As August approaches, now is the time to be scouting peanuts for leaf spot and soilborne diseases and making timely fungicide applications. Calendar-based or advisory-based spray programs can be followed, but be sure to make your fungicide applications before rainy weather makes it difficult to get into fields. Many of our leaf spot outbreaks over the past couple of years were due to extended periods of rainfall and delayed fungicide applications. Cooler, wet weather over the past several days has increased the risk for Sclerotinia blight. In our research plots at the Tidewater AREC, we found small amounts of late leaf spot, Sclerotinia blight, and southern stem rot this week. The leaf spot and Sclerotinia blight advisories, which can be found on the Peanut Cotton Infonet website, indicate disease risk is currently high. For fungicide recommendations, contact your county extension agent or Dr. Hillary Mehl (hlmehl@vt.edu).
Category Archives: Peanut-Cotton Infonet
Peanut iPiPE and Disease Advisories
Especially with all the wet weather we have been having in much of the region, it is time to start thinking about peanut diseases. We do not typically see a lot of disease until the canopy closes, but once the vines are touching the environment within the canopy becomes favorable for disease development. Leaf spot programs should be applied beginning at early beginning pod then according to a calendar-based (usually 14 day intervals) or advisory based program. The leaf spot advisory for Virginia can be found at https://webipm.ento.vt.edu/cgi-bin/infonet1.cgi. Some keys to a successful leaf spot fungicide program include:
- Make the first application at the appropriate time (not too late).
- Apply fungicides regularly before leaf spot outbreaks are observed (once disease is present it is difficult to slow down the epidemic).
- Stick to a regular calendar-based program or utilize leaf spot advisories.
- Be mindful of fungicide resistance management (rotate chemistries and/or tank mix with chlorothalonil).
- Scout for soil-borne diseases and utilize fungicides with activity against both leaf spot and other target diseases (e.g. for both late leaf spot and southern stem rot control use a product such as Provost, Elatus, Priaxor, etc.).
Data are currently being collected to improve both leaf spot and Sclerotinia advisories and to develop a southern stem rot fungicide advisory for peanut. This is being conducted through the Peanut iPiPE program. The Integrated Pest Information Platform for Extension and Education (iPiPE) is a program that allows farmers and extension agents to share information with each other through the internet. iPiPE works by allowing users to enter pest data such as presence and severity of diseases or insects. This data will be shared with everyone in an effort to create a more precise system of pest monitoring and management. The Plant Pathology program at the Virginia Tech Tidewater AREC is leading the Peanut iPiPE and using it to improve disease advisories based on observations of disease onset in peanut fields throughout the region. Two undergraduate interns are currently scouting for peanut diseases in the region, and they will enter disease observations into the iPiPE database.
Disease and pest observations can be easily uploaded to the database through a mobile phone app or the online platform. We are encouraging anyone who scouts peanuts to help us collect disease observations. To become a participant, you can request an iPiPE account by visiting the iPiPE platform (http://www.ipipe.org/). Detailed information on the iPiPE platform and a user guide for the mobile app can be downloaded below. Alternatively, you can email disease observations to Dr. Hillary Mehl (hlmehl@vt.edu). In addition, if you are located in southeastern Virginia or northeastern North Carolina and are interested in having your peanut crop scouted for diseases by our iPiPE interns, please contact us.
Peanut iPiPE Stakeholder Card 2018
For more information or questions regarding the Peanut iPiPE contact Dr. Hillary Mehl (hlmehl@vt.edu).
Peanut-Cotton Infonet Update
The Peanut-Cotton Infonet is up and running for the 2018 growing season. As in previous years, the website will provide:
- Maximum, minimum, and average air temperatures
- Average soil temperature at a 4 inch depth
- Daily and accumulated (from May 1) peanut heat units
- Daily and accumulated (from May 1) cotton degree-days
- Daily and total seasonal (from May 1) rainfall
- Last effective spray date for peanut leaf spot
- Sclerotinia blight risk
- Frost advisory (from September 25th to completion of harvest)
The web address has changed slightly and the website can be found here.
Soil temperatures in southeastern Virginia have been cool over the past couple of weeks (average less than 60 °F), and cool, wet conditions in some fields will favor seedling diseases in early planted crops. A warming trend over the next week will hopefully result in more favorable planting conditions towards the beginning of May.
