Guy D. Collins, Ph.D. Extension Cotton Agronomist Overview of Cotton Agronomic Research & Extension Program

What is your most limiting factor ??? Water (soils, irrigation capacity, historical rainfall) Weed control (technology options for pigweed control) Plant growth (achieving optimal height, droughty soils, PGRs) Diseases, nematodes, insects (leaf hairiness) Planting date, timeliness of inputs Realistic Yield Potential – field x field basis Variety performance information… Official Variety Trials (OVT) UGA Uniform Cotton Variety Performance Evaluation Program (County agents) Industry variety trials Growers with similar soils/practices Your own experience Variety selection criteria

UGA OnFarm Cotton Variety Performance Evaluation Program

Variety Combined Average DP DP ST FM PHY PHY ST DP Loc. Average UGAUCVPEP Stability & Consistency (TOP 2) Collins & Whitaker, 2010

Variety Combined Average PHY DP DP DP ST FM ST PHY PHY Loc. Average UGAUCVPEP Stability & Consistency (TOP 1) Collins & Whitaker, 2011

Variety Combined Average DP 1252 B2RF DP 1137 B2RF DP 1050 B2RF PHY 499 WRF ST 5458 B2RF FM 1944 GLB FM 1740 B2F AM 1511 B2RF PHY 565 WRF DP 0912 B2RF PHY 375 WRF Loc. Average Roundup-Based On-Farm Trials (TOP 3) Collins & Whitaker, 2012

Variety Combined Average PHY 499 WRF FM 1944 GLB PHY 565 WRF FM 1845 LLB ST 5445 LLB PHY 375 WRF ST 4145 LLB Loc. Average Liberty-Based On-Farm Trials (TOP 2) Collins & Whitaker, 2012

Variety Selection Error Cotton Price $ / lb. Highest Cost $ / A Lowest Cost $ / A Average Cost (14 Trials) $ / A Top Variety vs Bottom Variety $ Top 4 Avg. vs Mid 4 Avg. $ Top 4 Avg. vs Bottom 3 Avg. $ Top Variety vs Bottom Variety $ Top 4 Avg. vs Mid 4 Avg. $ Top 4 Avg. vs Bottom 3 Avg. $ Cost of Improper Variety Selection (Roundup-based Trials) Collins & Whitaker, 2012

Variety Selection Error Cotton Price $ / lb. Highest Cost $ / A Lowest Cost $ / A Average Cost (14 Trials) $ / A Top Variety vs Bottom Variety $ Top 4 Avg. vs Mid 4 Avg. $ Top 4 Avg. vs Bottom 3 Avg. $ Top Variety vs Bottom Variety $ Top 4 Avg. vs Mid 4 Avg. $ Top 4 Avg. vs Bottom 3 Avg. $ Cost of Improper Variety Selection (Roundup-based Trials) Collins & Whitaker, 2012 For 2012 Acreage: $157,300,000 - $444,600,000

Variety IrwinPierceColquitt Combined Average GA GA All-Tex LA LA DP PHY 440W LA SSG Linwood Loc. Average GA County Variety Trials - Conventionals Stability & Consistency Collins & Whitaker, 2010

1 st Position Boll Distribution Main-stem Node Bolls/A

Height, main-stem nodes, lint yield and gin turnout affected by PGR regime in Midville and Tifton. 1 PGR Regime HeightMain-stem NodesLint YieldGin Turnout MidvilleTiftonMidvilleTiftonMidvilleTiftonMidvilleTifton ---- inches no lbs/A % No PGR55.4 a48.4 a22.1 a19.4 a1453 b1970 a40.3 a42.0 a PGR40.7 b39.9 b20.4 b18.7 b1521 a1710 b39.6 b40.6 b 1 Means within a column followed by same letter are not significantly different at P=0.1.

