Agricultural research is vital for the development of more sustainable farming practices, crop protection methods, and overall improvements in agricultural productivity. A key component to drive this innovation in agriculture, is through replicated small plot research trials. These can be completed by large research organisations aiming for a product registration, or small businesses looking to improve their agronomic advice to growers. Small plot research trials can achieve many objectives including assessing the efficacy, safety, and environmental impact of pesticides, herbicides, fungicides, fertilisers and other crop treatments. If you are just starting out in agricultural field trials (or a seasoned researcher), below is summary of the key areas to consider and equipment required for completing a trial.

Understanding Research Spray Trials in Agriculture

Research trials are designed to evaluate how well various crop protection products work under different conditions. Researchers typically test the application of biological and synthetic products on crops to understand their impact on pests, disease, and overall crop health. The main objectives of these spray trials include:

Pictured above: Our Lightweight Offset Trial Spray Boom, The Brolga.

• Efficacy testing: Does the spray effectively control or prevent pests, diseases, or weeds? Does the fertilizer application influence crop growth? How well does the tested product compare to current or emerging industry standards? 
• Environmental impact: What effects does the spray have on the surrounding environment, including soil, water, and non-target organisms?
• Safety and regulatory compliance: Does the spray meet the necessary standards for agricultural use and consumer safety? Are crop residue spray trials required? 
• Application techniques: What is the most appropriate method of application, ie ground or aerially applied, fertigated, in-furrow or broadcast. Does the product being tested require an adjuvant for better coverage and penetration into the plant or pest?

Step-by-Step Guide to Starting Your Spray Trials

If you are new to agricultural research spray trials, follow these steps to increase your chance of achieving your required results. A well-researched and thought-out protocol, will give you the best chance of answering your aims. 

1. Define Your Research Objectives

Before jumping into the field component of your research trial, it’s essential to have a clear set of research objectives. Ask yourself:

• What are the questions I am trying to answer? What are my aims? 
• Has this work already been completed? Will these results generate value for me, my team, my clients, the industry? 
• Do I need to evaluate the application technique used as well? 
• Am I trying to answer too many questions in this trial? Should I simplify the aims to ensure the core objectives will be adequately answered? Or should I split the trial into 2 separate trials?  
• Does my proposed treatment list of products, rates and timing answer these questions? 

Clearly defined objectives will guide the design and execution of your trials.

Different nozzles, pressure and water rate will impact spray coverage.

2. Review Relevant Regulations

Agricultural research trials are subject to regulations governed in Australia by the APVMA (Australian Pesticides and Veterinary Medicines Authority). It is crucial to be familiar with your local laws regarding pesticide use, application methods, and data reporting. Understanding your local regulations will ensure you are compliant with trial aspects such as crop destruction when required, not exceeding maximum sprayed areas for experimental compounds and satisfying label requirements for the products you are trialing. 

3. Select the Right Products and Materials

Once your objectives are clear, you can begin selecting the products for your trials. This may involve reviewing the latest pesticides, fungicides, herbicides, fertilizers or biological products. You may need to purchase, request samples, or collaborate with manufacturers for new formulations that are still in development. The correct rates and application timings also need to be determined. Be careful to thoroughly review the relevant product labels for the correct information. It is a good idea to have a colleague review your protocol to ensure any oversights are corrected.  

The next step is to ensure you have the correct equipment required to complete an accurate spray trial. Trial Supplies was created to enable easy access to safe, efficient, accurate and affordable trial spraying equipment. 

• For broadacre/arable crop trials, the Brolga hand boom is the market leader with its 100% offset design, lightweight carbon fibre frame, high quality fittings and flexible spraying width and height (soil applications to flowering canola sprays). 
• The Jacana hand boom was developed for use in horticultural crops, with a reduced nozzle spacing of 30 cm and lower spraying height. 

Want to see the Brolga in action? Check out this short video:

Both the Brolga and Jacana hand booms can be paired with the Trial Supplies CO2 Pressure Pack to pressurize the boom. The hand booms can also be used with a high flow electric backpack sprayer (Solo 429Li) for larger mixes and cover spraying sites. Other items to consider are items for site marking, measuring out products, chemical storage and PPE. 

Below is a complete list of items available from Trial Supplies to complete your own spray trials. These items make up the Trial Supplies Spray Pack 3 – Complete, which is available to purchase direct from the website. Email the team at Trial Supplies to make any adjustments to this list or request a quote to generate a purchase order.

For international customers, the Brolga Hand Boom plus CO2 Pressure Pack is available for purchase here. If further items are required, please contact the team at Trial Supplies to request a customised quote. 

What You’ll Need:

4. Design Your Plot Layout and Mark Out the Site

Next, you’ll need to design the layout of your trial plots and identify the site. This involves deciding:

• The location of the trial: Choose an area with representative growing conditions and a uniform, even site. 
• Determine the number of replicates and any randomization required. Typically, trials will use 3 to 4 replicates, or up to 5 or 6 if pest pressure is likely to be uneven. This is more common in insect trials where the population is not evenly spread through a site. In some cases where the site is uneven, it is worthwhile to conduct a pre-application assessment. This then allows you to compare the post-application assessment directly to the same plot and not just the untreated treatment, which have started with a lower or higher level of pest pressure. 
• It is a good idea to have the site marked out prior to the spray event, as you are often trying to spray ahead of changing wind conditions or higher temperatures. This also gives the site owner (i.e. grower) more advanced notice of where the trial is, so they do not accidentally seed, spray, cultivate or harvest through it. 
• Fallow fields or sites using grower sown fields will require markers on each plot corner, along with more visible perimeter markings to alert people of the trial location. Trial Supplies has a number of plot and site marking options including a range of Trial Pegs in different colours and sizes, Field Flags, Pin Markers, Tape Measures, Right Angle Sight Glasses, Flagging Tape and Field Plant Labels for identifying treatments ahead of field walks. 

