DIAGNOSTIC TESTS FOR FUTURE DISEASE CONTROL Onions and Brassicas - - PowerPoint PPT Presentation

DIAGNOSTIC TESTS FOR FUTURE DISEASE CONTROL

Alison Wakeham, Roy Kennedy VCS Agronomy Allium & Brassica Centre G’s Kettle Produce Ltd

Onions and Brassicas

Onion downy mildew prediction

• Review progress
• Do we need a system?
• Current work
• Future development

Review

• Forecasting models
• Spore detection
• Trials

Low disease risk Moderate to High High risk of disease

0 spores 1000000 spores

10/05 17/05 24/05 31/05 07/06 14/06 2 4 6 Sporulation PERSHORE: Onion DM (15 Jun 2015) 10/05 17/05 24/05 31/05 07/06 14/06 0.5 1 Infection 10/05 17/05 24/05 31/05 07/06 14/06 0.5 1 Date (Day/Month) Latent Period

Integrated use with MILIONCAST to forecast risk in commercial salad and onion crops (AHDB study)

Results Site 2. Bulb Onions (Red Tide) drilled 20/03/2014

The total number of bulb onion plants exhibiting downy mildew symptoms across the two middle rows

• f each 10m treatment block
• seven

day spray interval

• forecast

(AHDB study)

• No

control measures applied

Need for forecasting

• Ok at present? – spray 7-10 days x 8
• Logistics – large area, spray days/timing
• Protection rather than cure
• Environmental benefit
• Approval changes:

– Revocation of actives – Reduced applications – New actives

• Overall fewer applications

– Targeting with DSS

2017 development work

FV456 – ‘Delivery of a Diagnostic test scheme for Brassicas and Onions’

• 2 year project
• Pershore College and Mologic
• Grower participation

Stoneleigh site: Trap located 500m to north Drilled 23rd May

0.2 0.4 0.6 0.8 1 1.2

SPRAYS

Spore trap results

• Sandfields

1st symptoms P Farm

First mildew outbreaks

11/8 15/8 22/8 4/9 29/9 25/9 18/9

49 day spread

20km

Conclusions 2017

• Detection of low spore numbers is possible
• Need to lower threshold (salad onion?)
• Siting of traps – proximity of crop, prevailing

wind, risk, number etc.

• Frequency of sampling
• Early start required

2018 plan

• Kits available for on-farm testing
• Use in conjunction with forecast

model (e.g. Milioncast)

• Early season start
• Trial spraying according to risk

Future vision

• Networked – regional/local
• Internet based alerts
• Integrated with forecast models (e.g. Milioncast)
• Fully automatic in-field kit

– Already in development for cereals, potatoes, beet – Innovate UK projects – Rothamsted & FERA

• Sampler includes DNA

release, isothermal amplification & wireless reporting.

• Result integrated with

infection models & risk prediction sent to user

• Current work: Arable

crops, sugar beet and potato pathogens

Real-time monitoring of airborne pathogen spores for disease forecasting

jon.west@rothamsted.ac.uk

Automated spore detection

• 360 degree cyclonic air sampler (c.f. wind directional)
• Increased air intake operating at 100L/min
• Battery operated
• Not 24/7
• Programmable for optimal conditions or time of day
• Automated sample preparation and testing using
• LAMP methodology
• Loop mediated isothermal AMPlification
• Low temperature DNA amplification
• Simple DNA preparation
• Result in 20 minutes
• Multiple targets (yellow rust, brown rust and septoria)
• Results of tests plus weather data communicated to hub

Prototype version Commercial version