SCOTT TUBBS
ATHENS, GEORGIA
Planting Date: The ideal planting window is between late April and late May in regards to yield potential. A good peanut crop can be grown outside of this planting window, although the risk of reduced yield is greater because of weather and risk of disease problems. Please keep these points in mind before and as you plant:
-
Planter Maintenance – Clean seed tubes, metering units, vacuum system, inoculant tubes, insecticide hoppers and tubes.
o Calibrate liquid and dry applicators (inoculant, insecticide, herbicide, etc.)
o Check and replace worn parts that may affect seed placement.
o Make sure seed meters are applying correct amount of seed.
-
Soil Temperature – The average daily soil temperature at the 4″ depth should be greater than 68 Degrees F for 3 consecutive days without risk of a cold front after planting
-
Tractor/Planter Speed – Plant at appropriate speeds to allow for more precise placement of seed. As speed increases, planter efficiency and number of seed dropped in the furrow both decrease. This leads to increased gaps between plants which increases TSWV risk, especially if you plant before May
-
Seeding Rate -To reduce the impact ofTSWV, growers need to plant enough seed to provide at least 4 plants/ft of row. Therefore, seeding rates of 6 seed/ft on singles and 6 to 7 combined seed/ft on twins (3 to 3.5 seed/ft per twin furrow) are recommended. Seeding rates also need to be adjusted for% germ of the seed being planted to ensure you have the desired plant population.
-
Seed Depth – Check your planter in each field for adequate down pressure to ensure ideal planting depth. Seed depth is typically 0 to 2.5″ deep. You can plant shallower with good moisture but risk losing moisture before germination, and injury from Valor herbicide is increased. Peanut can emerge from depths up to 3″ as long as the seed has good germ and vigor, but deep planting can cause delayed emergence and subject the seedling to greater risk of soilborne pathogens causing rot before it emerges.
-
Soil Moisture -Planting peanut in subpar moisture can result in poor germination and erratic emergence causing less than optimum plant population and increased risk of TSWV.
o Peanut seed is too expensive to risk planting in dry conditions
o Irrigated fields – planting in dry and hot conditions followed by irrigation with cold water can shock the seed and cause erratic emergence. Irrigate 1/3 to 1/2″ and then plant.
-
Pre-plant Herbicides and Irrigation – water pre-plant/at-plant herbicides into the soil before peanut emerge to improve weed control.
-
TSWV Risk – To reduce TSWV risk on peanut – plant after May 10, apply phorate for thrips control, and use twin row configuration (see Peanut Rx Disease Risk Index).
-
Inoculants – apply inoculants in fields that have been out of peanut for more than 5 years. However, it’s a good practice to apply inoculants each year, especially following years of extreme weather like prolonged hot and/or dry periods, or extended water-logged soils.
Peanut is a legume that fulfills its own nitrogen (N) requirement through symbiosis with Bradyrhizobia when properly nodulated. These soil bacteria allow the peanut plant to convert atmospheric N to a form utilized by the plant.
Inoculant Reminders
-
Handling
o Store in a cool, dry place shaded from direct sunlight until used.o Use fresh inoculant of the proper strain.
o Do not let unused inoculant remain in hoppers for extended time. If liquid inoculant sits in tank overnight, add a fresh batch before planting.
o Fungicide seed treatment may be detrimental to adherence of powder/sterile peat formulations of inoculants.
o Shallow planting may result in the loss of bacteria due to hot, dry soils.
o Prepare well-drained fields to reduce risk of water-logging.
o If using a liquid inoculant, apply with chlorine-free water to avoid killing the bacteria using at least 5 gal/A of water.
o If a heavy rain occurs shortly after planting, a liquid inoculant may be diluted or carried away from the seed, reducing efficacy.
o Nodulation is delayed or reduced in the presence of excess soil N.
o Adequate soil levels of Ca, P, and Kaid in Bradyrhizobia survival.
o Follow all label directions when applying pesticides and inoculants as mixes.
o Deliver product at labeled rates (1.0 fl oz per 1,000 linear row feet for most).Twin rows use same rate on a per furrow basis, which doubles total quantity applied per acre compared to a single row planting.
o Addition of biological enhancement products should be used with caution and may have an adverse effect on viability of the inoculant.
-
Nitrogen deficiency is occasionally a problem for peanuts. This could be due to a failure to artificially inoculate peanuts when needed.
o In extreme cases of poor nodulation, it may be necessary to apply N fertilizer. If you note N deficiency, apply 60 lb N/A when plant is 40 to 60 days old. A granular form (such as ammonium sulfate) is recommended.
-
Benefits
o Fertilizer savings- N-fixing ability replaces the need to apply N fertilizers.o Residual soil N – 5 0 to 1 0 0 lb N/ A may be residually available in the soil after growing an effectively nodulated peanut crop.
o Benefit to rotated crops – W ill provide subsequent crops with available N, enhancing yield and reducing fertilizer costs of the following crop.
o Improved soil conditions – legumes decompose rapidly, leaving orgamc matter m the soil which improves its physical, chemical, and biological condition. ∆
