Cucurbit Downy Mildew Reports for 2004

Site of
Outbreak
Date
Reported
Reported
by:
Host
Description

Immokalee, Florida (1)
January 9, 2004
Gene McAvoy
Squash, cantaloupe, watermelom
Initial reports on squash across south Florida; widespread in south Florida on squash and cantaloupe by 5 April; moved aggressively onto watermelon by 14 May.

Hidalgo County, Texas (2)
May 19, 2004
Thomas Isakeit
Watermelon (and cantaloupe?)
Downy mildew was discovered in a 200-acre field of watermelon. First lesions are estimated to have appeared around April 23, 2004. There are unconfirmed reports of widespread downy mildew in the cantaloupe and watermelon growing areas of the lower Rio Grande Valley, primarily Hidalgo and Starr counties. Recent weather has been favorable, and the wetter-than-normal spring in this area has played a major role.

Sampson County, North Carolina (3)
May 30, 2004
Gerald Holmes
Cucumber
Downy mildew was discovered in a field of cucumber after a sample was submitted to the disease clinic. Sporulation was heavy. Estimated appearance of first lesions was May 20, 2004. Recent weather has not been favorable for disease development. A consultant commented that disease was only found in an area where the crop was burned with an application of Command.

Reno County, Kansas (4)
June 23, 2004
Ned Tisserat
Cantaloupe
Grower reported downy mildew at the end of his drip rows where water had accumulated. Less than 5% of crop infected (Cultivar Athena). Applied Quadris at first sign of disease.This is an approximately 5-acre field, with less than 5% infected. Recent weather favorable.

Cumberland County, New Jersey (5)
June 25, 2004
Andy Wyenandt
Winter Squash
25% of 20 acres of winter squash are infected. Recent weather has been favorable. Dr. Wyenandt rates this as a moderately serious though questionable source.

Southern (?) Georgia (6)
June 28, 2004
David Langston
Butternut Squash
Downy Mildew has been observed in a butternut squash trial that was (is) being studied for powdery mildew. Pristine @ 14.5 oz / acre worked very well and was applied twice prior to onset of disease. Other materials applied were all for powdery mildew (Quintec, Nova, etc.) and "got hammered", i.e. the plants became completely defoliated. Flint at 2.0 oz./acre was ineffective. Only plots left standing in the test were the Pristine. (Description paraphrased from informal report - tk)

Accomack County, Virginia (7)
July 7, 2004
Christine Waldenmaier
Cucumber
Downy mildew was observed on July 7 in a cucumber research trial that had not been sprayed with fungicides. Incidence level is around 40% infected leaves throughout. Severity on individual leaves is rather high and there are hot spots within the field (0.6 acre). Cucumber variety is Dasher II.

Boston, Massachusetts (8)
July 21, 2004
David Martin
Cucumber, pumpkin, summer squash
Unconfirmed. 20 X 70 acre field, 25% infected.

Hunterdon County, New Jersey (9)
July 21, 2004
Kris Holmstrom
Pumpkin
Small plot that is to be used for a powdery mildew fungicide trial. The field was being scouted for PM when downy mildew was found on July 20. Only a few plants were affected, but sporulation was occurring. DM has been present in southern NJ for about 3 weeks, and recent storms from the SSW with heavy rains, high temps, and humidity have likely contributed to the "outbreak" in the northern NJ counties. We expect to see more DM in the next 1-2 weeks.

Lexington County, South Carolina (10)
July 22, 2004
Powell Smith
Cantaloupe
DM noticed on "Armenian Cucumber" (Cucumis melo Flexuosus group). It had rained about 3 inches one week earlier and before and after the 3 inch rain had been raining a few 10th's daily. Temps were high 80's to low 90's daytime and around 70 - 72 at night. It is a home garden situation with moderate fertility and no fungicide applications. Standard pickling types in the same are were affected but not as severely. No voucher samples were sent to the clinic, and plants have now been removed. Other cucurbits such as summer squash and chayote were not affected.

Wicomico and Dorchester, Maryland. Sussex, Delaware. (11)
July 22, 2004
Kathryne Everts
Cucumber and Watermelon
Nearly all the pickling cucumber acreage in the Eastern Shore of Maryland and in Delaware is affected. Many watermelon fields are also infected. Growers are spraying cucumbers with Ridomil Gold Bravo. New fields of cucumber are infected at a very early growth stage (first true leaf). Watermelons became infected and are being sprayed with chlorothalonil and other products, including Tanos. No confirmed reports on muskmelon, yet.

Wayne County, North Carolina (12)
August 2, 2004
Bruce Howell
Cucumber
15% of a 25-acre field is infected.

