What was it all about?

This project aimed to develop fertigation guidelines for growers, and ultimately increase industry productivity and sustainability.

The research team investigated the effects to apple trees of:

• Water stress and surplus
• Nitrogen and potassium fertigation
• Application type
• Soil type
• Leaching
• Nitrogen deficiencies.

Findings suggested total seasonal nitrogen supply should be tailored to the soil type and desired tree nitrogen status of the particular growing region.

To maximise fruit quality outcomes, the research suggested no more than 25 per cent of the recommended total seasonal nitrogen should be applied pre-harvest and no earlier than four weeks after bud burst. It also suggested pre- and post-harvest nitrogen applications should be split into multiple applications to minimise nutrient leaching.

The project also found water-stressed orchards do not need extra fertiliser compared to fully irrigated orchards and frequent smaller applications of nitrogen may prevent leaching after winter and spring rain.

Local growers and advisors took part in the design, implementation and assessment of the project’s trials. Results and outcomes were presented at annual state conferences, Future Orchards events and other information sessions such as Speed Updating sessions.

Other outputs included three magazine articles that were published in Australian Fruitgrower, two posters distributed to industry, a fact sheet, and four journal articles in international peer-reviewed journals. Two honours programs were also completed, adding substantial value to the research program.

ACT NOW

• Read this summary of the project’s findings from researcher Nigel Swarts on the APAL website  
  
  
• View presentation slides from a wrap-up of the project's findings here
  
  
• Read a fact sheet about the fertigation study here