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Program 2. Program 7. Curative Program 10. Results Penncross. Program 2 Program 7 Curative Program 10. Programs 2,7. Spray 5. Spray 2. Spray 4. Spray 3. Spray 6. Spray1. Difference Between Varieties. Program 7. Clearys 3336. Daconil Ultrex. Prostar. Heritage. Fore. Banner
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ResultsPenncross • Program 2 • Program 7 • Curative Program 10
Programs 2,7 Spray 5 Spray 2 Spray 4 Spray 3 Spray 6 Spray1
Program 7 Clearys 3336 Daconil Ultrex Prostar Heritage Fore Banner Maxx
Fungal Isolations • Rhizoctonia solani • Rhizoctonia zeae
Objectives • Determine which Rhizoctonia species are present • Determine when they occur • Determine if some fungicides are more effective than others for control of the different species
Materials and Methods • Samples of Brown Patch taken twice monthly • Diseased leaves surface sterilized and plated out on water agar • Mycelia transferred to Potato Dextrose Agar • Fungi identified after cultures have matured
Typical AG 2,2 IIIB (“mat rush”) culture appearance ~ 3 wk, PDA
Isolates Results 1999 2000
Results 1999
Results 2000
Programs 6,7 Daconil Ultrex Clearys 3336 Heritage Clearys 3336
Clearys 3336 Clearys 3336
RhizoctoniaReported from Turfgrasses Rhizoctonia solani AG 1 1 A - “sasakii” type - primary pathogen of tall fescue 1 B - “web blight” - sometimes from Poa AG 2,2 IIIB - “mat rush” type - cool season grasses “Turf “ - warm season grasses AG 4 - “praticola” - damping-off; unspecialized AG 5 - rare in tall fescue Rhizoctonia zeae Rhizoctonia oryzae Rhizoctonia cerealis CAG 1 or AG-D -yellow patch in the US AG Q - yellow patch in Japan Weakly virulent or avirulent Binucleate species
Rhizoctonia Blight (Brown Patch) of Cool-season Turfgrasses • Agrostis, Poa, Festuca, Lolium spp. all affected • Favored by warm, humid summertime conditions • “Smoke Ring” symptom characteristic on low mowing heights ( especially Agrostis) • Leaf lesions initially result from mycelium from sclerotia or colonized host tissue; lesions may consume entire leaves • Rhizoctonia solani AG 1, 1A “sasakii” type and Rhizoctonia solani AG 2,2 IIIB “mat rush” type are the most prevalent pathogens
AUDPC =843.5 cd Al Sig + Fore Dac + Al Sig. Dac Ult Banner + Dac Ult Banner + Daconil Ult. Heritage
AUDPC = 673.8 d DacUlt + Al Sig Prostar Al Sig + Fore Heritage + Prostar Al Sig + Fore Heritage
AUDPC = 722.8 d Sentinel + Daconil Ult. Daconil Ultrex Consyst Heritage Daconil Ultrex+ Aliette Sig Daconil Ult + Banner
AUDPC =1374.6 b Heritage Prostar Dac Ult Clearys 3336 Banner Maxx Fore
AUDPC =1103.4 bcd Heritage Prostar Prostar Consyst Chipco 26019 Dac Ult
Crenshaw Bent Dollar Spot Fungicide Trial Martin, 1999
AUDPC =855.8 Heritage- 0.2 oz Banner + DacUlt- 1 + 3.8 oz DacUlt - 3.8 oz Consyst - 4 oz DacUlt+ Al Sig - 3.8+4 oz Banner + DacUlt - 1 + 3.8 oz
AUDPC =822.5 DacUlt - 3.8 oz Eagle + DacUlt - 0.4+3.1 oz Eagle + DacUlt- 0.4 + 3.1 oz Fore + Eagle - 6 + 0.34 oz Heritage - 0.2 oz Fore + Aliette - 8 + 4 oz
Dollar Spot Lesions Bermudagrass Leaves
ResultsA 1 • Program 2 • Program 3 • Program 7 • Curative Program 10
Programs 2,3,7 Spray 5 Spray 6 Spray 4 Spray 2 Spray 3 Spray 1
Program 2 Fore Daconil Ultrex + Chipco Sig. Chipco 26GT Daconil Ultrex Daconil Ultrex + Chipco Sig. Daconil Ultrex
Program 3 Daconil Ultrex + Chipco Sig. Daconil Ultrex Heritage Chipco 26GT Daconil Ultrex Chipco 26GT
Program 7 Heritage Fore Daconil Ultex Prostar Clearys 3336 Banner Maxx
Program 10 Heritage + Daconil Ultrex Daconil Ultrex Heritage Chipco Sig. + Daconil Ultrex
Program 3 Daconil Ultrex Heritage Chipco 26GT Daconil Ultrex + Chipco Sig. Chipco 26GT Daconil Ultrex
Conclusions • Preventative programs more effective than curative programs • Fungicide selection and timing critical • Rhizoctonia zeae most likely to occur during hottest times of the summer • Varieties of bentgrass do differ