For questions or concerns regarding the Peanut-Cotton Infonet throughout the growing season, contact Dr. Hillary Mehl (hlmehl@vt.edu).
EPA decision on chlorpyrifos
The head of the EPA, Scott Pruitt, signed an order last night denying the petition to ban chlorpyrifos (Lorsban). This decision will allow peanut growers in our area the continued use of this insecticide for the foreseeable future, perhaps until 2022 when the EPA is required to reevaluate safety of this product. The environmental group that filed the 2007 petition to ban chlorpyrifos has announced its plans to appeal the decision. More information can be found here – https://www.epa.gov/newsreleases/epa-administrator-pruitt-denies-petition-ban-widely-used-pesticide-0
Virginia Frost Advisory
The Virginia Frost Advisory predicts that a frost is expected next Monday morning (10/19) for Suffolk, Capron, Waverly, Skippers, and Lewiston. A copy of the report can be downloaded below. For up-to-date frost advisories for the region, see the Peanut-Cotton Infonet (http://webipm.ento.vt.edu/cgi-bin/listfrost).
Peanut Disease Update
Recent warm, wet weather has been optimal for both plant growth and fungal disease development in peanut and other crops. Early planted peanut in southeastern Virginia is near the R3 (beginning pod) stage, so it is almost time to make the first fungicide application for leaf spot. The first spray can be delayed until two weeks after R3 on Bailey. Last effective spray dates for leaf spot can be found on the Virginia Peanut-Cotton Infonet website.
Sclerotinia blight risk in based on temperature, rainfall/humidity, and crop growth. Temperature and rainfall have been conducive for Sclerotinia blight, but Sclerotinia risk is considered low to moderate prior to canopy closure. However, rapid growth of the peanut crop in some fields has resulted in thick canopies that provide the moist micro-climate necessary for disease development. Thus, now is the time to start scouting for Sclerotinia blight in peanut fields, especially if vines are within six inches of touching. If the wet weather continues, Sclerotinia blight risk is expected to be high within the next couple of weeks.
The Virginia Peanut-Cotton Infonet has moved (back)
The Virginia Tech Tidewater AREC (TAREC) maintains the Peanut-Cotton Infonet which provides growers in the region with daily weather data (e.g. temperature, rainfall), peanut leaf spot and Sclerotinia advisories, peanut heat units, cotton degree days, and a frost advisory. Four weather stations located in Suffolk, Capron, Skippers, and Waverly are maintained by the TAREC Plant Pathology program. These weather stations transmit data to a computer at the Tidewater AREC, and the data is used to run fungicide advisory models. Data are available on the Virginia Peanut-Cotton Infonet website (http://webipm.ento.vt.edu/cgi-bin/infonet1.cgi).
The data and information available here include:
Maximum, minimum, and average air temperatures
Average soil temperature at a 4 inch depth
Daily and accumulated (from May 1) peanut heat units
Daily and accumulated (from May 1) cotton degree-days
Daily and total seasonal (from May 1) rainfall
Last effective spray date for peanut leaf spot
Sclerotinia blight risk
Frost advisory (from September 25th to completion of harvest)
In addition to the data provided on the Infonet, current information on peanut diseases in the region and disease management recommendations will be provided here on this blog, so be sure to check back for updates.
The Peanut-Cotton Infonet has moved
The Virginia Tech Tidewater AREC (TAREC) maintains the Peanut-Cotton Infonet which provides growers in the region with daily weather data (e.g. temperature, rainfall), peanut leaf spot and Sclerotinia advisories, peanut heat units, cotton degree days, and a frost advisory. Four weather stations located in Suffolk, Capron, Skippers, and Waverly are maintained by the TAREC Plant Pathology program. These weather stations transmit data to a computer at the Tidewater AREC, and the data is used to run fungicide advisory models. Data are available on the Virginia Peanut-Cotton Infonet website (http://webipm.ento.vt.edu/cgi-bin/infonet1.cgi).
The data and information available here include:
Maximum, minimum, and average air temperatures
Average soil temperature at a 4 inch depth
Daily and accumulated (from May 1) peanut heat units
Daily and accumulated (from May 1) cotton degree-days
Daily and total seasonal (from May 1) rainfall
Last effective spray date for peanut leaf spot
Sclerotinia blight risk
Frost advisory (from September 25th to completion of harvest)