With the loss of Alto Elite - What next for bean disease control?
With the loss of Alto Elite et al as of 20 May 2020, what are growers going to do about disease control in beans? Syngenta’s vegetable field technical manager, Simon Jackson has been looking at alternative fungicides and fungicide programmes going forward. And we have an exciting new fungicide coming in the future, so watch this space…..
Syngenta have bean trials both at Stubton, near Grantham and Luton. At both sites, Simon has been looking at application timings. Is it better to treat at T0 and T1 or T1 and T2? He also wanted to see whether earlier applications could benefit the crop and grower by helping it to senesce quicker which would eliminate the need for a desiccant. Simon says ‘With the loss of diquat, this would be ideal situation if the crops senesced naturally, which they did in 2018 due to the drought conditions’. He also wanted to illustrate the strength of Amistar in beans.
The spring beans at Stubton were drilled in early March, and today (25/7/19) the crop is defoliated due to rust infection. Very high rust infection throughout the plots which gives an idea of the strength of some of the fungicides.
Simon has been comparing programmes of 2 x 0.75 l/ha Amistar with 0.75 kg Signum, also 0.75 l/ha Amistar followed by 0.6 l/ha A19020T (solatenol) or 0.6 l/ha A19020T (solatenol) followed by 0.75 l/ha Amistar vs 2 x 1.5 l/ha Alto Elite at T0 and T1 and then at T1 and T2 respectively.
Amistar applied twice is currently looking as good as the current standard, and will be a great alternative to Alto Elite until Syngenta’s new SDHI is launched. The Amistar treated plots are much taller and greener than the rest. ‘This will be our recommendation for 2020 if there is no Alto Elite available’ says Simon.
The best treatment overall was the A19020T (solatenol) followed by Amistar, which was giving excellent disease control.
Signum was not fairing particularly well against the Alto Elite plots. These were applied at the T1 and T2 timings in June. The Signum should probably go on at the earlier timing as it is not as systemic as Alto Elite.
‘The earlier timing treatments have given better control of the rust than the later timings. This could be due to the fact that there was very little, if any disease earlier, so the products were applied in a protectant situation’, according to Simon.
‘Two years ago when these trials were carried out, I counted the beans in the pods on the plots, and the Amistar treated had more beans/plant than the other treated plots, and the solatenol treated plants had heavier beans/plant, Simon commented. ‘We will see if the same happens again this year!’
Bruchid beetle were prevalent throughout the plots and the pea and bean weevil had made a meal of the leaves!