Determine the effect of fungicide management strategies on disease control (especially crown canker blackleg, upper canopy blackleg and sclerotinia stem rot) and grain yield in HyTTec Trifecta (Resistant, Blackleg Group ABD) and 45Y28 RR (Moderately Resistant, Blackleg Group BC).

ï‚· Grain yield of 45Y28 RR increased by 0.92t/ha from nil fungicide to where four separate fungicides were used, including seed, 6-leaf, 20% bloom and 50% bloom. However there were treatments that incorporated fewer fungicide applications that yielded similarly to where four applications were used. The highest of these was where Maxim XL was applied to the seed
and a single application of Miravis Star was applied at 20% bloom.
ï‚· It was difficult to ascertain which disease was responsible for the yield loss. Sclerotinia levels were low with only 1.5% plants infected in the untreated control. Crown canker infection (% of cross section of basal stem) was reduced by fungicide but was not observed in high levels. Upper canopy blackleg infection on the main stem was also reduced by fungicide but was also
only present at low levels. Pod Upper canopy blackleg was present at higher levels than 2021, it was reduced best by the treatment that included a 20 and 50% bloom spray.
ï‚· There was no statistical benefit of fungicide on HyTTec Trifecta. Upper canopy blackleg infection was generally lower than 45Y28 RR. Sclerotinia levels were also low in HyTTec Trifecta with infection on 2.5% of plants in the untreated control.
ï‚· There was no effect of fungicide on any grain quality parameter in either cultivar.

2020 Crop: Pasture
Soil type & management: Red Ferrosol
Available Nitrogen (kg/ha) 0-60 cm: 340
Colwell P 0-10 cm: 63 mg/kg
pH (CaCl2) 0-10 cm: 5.2
Organic Carbon 0-10 cm: 2.0