GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 The effects of reducing herbicides in New Zealand vineyards

The effects of reducing herbicides in New Zealand vineyards

Abstract

Context and purpose of the study – Herbicides are commonly sprayed in the vine row to prevent competition with vines for water and minerals and to keep weeds from growing into the bunch zone. Sprays are applied before budbreak and reapplied multiple times during the season to keep the undervine bare. There is growing concern about the negative effects of herbicides on humans and the environment, and weeds in New Zealand have developed resistance to herbicides. Therefore, it is imperative that we reduce our reliance on herbicides in viticulture and incorporate methods that do not engender resistance.

Material and methods – This trial was conducted in the 2016-17, 2017-18 and 2018-19 seasons in three Merlot and three Sauvignon blanc vineyards in New Zealand. The trial was a split plot, with half the vineyard receiving multiple sprays (the industry standard). The other half received a single spray around budburst, and any subsequent undervine weeding was done using nonchemical methods (mowing or cultivation). In each vineyard half, five sampling locations were established for vine, fruit, and undervine measurements. Vines were assessed for canopy gaps by image analysis, yield, and rot severity. Fruit was sampled during ripening and at harvest to assess differences in chemical composition. The undervine area was surveyed at budburst, flowering, veraison, and harvest to assess differences in bare area and presence/abundance of various plant species.

Results – Reducing herbicide had a dramatic effect on the percent bare area under vines, as well as the species of undervine vegetation from flowering onwards. In most vineyards, canopy growth was similar for both the control (C) and reduced herbicide (RH) treatments, though a few differences were found, generally with the RH treatment having more gaps. A few differences were found in midday water potential, with the RH treatment generally having more negative SWP. Despite differences in canopy gaps and SWP, there were few effects on berry size or soluble solids. There were few other fruit compositional differences, though the RH fruit tended to have lower yeast assimilable nitrogen (YAN) than the C fruit. Yield was generally not affected by reducing herbicide, and rot severity tended to be similar between treatments, indicating no negative effects on fruit quantity or health from allowing more vegetation to become established under vines. These data show that herbicide use can be reduced by 50-75% with little negative effect on grapevines or their fruit. It is anticipated that adopting this technique will reduce herbicide residues in/on fruit and slow or stop the spread of herbicide resistant weeds.

DOI:

Publication date: September 26, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Tingting ZHANG1, Allison HAYWOOD2, Mark KRASNOW2*

1 Thoughtful Viticulture, Napier, Hawke’s Bay, New Zealand
2 Thoughtful Viticulture, PO Box 312, Blenheim, 7240, New Zealand

Contact the author

Keywords

herbicide, resistance, grapevine, weeds, sustainability

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Using open source software in viticultural research

Many high quality Open Source scientific applications have been available for a long time. Some of them have proved to be particularly useful for carrying out the usual activities involved in viticultural research projects, such as statistical analyses (including spatial analyses), GIS work, database management (possibly integrated with statistical and spatial analysis) and even “low-level” often highly time-consuming activities (e.g. repetitive task on text files).

Classification of the wine-growing environment of Central Mancha (Spain). First works

This paper describes a zoning study performed on a vast territory of around 86,500 hectares, situated in the countryside area of La Mancha Central (Castilla-La Mancha). The aim of the study was to classify the environment according to a small number of ecological criteria, establish the relevant territorial units and generate thematic maps with the different levels of criteria employed and synthetic maps by crossing these criteria.

The effect of ultrasounds in syrah wine quality is not dependent on the ripening or sanitary status of the grapes

Different studies have demonstrated that the application of ultrasounds (US) to crushed grapes improves chromatic characteristics of the wines (1,2), increases their polysaccharide content (3) and some aroma compounds are also favored (4,5)

Beyond colors of rosé wines: impact of origin and winemaking technology on their color, polyphenol and thiol compositions

Rosé wine consumption is rapidly increasing with its market share in France that has grown from 11 % to 32 % in less than 20 years. A recent trend is also to produce rosé wines with lighter colors. Varieties, terroir and technology certainly have an influence on rosé wine colors.

Successive surveys to define practices and decision process of winegrowers to produce “Vins de Pays Charentais” in the Cognac firewater vineyard area

Le vin est un des produits finis que l’on obtient à partir de raisins. La vigne réagit à de nombreux facteurs environnementaux et son comportement est directement influencé par les pratiques culturales