[SOLVED] Agricultural Research Methodologies

 

Agricultural Research Methodologies- Crop Protection

 

Crop Protection Researchers establishing projects on species where the mechanism or processes they are investigating are new, or unusual often face the challenge of devising new methods to measure variation in these biological systems.
Today, I will present 2 problems that require you to think about and develop some approaches to biological measurement. In doing so, you need to consider the basic experimental design (provided for you) the anatomy and morphology of the plat species in question, the biological phenomenon that we are investigating and the outcome we wish to achieve. Your answers should be justified with logical reasoning.

 

Case # 1 Assessment of the effectiveness of a soil applied fungicide for root rot in beans

 

Experimental design – This is a pot trial to investigate the effectiveness of a new fungicide for control (prevention) of Pythium root rot in beans compared to an existing industry standard (Benchmark product). Seed will be sown in pots containing pasteurised field soil (disease free) and the following treatments applied:

Treatment # Inoculation status Fungicide treatment
1 – –
2 – Test product
3 + –
4 + Test Product (standard dose)
5 + Test product (double dose)
6 + Benchmark Fungicide (standard dose)

Inoculation of the pots will be achieved by applying a solution of Pythium spores (zoospores) at a concentration of 5 x 106 spores per mL (10 mL volume).

The trial will run for 8 weeks after which assessment will occur.

Consider how Pythium root rot affects the plant and in reflecting on the following questions, develop some assessment criteria.
Please answer these questions and give your reasoning behind these answers

⦁ Which part of the plant is affected by this pathogen?
⦁ What are the primary symptoms on the plant?
⦁ What are the secondary symptoms on the plant?
⦁ How does this disease affect crop productivity?
⦁ How can we measure each of these effects?
⦁ Do we need more than one rating system?
⦁ Are these methods of measurement qualitative or quantitative?
⦁ Is data transformation required?

⦁ Please design your assessment system and provide a justification

⦁ Review the experimental design – can you suggest any improvements?

Case # 2 Assessment of the effectiveness of a stem applied herbicide for the control of a woody tree (Chinese elm)
Chinese elm is an invasive woody weed of creek lines and bushland on the east coast of Australia. A trial will be conducted to compare the effect of 2 previously untried herbicides (at normal and double rates) applied to drilled holes in the stem to control this species compared to the industry standard of a stem applied herbicide (Access™ in diesel) according to the following treatments:

Treatment # Treatment
1 No treatment
2 Benchmark (Access™) at recommended rate
3 Test Product 1 (recommended dose)
4 Test Product 1 (double dose)
5 Test product 2 (recommended dose)
6 Test Product 2 (double dose)

Chinese elms are tall trees which are semi-deciduous, this means that they can hold green leaves all year round, however, a good proportion of their leaves will drop during the winter months and are replaced by a heavy flush in spring. Therefore, leaf cover fluctuates during the year. Leaves go through a standard process of senescence turning colour from green to yellow to brown. Leaf cover is reduced as leaves drop from the tree.

Some symptoms of herbicide damage. When Chinese elms are affected by herbicide the following can occur:

⦁ Leaves can rapidly undergo senescence
⦁ Rapid leaf fall can occur
⦁ The trunk can begin to die – this can manifest itself in various ways, a key symptom is that the green layer just below the bark can change colour from green, to brown to black
⦁ The stem death can be identified by striking the surface with a hammer. A live stem has a dull note (tissue is moist). A dead stem has a hollow ringing note (tissue is dry).
⦁ Trees can take between 12 and 18 months to die

 

Please answer these questions and give your reasoning behind these answers

⦁ How long should this trial run for?
⦁ How frequently should assessments be performed?
⦁ When should the first assessment be made?
⦁ Which symptoms would you consider to be most relevant considering the purpose of this trial?
⦁ What might we learn from changes in leaf colour?
⦁ What might we learn from the process of leaf drop?
⦁ Could there be other aspects we could measure, and how can we do this?
⦁ Design a set of assessment ratings that can be applied in this field trial and justify the logic behind them
⦁ Review the experimental design – can you suggest any improvements?

 

 

 

Rubric: Presentation 15%, Research 30%, Reasoning/Logic 30%, Expression 25%. 1-2 pages maximum (~1000 words).