May-August 2012-5 th driest on record-indiana
DRY WEATHER AND FUNGICIDE APPLICATIONS How does dry weather affect foliar fungal diseases. Examples of foliar fungal diseases that require leaf wetness. Applying fungicides according to the weather. Examples of diseases that do not require leaf wetness. Bacterial diseases as affected by weather. Phytophthora blight as affected by weather.
DRY WEATHER AND FUNGICIDE APPLICATIONS How does dry weather affect foliar fungal diseases. Examples of foliar fungal diseases that require leaf wetness. Applying fungicides according to the weather. Examples of diseases that do not require leaf wetness. Bacterial diseases as affected by weather. Phytophthora blight as affected by weather.
Rain/irrigation Fungal spores Leaf wetness Healthy leaf
Infected leaf
Fungi infects leaf Leaf cross-section
Rain and disease-how does water influence foliar disease Rain is necessary for many disease organisms to enter plants. Rain spreads disease from plant to plant.
DRY WEATHER AND FUNGICIDE APPLICATIONS How does dry weather affect foliar fungal diseases. Examples of foliar fungal diseases that require leaf wetness. Applying fungicides according to the weather. Examples of diseases that do not require leaf wetness. Bacterial diseases as affected by weather. Phytophthora blight as affected by weather.
Early blight Leaf wetness required- Early blight of tomato.
Leaf wetness required- Septoria leaf blight of tomato.
Leaf wetness required- Gummy stem blight of cucurbits
Leaf wetness required- Anthracnose of cucurbits.
Leaf wetness required- Common rust of sweet corn.
Leaf wetness required- Northern corn leaf blight of sweet corn.
Leaf wetness required- Downy mildew of pumpkin.
Powdery mildew is a foliar disease that does not require leaf moisture Powdery mildew of pumpkin infection can take place with RH as low as 50%.
DRY WEATHER AND FUNGICIDE APPLICATIONS How does dry weather affect foliar fungal diseases. Examples of foliar fungal diseases that require leaf wetness. Applying fungicides according to the weather. Examples of diseases that do not require leaf wetness. Bacterial diseases as affected by weather. Phytophthora blight as affected by weather.
Dry conditions Fungicide applications- 14 days Frequent Rains Fungicide applications- 7 days
HOW OFTEN SHOULD I SPRAY? Most intervals should be 7-14 days. The frequency of rain is more important than the amount. A rain in the evening may be more impt than one at midday. It is best to spray before rain if possible. Poor crop rotation affects spray intervals.
MELCAST-a Purdue Program That allows melon growers to schedule fungicide applications according to the weather. Use toll-free # or Internet to get values. Apply fungicides every 14-days unless weather is conducive for disease.
DRY WEATHER AND FUNGICIDE APPLICATIONS How does dry weather affect foliar fungal diseases. Examples of foliar fungal diseases that require leaf wetness. Applying fungicides according to the weather. Examples of diseases that do not require leaf wetness. Bacterial diseases as affected by weather. Phytophthora blight as affected by weather.
SOIL BORNE DISEASES Pathogen may survive in soil w/out host Leaf wetness not needed for infection
Examples of plant diseases that do not require leaf wetness-soil borne diseases Fusarium wilt of watermelon Root knot of many crops Scab of potato
INSECT VECTORED DISEASES Insects spread pathogen from plant to plant. Leaf wetness not necessarily needed.
Examples of plant diseases that do not require leaf wetness-insect vectored Mosaic viruses of pumpkin Stewart s wilt of Sweet corn Bacterial wilt of cantaloupe
DRY WEATHER AND FUNGICIDE APPLICATIONS How does dry weather affect foliar fungal diseases. Examples of foliar fungal diseases that require leaf wetness. Applying fungicides according to the weather. Examples of diseases that do not require leaf wetness. Bacterial diseases as affected by weather. Phytophthora blight as affected by weather.
BACTERIAL DISEASES & WEATHER Leaf wetness is required for infection of most bacterial diseases. Rain helps to spread bacterial diseases. However, dew is often sufficient to cause serious disease.
Bacterial speck/spot of tomato requires 24 hrs RH for infection. Bacterial spot Bacterial speck
Bacterial canker requires leaf wetness for infection, but systemic in plant w/out moisture. Bacterial canker
= bacteria = water film Bacteria ingress into leaf Leaf cross-section Pore in leaf (stomate)
DRY WEATHER AND FUNGICIDE APPLICATIONS How does dry weather affect foliar fungal diseases. Examples of foliar fungal diseases that require leaf wetness. Applying fungicides according to the weather. Examples of diseases that do not require leaf wetness. Bacterial diseases as affected by weather. Phytophthora blight as affected by weather.
PHYTOPHTHORA BLIGHT Causes lesions on stems & leaves-foliar pathogen Survives in well in soil w/out host-soil borne Leaf wetness & waterlogged soils increase severity
Phytophthora blight watermelon squash
TOTAL NUMBER OF VIEWS FOR THE ID-56 WEBSITE IN 2012 1200 1000 800 Total Views 600 400 200 0 Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Total=8,238
NEW FUNGICIDES Torino 10 SC (U6) is labeled on cucurbits for powdery mildew Quash 50 WDG (3) is registered for potato and sweet potato for several diseases. Inspire Super (9, 3) restrictions on tomato size have been removed. Zampro (40,45) brassicas & bulbs (downy mildew), cucurbits (downy & Phytophthora), fruiting vegs (late blight).
FUNGICIDES-NEW LAST YEAR Fontelis 1.67 SC (7) is registered on cucurbits, tomatoes etc. for several diseases. Luna Experience (7,3) & Luna Sensation (7,11) is labeled on watermelon for several diseases Luna Tranquility (7,9) is labeled for several diseases on potato.