Shade vs. Low Light Conditions

Transcription

1 /13/13 Current Turfgrass Research Update J. Bryan Unruh, Ph.D. University of Florida Shade vs. Low Light Conditions BMPs specifically address shade but not low light. Low Light Conditions Season fluctuation in solar radiation Low pressure systems tropical weather High pressure systems extended fog Atmospheric Environment Light Reflection Absorption Transmission 1

2 /13/13 Effects of Light on Turfgrass Growth Effect of Light Quality on Turfgrass Growth Light intensity Light quality Light duration 7 Absorbance peaks: Chlorophyll a = 3 nm, nm Chlorophyll b = nm, 3 nm Effect of Light Duration on Turfgrass Growth Light duration refers to the amount of time (hours) that the turf is exposed to sunlight. Influences plant growth and development. Physiological Responses Development Responses Solar Radiation Energy (photons) delivered per unit of time over a specified area Watts per meter square per day (w m day 1 ) Langley per day (cal cm min 1 ) Micromoles per meter square per second (µmol m s 1 ) 9 7 Average Monthly Solar Radiation Ft. Pierce, FL Solar Radiation (Ly/Day) 3 1 days =.7 rain JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 11

3 /13/13 Daily Light Integral DLI across the United States Compilation of µmol m s 1 Measures total light absorbed in mol m d 1 Previous research focused on greenhouse bedding plant production DLI used for flower initiation and controlling plant growth and quality Warm Season Turfgrasses Summer Maintain acceptable quality Tifeagle hybrid bermudagrass 3. mol m d 1 Tifway hybrid bermudagrass.9 mol m d 1 Celebration bermudagrass 1. mol m d 1 Meyer Japanese zoysiagrass 1.7 mol m d 1 Brian Glenn Ph.D. Student 1. Quantify the DLI requirement for most common warmseason turfgrasses.. Identify parameters that contribute to shade tolerance. 3. Determine effect of light fluctuation on plant health. Hybrid bermudagrass Tifway and TifGrand Common bermudagrass Celebration Zoysiagrass (Zoysia japonica) Palisades and JaMur Zoysiagrass (Zoysia matrella) PristineFlora and Diamond St. Augustinegrass Floratam and Captiva Centipedegrass TifBlair Bahiagrass Argentine Seashore paspalum SeaDwarf Minimum Acceptable Quality: 1.1 mol m d 1 Jan Mar Average temp: 73. F Minimum Acceptable Quality: 1. mol m d 1 Minimum Acceptable Quality:.7 mol m d 1 3

4 /13/13 Tifway Bermudagrass TifGrand Bermudagrass % 3% % 9% % 3% % 9% Stanford et al., Tifdwarf bermudagrass grown in growth chambers with 1 hours light at 1/3 of full sunlight. 9/1 F 1/ F Celebration Bermudagrass % 3% % 9% Influence of Temperature and Shade on Warm Season Turfgrasses Temperature regimes Summer (9, 7 F) Spring/Fall (, 1 F) Winter (7, F) Shade Levels % 3% % 9% Shade Avoidance vs. Shade Tolerance Henry and Aarssen 1997 Low Light Influences: Morphology Elongation Decrease in weight per unit leaf area Increase in leaf area per unit shoot weight Longer internodes Erect growth Physiology Higher chlorophyll content Lower respiration Lower compensation point Reduced carbohydrate reserves Lower demand for water, nutrients Reduced heat, cold, drought, wear tolerance Increased production of gibberellic acid (GA) Leads to weakened structure Decision Tools to aid the turf manager: Injury estimator for cultivation practices Scalping predictor Predictive pesticide applications

5 /13/13 LightScout DLI 1 Light Meter Compare light between locations Displays light intensity levels every seconds for hours Measure PAR light (Photosynthetically Active Radiation) Meter runs for hours and calculates your Daily Light Integral (DLI) Packaged in sets of 3 light meters, or individually $9/each; $19/three LightScout DLI 1 Meters Ring of Responsibility Use a deflector shield near water BMP Leave at least 3 untreated buffer Without deflector shield leave 1 ring Ordinances may vary; respect required fertilizer-free conservation easements and stormwater treatment buffers. 7 7 BMPs for the Enhancement of Environmental Quality on Florida Golf Courses pg. 13 Objective: To determine the effective size of an untreated buffer strip or ring of responsibility located adjacent to a body of water. 9 3

