Contents

• Purpose of module
• Using the module
• Input boxes explained
• Output boxes explained
• How the module works

Purpose

This is presented as a demonstration module to assess users' views. Only the more established varieties are included in this demonstration as users will have knowledge of how they perform locally.

We would appreciate feedback from users and ask that you give your comments using the feedback form.

Using the module

1. Select varieties by clicking on their names.

2. Specify the conditions under which you plan to grow the crop using the pull-down menus.

3. Click the position of your farm on the map. This is used to determine average rainfall and regional variation in disease.

4. A new set of pull-down boxes will appear which show the importance of each problem relative to the average for the whole of the UK

• If you think that these are not typical of your own experience then change them using the pull-down menus.

• Also check that the soil nitrogen supply is as you would expect. The module may not take recent grassland or some previous crops fully into account.

5. Click on "next".

6. The next screen shows the calculated risk for each factor and also rates the average fungicide response in RL trials for each variety.

7. Further information can be found by clicking the "v" or "i" boxes at the side and top of the table.

To change your selection use the "back" button to return to the first screen when you can either:

• adjust the preliminary results in the bottom set of pull-down menus
• or adjust the initial set in the top menus and click on the map again to load the new values .

Input boxes explained

1. You select varieties by clicking on their name.
   You can select as many or as few varieties as you want but you will notice that we have omitted varieties recommended in the last two years. This is because we are still fine-tuning the models used in the module but we want you to compare the output from the module with your own experience.

2. Specify your conditions using the pull-down menus at the right of each box.

3. Click on the map to show where you farm.

4. A new box then appears which shows our prediction of the severity of each problem compared to the average of the UK for that problem.
   We do not compare the risks of each problem, for example yellow rust vs Septoria tritici, at this stage. This is done in the next step.
   If you think we have given the wrong values, change these with the pull-down menus.
   For example, if you are above average for mildew and we have suggested you are only average, then change it to average.

5. You then press the "next" button to move to the output screen

Output boxes explained

Fung response

Varieties are classified according to the percent difference in their average grain yield between fungicide treated and untreated trials.

Foliar diseases

The risks given are intended to show the likely need for disease control in your crop. They are on the following scale:

The number of sprays and appropriate fungicide dose will relate to the risk rating but will vary according to seasonal disease risk.

These risks take into account the predicted incidence of each disease; the affect of that disease on yield and the relative cost of control.

Because Septoria tritici is always found right across the UK, its affects on yield are high and it is costly to control; the risk factor will nearly always be high or very high even if you are growing a variety with better than average disease resistance.

Conversely, because brown rust is less common in the north, if you farm in Scotland the risk factor will be no more than "medium", even if you are growing a susceptible variety.

The lodging risk is based the calculations suggested in the HGCA Guide - Avoiding lodging in winter wheat but these only take into account the factors which would be known before the crop is sown and is based on average winter rainfall for each location. The lodging guide itself also considers crop growing conditions and winter rainfall, so it should be consulted to help manage the crop during the growing season.

The eyespot risk is based on the HGCA Guide - Determining eyespot risk in winter wheat. Again only factors known before drilling are taken into account so growers should consult the full guide to help manage crops during the growing season.

How the module works

For foliar diseases the module works by combining:

• the genetic resistance score from the HGCA Recommended List which rank varieties for susceptibility under ideal conditions for each disease.

• disease distribution information from Defra/CSL/ADAS Crop Monitor.

• an assessment of the effect of sowing date and cultivation on disease incidence.

• an overall assessment about the relative damage caused by each disease and of the cost of control.

to give a rating of the risk of that disease causing problem in each specific situation.

The calculations are done by taking the variety rating from the RL and adding on adjustments for locality, yield loss, cost of control, sowing date and cultivation. This adjusted score is then converted into a risk rating from "very low" to "very high". The attached document gives details of the calculations used.

The lodging risk is based the calculations suggested in the HGCA Guide - Avoiding lodging in winter wheat but only takes into account the factors which would be known before the crop is sown and is based on average winter rainfall for each location. The lodging guide itself also considers crop growing conditions and winter rain fall so should be consulted to help manage the crop during the growing season.

The eyespot risk is based on the HGCA Guide - Determining eyespot risk in winter wheat. Again only factors known before drilling are taken into account so growers should consult the full guide to help manage crops during the growing season.