Peanut Growth Stages From Dr. Phipps

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Here is information from Dr. Phipps. Barbara has very similar information. This will be helpful for disease control recommendations. Barbara will clarify recommendations for North Carolina.

The Virginia Peanut Hotline (1-800-795-0700) will provide Peanut Leafspot and Sclerotinia blight Advisories, daily weather summaries, soil temp reports, and heat unit reports daily for Suffolk, Capron, Skippers, and Waverly starting today until the beginning of harvest. In addition, the same data continues to be reported on the Peanut/Cotton InfoNet at http://webipm.ento.vt.edu/cgi-bin/infonet1.cgi . Currently, peanut growth has reached or soon will be in the beginning pod stage (R3) which is the time when the 1st application of leaf spot fungicide is need for peanuts planted in a 2- or 3-year rotation. If peanuts are planted in 4-year or longer rotation, the 1st application of leaf spot fungicide is not needed until the beginning seed stage (R5). See attached ppt file that illustrates peanut growth stages. This stage once pods are full size and beginning to develop a seed inside. After making the 1st application of fungicide, all subsequent sprays for leaf spot control should be applied according to the “last effective spray date or LSED reported in the daily advisory on the Peanut Hotline and the Peanut/Cotton InfoNet. Historically, the advisory has allowed most growers to achieve good to excellent leaf spot control with as few as 3 to 4 sprays in 2- or 3-year rotations, and 4 to 5 sprays in 4-year or longer rotations.

Another important matter is that Sclerotinia blight has been found in 5 fields of Bailey peanut in Gates County, NC. All 5 fields with the disease were planted in twin rows and vine growth was less than 6 in. from touching in the row middles. The weather conditions that triggered this outbreak are largely a result of our prevailing weather patterns with frequent rainfall and cooler air and soil temps, and rapid vine growth during the previous 10 days. Currently, growers should scout fields for the disease and consider application of a recommended fungicide (Omega, Fontelis, Propulse, or Priaxor). Omega fungicide has been the most tested and widely used for control of Sclerotinia blight whereas Fontelis, Propulse, and Priaxor are registered products that have undergone a lesser amount of testing.

Article first appeared as North Carolina Peanut Note (PNNC-2013-040)