6 /13/13 Experimental Design Fertilizer Sources (1. lb N/1 ft ) Ammonium Sulfate Polymer Coated Urea Nitroform Buffer Distances, 3, and 1 Rainfall Simulation per hour TSN Loads (g) 1 Distribution of TSN AS UF PCU UTC Nitrogen Source 3 Preliminary Observations Ammonium Sulfate treatments were comparable regardless of fertilizer upslope placement. Between 1.% and.% of the applied N was recovered in the runoff. Urea formaldehyde A 3. m unfertilized buffer distance reduced N losses to 3.9% of applied N, while all other distances were comparable and ranged from.9 7.7%. The 3. m buffer provided % less N in comparison to placement closer to the source. No prill movement was observed. Polymer Coated Urea regardless of slope placement, N losses were negligible. Only.1% of the applied N from PCU was recovered across all distances. No prill movement was observed Statewide Fertilizer Rule Limits N to 1 lb per 1, ft maximum application rate or.7 lb per 1, ft for quickrelease N Limits P to 1/ lb P O per 1, ft per application and 1/ lb P O per 1, ft annually Annual N rates follow UF recommendations Requires lawn care industry to follow Green Industries BMP manual What Does the Rule Mean to Commercial Fertilizer Applicators? They are required to follow the Green Industry BMPs. Must be certified by January 1. Golf courses required to follow golf course BMPs. Must of GIBMPs to apply fertilizer to landscaped areas of the golf course (i.e., club house). Athletic fields, park and recreation required to follow UF fact sheets. Sod growers follow sod BMPs

7 /13/13 SR Nitrogen Source Study Jay, FL Percent Growth Potential 1 GP obst optt sd e Pensacola Tallahassee Jacksonville Gainesville Daytona Beach Orlando Tampa Ft. Pierce Naples Ft. Lauderdale Homestead Key West Total NO 3 Leached (kg ha -1 ) 1 1 /1/ /1/9 /1/9 /1/1 /1/1 /1/11 /1/11 Precent Growth Potential JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC SR Nitrogen Source Study Jay, FL 1 Estimating Release Properties of Slow Release Fertilizer Materials Dr. Jerry Sartain Total NO 3 Leached (kg ha -1 ) 3 1 Percent Growth Potential /1/9 /1/9 /1/9 /1/9 1/1/9 1/1/9 Arrows denote fertilizer application dates. PERCENT N RELEASED OVER TIME FOR SELECTED CRN MATERIALS NITROFORM NUTRALENE MILORGANITE POLYON SCU AN 7

8 /13/13 Getting a Response... Research shows that you need.3 lbs / 1, ft of available nitrogen to see a response in N Source turf % of Applied Nitrogen Released Nitroform Nutralene 3 3 Polyon SCU IBDU Osmocote Total NO 3 Leached (kg ha -1 ) SR Nitrogen Source Study Jay, FL 3 1 /1/9 /1/9 /1/9 /1/9 1/1/9 1/1/9 Arrows denote fertilizer application dates. Days Percent Growth Potential Percent Growth Potential 1 GP obst optt sd e Pensacola Tallahassee Jacksonville Gainesville Daytona Beach Orlando Tampa Ft. Pierce Naples Ft. Lauderdale Homestead Key West JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC SR Nitrogen Source Study Jay, FL 1 1 Ocala Daytona Orlando Tampa JAN.3... FEB.... MAR APR MAY..1.. JUN..9.. JUL...7. AUG.... SEP.7... OCT NOV DEC Total NO 3 Leached (kg ha -1 ) /1/ /1/9 /1/9 /1/1 /1/1 /1/11 /1/11 Precent Growth Potential

