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 Dont 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
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) Oklahoma State University – B. J. Fast, C. R. Medlin, D. S. Murray, and L. M. Verhalen Rainfall received within 10 days of planting
Wildoat Research Hardeman 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 You never know what is there unless you test It is plant available and it is yours!
Effect of Nitrogen Rate on Cotton Lint Yield N Rate Yield (lbs/A) (lbs/A) Calhoun Wharton San Pat. William. Falls 0 747 7171240804 729 50 835 7571170889 712 100 814 7791319880 742 150 692 6581278886 676 Means within a column are not significantly different (P<0.05). McFarland, 2009
Deep Sampling for Nitrogen 2820 2422262210612 inches 96808896947886210Total 40 20 10 Site 7 48404442464215424 282428241620 36 – 48 2024 2816243624 – 36 20 4812 – 24 121012 10 426 – 12 161012101612640 – 6 Site 8 Site 6Site 5Site 4Site 3 Site 2 Site 1 Depth (inches) Lbs of Plant Available Nitrogen McFarland, 2009
Starter Fertilizer Rates Fine Textured SoilsSandy Textured Soils Row Spacing (in) 203040203040 Pop-up 8-125-86854 2-in side 604030402015
Effects of Humic Acid on Cotton Lint Yield, Stiles Farm 2003-2006 Cotton Lint Yield (lbs./A) P>F = 0.7721 CV% = 15.8 Untreated1 gal Humic acid 3 gal Humic acid Humic acid applied with liquid fertilizer prior to planting
Click to edit the outline text format Second Outline Level Third Outline Level Fourth Outline Level Fifth Outline Level Sixth Outline Level Sevent h Outline Level Eighth Outline Level Ninth Outline LevelClick to edit Master text styles Second level Third level Fourth level Fifth level Potassium Functions in Plant: Water use efficiency Disease resistance Fiber production Late season deficiency
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 Late Season K Problems
Effects of Soil and Foliar Applied K on Cotton Lint Yield (San Patricio County) Lint Yield (lbs./acre) P>F = 0.1169 Variety FM819 Soil test = 173 ppm K (medium-high)
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) 1. Palmer amaranthGA, NC, AR, TN, MS2005, 05, 06, 06, 08 2. common waterhempMO*, IL*, KA, MN2005, 06, 06, 07 3. common ragweedAR, MO, KA2004, 04, 07 4. giant ragweedOH, AR, IN, KA, MN, TN2004, 05, 05, 06, 06, 07 5. hairy fleabaneCA, other countries2003-07 6. horseweedOH*, 17 states2000-07 7. SourgrassParaguay, Brazile2006, 08 8. JunglericeAustralia2007 9. goosegrassMalaysia*1997 10. wild pointsettiaBrazil*2006 11. Italian ryegrassOR, MS2004, 05 12. rigid ryegrassCA, many*1998 13. Ragweed parthenium Columbia2004 14. buckhorn plantainS. Africa2003 15. johnsongrassArgentina, AR2005, 2007 16. LiverseedgrassAustralia2008
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