Author Archives: Don Ferrin

About Don Ferrin

I am an associate professor and extension specialist in the Department of Plant Patholgy & Crop Physiology with the LSU AgCenter in Baton Rouge. I have statewide responsibility for issues and educational programs related to diseases of all horticultural crops in Louisiana.

Gaura Rust

Gaura lindheimeri is a plant native to southwestern Louisiana and Texas that is becoming increasingly popular as a landscape plant because it is a sun-loving, summer-flowering perennial that once established is fairly drought tolerant. For more on the horticultural merits … Continue reading

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Cercospora Leaf Spot of Hydrangea

Received these photos of Cercospora leaf spot on hydrangea from Gerald Roberts, county agent in Lafayette Parish.  This disease is caused by the fungus Cercospora hydrangeae, which reproduces on infected leaves that have fallen to the ground. The spores produced … Continue reading

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Fig Rust Causing Early Defoliation

Fig rust, caused by the fungus Cerotelium fici, is already causing defoliation of fig trees in parts of southern Louisiana. This is considerably earlier than normal, but this spring’s abundance of rainfall made conditions ideal for disease development. For more … Continue reading

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Powdery Mildew Blighting Crape Myrtles Now

Powdery mildew, caused by the fungus Erysiphe lagerstroemeriae, is once again wreaking havoc on the blooms of susceptible crape myrtle varieties. The warm, humid weather during late spring and early summer has been ideal for disease development on plants in partially … Continue reading

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Cucurbit Downy Mildew 2012

We have yet to see downy mildew on cucurbits here in Louisiana this year, but it was recently reported on cucumbers in Baldwin County, Alabama, which is east of Mobile Bay. Growers, especially those growing watermelons and pumpkins, and county … Continue reading

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Impatiens Downy Mildew Update

Downy mildew was observed on Impatiens walleriana in a residential landscape in New Orleans today. The affected plants had been purchased at a “big box” store in the area, but it was not the same chain as the store in the … Continue reading

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Gummy Stem Blight of Watermelon

Visited a couple of commercial watermelon producers in Washington and Tangipahoa Parishes with Henry Harrison last week. Poor pollination early in the season has been the major problem in the area due to lack of bee activity early in the … Continue reading

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