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Wheat, Cotton, & Peanut Management Update. Todd Baughman Extension Agronomist 940-552-9941 x 233 ta-baughman@tamu.edu. The outcome of any serious research can only be to make two questions grow where only one grew before. Timing N Applications. Wheat requires very little fall nitrogen
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Wheat, Cotton, & Peanut Management Update Todd Baughman Extension Agronomist 940-552-9941 x 233 ta-baughman@tamu.edu
The outcome of any serious research can only be to make two questions grow where only one grew before
Timing N Applications • Wheat requires very little fall nitrogen • In-furrow DAP usually enough for grain-only • Delay N applications until late-winter or early spring • Have N moved into soil by jointing
Top Dressing Wheat Factors Soil Test Residual N Preplant N Yield Goal – 30 bu/A Stocking Rate – 1/2A Grazing Time – 105 days Total N Requirement Total N/A +10 lbs/A +20 lbs/A -45 lbs/A -24 lbs/A -39 lbs/A Yield N based on 1.5 lbs/bushel Grazing N based on 15 lbs dry matter/day/animal and 0.03 lbs N per pound of forage (105/2 * 0.45)
Prevention is the Cheapest Form of Weed Control • Use good quality weed-free seed • Raise a good healthy crop • Rogue fields of new infestations • Manage turnrows, fences, corners, and ditches • Combine worst fields last • Don’t plant something that you cannot control later • Crop rotation • Graze out worst fields and control weeds with glyphosate
Proper Weed I.D. is Critical • Knowing what weed you are trying to control makes decisions easier and better • Crucial to proper herbicide choice and correct timing
Rescuegrass Wild Oat Ryegrass Japanesse Brome
Wildoat • Seedling leaves roll counter-clockwise • Hairs on margin of the leaves • No hairs usually on top of leaf blade • Multiple Flushes in fall and spring
Rescuegrass(Wild Rye) • Large flat seedhead • Leaf blades and sheath hairy • Mature plant maybe hairy on upper-side of leaves only • Difficult to control
Japanese Brome • Leaf blades and sheath hairy • Mature plant leaves hairy on both sides • Dropping head, noticeable awns (beards)
Cheat/Cheatgrass • No true cheat in West Texas DO NOT MAKE THE SOLUTION WORSE THAN THE PROBLEM!!!
Timing is Everything • Often times weed control will be better with early (fall) applications of a herbicide • However, yields will almost always be higher with early (fall, 1-4 wks after planting) applications • With wheat and cotton this is due to early season competition between weeds and wheat
Weed Competition • Percent Yield Loss (30 plants/yd2) • Feral Rye = 51 (84) • Wild Oats = 27 (41) • Italian Ryegrass = 23 (46) • Cheat = 21 (33) • Jointed Goatgrass 21 (25) Rainfall received within 10 days of planting Oklahoma State University – B. J. Fast, C. R. Medlin, D. S. Murray, and L. M. Verhalen
Wildoat ResearchHardeman County 09-10 LSD = 7.5
WARNING THE DIRECTIONS ON THIS LABEL ARE ONLY GOOD IF YOU FOLLOW THEM
Marestail Control • Marestail germinates in both fall and spring. Add a phenoxy herbicide and possibly ALS residual herbicide
Windmillgrass Control • Windmill grass control approximately 90% with 2 lbs ai/A glyphosate (48 fl oz/A Powermax) may take 2 applications
Soil Testing • Foundation of a sound fertility program • Soil analysis is only as good as the sample • Annual testing to credit residual nutrients. • Sampling with depth to detect mobile nutrients (N, S, B) and deeper K.
Residual Nitrogen in the Soil Profile It is plant available and it is yours! You never know what is there unless you test
Effect of Nitrogen Rate on Cotton Lint Yield N Rate Yield (lbs/A) (lbs/A) Calhoun Wharton San Pat. William. Falls 0 747 717 1240 804 729 50 835 757 1170 889 712 100 814 779 1319 880 742 150 692 658 1278 886 676 Means within a column are not significantly different (P<0.05). McFarland, 2009
Deep Sampling for Nitrogen Depth (inches) Site1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 7 Site 8 Lbs of Plant Available Nitrogen 0 – 6 64 12 16 10 12 10 10 16 6 – 12 42 10 10 12 12 10 10 12 12 – 24 48 20 20 20 20 20 20 20 24 – 36 36 24 16 28 24 24 20 20 36 – 48 20 20 16 24 28 24 20 28 Total 210 86 78 94 96 88 80 96 12 inches 106 22 26 22 24 20 20 28 24 154 42 46 42 44 40 40 48 McFarland, 2009
Effects of Humic Acid on Cotton Lint Yield, Stiles Farm 2003-2006 P>F = 0.7721 CV% = 15.8 Cotton Lint Yield (lbs./A) Untreated 1 gal Humic acid 3 gal Humic acid Humic acid applied with liquid fertilizer prior to planting
Potassium Late season deficiency • Functions in Plant: • Water use efficiency • Disease resistance • Fiber production
Late Season K Problems • Environmental conditions (effects on root system) - very wet (waterlogged soils) - very dry • Yield potential - heavy boll load (relative) • Severe deficiencies - secondary pathogen infection → premature defoliation
Effects of Soil and Foliar Applied K on Cotton Lint Yield(San Patricio County) P>F = 0.1169 Variety FM819 Soil test = 173 ppm K (“medium-high”) Lint Yield (lbs./acre)
Potassium Management • Medium/heavy soils typically sufficient. - high-end production may tax soil K- supplying potential. • Foliar application possible, but may not be economical. • Soil applications more cost effective. • Soil tests showing marginal sufficiency (125 ppm K) may justify application.
Glyphosate Resistance to date (12/07/09) • Palmer amaranth GA, NC, AR, TN, MS 2005, 05, 06, 06, 08 • common waterhemp MO*, IL*, KA, MN 2005, 06, 06, 07 • common ragweed AR, MO, KA 2004, 04, 07 • giant ragweed OH, AR, IN, KA, MN, TN 2004, 05, 05, 06, 06, 07 • hairy fleabane CA, other countries 2003-07 • horseweed OH*, 17 states 2000-07 • Sourgrass Paraguay, Brazile 2006, 08 • Junglerice Australia 2007 • goosegrass Malaysia* 1997 • wild pointsettia Brazil* 2006 • Italian ryegrass OR, MS 2004, 05 • rigid ryegrass CA, many* 1998 • Ragweed parthenium Columbia 2004 • buckhorn plantain S. Africa 2003 • johnsongrass Argentina, AR 2005, 2007 • Liverseedgrass Australia 2008
Volunteer Cotton Control Buctril, Ignite, Aim, & ET all effective at 5-8 leaf Layby Pro effective at 5-8 leaf Valor somewhat effective at 5-8 leaf No product effective at 10-12 leaf
Peanut Management Considerations ROTATION! ROTATION! ROTATION!!! Proper rotation is the key to maintaining high yields. High yields key to maintaining peanut profitability. WATER! WATER! WATER! Adequate water quality and quanity are needed for high yielding peanut. Timely Disease Management
ANY QUESTIONS??? THOSE WHO THROW OBJECTS AT THE ALIGATOR WILL BE ASKED TO RETRIEVE THEM
Todd Baughman • 940-552-9941 x 233 • ta-baughman@tamu.edu • http://peanut.tamu.edu