Two Insecticides In Furrow?
Would it be worth applying both imidacloprid/generic Admire Pro and Thimet in furrow to improve early season protection against thrips? While multiple different approaches often are helpful in improving our overall management of different pests and are at the heart of IPM, the specific combinations are also important. We have looked at this specific combination a few years back in 2018 and did not see a benefit of adding imidacloprid in the furrow with Thimet. Numerically, the combined imid + Thimet treatment had a little greater TSW than Thimet alone, and the combined treatment had significantly less yield, about 220 lb/A, compared to Thimet alone. If a granular insecticide is on the table for going out in furrow, either Thimet or AgLogic have provided consistent protection in managing early season thrips injury, with AgLogic having an edge on thrips and Thimet an edge on TSW management. Many of our modern cultivars have good TSW resistance, so we have good flexibility in choice of individual products.
Twin Row Inoculant Rate
The question came up what rate of inoculant is recommended when planting twin rows, since there are twice the number of furrows out there but often a lower rate of seed per foot (per furrow) compared to the same population planted in single rows. The labels for Exceed, Vault, and Optimize all list as equivalents for linear row feet, with the Exceed label also specifically stating to double the rate for twin rows. That would be the best positioning for maximum inoculation, though farmers have had experience that it can be fine with a single-row equivalent. New ground still needs the full amount, and it is good to add at least a half rate of a different product and formulation there to buffer against the heartburn of potential inoculant failure, which is costly on yield potential and expensive to try to correct.
In single row tests, in a field with recent history if we did not have an inoculant treatment our yields have been good where we would not readily notice a difference if we didn't have a with and without to compare against. Last year we ran a single row inoculant test where the field had been out of peanut for 2 years before coming back in. The no-inoculant check yielded 5065 lb/A, which was good. The inoculant treatment yielded 5233 lb/A, which was significantly better and represented a little more than $40/A increase at a $485/ton price. Part of the twin row spreading is like a seeding rate effect, where if the same as a single row seed rate would have the seed more/twice spread out, but the stream of inoculant for liquid is steady and constant, so ideally getting a full (double) rate would be a best case and the standard recommendation. We are planning to look at this further in a test this year.
A liquid inoculant is typically the most convenient, but another option to get around the single versus double bladder rate is to do a peat seed treatment, that way the inoculant stays with the seed, but that method is more work and potentially opens consistency issues.
Dan Anco
Extension Peanut Specialist and Associate Professor
Department of Plant and Environmental Sciences
Clemson University – Edisto Research and Education Center
64 Research Road
Blackville, SC 29817
630-207-4926 cell