763 (PMR)87bcdefg72defgh Rupp 764 (PMR)82bcdef71defgh Magician (PMRR)96efghi71cdefg Hobbit (PMR)91defghi66cdef Magic Lantern (PMR)88cdefgh43abcd * Control relative to Howden. All received reduced-fungicide program. PMRR = resistance from both parents. Variety * UpperLower Powdery Mildew Control - Pumpkin Leaves, 2004

7. Fungicides Evaluated for Powdery Mildew in 2001 and 2002 Copper (Kocide) Sulfur (Microthiol Disperss) Mineral oil (JMS Stylet-oil) Biofungicide (Serenade) Potassium bicarbonate ( Armicarb 100, Kaligreen ) Monopotassium phosphate (Nutrol) Plant extract (Milsana)

9. Kocide 2000 (Copper hydroxide) 141ef1152cd AUDPC Treatment (7-day, 5X) UpperLower Powdery Mildew of Pumpkin, 2001 Nontreated884a1415a Serenade (Bacillus subtilis) 563b1301abc Kaligreen (Potassium bicarbonate) 335c1347ab Armicarb (Potassium bicarbonate) 332c 1194bcd Milsana (Extract of giant knotweed) 359c1267abcd Nutrol (Monopotassium phosphate) 286cd1111d JMS Stylet-oil (Mineral oil) 64gh638f Microthiol Disperss (Sulfur) 64gh663f Bravo (Chlorothalonil) 20i895e Quadris alt. Bravo + Nova47ghi400gh

10. Nontreated73a76 Serenade (6 lb)58ab60 Kaligreen (5 lb)41bcd71 Quadris alt. Nova + Bravo37cde53 Nutrol + Prudent Plus 28d-h68 Kocide 2000 (2 lb)21d-h78 Serenade (4 lb) + Kocide 200014gh68 Bravo (2.7 lb)12h68 * 7/19, 7/25, 8/1, 8/8, 8/15 (N+P); All on 8/21, 8/27-28, 9/6, 9/13. Severity on 9/3/02 Treatment (7-day) * UpperLower Powdery Mildew of Pumpkin

11. Nontreated73a76 Quadris alt. Nova + Bravo37cde53 JMS Stylet-oil (1.5%)33c-g70 Kocide 2000 (2 lb)21d-h78 Microthiol Disperss (4 lb)15fgh70 Bravo (2.7 lb)12h68 * 7/19, 7/25, 8/1, 8/8, 8/15 (N+P); All on 8/21, 8/27-28, 9/6, 9/13. Severity on 9/3/02 Treatment (7-day) * UpperLower Powdery Mildew of Pumpkin

12. Powdery Mildew Fungicide Costs ProductRate/ACost/A Quadris11-15.4 oz$24.92-$34.89 Flint1.5-2 oz$18.75-$25.00 Nova5 oz$19.25 Bravo Ultrex1.8-2.7 lb$13.86-$20.79 Microthiol Disperss4 lb$3.00 Kocide2 lb$6.20 JMS Stylet-oil0.75-1.5%$8.27-$16.53 Nutrol10-20 lb$11.70-$23.40 Kaligreen 4 lb$21.41 Armicarb 1004 lb$34.00 Serenade6 lb$37.50

13. Fungicides for Cucurbit Crops BravoAlternaria LS, Anthracnose, DM, GSB, Powdery mildew, Scab Kocide Alternaria LS, Anthracnose, DM, GSB, Powdery mildew, Angular LS JMS Stylet-oilAlternaria LS, GSB, Powdery mildew, Viruses Armicarb 100Alternaria LS, Anthracnose, Powdery mildew SerenadePowdery mildew KaligreenPowdery mildew SulfurPowdery mildew NutrolPowdery mildew LS = leaf spot DM = Downy Mildew GSB = Gummy Stem Blight

14. Biopesticides - Powdery Mildew OxiDate27% hydrogen dioxide. OMRI soon? Bugitol0.42% capsaicin + related capsaicinoids, 3.7% allyl isothiocyanate. Eco E-RASE97.5% jojoba oil. OMRI. Trilogy70% clarified extract of neem oil. OMRI. GC-3 Organic30% cottonseed oil, 30% corn oil, 23% garlic extract. Exempt. OMRI. Organocide5% sesame oil (ai); 92% fish oil + 3% emulsifiers (inerts). Exempt. OMRI. Sporan17.6% rosemary oil (ai); 82.4% winter- green oil (inerts). Exempt. OMRI. Exempt = Exempt from EPA registration. fungicide

15. Fungicides - Powdery Mildew Organic97% Food-grade paraffinic oil, JMS Stylet-oil petroleum-based. SulfurSeveral products OMRI listed. DF formulation recommended. Microthiol Disperss used (not on OMRI list yet).

