Reference no: EM132386659

Modelling Weed Seedbank Dynamics with RIM and the Wizard

Please work through the instructions below. Don't write more than a paragraph (~150 words) for each question.

Make sure you have had a good look at the RIM 2004 model, looking at the various crop/pasture and weed management options, and trying to find a rotation and weed management strategy that maximises profit over 10 years. You should spend at least an hour doing this (if you attended the RIM lab then you have already done this).

1. Briefly describe your best rotation and weed management strategy and the 'average' annual profit that it results in. Don't give every detail of every weed management action you used for every year, but rather try to summarise the overall strategy.

2. Briefly describe the reasoning that you used to find this best strategy.

3. State a few things that you learned (or that you think other people might learn) about weed management from this exercise.

Now spend some time trying to find a rotation and weed management strategy that maximises profit over 20 years.

4. Briefly describe your best rotation and weed management strategy and the 'average' annual profit that it results in. Don't give every detail of every weed management action you used for every year, but rather try to summarise the overall strategy.

5. Was there any difference in the longer term strategy compared to the 10-year strategy? If so, what was the difference and why didn't the same strategy work again? If the same strategy worked again, why?

Now download the 2012 version of the RIM model, and have a good look at it. Once again, spend some time trying to find a rotation and weed management strategy that maximises profit over 10 years

6. In what ways do you think the 2012 version has improved on the 2004 version?

7. In what ways do you think the 2012 version is not as good as the 2004 version?

Now it's time to look at the Weed Seed Wizard. You should find this installed on the lab computers, or you should be able to download it and install it on your own computer. Open up the Weed Seed Wizard and start with a new default scenario, based on Western Australia. Look carefully at the event list, and choose a few events to look at with the event inspector. Now double click on each event in 2005 to open the event editor, just to see what kinds of things can be changed. Change the harvest date of the final harvest to three months earlier and see how it changes the pictorial icon representation. Look at the 'Scenario Setup' tab. Simulate the scenario by clicking the green arrow, and then look at the 'Simulation' tab. Go across each of the output tabs (Harvest, Plants, Seeds, etc...) and see if you can understand what each one is showing. (Don't worry about Degree Days... it shows technical details about how the seeds are losing dormancy over time.) Displaying the event markers may help understand. Save your scenario with a good name. Now open the scenario again, so you have two copies of it open. Save one with another name like 'resistance'. Simulate both scenarios and compare their predictions - they should be the same of course! Now edit the 'resistance' scenario so that the eclipse applications no longer have any effect against ryegrass or wild radish. Simulate both scenarios again and compare their predictions - they should be different now!

8. What differences do you notice between the predictions for the two scenarios? Make sure you look at and compare the harvest predictions, the plants predictions and the seeds predictions.

Create a third scenario by copying the 'resistance' one. Edit the harvest events so that no harvest seed control is used. Simulate all scenarios again and compare their predictions.

9. What differences do you notice between the predictions for the second and third scenarios? Make sure you look at and compare the harvest predictions, the plants predictions and the seeds predictions.

Have a good look at the Wizard website. Read through the five case studies described on the website, and then the description of the Weed Seed Wizard details. Now look at the 'Weed Seed Wizard Download and Help' page and either Download the Weed Seed Wizard and have a look at the 'build your own scenario' help guide (either as a PDF or an accessible word document) and/or view the two video tutorials (Setting the scene and Understanding the results). Now go the 'Weed Seed Wizard scenarios' webpage and read the introduction. Then choose the SA, NSW or QLD scenario and try to reproduce the comparisons described on the website - see if you can get the Wizard to reproduce the results shown on the webpage for your scenario(s).

Now create your own comparison. Start with one of the four default scenarios or build your own from scratch. Create two copies of the scenario. Modify the scenarios to show the effect of some difference in weed management or resistance or weed biology or anything else you'd like to consider. Create a pair of graphs that directly compare the harvests for the two scenarios, and then another pair of graphs that directly compare the plant numbers (just like on the website scenarios).

10. Copy and paste the two pairs of graphs in below (using a screenshot, or exporting the graph as a png file, or exporting to Excel and making your graph there)

11. Describe the comparison you have made. What were the differences you created in your two scenarios, and what do the results show?

12. In what ways do you think the Weed Seed Wizard is better than RIM?

13. In what ways do you think RIM is better than the Weed Seed Wizard?

Attachment:- Assignment Files.rar