Georgia Peanuts: Inoculation Tips For 2012 After Last Year’s Long, Hot Summer
It’s warmer than normal. It’s dryer than normal. We’re coming off one of the hottest and driest years on record.
Sounds like a good time for a refresher about peanut inoculant application.
Because of the conditions mentioned above, the rate of survivability of native Rhizobia present in the soil is likely to be much lower than in most years (regardless of how many years it has been since the last time peanut or a cross-inoculating species was grown in a field).
SoI would highly recommend growers strongly consider investing without in a peanut inoculant at-planting this year, especially in non-irrigated fields where prolonged hot and dry soil conditions last year undoubtedly killed a large percentage of the bacteria. It has been stated before by my predecessors and colleagues, and by me in previous years as well – an inoculant application is one of the most cost-effective “insurance policies” at a grower’s disposal.
Without taking the time to run the dollar values at current prices, I can still safely say that in most years it takes merely a 50-80 lb/ac increase in yield to cover the cost of the inoculant application at planting.
You will not see benefits from inoculants each and every year, but considering it only takes a 250 lb/ac yield bump once every 3-5 years to break even on an annual product application, such a decision should be an easy one for most growers to make since the chances of a profitable outcome in the long-term is much greater than not.
Some additional reminders regarding formulation decisions:
- When applied at labeled recommendations, the amount of viable cells delivered on a per acre basis does vary by formulation, with the liquid inoculants supplying the most (8.3 x 1011 cells/ ac), followed by sterile peat products (5.8 x 1011 cells/ac), and granular supplying the least (2.4 x 1011 cells/ac). However, this should not be the primary deciding factor on which formulation to select.
- Sterile peat/powder formulations are only recommended if there is no way of applying the other formulations. To get good coverage/sticking of the product to the seed, the seed need to be mois tened. This requires drying time to prevent messy planter problems. When applied dry, there will be inadequate seed coverage. I have data showing reduced nodulation and yields using this for mulation compared to the other formulations.
- Do not confuse the granular inoculant formulation with the sterile peat/powder formulation, they are not the same. The granular formulation, while also a dry product, is not applied to the seed prior to planting, it is metered through a dry metering box such as an insecticide/herbicide hopper and placed in-furrow.
- Regardless of formulation, these are living organisms. If you want them to remain alive/viable, then don’t leave them sitting in the cab of a hot pickup truck or tractor, nor exposed to direct sunlight.
- Likewise, since this is a living medium, exposure to certain pesticides designed to kill living or ganisms (insecticides, fungicides, etc.) may adversely affect the product. Minimize exposure to such products, and consult the labels/websites/representatives for more information about mix ing of products. There should be minimal concerns of exposure to typical peanut seed treat ments, and short-term exposure to common in-furrow fungicides in the case of tank-mixes. But a chlorine-free water source must be used as the carrier for liquid inoculants.
- When soil conditions are relatively dry, liquid inoculants will disperse away from the intended target, thus the concentration of Rhizobia near the seedling upon emergence and early season growth when infection should be occurring may be hindered. The granular formulation will re main at the bottom of the seed furrow, where intended. Therefore, in non-irrigated conditions with only marginal soil moisture, granular products should be considered.