16. Oxidate (IPM) 95bc ** 69bc Oxidate Sporan98c74bc Trilogy 99c83bcd Bugitol 96bc 80bcd Eco E-RASE98c87cd Organocide97bc69bc GC-396bc80bcd JMS Stylet-oil97bc81bcd Microthiol Disperss (S)100c95cd Bravo Ultrex97bc71bc Quintec + S; Procure + S100c97cd 8/6-7 (8/11 for Bugitol), 8/12, 8/19, 8/25, 9/1, 9/6, and 9/12-13 (7X). * 8/6-7 (8/11 for Bugitol), 8/12, 8/19, 8/25, 9/1, 9/6, and 9/12-13 (7X). a’ indicates no control; severity not different from non-treated. ** ‘a’ indicates no control; severity not different from non-treated. Upper surface Lower surface Treatment (7-day) * 8/23 8/239/16 Powdery Mildew Control - Pumpkin Leaves, 2004 (curative)(8/25+8/26+8/27)

17. Oxidate (IPM) 95bc13a **69bc7ab Oxidate33ab21abc Sporan98c41ab74bc18abc Trilogy 99c63cd83bcd21abc Bugitol 96bc62cd 80bcd14abc Eco E-RASE98c76cd87cd28abc Organocide97bc85cde69bc36bc GC-396bc83cde80bcd42c JMS Stylet-oil97bc77cd81bcd30abc Microthiol Disperss (S)100c92def95cd21abc Bravo Ultrex97bc76cd71bc18abc Quintec + S; Procure + S100c99f97cd82d 8/6-7 (8/11 for Bugitol), 8/12, 8/19, 8/25, 9/1, 9/6, and 9/12-13 (7X). * 8/6-7 (8/11 for Bugitol), 8/12, 8/19, 8/25, 9/1, 9/6, and 9/12-13 (7X). a’ indicates no control; severity not different from non-treated. ** ‘a’ indicates no control; severity not different from non-treated. Upper surface Lower surface Treatment (7-day) * 8/239/16 8/239/16 Powdery Mildew Control - Pumpkin Leaves, 2004 (curative)(8/25+8/26+8/27)

18. Biopesticides - Powdery Mildew Microthiol Disperss 4 lb /A$2.64 /A JMS Stylet-oil5 qt/100 gal$7.50 /A GC-3 Organic1% (50 gpa)$23.75 /A Organocide2 oz/gal (50 gpa)$46.88 /A Eco E-RASE0.5-1% (50 gpa)$15 - 30.00 /A Bugitol96 fl oz/100 gal$28.56 /A Trilogy1% (50 gpa)$11.75 /A Sporan1.5 qt/A$29.25 /A OxiDate40-128 fl oz/100 gal$6.41- 20.50 /A

19. Powdery Mildew - 2004 Compost tea Champion (copper hydroxide) Sonata (Bacillus pumilus) Serenade (Bacillus subtilis)

20. Compost Tea - Regulations National Organic Standards approved compost no molasses or other sugar NYS DEC Bureau of Pesticide Mgt must be registered as a fungicide when used for disease control

21. Compost Tea Recipes 20032004Ingredient 4 lb Grape pumice compost 4 lbLeaf-based compost 4 lbLeaf-based compost 4 lb4 lbVermicompost (manure-based compost) 12 oz 12 ozKelp (Fertrell Liquid Kelp) 7 oz4 ozFish hydrolysate ( Organic Gem Liquid Fish or Neptune’s Harvest Benefits of Fish ) 7 oz4 ozFish hydrolysate ( Organic Gem Liquid Fish or Neptune’s Harvest Benefits of Fish ) 7 oz16 ozHumic acid (Fertrell Bio-Hume) 60 gal water Brewed 24 hr in Sotillo Brewer

23. Compost Tea Applications, 2004 NuFilm P (6 oz/A) + fish hydrolysate (1 oz/30 gal) added after filtering Applied at full strength FloodJet nozzles (large orifice, low resistance) Low pressure (40 psi) Tractor sprayer with diaphram pump (pumpkin)

24. Compost Tea Expenses, 2004 $6.72 8 lbVermicompost $1.89 16 ozHumic acid (Fertrell Bio-Hume) $1.3112 ozKelp (Fertrell Liquid Kelp) $0.524 ozFish hydrolysate (Neptune) $0.524 ozFish hydrolysate (Neptune) $10.3560 gal $10.3560 gal $19.16110 gal/A $1.92 Fish hydrolysate (2 oz/15 gal) $1.64nuFilm P spreader (6 oz/A) $1.64nuFilm P spreader (6 oz/A) $22.72per acre cost undiluted

