effects of a surfactant on turfgrass quality, hydrophobicity ...
EFFECTS OF A SURFACTANT ON TURFGRASS QUALITY, HYDROPHOBICITY AND FUNGICIDE LEACHING FROM A USGA GREEN ESTABLISHED WITH AND WITHOUT ORGANIC AMENDMENT TO THE SAND-BASED ROOTZONE Trygve S. Aamlid1, Mats Larsbo2 and Nick Jarvis2 1
The Norwegian Institute of Agricultural and Environmental Research, N-4886 Grimstad, Norway 2 Swedish University of Agricultural Sciences (SLU), PO Box 7014, S-750 07 Uppsala, Sweden Corresponding author: [email protected] SUMMARY Fungi, especially those causing winter diseases, are major problems on golf course putting greens in Scandinavia. Although diseases can be prevented by cultivar selection and optimal maintenance, it is difficult to manage creeping bentgrass (Agrostis stolonifera) and annual bluegrass (Poa annua) greens totally without fungicides. Previous research showed that three commonly used fungicides; iprodione, azoxystrobin, and propiconazole, are liable to leaching when used on sand-based putting greens. One possible reason for this liability is the development of hydrophobic layers, or spots, causing water to percolate in fingers instead of uniformly through the root zone. The objective of this project was to study the effect of organic amendment and surfactant on turfgrass quality, hydrophobicity and fungicide leaching, from a USGA putting green. An experiment was conducted from May 2006 till May 2007 on a three year old experimental green, seeded to creeping bentgrass ‘Penn A-4’, in the field lysimeter facility at Bioforsk Øst Landvik, SE Norway (Fig. 1).
FIG. 1: USGA green being constructed over lysimeters, at Bioforsk Landvik, Norway, 2003.
The experimental plan included two root zone compositions (straight sand vs the same sand amended with 2.3 % (w/w) garden compost (‘Green Mix’)); two surfactant Proceedings of the 8th International Symposium on Adjuvants for Agrochemicals (ISAA2007) Publisher: International Society for Agrochemical Adjuvants (ISAA) Editor: RE Gaskin Produced by: Hand Multimedia, Christchurch, New Zealand
6-9 August 2007 Columbus, Ohio, USA ISBN 978-0-473-12388-8
treatments (no surfactant vs ‘Primer 604’, 19 L/ha applied at monthly intervals from May to September 2006); and two fungicides, Rovral 750 (iprodione 1.5 kg a.i./ha) and Amistar Duo (azoxystrobin + propiconazole, 600 + 375 g ai/ha), sprayed on three occasions (June, July and October 2006), in factorial combination. Turfgrass quality and disease occurrence, infiltration of water vs ethanol, water droplet penetration time, and spatial variability in soil water content were determined at regular time intervals. Fungicides in leaching water were analyzed 2 - 3 weeks after each application and after snow melt / soil thaw in spring 2007. Regular application of ‘Primer 604’ reduced dry spot occurrence and improved turfgrass quality during the summer months, especially on straight sand plots. This improvement was associated with increased water infiltration rates and a reduction in the spatial variability in soil water content at 4 - 10 cm depth, suggesting that hydrophobicity extended deeper in the profile than the 14 - 19 mm thatch/mat layer. However, despite pesticide application, ‘Primer 604’ also increased snow mold (Microdochioum nivale and Typhula spp.) incidence in spring 2007. This was probably due to a significant increase in the mean soil water content in the thatch–mat layer during the unusually mild and wet winter months (mean temperature / total precipitation from November 2006 to March 2007 was 3.5°C / 751 mm compared with 30 year normal of 0.2°C / 516 mm). Leaching of fungicides from root zones with 2.3 % organic matter was always negligible, but regular use of ‘Primer 604’ on root zones reduced the total leaching of iprodione, azoxystrobin (Fig. 2), and propiconazole from straight sand by 60, 63 and 80 %, respectively. In conclusion, ‘Primer 604’ offers many advantages on straight sand root zones, but there is also a need for new surfactants that retain less water in the thatch layer during the winter months.
Oct.
April
10.0
160
8.0
120 80
4.0
N o
N o
N o
su rfa ct a P rim nt er 60 4
0
su rfa ct a P rim nt er 60 4
0.0
su rfa ct a P rim nt er 60 4
40
su rfa ct a P rim nt er 60 4
2.0
Total leaching, ug/m2
July
6.0
N o
Concentration in lechate, ug/L
June
Concentration, ug/L
Total, ug/m2
FIG. 2: Effect of Primer 604 on leaching of azoxystobin from straight sand root zone on four occasions during the experimental period.
