University of Illinois Plant Clinic

Downy Mildew of Cucurbits has Arrived in Illinois for 2020

On August 13, 2020, University of Illinois State Extension Pathologist Mohammad Babadoost detected downy mildew from samples submitted from White County. With current weather conditions, the pathogen could spread very fast and affect all cucurbit crops statewide.

Dr Babadoost recommends the following fungicides for control of cucurbit downy mildew in Illinois: Orondis Ultra (8 fl oz/acre) or Orondis Opti (2.5 pt/acre) alternated with Ranman (2.75 fl oz/acre) at weekly intervals.

For complete pumpkin fungicide recommendationshttps://extension.illinois.edu/sites/default/files/pumpkin_spray_2020.pdf

Be sure to follow all label recommendations, particularly pre-harvest intervals (PHI).

For additional information and photos of downy mildew, visithttps://extension.illinois.edu/sites/default/files/925_downy_mildew_1.pdf

Turf rust can turn grass -- and shoes -- bright orange. Thankfully it's not harmful to pets or people, but it can be quite striking.

"'The curse is come upon me,' cried the basil of Shallot"

Southern rust on corn showed up in northern Illinois last week.

I've seen this from a few different states, including Washington, Arizona, Kansas, and Indiana. If you receive seeds that you did not order, do NOT plant them. Instead, contact USDA here: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/import-information/sa_sitc/ct_antismuggling?fbclid=IwAR23Mx7CVIHvb7_oFbRnFEb8poG4PGRbb8Q8BOyJHGdbOa7wFyVYzrmoMzE and keep the bags sealed until you are given instructions on how to dispose of them.

UPDATED to reflect new reporting instructions! https://agr.wa.gov/about-wsda/news-and-media-relations/news-releases?article=31411

Today we received reports of people receiving seeds in the mail from China that they did not order. The seeds are sent in packages usually stating that the contents are jewelry. Unsolicited seeds could be invasive, introduce diseases to local plants, or be harmful to livestock.

Here's what to do if you receive unsolicited seeds from another country:

1) DO NOT plant them and if they are in sealed packaging (as in the photo below) don't open the sealed package.

2) This is known as agricultural smuggling. Report it to USDA. Information in our latest press release on how to report: https://agr.wa.gov/about-wsda/news-and-media-relations/news-releases?article=31411

Basil downy mildew was reported earlier in July in NE Illinois and today we received a sample from east central Illinois. If you are growing basil plants, especially sweet basil (Ocimum basilicum) scout your plants and consider an early harvest! For more information, please see:http://extension.cropsciences.illinois.edu/fruitveg/pdfs/1216.pdf

One of the cornerstones of integrated pest management is correctly identifying what you have before you treat it! Chelsea talks about why it's important to know what's present before you spray:

Cornfields across the state are at or nearing tassel, which means it is time to begin fungicide applications to help manage fungal diseases. Before you spray, have you stopped to check what's in your cornfields?

🌽 https://go.illinois.edu/WhatsInYourCornfield

Pear sample with suspect pear trellis rust from northern Illinois. This is a fairly new disease to the United States and to our state; so far we've only seen a few samples from the northern part of Illinois. For more information: http://hyg.ipm.illinois.edu/article.php?id=1096

In honor of our friends up north: an oldie but a goodie talking about common maple leaf diseases http://hyg.ipm.illinois.edu/article.php?id=473 😁🍁

We will be closed Friday, July 3 in observance of Independence Day. If you're thinking of sending a sample, we suggest either sending it today or waiting until early next week.

I ran two ELISAs yesterday (testing for blueberry shock virus and blueberry scorch virus in blueberry plants prior to export). It's always nice when the positives are so perfectly positive (yellow), and the negatives are so perfectly negative (clear). 😊