Monday, May 20, 2013

Nationwide Caneberry Survey

Hello Caneberry Grower

This in from Dr, Gina Fernandez:

Debby Wechsler, Executive Secretary of the North American Raspberry and Blackberry Association is conducting a nationwide survey. She  is asking growers to share the prices that they will be charging for thier berries. The results will stay confidential, and anyone that sends in data will be sent the compiled results. Here is a link to her message:

Thursday, May 9, 2013

Food Safety Issues Related to Flooded Fields

Food Safety Issues Related to Flooded Fields

Hello vegetable growers!  You got a blog posting yesterday regarding flooded fields and possible plant pathogens; today's posting focuses on food safety issues.   This in from Diane Ducharme our Extension Associate:

There is another issue here to consider safety.   FDA issued guidance effective immediately on flooded crops and fields.  While crops are not in the fields, the soil has been flooded and I have take only this section out of the full guidance for reference below.  Full document can be found at:

Essentially, it says to do a field assessment using the outlined bullets below.  I have bolded several of these of particular attention.    The FDA's guidance documents reflect the agency's current thinking ,on a topic and should be viewed only as recommendations, unless specific regulatory or statutory requirements are cited.  The use of the word should in Agency guidances means that something is suggested or recommended, but not required.   These guidances  do not establish legally enforceable responsibilities. 

V. Assessment of Flood-affected Fields before Replanting

FDA recommends not replanting in flooded fields if flood waters have not receded and the soil has not sufficiently dried.  In the Draft Guidance to Industry to Minimize Microbial Food Safety Hazards of Leafy Greens (Ref. 1), FDA recommends the following assessment for formerly flooded production ground:
  • Assessing field history and crop selection.
  • Determining the time interval between the flooding event, crop planting, and crop harvest.
  • Determining the source of flood waters (e.g., drainage canal, river, or irrigation canal) and whether there are significant upstream potential contributors of human pathogens.
  • Allowing soils to dry sufficiently and be reworked prior to subsequently planting crops on formerly flooded production ground.
  • Sampling previously flooded soil for the presence of microorganisms of significant public health concern or appropriate indicator microorganisms. Note: Microbial soil sampling can provide valuable information regarding relative risks, but sampling by itself does not guarantee that all raw agricultural commodities grown within the formerly flooded production area are free of the presence of human pathogens.  
The waiting period before growers can replant depends on conditions such as temperature, weather, and soil type.  Currently, FDA has not completed studies to determine the length of waiting time that is generally considered safe for replanting.  State, industry, and university extension specialists have recommended a 30-60 day waiting period and/or soil testing prior to replanting to (Ref. 12, 13, 14, 15). While this time period is generally considered sufficient for fecal contamination to decline, chemical contamination, if present, may continue to remain in the flood-affected soil (Ref. 12).
And now you have the current recommendations, not laws from FDA on flooded fields concerning Food Safety concerns."

Do keep in mind that if you have products in the flooded fields- (lettuce, greens, etc) that were contaminated by the flood waters, that these items MUST not be harvested and sold.  Food safety is a very critical and hot button topic.   If you have any questions contact your local Horticulture Extension Agent.

Wednesday, May 8, 2013

Flooded Fields and Planting Recommedations

Hello Vegetable and Small Fruit Growers
I am posting items to the WNC Vegetable and Small Fruit Blog temporarily in the absence of a vegetable agent.  Some of you have fields that were recently flooded by the tremendous amount of rain that we have had over the past weekend.  The information following comes from Dr. Kelly Ivors and are her most current recommendations as to how to prepare these fields for the crops you plan to plant in particular tomatoes and peppers.  