Proceedings of the 8th International Symposium on Adjuvants for Agrochemicals (ISAA2007) Publisher: International Society for Agrochemical Adjuvants (ISAA) Editor: RE Gaskin Produced by: Hand Multimedia, Christchurch, New Zealand
6-9 August 2007 Columbus, Ohio, USA ISBN 978-0-473-12388-8
The Norwegian Institute of Agricultural and Environmental Research, N-4886 Grimstad, Norway 2 Swedish University of Agricultural Sciences (SLU), PO Box 7014, S-750 07 Uppsala, Sweden Corresponding author: [email protected] SUMMARY Fungi, especially those causing winter diseases, are major problems on golf course putting greens in Scandinavia. Although diseases can be prevented by cultivar selection and optimal maintenance, it is difficult to manage creeping bentgrass (Agrostis stolonifera) and annual bluegrass (Poa annua) greens totally without fungicides. Previous research showed that three commonly used fungicides; iprodione, azoxystrobin, and propiconazole, are liable to leaching when used on sand-based putting greens. One possible reason for this liability is the development of hydrophobic layers, or spots, causing water to percolate in fingers instead of uniformly through the root zone. The objective of this project was to study the effect of organic amendment and surfactant on turfgrass quality, hydrophobicity and fungicide leaching, from a USGA putting green. An experiment was conducted from May 2006 till May 2007 on a three year old experimental green, seeded to creeping bentgrass ‘Penn A-4’, in the field lysimeter facility at Bioforsk Øst Landvik, SE Norway (Fig. 1).
FIG. 1: USGA green being constructed over lysimeters, at Bioforsk Landvik, Norway, 2003.
The experimental plan included two root zone compositions (straight sand vs the same sand amended with 2.3 % (w/w) garden compost (‘Green Mix’)); two surfactant Proceedings of the 8th International Symposium on Adjuvants for Agrochemicals (ISAA2007) Publisher: International Society for Agrochemical Adjuvants (ISAA) Editor: RE Gaskin Produced by: Hand Multimedia, Christchurch, New Zealand
6-9 August 2007 Columbus, Ohio, USA ISBN 978-0-473-12388-8
treatments (no surfactant vs ‘Primer 604’, 19 L/ha applied at monthly intervals from May to September 2006); and two fungicides, Rovral 750 (iprodione 1.5 kg a.i./ha) and Amistar Duo (azoxystrobin + propiconazole, 600 + 375 g ai/ha), sprayed on three occasions (June, July and October 2006), in factorial combination. Turfgrass quality and disease occurrence, infiltration of water vs ethanol, water droplet penetration time, and spatial variability in soil water content were determined at regular time intervals. Fungicides in leaching water were analyzed 2 - 3 weeks after each application and after snow melt / soil thaw in spring 2007. Regular application of ‘Primer 604’ reduced dry spot occurrence and improved turfgrass quality during the summer months, especially on straight sand plots. This improvement was associated with increased water infiltration rates and a reduction in the spatial variability in soil water content at 4 - 10 cm depth, suggesting that hydrophobicity extended deeper in the profile than the 14 - 19 mm thatch/mat layer. However, despite pesticide application, ‘Primer 604’ also increased snow mold (Microdochioum nivale and Typhula spp.) incidence in spring 2007. This was probably due to a significant increase in the mean soil water content in the thatch–mat layer during the unusually mild and wet winter months (mean temperature / total precipitation from November 2006 to March 2007 was 3.5°C / 751 mm compared with 30 year normal of 0.2°C / 516 mm). Leaching of fungicides from root zones with 2.3 % organic matter was always negligible, but regular use of ‘Primer 604’ on root zones reduced the total leaching of iprodione, azoxystrobin (Fig. 2), and propiconazole from straight sand by 60, 63 and 80 %, respectively. In conclusion, ‘Primer 604’ offers many advantages on straight sand root zones, but there is also a need for new surfactants that retain less water in the thatch layer during the winter months.
Oct.
April
10.0
160
8.0
120 80
4.0
N o
N o
N o
su rfa ct a P rim nt er 60 4
0
su rfa ct a P rim nt er 60 4
0.0
su rfa ct a P rim nt er 60 4
40
su rfa ct a P rim nt er 60 4
2.0
Total leaching, ug/m2
July
6.0
N o
Concentration in lechate, ug/L
June
Concentration, ug/L
Total, ug/m2
FIG. 2: Effect of Primer 604 on leaching of azoxystobin from straight sand root zone on four occasions during the experimental period.
Proceedings of the 8th International Symposium on Adjuvants for Agrochemicals (ISAA2007) Publisher: International Society for Agrochemical Adjuvants (ISAA) Editor: RE Gaskin Produced by: Hand Multimedia, Christchurch, New Zealand
6-9 August 2007 Columbus, Ohio, USA ISBN 978-0-473-12388-8
