FAQ

NVT is a national program of comparative crop variety testing with standardised trial management, data generation, collection and dissemination. The NVT program is part of GRDC (Grains Research and Development Corporation).

What is the National Variety Trials (NVT) program?

Answer: The National Variety Trials (NVT) program is an independent approach to variety evaluation, generating credible information for growers and advisors about newly released varieties. It is a national program established by the Grains Research and Development Corporation (GRDC) and includes the most advanced lines from all plant breeding programs in trials across Australia. NVT replaces the previous Crop Variety Trials which were also designed to aid public breeders in making their variety release decisions. Under the new system, breeders will be expected to make their release decisions prior to nominating lines for testing in the NVT. As a result, NVT data will be more relevant to growers as varieties in the trials will be close to public release.

What is the main purpose of NVT?

Answer: NVT aims to increase grower profitability through providing growers and their advisers with independent, relevant and robust information on the performance and characteristics of grain crop varieties. This ensures valid comparisons between varieties can be made, and helps optimise variety selection decisions.

Who manages the NVT program?

Answer: NVT is managed by the Grains Research and Development Corporation (GRDC).

What is GRDC?

Answer: The Grains Research and Development Corporation (GRDC) is one of the world’s leading grains research organisations. GRDC's purpose is to invest in R,D&E to create enduring profitability for Australian grain growers.

How is NVT funded?

Answer: NVT is solely funded by the Grains Research & Development Corporation (GRDC). GRDC investment covers the managements of the trials through the various regional Service Providers, the seed production of commercial cereal varieties for the following year’s trials from a common seed source, and the overall NVT program management.  It also invests in the development of cultivar disease resistance ratings for wheat, barley, oat, pulse and canola crops through investments with state departments, universities, and other pathology R&D organisations.

What crops are tested in NVT trials?

Answer: The NVT program tests potential new varieties for Wheat, Barley, Canola, Chickpea, Faba Bean, Field Pea, Lentil, Lupin, Oat and Sorghum crops.

How many trials are there?

Answer: More than 650 trials are sown at over 300 locations each year in the NVT system. An additional 100 National Breeding Initiative trial results are also reported upon to expand and enhance the information available.  More information can be found on the NVT Results & Reports webpage.

How are the NVT trials managed?

Answer: NVT trials are managed by regionally contracted field trial providers who sow, maintain and harvest trials. They manage the trials in accordance with NVT trial protocols to provide consistent quality across the nation. Regionally and at site level, trials are managed to district practice sowing dates and include regionally relevant varieties which are managed to allow them to express their water-limited yield potential. As such, trials are managed to reduce disease, weed and fertiliser constraints. NVT trials should not be confused with gross margin trials. The trials are conducted in accordance with the established NVT protocols.

How are varieties selected for inclusion?

Answer: Cultivars are nominated into the NVT program on a regional basis by the breeding programs. These lines have to meet the acceptance criteria of being “available to growers to purchase on commercial scale” within two years from the first year of nomination. Thus, each line will be tested for up to two years before it is available to growers. If a line is released, it will remain in the trial for more years, depending on its adoption by growers in that area. The commercial lines are selected using information on the uptake of varieties, delivery percentages across a state and from feedback from the NVT Advisory Committees.

Where do I access NVT trial results?

Answer: Use NVT Online website to access trial results. This website allows growers to view results of local trials, including sowing and harvest dates, chemical, fertiliser and herbicide inputs, soil test results and statistically analysed results. The NVT Online website reports yield results from the single site and Multi Environment Trial (MET) analysis. The website is complimented by the state based sowing guides and other localised publications.

What is the difference between Single Site and MET yield results?

Answer: The ‘Single Site’ yield results are from the analysis of a single trial from one season at one location.  Thus, each variety estimate is based on only three data points (plots), for example, the wheat variety, CutlassPBR at Merrinee (Victoria) in 2018 had three values which contributed to the single site variety mean estimate. These results are typically what were previously presented on the NVT Online website and they do not consider the similarities and differences between locations and years. The MET data contains trials over a range of geographic locations and seasons (usually a five year period). For example, 152 wheat trials from South Australia and Victoria between 2014-2018. These trials are analysed together in a MET analysis which enables each variety prediction for an individual environment to be based on many more data points (393 in the case of the CutlassPBR example) and to borrow information from other environments in the dataset. The MET analysis provides robust yield results for each variety in a region of interest to the grower. The MET results are the preferred information to use when making variety selection decisions because the predictions are accurate and repeatable.

How is the data collected?

Answer: Information on the NVT trials is captured, stored and made available on the NVT website and database. NVT trial managers use a computer-based system that is able to facilitate the trial management process (creating trials, producing field books and labels) and well as store and manage data.

What data is collected?

Answer: Along with the yield and grain quality information, NVT also capture site characteristics. This includes soil test results, rainfall, sowing & harvest dates, fertilisers & chemicals applied and paddock rotation histories which are collected at every trial. Commercial variety information and disease resistance ratings are also collected and made available to the public.

What rates of fertiliser are used?

Answer: All trial sites are comprehensively soil tested up to one metre depth prior to sowing, which aids fertiliser application decisions. Fertiliser rates are then calculated using nitrogen budgets considering soil fertility, moisture and yield potential, and are adjusted to suit each trial’s needs. As NVT trials are managed to reach their water-limited yield potential, crop nutrition should not be limiting, and fertiliser rates may exceed common commercial practice.

Are fungicides used in NVT trials?