"Our NCSU labs  can test water for Phytophthora (that isn't the problem), but the water samples will be variable and very hard to determine what was in the exact flood waters that each field was exposed to when the flooding occurred. Samples would have needed to be taken during the flooding. Flooding also carries debris and anything else that is water soluble or water 'floatable'. You just have to assume that there is a increased potential that Pythium and possibly Phytophthora could have been introduced, or other pathogens that are water dispersable. My chapter on oomycetes in the new APS Press book "Waterborne Plant Pathogens" (IN PRESS!) goes over this variability in detail.
Main point is this: Phytophthora and Pythium infections almost always show up in the wettest spots in the field. In ornamentals, it is where they have water pooling or leaky irrigation heads. In Fraser fir fields, Phytophthora root rot was correlated with soils high in clay. In vegetable fields, these pathogens seem to be most problematic in low spots and areas that drain poorly. I bet the same areas that flooded recently have been flooded before. We have had quite a bit of flooding since I have been working at NCSU.
Hopefully the surrounding soils weren't that warm enough to have active populations of bacterial wilt. I think my main concern in setting transplants in recently flooded fields would be Pythium or Phytophthora crown/root rot (or both organisms... maybe even a complex with Rhizoctonia/Fusarium if contaminated debris / small pieces got under the plastic). I would worry the most about direct-seeding/setting cucurbits in these flooded fields, and also worry equally about setting pepper and tomato transplants in these fields as far as Pythium and Phytophthora goes. While P. capsici isn't a big problem on tomatoes, young plants are very susceptible to Phytophthora crown rot / stem blight.
If you want to still plant tomatoes or peppers in these fields, I think the best bet would be to apply mefenoxam PREVENTIVELY in the drip RIGHT AFTER plants are set. Mina did a study on black shank of tobacco a few years back, and Ridomil worked the best when it was applied on the date closest to transplanting.  The rate for Ridomil Gold is 1 pint / acre. I have attached a screen shot of further application details. RATE IS VERY IMPORTANT when dealing with young plants. Do NOT OVER APPLY MEFENOXAM to young seedlings.
If you are going to set tomatoes, then I would recommend a variety that has Fusarium race 1, 2 and *3* resistance, as Dr.Shoemaker has also suggested. We really appreciate your input and advice Paul. Two pathologists are better than one !!!"

Posted with minor edits by Cliff Ruth, Extension Area Agent.  

Please help spread the word,  We may not have e-mail addresses for many of your fellow growers so feel free to pass this information to them or to your clients.  

Saturday, May 4, 2013

Pest News for the Week of May 5


From: Hannah Burrack, Extension Entomologist

What To Watch For: Broad Spectrum Insecticides Can Flare Spider Mites

Broad spectrum insecticides, including materials like pyrethroids (IRAC Group 3 materials), organophosphates (IRAC Group 1B), and carbamates (IRAC Group 1A) (, have been demonstrated by our laboratory and lots of other entomologists to flare spider mite populations following their use. The reasons each of these classes of insecticides flare mites differ, but the result is the same–more mites following treatment than you start out with.

Unfortunately, many of these materials are also recommended for spotted wing drosophila (SWD) ( management. As I wrote two years ago (, at the beginning of the SWD invasion in North Carolina:

“. . . A good rule of thumb is to observe at least 10 leaves or leaflets per acre or per variety block, if they are smaller than an acre. Spider mites can be observed and counted with a 10x hand lens. If spider mites are present, the planting should be treated with a miticide before beginning organophosphate or pyrethroid (update: or carbamate) treatments.

Spider mites may not be the only non target (unintentional) pest made worse by SWD treatments. Organophosphates and pyrethroids are broad spectrum materials, meaning they kill many different types of insects, including beneficial predators. The insects these predators may control could increase in their absence, but we cannot necessarily predict which insects these may be. Growers treating for SWD should be vigilant and scout their fields at least weekly to assess whether any new or unexpected insect or damage is present.”

In our 2012 SWD experiments in strawberries (, we tanked mixed all our initial SWD treatments with a miticide, Acramite. This tank mix was effective against the large spider population present and did not damage plants. I do not have firsthand experience with tank mixing other miticides with insecticides, so I would be cautious. When tank mixing two materials, be sure to test for compatibility [a jar test ( is one way] and treat a small area first before treating your whole field.

More information

What to watch for: When treating for SWD (NC Small Fruit & Specialty Crop IPM):

What to watch for: strawberry update (NC Small Fruit & Specialty Crop IPM):

All SWD posts (NC Small Fruit & Specialty Crop IPM):