Foliar nutrition notes

In field days at all of our Organic Focus Vineyard sites this November, Andrew Naylor, National Viticulturist for Pernod Ricard Winemakers, gave a featured talk on his corporate perspective on foliar nutrition for vines. Organic Focus Vineyard project viticultural advisor Bart Arnst also discussed how he advises his organic clients on foliar nutrition. Their approaches are described in this Marlborough Express article about the event.

Here below are Andrew’s own notes from his talk.

Foliar Nutrition - Andrew Naylor

Context
• I’m not a specialist
• Science background – real results are important
• Guide decisions
• No silver bullet

Nutrition – What is Best
Roots
• Nutrients carried by water
• Fertigation
Balance
• Right nutrients at the right time
• Avoiding toxicity and deficiency, not inducing either
• Vine balance – is it OK already?

Foliar Nutrition – is there a need?
4 things to consider
Soil Tests – Topsoil (subsoil @ establishment)
• Subsoil – Where the plant resorts to when the topsoil is dry.
• Is anything lacking or out of balance?
• Topsoil – anything that’s lacking? CEC, texture, pH
• Is anything out of balance?

Petiole/Leaf Tests
• Anything that is lacking or out of balance?

History
• Physiology, leaf or fruit symptoms, not responding to other plans

Situation
• Rootstock
• Vine age / crop level / soil moisture (Potassium)
• Soil conditions – sandy, pH, CEC, % OM.

When would I use Foliar Feeds
To address micro nutrients in particular
• typically only a little needed for a result, so uptake through leaves may be sufficient
• required at specific growth phases of the vine
• avoids having to treat the soil, and risking losses to leaching or over treatment

At times of stress
• cold periods, drought, crop load (in assoc with these)
• this can include macro nutrients

Pre-flowering
Boron – Low B soils such as sandy or low CEC high pH soils
Molybdenum – low OM, sandy, leachable soils
Zinc – low soil temps, low OM soils

Throughout the season
Nitrogen – low vigour, pale green or yellow foliage

Veraison onwards
Potassium – compromised root systems… drought, phylloxera, young vines relative to crop load,

Post flowering
Magnesium – Rootstocks (SO4, 5C, 5BB), history

What would I use?
Good number and big numbers

Good Numbers
• Results to back it
• does it really work
• based on science – or evaluation
• seek (independent) advice

Big numbers
• Use a product that has enough nutrient content to give you a result
• If it’s a macro nutrient then the plant needs a lot
• Nutrient that is in an available form

What wouldn’t I use?
Anything with poor science, data or representation
• i.e. Remove the filters
• i.e. Plants develop a memory
Low % products when a large intervention is required

Andrew Naylor is the National Viticulturist for Pernod Ricard Winemakers. Back in 1984 Andrew was part of the Marlborough Research Centre’s original team, transferring from the Ministry of Agriculture and Fisheries in Nelson to work as a science technician at the new Centre. A graduate of Lincoln College with a Diploma in Horticulture and a Diploma in Field Technology, Andrew spent 13 years at the Research Centre before moving to Montana. Today, with a Masters in Applied Science from Lincoln added to his credentials, Andrew is responsible for coordinating Pernod Ricard Winemakers crop productivity and quality and overseeing the technology used in the company’s vineyards and those of its contract growers.