Managing Pink Snow Mold Disease on Golf Courses. Bruce B. Clarke Rutgers University New Brunswick, NJ USA

Transcription

1 Managing Pink Snow Mold Disease on Golf Courses Bruce B. Clarke Rutgers University New Brunswick, NJ USA

2 SNOW MOLDS AND BLIGHTS Pink Snow Mold Fusarium Patch Gray Snow Mold Snow Scald Cottony Snow Mold Frost Scorch Pythium Snow Blight Microdochium nivale Microdochium nivale Typhula incarnata, T. ishikariensis Myriosclerotinia borealis Coprinus psychromoribidus Sclerotium rhizodes Pythium graminicola, P. vanterpoolii

3 Pink Snow Mold and Fusarium (Microdochium) Patch Pathogen: Grasses Affected: Microdochium nivale (Fusarium nivale) Poa annua, Agrostis stolonifera, Poa pratensis, Poa trivialis, Lolium perenne, Festuca arundinacea, Festuca rubra

4

5

6

7 Fusarium (Microdochium) Patch Symptoms and Signs: Visible in spring and fall during cool, moist conditions. Common on annual bluegrass and bentgrasses as pale yellow to reddish brown patches initially 3-5 in (7-13 cm) enlarging up to 12in (30 cm) dia. Infection centers may coalesce into large areas. White, fluffy, mycelium at advancing margin, with slimy, orange to pink, spore masses. Severe damage to leaves and crown, natural recovery slow.

8

9

10 Pink Snow Mold (PSM) and Fusarium (Microdochium) Patch (FP) Conditions Favored by wet conditions, high Favoring humidity and air temp. from 0- Disease: 12 C (32-55 F). Prolonged snow cover on unfrozen ground ideal for PSM, but necessary for FP. More severe when soil ph is neutral or alkaline. Lush, succulent growth in fall is very susceptible.

11

12

13

14 Cultural Control of Snow mold Avoid fall fertilization that would encourage lush growth in mid- to late-october (use slow release N). Reduce soil ph below 7.0 whenever possible (acid fertilizer) Maintain adequate K in late-fall to increase cold tolerance Reduce compaction/improve drainage (important in spring) Remove tree leaves and mow until dormancy Use snow fences to prevent excess snow accumulation If covers are used on greens, treat turf with fungicides prior to installation. Lightly fertilize (25 kg N/ha; 0.5 lb/m) in spring for recovery.

15 Chemical Control of Pink Snow Mold I Aromatic Hdrocarbons : PCNB II Benzimidazoles : Cleary 3336, Fungo III DMIs : Banner, Tourney, Trinity, Torque IV Dicarboximides : Chipco 26GT, Fungicide X V Nitriles : Daconil, Echo, Concorde VI Strobilurins : Compass, Heritage, Insignia (two applications may be required in areas with a history of heavy snow mold October and November; reapply in January if snow melts)

16 # Patch/plot Pink / Gray Snow Mold : CBG Green - Pullman, WA b a a a a Turfcide fl oz 4. Banner MAXX 1.3ME 2 fl oz 2. Compass 0.25 fl oz 5. Non-treated check 3. Medallion 50WP 0.5 oz F & N 56: T11 (2000)

17 % Disease Pink Snow Mold : KBG Fwy Pullman, WA c c b ab a a Chipco 26GT 2SC 4 fl oz + Terraclor 75W 4 oz 2. Chipco 26GT 2SC 4 fl oz + Heritage 50WG 0.4 oz F & N Tests 55:515 (1999) 3. Chipco 26GT 2SC 4 fl oz + Daconil Ultrex 82.5W 4 oz 4. Chipco 26GT 2SC 4 fl oz 5. Terraclor 75W 4 oz 6. Non-treated check

18 % Disease Pink / Gray Snow Mold : CBG Fwy - British Columbia d d d c b a Heritage 50WG 0.8 oz + Banner 1.1EC 4 fl oz 2. Heritage 50WG 0.4 oz + Daconil Ultrex 90WG 5.3 oz + Terraclor 75W 2.1 oz 3. Heritage 50WG 0.8 oz + Terraclor 75W 5.6 oz 4. Terraclor 75W 8.8 oz 5. Heritage 50WG 0.4 oz 6. Untreated control F & N Test 58 : T058 (2001)

19 Umass Snow Mold Sites Glens Falls CC, NY Manchester CC VT North Adams CC, MA Berkshire Hills CC, MA

20 Snow Mold Control with Mixtures Wi & NY Concert (chloro. + propic.) Renown (chloro. + azoxy.) Mixture of Pink & Gray Snow mold - G. Jung % disease area

21 Civitas treatments Mixture of Pink & Gray Snow mold - G. Jung, UMASS % disease area

22 32 oz/m Civitas 1.5 oz/m Propiconazole 16 oz/m Civitas 0.75 oz/m Propiconazole

23 5 oz/m Chlorothalonil 0.25 oz/m Medallion 3 oz/m Propiconazole 32 oz/m Civitas 1.5 oz/m Propiconazole

24 Recovery from Snow Molds Berkshire Hills CC Snow mold rating on March 28, 2011 Recovery rating on April 21, 2011

25 Civitas 16 oz + Harmonizer 4 oz

26 Civitas 16 oz + Harmonizer 4 oz + Concert 4 oz

27 Turfcide (8 oz/m)

28 Untreated

29 Chemical control Two- or three-way combinations of products due to multiple snow mold species DMI, Strobilurin, Iprodione, Chlorothalonil, Fludioxonil, Thiophanate-methyl, Polyoxin-D