29 May 1998


THIS spring must have provided the most testing conditions ever for septoria control. And while that was bad news for growers, it suited IACR Long Ashton researchers just fine.

They were able to put a new monitor, which helps show how rain splash contributes to the spread of cereal diseases, well and truly through its paces.

The Precipitation Impact Sensor, which is being evaluated by Darren Lovell, can distinguish between 14 types of rainfall, recorded as splash intensity, over periods ranging from 5min to 24 hours.

Data from the sensor will provide the missing link in establishing septoria risk, as well as showing how rain splash can carry other diseases within crops, he believes. That would involve distinguishing between misty or wind driven rain and large drops and fine.

"Once we know the impact characteristics, including the effect on wind-blown drops, we can calculate the dispersion effects," Mr Lovell explains.

He has applied for MAFF funding to finance the two years of data collection needed. "This is a potential breakthrough for this area of research."

Agronomy impact

He stresses the importance of determining the interactions between types of rainfall, the crops genetic disease resistance and the characteristics of the crop canopy – in turn dictated by agronomic factors.

"Nitrogen applications, sowing date, use of pgrs and other factors change the canopy structure. We want to discover what type of rainfall is needed to get the pathogen from infected areas to the upper leaves at each stage of crop growth," he says.

The data is particularly important for building into the DESSAC computerised agronomic advice database, and could be used to indicate spray timing, if not rate.

The sensor which can also be used to evaluate soil erosion risk and hail intensity and damage will be demonstrated at Cereals 98. It can form part a new and more powerful meteorological station from Aardware Design, marketed by Agmet.

The weather station can take 17 readings, including soil temperature, leaf wetness, wind speed and direction. Information is collected by a Smaartlog data logging unit, which can hold several years of records.

It can also be down-loaded as required, either to a laptop, or it can be sent at timed intervals directly by land line to a host computer. Alternatively, it can be sent by modem and cellular telephone to show "weather now" live.

Septorias secrets could be revealed by this novel gadget, now under evaluation at IACR Long Ashton. Seen here are Mark Dimmick and David Morris of Agmet (l + r) and Graham Moss of Aardware Design.

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