Northampton County, Pennsylvania (13)
August 10, 2004
Jane Burkholder
Pumpkin
Hit the pie pumpkins first and today (August 10). I noticed it in the field pumpkins. Treated pie pumpkins with copper 7 days ago, but have not seen improvement. Will treat entire crop with Bravo as soon as I can get the local farm bureau to get some in and I have a rainfree period.

Livingston County, Michigan (14)
August 14, 2004
Mark Tinder
Cucumber, winter squash
Have 10 pickle cucumber and 10 acorn squash plants. Ranges from few spots to leaves dead and brownish yellow. Going to try to get some medicine toaday to try ato save them. Been very cool and rainy all summer.

Barnwell County, South Carolina (15)
August 17, 2004
Anthony Keinath
Cantaloupe
Fungicide trial plots at Clemson University's Edisto REC. Good control of DM with biweekly applications of chlorothalonil, but vines in nonsprayed plots and plots sprayed with Serenade are going down fast. Plots will be held until the field day on Sep. 2

Chester County, South Carolina (16)
August 17, 2004
Anthony Keinath
Pumpkin
Grower e-mailed me on 11 August to request assistance. They have seen downy mildew at this location consistently the past 5-6 years. Based on digital photos, the disease is fairly advanced and they were not able to spray again before rain from Tropical Storm Bonnie reached their area on 12 August.

New Haven / Litchfield Counties, Connecticut (17)
August 18, 2004
Jude Boucher
Cucumber
On 3 August, Bill Lamount at Penn State told me that most of the pumpkin (cucurbit?) fields in PA were hit with downy during the last week of July. During scouting on 6 August, we found many plants in a grower's 3 pumpkin fields (total of 20 acres in Middlebury and Morris) were infected with downy mildew (numerous yellow spots on many leaves / plant). Fields are 2 to 10 miles apart. The grower had applied Quadris on 26 July and Bravo + Nova on 5 August. I had him apply another shot of Ridomil Gold / Bravo + Sulfur on 9 August. Disease covered most leaves on all plants by 13 August. Yellow spots had necrotic centers and had expanded. Some leaves with half the area dead. A second grower's fields (10-20A) in Bethlehem, treated with the ame program and timing, has downy even more severe than first grower (he does the spraying for the first grower). I expect complete defoliation in next week or two in Bethlehem. This morning (17 August) received a call from third grower (Watertown) that also has the problem on his cucurbits (identified by the second grower who now knows what it looks like). No fungicides applied yet in Bethlehem. Will spray Ridomil Gold Bravo + sulfur. The sulfur is for powdery mildew.

Back to NCSU Cucurbit Downy Mildew Forecast Home Page

Page last updated July 2, 2004.

