Disease Assessments for Agriculture Trials

What we do

GreenGuard Crop Assessments has experience assessing both conventional and organic crop trials. We can work with you on projects ranging from evaluating disease resistance capabilities of new cultivars to carrying out efficacy evaluations of new plant protection products (PPP) and fertilisers.

All assessments cater to your company's needs, whether you are looking for an independent efficacy dataset for a new product or an evaluation of an organic fertiliser.

Assessments will follow EPPO guidelines. Any data that is collected on your behalf will be treated confidentially and will be 100% yours.

Plant samples that you send to us will either be returned to you or disposed of following your guidance.

All datasheets and images will be automatically deleted from GreenGuard Crop Assessments' database after two months unless instructed otherwise by you.

Protocols and procedures

As a customer you can chose how we assess your plot trials. We are happy to use your protocols to ensure that data is collected in accordance with your methodologies. We are also happy to work with you if you need to establish a working protocol.

How we can assess your trials

You are welcome to send plant samples here to us for assessment or we are happy to travel to your trial sites to do in person assessments. A sixty-plot wheat trial for example will usually take a day to assess if we do observations on four one-meter points per plot.

If you opt for a field visit, it will be your responsibility to notify us when your trial has reached the appropriate growth stage.

Please see below for details of what we assess.

Sending samples to the lab

To ensure that disease levels on the flag leaf have had chance to develop please wait two weeks after the flag leaf has fully emerged before collection.

For each plot have a separate bag labeled with trial code and plot number. Collect ten tillers per plot selected at random from across the plot. Cut each tiller at ground level. Wrap the plant samples in blue roll before placing them into their assigned bag. Place all the bagged samples in a box, use some form of packing material to stop the samples moving around. Post the samples to get to us by the next day.

To assure that your samples are assessed blind there is no need to send any details of treatments or plant variety with your sample. This will also assure confidentiality when it comes to evaluating PPP. If you have smaller plot sizes, then the number of tillers can be adjusted; we suggest sending in no fewer than five tillers to ensure the robustness of your data.

To avoid getting caught in the weekend post we suggest collecting plant material early in the week. Send any parcels by first class post or by recorded delivery to get to us within one to two days. 

How long will an assessment take

An in-person field assessment will take anything from a day to five days to complete depending on the number of trial plots.

Samples that are sent to us for visual/microscopic disease assessments are likely to take longer to process. A sixty-plot trial will generate 600 tiller samples. Untreated trial plots will take longer to assess than treated plots depending upon the level of disease observed on the leaves. We estimate that a trial will take between 1 to 5 days to assess depending on disease level.  

*Ear grain and floret counts will take longer to assess.

Assessment costs

Prices are from £350 per day.

There is an additional charge of 40p per mile for in person field trial assessments, and overnight costs may also apply.

We will notify you when your assessments have been completed; this will then generate an invoice. Your datasheet and images will be sent to you once we have received payment.

What you will receive

  • Independent evaluation of your trial
  • Detailed datasheet listing:
    • the diseases observed,
    • percentage of infected on each leaf, ear, or stem 
    • lesion size measurement
  • Photographic records of tillers, ears or stems linked to the datasheet
  • Digital microscope images of lesions
  • A digital copy of the data sent to you on a pen drive
  • A printed hard copy of the data. (Unfortunately, we will be unable to send prints of all the photographic images we take of your plant materials). 

How we will send the data to you:

We will notify you that the assessments have been completed. This will then generate an invoice. After we have received payment your data will be sent to you by Special Delivery Guaranteed by 1pm the next day. 

What happens to data on our systems:

Your data will be kept by GreenGuard Crop Assessments for two months. Once this period elapses, we will email you a deletion of data notification. If we don't hear from you within five working days, we will assume that it is safe to delete your data. 