Answer: Yes, NVT trials are managed to minimise the impact of preventable diseases and allow crop varieties to express their yield potential. Diseases are managed using label recommended seed treatment and in-crop fungicide applications.

How is the quality of NVT trial maintained?

Answer: Quality of NVT trials is maintained through the use of carefully documented protocols which are regularly reviewed by industry. GRDC-NVT staff audit trials throughout the season to ensure the relevance and quality of trials are maintained. Trials are also inspected by participating breeding companies, local growers and agronomists who provide continuous feedback throughout the year.

What happens to trials that do not meet the NVT quality requirements?

Answer: NVT trials that do not meet the quality requirements for publication through the NVT reporting tools are published in the ‘NVT Quarantine Trial Report’. Quarantine reports include trials compromised by seasonal or management issues and should not be used to make variety selection decisions. These trials may have been affected by frost, drought, animals or spray drift. The purpose of NVT is to allow growers to make informed variety selections and compromised trials can be misleading and result in poor variety selection.

When are NVT trial results delivered?

Answer: NVT aims to deliver results as soon as possible after harvest. Results should begin appearing on the website from late October each year and trials will continually be released through to mid-January.

Does it cost to access the web site or the data?

Answer: No, there is no cost. Access to the NVT trial results is free and publicly available without the need to login to the website or database. Login functionality exists on the NVT database to allow Trial Managers and Breeding company representatives to securely update or view confidential information.

Can I access the NVT results on browsers other than Internet Explorer?

Answer: Yes, the NVT website AND database will run on most internet browser programs including Internet Explorer, Safari, Mozilla Firefox, Chrome and many more. All public information can be accessed through the website on these browsers. Historically, trial managers and breeding companies logging into the NVT database to access confidential information needed to use Internet Explorer. However, this was upgraded in 2014 so all functionality was available across multiple browser platforms.

With favourable data, seed companies may benefit from the trials. Do they contribute funds or in-kind to the trials?

Answer: There is no direct monetary expense for plant breeding companies to enter varieties into the NVT program. Canola breeding companies provide seed of the commercial varieties used in the NVT trials as well their new promising lines. Breeding programs regularly visit NVT trials and are pivotal in providing feedback to help ensure integrity in the trials and the data produced. 

What are the sowing windows for NVT trials and how are they determined?

Answer: NVT trials have set sowing windows for each crop and trial type across the different regions of Australia. These sowing windows aim to follow district best practice and are determined with input from the region based NVT Advisory Committees. For wheat, the Long Season trials are sown as early as possible from April onwards. Early season trials are not usually after May 20, but because the Mayrung and Willbriggie sites in NSW are fully irrigated they are exempt from the May 20 cut-off as later sowing is less of an issue. The Main season window stretches from May to early June. Sometimes a partial or weak autumn break will result in conditions being too dry for wet seeding but too wet for dry seeding. This can delay the sowing of the Early season trials to more closely match that of the Main season trials. Varieties of similar maturity are grouped together in each of the Long, Early and Main season trials which allows each specific trial to be optimally managed for that particular maturity group. This eliminates the risk of have some varieties still green at harvest time while others are shattering or dropping heads.

Sowing and spraying equipment can have an impact on plant establishment and ultimately yield. Given the majority of farmers are no-till planting into stubble. Are trials planted into stubble, and what equipment is used to sow and spray each trial site? Is this common across all trial sites?

Answer: Some NVT trials are planted into stubbles, but this is not always possible at all sites. Trial managers tend to have one seeder to handle all seeding conditions and all crops, obviously on a much smaller scale than broad-acre farm equipment. Trash clearance can be an issue and heavy stubble loads can adversely affect the establishment of plants in a trial. This can have a drastic affect on the evenness of results in a small scale trial while being less significant in a broad-acre crop. Trials are generally sown with 6-8 tyne seeders spread across two or three bars for straw clearance. Spraying is most often done with ute mounted booms. The equipment is general similar, but not identical, across regions.

How are trial sites selected? When selecting a site for a trial, do researchers utilise paddock history and previous yield, biomass or EM maps to minimise variability of soil-type or geographic influence in the yield data?

Answer: NVT trial managers work very closely with the co-operators who own or manage the land where the trials are sown. They aim to sow trials into a paddock of the same surrounding crop type on a well drained site with even soil type, away from trees, fence lines, sheep camps and anything else that might add variability. Paddock histories are recorded and paddocks with weed, disease or herbicide residue problems are avoided.

Single-season NVT trial results vary every year due to variables like growing-season rainfall and other climate related influences. Given the season ahead is unlikely to replicate that of the previous year, are longer-term averaged results for any variety available to assist growers make varietal decisions that may better fit the long-term average?

Answer: Each year, a long term MET (Multi Environment Trial) analysis is conducted by biometricians from the Statistics for the Australian Grain Industry (SAGI) project funded by GRDC.  The MET analysis produces yield comparisons using data from trials across numerous years, but the exact time-frame varies depending on the crop being analysed. Long Term MET reports are developed for each crop type on a regional basis and are published on the NVT website. This is the best source of information to gauge variety performance over multiple years. 

Seed costs or royalties can vary significantly, particularly for GM varieties. Given this cost variation can play a part in variety selection, are seed prices or royalties associated with each variety published?

Answer: NVT are very wary that seed costs and royalties play an important part in variety selection, which is why the NVT website provides links to the Variety Central website. Variety Central is an information source for Australian grain growers and industry, encompassing plant breeding, seed commercialization, varieties, royalties and other relevant information. It is a joint initiative, developed by the EPR (End Point Royalty) steering committee.

NVT Resource Library