25. Treatment Costs ($/A) $22.72Compost tea (undiluted) $26.50Serenade (4 lb/A) $6.50Champion (2 lb/A)

26. 20032004Biomass 33.816.0Active bacterial (  g/ml) 576.0288.0Total bacterial (  g/ml) 1.280.91Active fungal (  g/ml) * 1.732.78Total fungal (  g/ml) 46,060.0- Flagellates (#/ml) 58.0- Amoebae (#/ml) 277.0- Ciliates (#/ml) * Fungal community present not highly beneficial. * Fungal community present not highly beneficial. Soil Foodweb, Inc. Organism Biomass in Compost Tea

27. Leaf Organism Assay Results Tomato Nontreated342256 (inadequate) Compost tea before treatment15318 (inadequate) after treatment761793 (very good) Pumpkin Nontreated32133 (inadequate) Compost tea before treatment34135 (inadequate) after treatment61566 (adequate) * Soil Foodweb, Inc. NY (Sept 8 2004) Leaf surface coverage (%) * Treatment BacteriaFungiTotal

28. Compost Tea Applications, 2004 Diseases first seen: Powdery mildew in pumpkin on 26 Jul Compost tea applied: July: 16, 23, and 29 August: 4, 11, 17, and 25 September: 1 and 8

29. 5/12 plastic laid 7/28/04 5/14 Dutch white clover seeded

30. Compost tea ** 17a 0a Compost tea ** 17a *** 0a Compost tea + Sonata77bcd69abc Compost tea + Serenade74bc46ab Sonata (biofungicide)43ab3a Champion (copper)99de85bc Sonata + Champion 99e86bc Flint + Microthiol 97cde95c (sulfur); Procure + Bravo (sulfur); Procure + Bravo * 7/27, 8/4, 8/11, 8/18, 8/24, 8/30, and 9/6 (7X). ** 7/16, 7/23, 7/29, 8/4, 8/11, 8/17, 8/25, 9/1, and 9/8 (9X). a’ indicates no control; severity not different from non-treated. *** ‘a’ indicates no control; severity not different from non-treated. Upper surface Lower surface Treatment (7-day) * 8/9 8/9 Powdery Mildew Control - Pumpkin Leaves, 2004

31. Compost tea ** 17a 29abc 0a4a Compost tea ** 17a *** 29abc 0a4a Compost tea + Sonata77bcd17a69abc7ab Compost tea + Serenade74bc70bcd46ab43bcd Sonata (biofungicide)43ab22ab3a14abc Champion (copper)99de87d85bc49cde Sonata + Champion 99e83d86bc45bcd Flint + Microthiol 97cde95d95c85ef (sulfur); Procure + Bravo (sulfur); Procure + Bravo * 7/27, 8/4, 8/11, 8/18, 8/24, 8/30, and 9/6 (7X). ** 7/16, 7/23, 7/29, 8/4, 8/11, 8/17, 8/25, 9/1, and 9/8 (9X). a’ indicates no control; severity not different from non-treated. *** ‘a’ indicates no control; severity not different from non-treated. Upper surface Lower surface Treatment (7-day) * 8/98/23 8/98/23 Powdery Mildew Control - Pumpkin Leaves, 2004

32. Powdery Mildew

33. Evaluation of New Nozzles and an Air Assist Sprayer for Improving Spray Coverage on Under Side of Leaves

34. Nontreated912a961a899a1104a Bravo Flat fan18b654bc51b975a D3-45 hollow cone23b601c29b968a Conejet4b617bc70b1099a Twin-jet flat fan21b627bc34b1054a Air inclusion15b780b49b1050a Air assist58b549c40b989a Quadris alt Bravo+Nova Flat fan1b239d27b611b Fungicide *Muskmelon Pumpkin Fungicide * Muskmelon Pumpkin Nozzle/SprayerUpperLowerUpperLower Nozzle/SprayerUpperLowerUpperLower Powdery Mildew Severity (AUDPC values) * applications made on 8/1, 8/8, 8/16, 8/23, and 9/2

35. Fungicide Programs Evaluated - Pumpkin, ‘00 StandardAlternatives Biocompatible WeekProgramto BravoFungicides 1QuadrisQuadris Sulfur 2Nova + BravoNova + Kaligreen Kocide 3QuadrisQuadris Kaligreen 4Nova + BravoNova + Kocide Kocide 5QuadrisQuadris Kaligreen Applications: 8/15, 8/22, 8/30, 9/6, and 9/13

36. Wizard, No Fungicide31a49a Wizard, Standard Program0d14bc Wizard, Bravo Alternatives 0d 6cd Wizard, Biocompatibles6bc69a Magic Lantern, No Fungicide 23a20b Magic Lantern, Standard Program 0d 0e Magic Lantern, Bravo Alternatives 0d 1de Magic Lantern, Biocompatibles2cd23b HMX 6687, No Fungicide10b 9c HMX 6687, Standard Program0d 0e HMX 6687, Bravo Alternatives0d 0e HMX 6687, Biocompatibles1d 0e Severity on 9/14/00 Variety, Treatment (7-day) UpperLower Powdery Mildew of Pumpkin