9 /13/13 Fertilizer BMPs Fertilizer BMPs Maintain a healthy, actively growing turfgrass to minimize the environmental impact of fertilizer and pesticide application, erosion, and stormwater runoff. SR Nitrogen Source Study Jay, FL 1 SR Nitrogen Source Study Jay, FL 1 Total NO 3 Leached (kg ha -1 ) Turf Density (1-9; minimum acceptable) Total NO 3 Leached (kg ha -1 ) Rain (mm) 1/1/11 3/1/11 /1/11 7/1/11 9/1/11 1/1/11 3/1/11 /1/11 7/1/11 9/1/11 Arrow denotes fertilizer application date. Arrow denotes fertilizer application date. Practical Considerations Nutrients must be applied based on the plant s ability to assimilate them. This should supersede any calendar based regimen. Healthy, dense turf is the key to minimizing environmental impact of applied nutrients. As the health of the plant deteriorates one can expect problems. Practical Considerations Timing of application of enhanced efficiency (SR) nutrient sources should coincide with periods of active growth potential. The release period should not extend beyond periods of active growth. 9

10 /13/13 Nutrient Import from Sod Properly harvested sod comes with ~ ½ of soil. Nutrients applied at the farm are likely transported with the sod. Irrigation during sod establishment can be excessive if guidelines are not followed properly. Total NO 3 Leached (kg ha -1 ) 3 1 Nitrate-N Leaching from Established Centipedegrass Sod installation 1-May- 1-Jun- 1-Jul- 1-Aug- 1-Sep- 1-Oct- 1-Nov- 1-Dec- Arrows denote fertilizer application dates..13 kg/ha 1. kg/ha. kg/ha 9. kg/ha Total NO 3 Leached (kg ha -1 ) Rainfall (mm) Nutrient Import from Sod Nitrate-N Leaching from Established St. Augustinegrass Sod installation 1.17 kg/ha 3.3 kg/ha.17 kg/ha 9. kg/ha Rainfall (mm) 1-May- 1-Jun- 1-Jul- 1-Aug- 1-Sep- 1-Oct- 1-Nov- 1-Dec- Arrows denote fertilizer application dates. Nutrient Import from Sod Total NO 3 Leached (kg ha -1 ) 1 1 Impact of Fertilizer Applications to Semi-Dormant and Dormant Lawn Grasses on Environmental Quality Arrows denote fertilizer application dates.. kg N ha kg N ha kg N ha -1. kg N ha kg N ha -1 1-Oct- 1-Nov- 1-Dec- 1-Jan-7 1-Feb-7 1-Mar-7 1-Apr-7 1-May-7 Sod installed -Sep- 3 1 Rain (mm) Practical Considerations Avoid fertilization of newly laid sod for 3 days. Sufficient nutrients likely exist. Encourage sod installers/landscapers to inquire about the timing of the last farm applied nutrients. Use ranges rather than specific dates < weeks = no fertilizer for days weeks = no fertilizer for 3 days > weeks = no fertilizer for 3 days This could prove burdensome for less tech savvy producers. 9 1

11 /13/13 Nitrogen Sources at High Rates Under High Rainfall/Irrigation Conditions Multi State, Collaborative Warm Season Turfgrass Breeding Project USDA-SCRI Funded, years, 3.9 million Research Objectives Turfgrass scientists from five institutions will exchange germplasm to capitalize on the genetic diversity of turfgrass species using classical and modern methods of plant breeding. Bermudagrass, zoysiagrass, St. Augustinegrass, seashore paspalum, and ryegrass. Genetic enhancement to improve drought and salinity tolerance following traditional methods of plant breeding, embryo rescue, and mutagenesis. Genetic enhancement using Marker Assisted Selection in order to tag and track native genes controlling drought and salinity tolerance. Turfgrass Canopy Research Objectives To determine differences of 1 genotypes warm season turfgrasses for canopy reflectance and WUE under well watered condition and dry down. To determine species or genotype differences in canopy characteristics including leaf area and leaf angle under well watered condition and dry down. To establish correlation between canopy characteristics and WUE of 1 genotypes. 11