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Relative PGR Requirements of Cotton Varieties (PGR REQUIRMENTS VARY – use only as guide) ClassificationVarietiesPGR Recommendations 1 Varieties with the most vegetative growth potential, require intensive PGR management DP 0949 B2RF DP 1048 B2RF DP 1050 B2RF DP 1137 B2RF DP 1252 B2RF PHY 499 WRF Applications - MULTIPLE Initiation - PRIOR TO BLOOM Product – MC (all applications, rates vary) 2 Varieties with similar growth potential of 1 st class, yet more responsive to PGRs or earlier in maturity PHY 565 WRF ST 4145 LLB2 Applications – MULTIPLE, MOST CASES Initiation – Squaring to 1 st Bloom Product - 1 st application - Stance or MC - Sequential app. – MC only 3 Varieties may require PGRs, but pre-bloom initiation not typically necessary, could result in premature cutout, esp. in dryland conditions AM 1511 B2RF DP 0912 B2RF PHY 375 WRF FM 1773 B2RF DP 1133 B2RF ST 5458 B2RF Applications – ONE to MULTIPLE Initiation - Bloom initiation likely sufficient Product - 1 st app. (Stance or MC, low rates) - seq. applications - Stance or MC 4 Varieties that may need no PGR applications, or almost always not applied prior to bloom FM 1740 B2RF FM 1944 B2RF FM 1845 LLB2 ST 4288 B2RF Application – NONE to ONE Initiation - Bloom initiation almost always Product – Stance or MC (  rates)

UGA Irrigation Recs Weekly Water Requirements (inches per week) First Bloom

SSDI & OVHD Irrigation Research

Sensor-Based Treatments Watermark moisture potential sensors

Treatments Checkbook method-UGA determination for water requirements: 100% UGA Checkbook65% UGA Checkbook Growth Stage Cm Per Week Cm/day (1/3 weekly rate) Applied on M, W, F Cm Per Week Cm/day (1/3 weekly rate) Applied on M, W, F Prior to Bloom st week of bloom nd week of bloom rd week of bloom th week of bloom th week of bloom th week of bloom th weed of bloom th week of bloom END OF BLOOM and afterwards

A AB B C C C D Lint Yield: Deep vs Shallow SDI* p < 0.1 * Data pooled over locations & varieties

A AB B C C C D Lint Yield: SDI Depth by Trigger* p < 0.1 * Data pooled over locations & varieties

Lint Yield – Variety * Irrigation Treatment (averaged across locations) C A E C B E C D CC FM 1740 > DP 1050 = 40 cb, 70 cb, and 100% FM 1740 = DP 1050 = dryland, 65% UGA recs.

Total Water (Irr & Rain)

Prebloom Irrigation DP 0912 B2RF FM 1944 GLB2

Prebloom Irrigation DP 1050 B2RF PHY 499 WRF

Final Plant Height* A * Data pooled over locations and PGR trt cm DP 555 FM 1740 * Data pooled over locations and variety p = < p = No PGR ST 2 ST 3 ST 4 MC 8 MC 12 B A B BC C C D

Final Plant Height* A cm * Data pooled over locations p = B B BC CDE DEF EFG CDE BCD FG DEF G

Final Plant Height* cm * Data pooled over locations p =

Lint Yield DP 555 BR* kg/ha * Data pooled over locations p = *** * **

Lint Yield FM 1740 B2F* kg/ha * Data pooled over locations p = * * *

DP 1050 B2RF FM 1740 B2F Mepex leaves Mepex leaves

Stance leaves Stance leaves DP 1050 B2RF FM 1740 B2F

Plant Height (inches) a abc de gh ab bcd cde gh abc bcd fg i de ef h i

Plant Height (inches)

Avoid yield-limiting PGR applications

2,4-D Drift

Leaf and bract characteristics of varieties from Georgia trials in Variety Company Rating Leaf Trichomes (cm -2 ) Bract Trichomes (cm -1 ) Leaf Area (cm²) Bract Area (cm²) Leaf Grade PHY 499WRF Semi- Smooth a† 52.2 a129.6 a9.56 a 3.50 ST 5458B2RFHairy286.4 b 37.5 bc b 3.25 PHY 367WRF Semi- Smooth b 39.1 b121.4 b7.45 bc 3.25 DP 1044B2RF Semi- Smooth b 33.1 c121.5 b6.90 c 3.75 FM 1740B2FSmooth38.3 c 39.8 b121.4 b7.96 b 3.00 P>F < <0.01 NS %CV LSD †Means followed by the same letter in a column are not significantly different at P = 0.05

Universal Quantification of Maturity

Lint Yield LSD = Application 2 Applications

Variety LSD (0.05) = 60 Lint to Seed ratio (%)

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