Immokalee, Florida (1)	January 9, 2004	Gene McAvoy	Squash, cantaloupe, watermelom	Initial reports on squash across south Florida; widespread in south Florida on squash and cantaloupe by 5 April; moved aggressively onto watermelon by 14 May.
Hidalgo County, Texas (2)	May 19, 2004	Thomas Isakeit	Watermelon (and cantaloupe?)	Downy mildew was discovered in a 200-acre field of watermelon. First lesions are estimated to have appeared around April 23, 2004. There are unconfirmed reports of widespread downy mildew in the cantaloupe and watermelon growing areas of the lower Rio Grande Valley, primarily Hidalgo and Starr counties. Recent weather has been favorable, and the wetter-than-normal spring in this area has played a major role.
Sampson County, North Carolina (3)	May 30, 2004	Gerald Holmes	Cucumber	Downy mildew was discovered in a field of cucumber after a sample was submitted to the disease clinic. Sporulation was heavy. Estimated appearance of first lesions was May 20, 2004. Recent weather has not been favorable for disease development. A consultant commented that disease was only found in an area where the crop was burned with an application of Command.
Reno County, Kansas (4)	June 23, 2004	Ned Tisserat	Cantaloupe	Grower reported downy mildew at the end of his drip rows where water had accumulated. Less than 5% of crop infected (Cultivar Athena). Applied Quadris at first sign of disease.This is an approximately 5-acre field, with less than 5% infected. Recent weather favorable.
Cumberland County, New Jersey (5)	June 25, 2004	Andy Wyenandt	Winter Squash	25% of 20 acres of winter squash are infected. Recent weather has been favorable. Dr. Wyenandt rates this as a moderately serious though questionable source.
Southern (?) Georgia (6)	June 28, 2004	David Langston	Butternut Squash	Downy Mildew has been observed in a butternut squash trial that was (is) being studied for powdery mildew. Pristine @ 14.5 oz / acre worked very well and was applied twice prior to onset of disease. Other materials applied were all for powdery mildew (Quintec, Nova, etc.) and "got hammered", i.e. the plants became completely defoliated. Flint at 2.0 oz./acre was ineffective. Only plots left standing in the test were the Pristine. (Description paraphrased from informal report - tk)
Accomack County, Virginia (7)	July 7, 2004	Christine Waldenmaier	Cucumber	Downy mildew was observed on July 7 in a cucumber research trial that had not been sprayed with fungicides. Incidence level is around 40% infected leaves throughout. Severity on individual leaves is rather high and there are hot spots within the field (0.6 acre). Cucumber variety is Dasher II.
Boston, Massachusetts (8)	July 21, 2004	David Martin	Cucumber, pumpkin, summer squash	Unconfirmed. 20 X 70 acre field, 25% infected.
Hunterdon County, New Jersey (9)	July 21, 2004	Kris Holmstrom	Pumpkin	Small plot that is to be used for a powdery mildew fungicide trial. The field was being scouted for PM when downy mildew was found on July 20. Only a few plants were affected, but sporulation was occurring. DM has been present in southern NJ for about 3 weeks, and recent storms from the SSW with heavy rains, high temps, and humidity have likely contributed to the "outbreak" in the northern NJ counties. We expect to see more DM in the next 1-2 weeks.
Lexington County, South Carolina (10)	July 22, 2004	Powell Smith	Cantaloupe	DM noticed on "Armenian Cucumber" (Cucumis melo Flexuosus group). It had rained about 3 inches one week earlier and before and after the 3 inch rain had been raining a few 10th's daily. Temps were high 80's to low 90's daytime and around 70 - 72 at night. It is a home garden situation with moderate fertility and no fungicide applications. Standard pickling types in the same are were affected but not as severely. No voucher samples were sent to the clinic, and plants have now been removed. Other cucurbits such as summer squash and chayote were not affected.
Wicomico and Dorchester, Maryland. Sussex, Delaware. (11)	July 22, 2004	Kathryne Everts	Cucumber and Watermelon	Nearly all the pickling cucumber acreage in the Eastern Shore of Maryland and in Delaware is affected. Many watermelon fields are also infected. Growers are spraying cucumbers with Ridomil Gold Bravo. New fields of cucumber are infected at a very early growth stage (first true leaf). Watermelons became infected and are being sprayed with chlorothalonil and other products, including Tanos. No confirmed reports on muskmelon, yet.
Wayne County, North Carolina (12)	August 2, 2004	Bruce Howell	Cucumber	15% of a 25-acre field is infected.
Northampton County, Pennsylvania (13)	August 10, 2004	Jane Burkholder	Pumpkin	Hit the pie pumpkins first and today (August 10). I noticed it in the field pumpkins. Treated pie pumpkins with copper 7 days ago, but have not seen improvement. Will treat entire crop with Bravo as soon as I can get the local farm bureau to get some in and I have a rainfree period.
Livingston County, Michigan (14)	August 14, 2004	Mark Tinder	Cucumber, winter squash	Have 10 pickle cucumber and 10 acorn squash plants. Ranges from few spots to leaves dead and brownish yellow. Going to try to get some medicine toaday to try ato save them. Been very cool and rainy all summer.
Barnwell County, South Carolina (15)	August 17, 2004	Anthony Keinath	Cantaloupe	Fungicide trial plots at Clemson University's Edisto REC. Good control of DM with biweekly applications of chlorothalonil, but vines in nonsprayed plots and plots sprayed with Serenade are going down fast. Plots will be held until the field day on Sep. 2
Chester County, South Carolina (16)	August 17, 2004	Anthony Keinath	Pumpkin	Grower e-mailed me on 11 August to request assistance. They have seen downy mildew at this location consistently the past 5-6 years. Based on digital photos, the disease is fairly advanced and they were not able to spray again before rain from Tropical Storm Bonnie reached their area on 12 August.
New Haven / Litchfield Counties, Connecticut (17)	August 18, 2004	Jude Boucher	Cucumber	On 3 August, Bill Lamount at Penn State told me that most of the pumpkin (cucurbit?) fields in PA were hit with downy during the last week of July. During scouting on 6 August, we found many plants in a grower's 3 pumpkin fields (total of 20 acres in Middlebury and Morris) were infected with downy mildew (numerous yellow spots on many leaves / plant). Fields are 2 to 10 miles apart. The grower had applied Quadris on 26 July and Bravo + Nova on 5 August. I had him apply another shot of Ridomil Gold / Bravo + Sulfur on 9 August. Disease covered most leaves on all plants by 13 August. Yellow spots had necrotic centers and had expanded. Some leaves with half the area dead. A second grower's fields (10-20A) in Bethlehem, treated with the ame program and timing, has downy even more severe than first grower (he does the spraying for the first grower). I expect complete defoliation in next week or two in Bethlehem. This morning (17 August) received a call from third grower (Watertown) that also has the problem on his cucurbits (identified by the second grower who now knows what it looks like). No fungicides applied yet in Bethlehem. Will spray Ridomil Gold Bravo + sulfur. The sulfur is for powdery mildew.