12 /13/13 Turfgrass Root Research Objectives An in situ study on sod based rooting dynamics of St. Augustine and Bermudagrass. A greenhouse study on root architecture and water absorption patterns of different warm season turfgrass species. A study on root morphological characteristics of warm season turfgrass species for their field drought performance. Images of root growth, trend throughout the season (Tube, mw ht ) //11 //11 //11 //11 /3/11 /17/11 Well watered tubes vs Dry down tubes Dry down tubes Well watered tubes 1

13 /13/13 High Turfgrass Water Stress Continuum Plant Health Relative Plant Health Dormant, Quiescent, Severely Damaged or Dead Recovery Possible Moderately Dry Optimum Excessive Drought Tolerance vs Drought Resistance: Understanding How Turf is Affected by Drought Low Low <<<<<<<<<<<<<<<<<<<<<<<<< Soil Moisture >>>>>>>>>>>>>>>>>>>>>> High Dehydration CH O Depletion Meristem Death More Discoloration Leaf Firing Dormancy Decreased PS Increased RS CH O Reduction Discoloration & Decreased: Growth Transpiration Photosynthesis Recovery Pest Resistance Stress Resistance Credit: Drs. Richard White and David Chalmers- Texas A&M University Maximum: Growth/Rooting Transpiration Photosynthesis Recuperation Density Uniformity CHO Balance Stress Tolerance Pest Resistance Discoloration & Decreased: Growth Rooting Transpiration Photosynthesis Recovery Pest Resistance Stress Resistance Turf Quality (1 9; 9=Best) June 3, Zoysiagrass Empire Ultimate JaMur El Toro Cavalier Palisades Zorro Emerald Zeon Pristine Empire Ultimate JaMur El Toro Cavalier Palisades Zorro Turf Quality (1 9; 9=Best) June 3, 9 Ultimat e JaMur El Toro Cavalier Palisade s Zorro Emerald Zoysiagrass Empire Emerald Zeon Pristine 13

14 /13/13 Floratam St. Augustinegrass Water Stress Continuum High Optimum Relative Plant Health Severely Damaged, slow recovery or Dead Recovery Possible Moderately Dry Plant Health Excessive Low Low <<<<<<<<<<<<<<<<<<<<<<<<< Soil Moisture >>>>>>>>>>>>>>>>>>>>>> High Zoysiagrass Water Stress Continuum Plant Health High Moderately Optimum Dry Relative Plant Health Severely Damaged, slow recovery or Dead Dormant or Quiescent, slow recovery Recovery Possible Excessive Low Low <<<<<<<<<<<<<<<<<<<<<<<<< Soil Moisture >>>>>>>>>>>>>>>>>>>>>> High May, 11 Acceptable Turf Color Preliminary Observations All grasses respond to drought they just do it differently. Zoysigrasses wilt and fire very quickly and very uniformly (green brown). St. Augustinegrass fades over time with some green foliage lingering for weeks (green yellow green yellow brown). Centipedegrass wilts quickly but also recovers (turns green again) very quickly. Seashore paspalum can be very slow to recover due to the plant s priority on producing below ground plant parts. Bermudagrass and bahiagrass are very drought responsive but may not provide the desired turf quality. 1

15 /13/13 1 a 3 Captiva root biomass (g) root biomass (g) a a a % 3% % 9% a ab abc abc abcd 1 1 root biomass (g) 1 1 abcde abcde % 3% % 9% bcde cdef cdef def ef f Cavalier EIToro-Z Emerald- Empire-Z Floratam Geo-ZM JaMur-ZJ Palisade Palmetto Pristine Ultimate Zeon-ZM Zorro-ZM f Water use (inches/day) Water use (ml/day) a ab ~ 1% difference in water use. abc abc abc abc abc bc bc bc bc c c c Water use (inches/day) Water use (ml/day) a b % 3% % 9% 3% Shade 19.% reduction in water use % Shade 3.% reduction in water use 9% Shade.% reduction in water use c d Bottom line: Advancing the science of warm season turf management moving beyond anecdotal information and supposition. Complex interactions exist among environmental and soil factors greatly complicates the research. Science must produce usable information the so what of our work. Questions? J. Bryan Unruh, Ph.D. West Florida Research and Education Center University of Florida/IFAS jbu@ufl.edu 1