Development of boscalid for Sclerotinia disease control in vegetable crops in Australia Doug Wilson Nufarm Australia Limited Hoong Pung & Susan Cross Peracto Pty Ltd
Sclerotinia sclerotiorum Sclerotinia minor
Fungicide Rank* Sclerotinia activity on beans & lettuces Sumisclex 5 Similar to Filan most of the time, but seems better under very high pressure + constant wet conditions ** Endocrine disruptor health safety concern? Filan 4-5 Similar to Sumisclex most of the time, except under constant wet conditions Switch 3-4 Similar to Filan, but Filan seems better at very high disease pressure Shirlan 2-3 Got efficacy at low rate, but maybe more effective at higher rates Rovral 0-3 Resistant isolates recorded Zero control if fungicide resistance isolates are present Amistar 0 Little or no control Folicur 0 Little or no control * 0 = no control, 5 = best control ** Endocrine disruptors are chemicals that may interfere with the body s endocrine system. The endocrine system is a system of glands, that produce more than 20 major hormones to regulate the body. The endocrine system is instrumental in regulating mood, growth and development, tissue function, and metabolism, as well as sexual function and reproductive processes.
Boscalid (Filan) almost equivalent to procymidone (Sumisclex) 70 60 50 Merseylea Trial 2005 % Bean plants infected by white mould 3 sprays at 7 day intervals; 1st spray at 20-30% open flower 40 30 20 10 0 Untreated control Amistar WG 300g/ha Sumisclex 1.0L/ha Filan 1.0kg/ha
Filan Point Unique chemistry Inhibits respiration at the fungal cell level. Low mammalian toxicity. Very safe to beneficial insects. Does not bio-accumulate. Notes Fungicide Group 7. Similar to,but different from the strobilurins. Classed as reduced risk by the EPA in America. E.g.predatory mites. Animals residue free >7day.
Boscalid (Filan) a new carboxamide chemistry Carboxamide Group Target site Chemical group Common name Complex 11 SD inhibitors Phenyl-benzamide benodanil flutolanil mepronil Furan-carboxamide fenfuram Oxathiin-carboxamide carboxin oxycarboxin Thiazole-carboxamide thifluzamide Pyrazole-carboxamide furametpyr penthiopyrad Pyridine-carboxamide boscalid Pyridinyl-e-benzamide fluopyram
Boscalid disease spectrum Boscalid controls disease in 3 of the 4 classes of fungi. This is is contrast to early carboxamide products such as carboxin that were active only on basidiomycetes. Class Example Boscalid Oomycetes Pythium, Phytophthora, downy mildew No activity Ascomycetes Sclerotinia, active Ascochyta Basidiomycetes Stem rust? active Deuteromycetes Alternaria, Botrytis active
Filan (boscalid) Mainly for Botrytis, sclerotinia and alternaria = bo sc al id. Single-site activity so resistance is an issue. Quite persistent so soil residues require management.
Boscalid MRL for wine
Boscalid soil residues after 3 months?, but no detectable level of residue in follow on crops
Levels of disease control by fungicides are affected by other factors such as : Disease pressure Soil types Locations Weather & crop conditions
Product & timing of applications on beans Merseylea, Tasmania 2005 80 % Sclerotinia infected plants 3 sprays applied at late flowering 60 40 20 3 sprays applied at early flowering 0 Control Amistar 0.5L Filan 1.0kg Filan 1.0 kg early application
Impact of the 1st fungicide application on beans Trial at Merseylea - 1999 Flowering based on % plants with first flower Untreated control 90% plants with 1st flower 10% plants with 1st flower %Diseased plants %Plants with severe infections 0 20 40 60 80 100
Du-Wett improves Filan performance Activator slightly reduces its performance when sprayed under alternate wet / dry crop conditions % Sclerotinia infected plants +/- standard error 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 Untreated control w ithout adjuvant Filan 250gai Filan 500gai Filan 250gai + Du-Wett + Du-Wett + Activator Filan 500gai + Du-Wett Filan 250gai + Activator Filan 500gai + Activator
Lettuce targeted application method
Managing Sclerotinia diseases Fungicide efficacy Optimising application methods Reduce conditions that increase disease Du-Wett improves fungicide coverage and absorption if applied under dry conditions
Leaf wetness in crop canopy major factor in disease incidence & severity 120.0 100.0 Wetness % 80.0 60.0 40.0 20.0 0-20.0 24/2 14:21 27/2 1/3 3/3 5/3 7/3 9/3 11/3 13/3 15/3 17/3 19/3 21/3 Trial at Merseylea - 2005 % Sclerotinia infected plants 50 40 30 20 10 0 3 sprays at 7 day intervals; 1st spray at 20-30% open flowers Control Amistar WG Sumisclex Filan
120.0 Constant wetness in a bean crop Merseylea - 2008 100.0 Wetness % 80.0 60.0 40.0 20.0 0-20.0 24/1 12:09 26/1 28/1 30/1 1/2 3/2 5/2 7/2 9/2 11/2 13/2 50 40 30 20 10 % Plants with severe infection - Sclerotinia wilting/wilted plants at 1 day before harvest 0 Untreated control Folicur 0.35L/ha Shirlan 0.25L/ha Filan 1.0kg/ha Filan 1.0kg + Du-Wett
Planned registered use of Filan label extension for Sclerotinia control Carrots, Lettuce, Cabbage, Broccoli Brussels sprouts, Chinese cabbage, Beetroot, Green beans, Snow peas, Green peas, Spinach,Onions.
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