5. Monitor Weather and Environmental Conditions

It is critical to ensure appropriate weather conditions at application. The efficacy and crop safety of a treatment can be significantly influenced by wind, temperature, humidity, dew and rainfall. Follow any label recommendations for correct weather conditions during application and ensure all conditions are recorded for inclusion in the trial report. 

You can keep track of local weather conditions using meteorological data or in-field weather stations. Try to spray when conditions are ideal, typically early in the morning or late in the afternoon when wind and temperature fluctuations are minimal. As some trials can take a few hours to spray, you are ideally aiming for consistent weather throughout this planned spraying window to ensure all results are treatment related, not weather related. 

6. Conduct the Spray Application

Carefully follow the protocol for spraying, ensuring the right treatments are mixed at the correct rate. Ensure to calibrate the hand boom prior to each trial, ensuring your output and walking speed are providing the correct application volume. The Brolga and Jacana hand booms come with a User Guide that explains the process of calibrating and spraying, and a video is also available from Trial Supplies that guides you through the process of connecting the pressure pack, pressurizing the boom, spraying the treatment and moving between treatments. 

Ensure to document all settings and outputs for inclusion in the trial report. Accuracy is key here to ensure results can be relied upon. If you are 5% out with your calibration, 5% out with your walking speed and 5% out with your syringed amount of product, you are already 15% off the treatment rate which is significant. 

Trial Supplies Spray Procedure Guide

7. Assess the Results

After spraying, monitoring and evaluating the effectiveness of the application is crucial. It is often a good idea to conduct the assessment ‘blind’ (treatments are unknown). This removes any potential subconscious bias. You may also want to re-assess your 1st replicate after completing an assessment, particularly for the visual assessments, as you may take a few plots to get your eye in and be consistent with your measurements. Some different types of assessments include: 

• Visual assessments: Observe and document any changes in plant health, pest reduction, or disease control over time. You can score the plots relative to an untreated, or relative to another treatment, such as the current standard. 
• Data collection: Record measurable data like pest counts, disease incidence, crop yield, or growth rates. Plan ahead for this measurement and ensure you have the appropriate equipment such as measuring scales, microscopes, secateurs or sample collection bags. 

Typically, results are recorded at multiple time points after application to capture the short-term and long-term effects of the treatments. Ensure the required assessment dates are noted in your calendar and are appropriate for the target being assessed. 

8. Analyze the Data

Once your trial data is collected, it’s time to analyze the results. Statistical analysis can help you determine the effectiveness and significance of the treatments. Some of the factors to consider during your analysis include:

• Treatment efficacy: Did the product perform as expected for pest control or disease management? How did it compare against the current industry standards? Were the results consistent between replicates? Were the differences between treatments statistically significant? Most trial analysis will use a 95% confidence interval (P<0.05), which means the results indicate that we are 95% confident there was a difference between treatments which was not due to other factors such as site or pest variability.  
• Crop response: How did the plants react to the treatments? Were there any signs of phytotoxicity (plant damage)? Was this commercially acceptable? 
• Environmental impact: Were there any unintended effects on non-target species or the surrounding environment?

9. Document and Report Your Findings

If you go to the effort of completing a trial, it is important to document your results. This could be a comprehensive trial report with an abstract, objectives, methodology, results, conclusions and weather data, or simply a short summary of key trial details and results. It is surprising how often you or a colleague/client will reference back to a well completed trial to help inform future decisions. 

Tips for Success in Spraying Trials

• Start Small: If you’re new to spraying trials, start with a small-scale trial before taking on too many objectives. This allows you to work out any equipment or technical issues. 
• Collaboration: Consider partnering with experienced agricultural researchers or universities. Their expertise can help guide you through the process. The team at Trial Supplies is also always available to discuss and assist with your trial queries. 
• Safety First: Always prioritize safety by using appropriate PPE and following safety protocols when handling chemicals (keep an eye out for our future blog post on PPE required when spraying research trials). 
• Data Integrity: Ensure your data is accurate, reproducible, and free from bias. Proper data collection techniques are essential for meaningful results that can be relied on for future decision making. 

Conclusion

Completing your own agricultural research trials can be a rewarding and insightful endeavor. They are an invaluable way to quickly build practical and technical knowledge of the products and crops being trialed. By carefully planning and executing your trials, adhering to safety protocols, and analyzing the results effectively, you can contribute valuable insights to your wider team and clients. 

Trial Supplies is committed to breaking down the barriers to research, enabling you to complete your own independent spray trials with high quality, safe, accurate and affordable equipment. So whether you are wanting to evaluate new products, register new compounds or check the crop safety of a number of new tank mixes, the team at Trial Supplies are ready to equip you with the right tools for the job. 

Get in touch today to get started on your own independent trials!