Terroir 2004 banner
IVES 9 IVES Conference Series 9 Pro-active management of grapevine trunk diseases by means of sanitation in nurseries

Pro-active management of grapevine trunk diseases by means of sanitation in nurseries

Abstract

Several trunk diseases cause decline and premature dieback of grapevines. In vineyards, these pathogens gain entry into plants through unprotected wounds. Wounds are also frequently infected during the propagation stages. The pathogens survive in infected plants in a latent form and cause disease in older grapevines or in plants that are subjected to stress. No curative management strategies are known and disease prevention strategies focus on the protection of wounds in nurseries and vineyards. The aim of this study was to determine the effect of different chemical and biological sanitising treatments of propagation material on infection of trunk disease pathogens.
Rootstocks (101-14 Mgt) and grafts (Shiraz) were drench-treated in captan, benomyl, bronocide, Sporekill, Bio-sterilizer, chinosol and Trichoflow prior to cold storage (1 h drench), prior to grafting (10 min drench) and prior to planting (5 s dip). Vines were bench-grafted by hand or Omega machine and cold or hot callused, respectively. For the hand-grafted treatment, half the number of plants was grafted with sterilised hands on sterilised tables, while the other half was grafted under standard conditions (dirty hands and tables). The treated, grafted rootstocks were planted in a field nursery in Wellington and grown for 7-8 months before it was uprooted. Take percentages, root and shoot mass, as well as the incidence of Botryosphaeria, Cylindrocarpon, Phomopsis, Phaeomoniella + Phaeoacremonium spp., total pathogen and Trichoderma in graft unions and basal ends of rootstocks of uprooted vines were determined.
Take percentages for most treatments did not differ significantly. None of the treatments impacted negatively on vine growth. Benomyl, Sporekill, captan and bronocide were consistently most effective in reducing the incidence of pathogens in the graft union and in the basal end of the rootstock. Bronocide did, however, cause a reduction in take percentage. Trichoflow, chinosol and Bio-sterilizer were not as effective and marginal to no reductions were observed. Significantly more Petri disease causing pathogens were isolated from the graft unions of cold callus vines, compared to the hot callus vines. This might be attributed to the bigger grafting wounds (hand grafted vs. Omega bench grafted), and might also indicate that these pathogens infect graft union wounds during the propagation process.
By isolating important trunk disease causing pathogens from the graft unions and basal ends of rootstocks of certified nursery vines, this study has clearly showed that sanitation practices during the propagation process is of utmost importance. Benomyl, Sporekill and captan provided the best protection against trunk disease pathogens. However, integrated treatment strategies with environmentally safe products should be considered in order to comply with environmental laws.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

P.H. Fourie (1) and F Halleen (2)

(1) Department of Plant Pathology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
(2) Disease Management, ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa

Contact the author

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Interaction among grapevine cultivars (Sangiovese, Cabernet-Sauvignon and Merlot) and site of cultivation in Bolgheri (Tuscany)

Different “landscape unit” have been identified in Bolgheri area (a viticultural appellation in the Tirrenian coast of Tuscany) by the aid of pedological, landscape and agronomic observations in the 1992-1993 period. In all cultivar (Sangiovese, Cabernet Sauvignon and Merlot) x landscape unit combinations, experimental plots were chosen in homogeneous vineyards, single cordon trained (about 3300-4500 vines/hectare). Grape maturation was studied by weekly samples of berries from veraison to vintage in the 1992-1995 period. At harvest yield and must composition traits were measured and, from the most représentative plots, sixty kilograms of grapes were harvested each year and vinified according to a standardised scheme. Wines were evaluated by standard chemical and sensory analyses.

Anthocyanin profile is differentially affected by high temperature, elevated CO2 and water deficit in Tempranillo (Vitis vinifera L.) clones

Anthocyanin potential of grape berries is an important quality factor in wine production. Anthocyanin concentration and profile differ among varieties but it also depends on the environmental conditions, which are expected to be greatly modified by climate change in the future. These modifications may significantly modify the biochemical composition of berries at harvest, and thus wine typicity. Among the diverse approaches proposed to reduce the potential negative effects that climate change may have on grape quality, genetic diversity among clones can represent a source of potential candidates to select better adapted plant material for future climatic conditions. The effects of individual and combined factors associated to climate change (increase of temperature, rise of air CO2 concentration and water deficit) on the anthocyanin profile of different clones of Tempranillo that differ in the length of their reproductive cycle were studied. The aim was to highlight those clones more adapted to maintain specific Tempranillo typicity in the future. Fruit-bearing cuttings were grown in controlled conditions under two temperatures (ambient temperature versus ambient temperature + 4ºC), two CO2 levels (400 ppm versus 700 ppm) and two water regimes (well-watered versus water deficit), both in combination or independently, in order to simulate future climate change scenarios. Elevated temperature increased anthocyanin acylation, whereas elevated CO2 and water deficit favoured the accumulation of malvidin derivatives, as well as the acylation and tri-hydroxylation level of anthocyanins. Although the changes in anthocyanin profile observed followed a common pattern among clones, such impact of environmental conditions was especially noticeable in one of the most widely distributed Tempranillo clones, the accession RJ43.

INVESTIGATION OF FILM COATINGS AS A PROTECTIVE LAYER IN REDUCING THE ABSORPTION OF SMOKE PHENOLS INTO PINOT NOIR GRAPES

Wine grapes exposed to wildfire smoke have resulted in wines with burnt and ashy sensory characteristics¹, that are undesirable qualities in wine. In extreme wildfire events, this can lead to total loss of grape crop. Currently there are no effective solutions in the market to prevent the uptake of smoke compounds into grapes. In this study, previously developed innovative film coatings were tested to analyze their effectiveness in reducing smoke phenol absorption². Four different cellulose nanofiber-based film types were investigated.

Effect of multi-level and multi-scale spectral data source on vineyard state assessment

Currently, the main goal of agriculture is to promote the resilience of agricultural systems in a sustainable way through the improvement of use efficiency of farm resources, increasing crop yield and quality under climate change conditions. This last is expected to drastically modify plant growth, with possible negative effects, especially in arid and semi-arid regions of Europe on the viticultural sector. In this context, the monitoring of spatial behavior of grapevine during the growing season represents an opportunity to improve the plant management, winegrowers’ incomes, and to preserve the environmental health, but it has additional costs for the farmer. Nowadays, UAS equipped with a VIS-NIR multispectral camera (blue, green, red, red-edge, and NIR) represents a good and relatively cheap solution to assess plant status spatial information (by means of a limited set of spectral vegetation indices), representing important support in precision agriculture management during the growing season. While differences between UAS-based multispectral imagery and point-based spectroscopy are well discussed in the literature, their impact on plant status estimation by vegetation indices is not completely investigated in depth. The aim of this study was to assess the performance level of UAS-based multispectral (5 bands across 450-800nm spectral region with a spatial resolution of 5cm) imagery, reconstructed high-resolution satellite (Sentinel-2A) multispectral imagery (13 bands across 400-2500 nm with spatial resolution of <2 m) through Convolutional Neural Network (CNN) approach, and point-based field spectroscopy (collecting 600 wavelengths across 400-1000 nm spectral region with a surface footprint of 1-2 cm) in a plant status estimation application, and then, using Bayesian regularization artificial neural network for leaf chlorophyll content (LCC) and plant water status (LWP) prediction. The test site is a Greco vineyard of southern Italy, where detailed and precise records on soil and atmosphere systems, in-vivo plant monitoring of eco-physiological parameters have been conducted.

Uncovering the interplay between Copper and SO2 tolerance in Saccharomyces cerevisiae

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...