Application on target to hit bean disease


With rust levels rising in PGRO field bean trials (below, pictured in mid-June), Syngenta research suggests growers should adopt new application techniques to optimise performance of fungicide programmes for applications this season.

Targeting Elatus Era on leaves throughout the dense crop canopy of field beans could effectively prevent disease build up and ensure better green leaf retention, to drive pod fill and seed quality.

Nozzle choice

Syngenta application research in dense potato crops has repeatedly proven the larger droplet spectrum and the specific angle of the 3D ninety nozzle spray pattern delivers better coverage of all foliage and stems throughout the canopy – resulting in more effective blight protection. The company’s Field Vegetable Technical Manager, Simon Jackson, believes the same principles should hold true for field bean applications.

“The trials have demonstrated that the coarser spray of the 3D ninety ensures that the larger droplets have the energy and momentum to penetrate deeper into the canopy,” he advised. “Coupled to that, the steeper angle of delivery, calculated to compensate for the larger droplets, means that more of the spray hits the leaf surface throughout the canopy.”

The 3D ninety nozzle has a 90% drift reduction rating to enable operators to make best use of every spraying opportunity at a particularly busy time of year, when cereal fungicide applications may be inclined to take priority over field beans. Elatus Era is exceptionally effective against both chocolate spot and rust, but is primarily preventative and provides best control with timely application prior to disease outbreaks.

Trials results

Initial Syngenta application trials with the design of the 3D ninety nozzle have shown 95% greater disposition of treatment spray on the middle and lower leaves of bean crops, compared to a conventional flat fan nozzle.

The work also demonstrated the improved performance of the 3D ninety design in targeting both middle and bottom of the canopy compared to other drift reduction nozzles. Assessment of leaf area using Helios trace dye clearly revealed greater and more consistent coverage with the 3D ninety nozzle operated at 200 l/ha.  

“We have also seen with the 3D ninety that the drift reduction maintains a far more stable spray pattern and more consistent coverage of the crop, if there are any gusts of wind during spraying,” added Simon. “Avoiding misses or patches of under application has been one of the key learns from the better blight protection achieved in potatoes.”

He also highlighted performance has been optimised at a water volume of 200 l/ha where crops have a dense canopy, to achieve better leaf coverage. “The formulation of Elatus Era has been designed to ensure larger droplets burst and spread across the leaf surface, and don’t bounce off. It also achieves a more even spread and adherence to the waxy surface of bean leaves.”

Spray pressure

Operators are advised to maintain sprayer pressure at around 2 to 2.5 bar and to select the nozzle size required to deliver the desired water volume at the operating speed, ideally no more than 10-12 km/hr – an 05 3D ninety delivers 196 l/ha at 10 km/hr when operated at 2 bar, for example.

Chocolate spot and rust on untreated beans mid season

“It may be tempting to increase the pressure of a smaller nozzle to ‘blast’ an higher water volume into a denser crop, but that can be counterproductive and creates a higher proportion of fine droplets, which are typically intercepted at the top of the crop and never reach the lower leaves,” he pointed out. “Worse still they are more susceptible to drift and a significant proportion may never even reach the target, reducing the efficacy and value of the application.”

Disease control strategies

The new application techniques for use of the 3D ninety in field bean crops will be trialed and evaluated with applications of Elatus Era and Amistar programmes on the Syngenta Future of UK Farming R&D trials site in Suffolk this season.