What we assess

Cereal Foliar Fungal Diseases:

Wheat

For wheat we are interested in evaluating the last four leaves to emerge Flag leaf, leaf 2, leaf 3 and leaf 4. Once the flag leaf has fully emerged between Growth Stage 37-39 (GS37-GS39) or Feekes stage 8-10, this is the best time to begin foliar disease assessing. Depending on your chosen assessment method you either need to notify us that your trial needs assessing or start to collect plant samples to send to the lab. What diseases we assess in wheat:

  • Septoria
  • Yellow Rust,
  • Brown Rust,
  • Powdery Mildew
  • Other (please state requirements)

Barley 

The procedure for assessing barley is the same as above, however we assess the last five leaves to emerge Flag leaf, leaves 2, 3, 4 and 5. What diseases we assess in barley:

  • Rhynchosporium
  • Powdery Mildew
  • Net Blotch
  • Yellow Rust
  • Brown Rust
  • Ramularia

(NB it is best to wait one to two weeks after flag leaf emergence to allow for disease build up) 

Cereal Fungal Ear Assessment

We carry out visual assessments on ears to establish disease levels. If you wish for us to assess cereal ear disease, it is important to be aware of your region's disease forecasts and the growth stage infection is likely to occur. For example: Fusarium head blight occurs during flowering (GS61) when the weather is warm and humid. The fungus spreads in high rainfall events. Rain splash and humidity allows infection to spread. Symptoms become visible around (GS75) when the crop is at the milky ripe stage. These symptoms become less visible as the plant starts to ripen.

Ear diseases that we assess  

  • Fusarium ear blight. Assessed around the milky ripe stage (GS75)
  • Loose smut black on barley (GS61)
  • Sooty moulds (GS75)
  • Other ear diseases (please contact for other disease assessment requirements (e.g. ergot). 

Grain and Floret Counts

We are also happy to carry out grain and floret counts. We suggest sending twenty ears per plot for assessment. We will weigh all twenty heads for each plot together, before starting floret and grain counts. This process has multiple steps to it so maybe more time consuming than other assessing processes.  

How collect and send in ear samples:

If possible, please use tied sealable envelopes that are large enough to accommodate twenty cereal ears. Use one envelope per plot. Labeled the envelopes with the date the samples were collected, trial identification number and plot number. Send all envelopes together in a cardboard box. After processing we are happy to send the grain back to you for analysis, please let us know.

How long will this assessment take:

*Grain and floret counts will take longer than the other disease assessments as there are several processes to complete to get your data, these are:

  1. The ears from each plot are weighed
  2. Ears from each plot are then weighed separately
  3. Florets are then counted from each ear
  4. The ear is then hand-threshed to make sure that grains are not damaged
  5. Grains are then counted and finally weighed
  6. Chaff is also weighed.
  7. After all the ears have been processed for each sample grain and chaff are bulked together separately then weighed to give an overall yield for each plot.

If you wish to request these services then feel free to contact us to negotiate a price. 

Take-All Root Disease Assessment: 

When to collect samples

The best time to collect Take-All root samples is at Growth Stage 60 (GS60).

How to collect samples

We suggest sample preparation according to established industry protocols, for example: For each plot, gather plants from along a spade width at five randomly selected spots within the plot. Carefully remove soil from the roots. Individually tie each sample from the five areas using string. Consolidate all samples from the five points into a labeled bag. Trim down the plants to a uniform length of 5 cm or 2 inches. Send the prepared samples by post. 

Eyespot Disease Assessment:

When to take samples:

To assess the percentage of risk for eyespot the best time to collect samples is around GS31-GS32. The scores can be combined to determine eyespot disease risk.

How to collect samples:

Follow the same procedure used for collecting Take-All samples.

Other Agricultural Crop Assessments

At GreenGuard Crop Assessments we have experience of carrying out other agriculture and horticulture fieldwork assessments. We are equipped to assess OSR crops and other brassicas, beans, and peas. 

We are also happy to carry out surveys on arable weed populations, including black grass counts.