Anco Comments Thrips SC Peanut Notes No. 47 2020

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In-Furrow Twin Row Rates

In-furrow rates for imidacloprid (Admire Pro and generics), Velum Total, AgLogic, and Thimet are all capped at a max per acre basis according to the labels. If planting in twin rows, this results in split total application amounts per row. If using a generic, verify the label rate and formulation, less active ingredient per gallon results in higher product rates to give equivalent active ingredient amounts.

Admire Pro max is 10.5 fl oz/A (5 fl oz/A per each row of the twin row)

Velum Total max is 19 fl oz/A (9 to 9.5 fl oz/A per each row of the twin row)

AgLogic max is 7 lb/A at-planting (3.5 lb/A per each row of the twin row)

Thimet recommended max is 6 lb/A (3 lb/A = 3.5 oz/1000 row ft per each row of the twin row)

Split applications, particularly if imidacloprid is used, may need a post emergence follow up with acephate (Orthene). Keep on the list to scout as they crack and emerge. Volunteer peanuts in nearby crops (if they haven’t been killed yet) are usually a good indicator of how much thrips pressure we have at the moment.

I have heard of some limited talk of weekly acephate applications post emergence, but I do not recommend weekly applications due to cost, practicality, and me having no data on this.

Leaf Spot Papers

Attached are three papers we recently had published on leaf spot management.

The first is our results of leaf spot suppression following phorate (Thimet) application. Most experiments were naked from in-season fungicide sprays to encourage disease development, but one year in FL had a full length fungicide program with consistent results still present. All things with a grain of salt, but our work shows consistent efficacy.

The second is our fungicide phenotypic resistance study, shows potential for phenotypic resistance in several counties based on pooled samples. There were certainly differences within individual counties, but data is shown here pooled by county to improve replication and interpretation.

The third was possible with the collaboration of many great people in the VC and SE regions. It is a little thick with numbers in sections but shows the relationship of defoliation and yield loss. The last paragraph summarizes the results. The thresholds there are suggested as a rough rule of thumb, lots of important different factors affect harvest. Growers are familiar with this.

Sixty One Years Following Registration, Phorate Applied In-Furrow at Planting Suppresses Development of Late Leaf Spot on Peanut

Rapid Detection of Fungicide Resistance Phenotypes Among Populations of Nothopassalora personata in South Carolina Peanut Fields

Peanut Yield Loss in the Presence of Defoliation Caused by Late or Early Leaf Spot

Dan Anco

Extension Peanut Specialist and Assistant Professor

Department of Plant and Environmental Sciences

Clemson University – Edisto Research and Education Center

64 Research Road

Blackville, SC 29817

803-284-3343 x261 office

630-207-4926 cell

danco@clemson.edu

Clemson Extension Peanuts