GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Assessing bunch architecture for grapevine yield forecasting by image analysis 

Assessing bunch architecture for grapevine yield forecasting by image analysis 

Abstract

Context and purpose of the study – It is fundamental for wineries to know the potential yield of their vineyards as soon as possible for future planning of winery logistics. As such, non-invasive image-based methods are being investigated for early yield prediction. Many of these techniques have limitations that make it difficult to implement for practical use commercially. The aim of this study was to assess whether yield can be estimated using images taken in-field with a smartphone at different phenological stages. The accuracy of the method for predicting bunch weight at different phenological stages was assessed for seven different varieties.

Material and methods – During the 2017-18 growing season in the Coombe Vineyard at the Waite Campus of the University of Adelaide seven different varieties were chosen for this study: Semillon, Grenache, Shiraz, Merlot, Sauvignon Blanc, Tempranillo and Cabernet Franc. After fruitset, 30 vines per variety were selected and two shoots were flagged on each vine. Images of bunches were taken five times from EL stage 30-31 to EL stage 37-38 using a smartphone. Bunch volumes were estimated from images. At harvest bunches were collected, weighed and imaged in the laboratory to compare with field images.

Results – This new approach using a smartphone to forecast the yield showed promising results. Accurate weight forecast models could be obtained by taking bunch images at veraison (R2 ranging from 0.71 to 0.84). As the bunch architecture of different varieties can vary further studies are required to improve the accuracy of this method. The tools used for this study are inexpensive, in common use, and do not need a high level of expertise to use them, furthermore, the labour required to obtain data, is not time-consuming.

DOI:

Publication date: September 28, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Marco ZITO*1, Massimiliano COCCO2, Roberta DE BEI3, Cassandra COLLINS3

1 Istituto di Scienze della Vita, Scuola Superiore Sant’Anna, Pisa, Italy 56127
2 Dipartimento di Agraria, Università degli Studi di Sassari, Sassari, Italy 07100
3 School of Agriculture, Food and Wine, Waite Research Precinct, The University of Adelaide, PMB I, Glen Osmond, SA 5064, Australia

Contact the author

Keywords

bunch architecture, yield prediction, image analysis, non-destructive method

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Exploring microbial interactions between Saccharomyces cerevisiae and non-Saccharomyces yeast starters in vinification

Winemaking is a complex microbial process involving the co-existence and interactions of various microorganisms [1].

Extreme vintages affect grape varieties differently: a case study from a cool climate wine region

Eger wine region is located on the northern border of grapevine cultivation zone. In the cool climate, terroir selection is one of the foundations of quality wine making. However, climate change will have a significant impact on these high value-added vineyards. This study presents a case study from 2021 and 2022 with the investigation of three grape varieties (Kadarka, Syrah, Furmint). The experiment was conducted in a steep-sloped vineyard (Nagy-Eged hill) with a southern exposure.

Contribution of phenolic compounds to the total antioxidant capacity of Pinotage wine

The South African wine industry is taking an interest in the enhancement of red wine total antioxidant capacity (TAC) with retention of sensory quality to satisfy the demands of increasingly discerning consumers. The focus is especially on the unique South African red wine cultivar, Pinotage.

20-Year-Old data set: scion x rootstock x climate, relationships. Effects on phenology and sugar dynamics

Global warming is one of the biggest environmental, social, and economic threats. In the Douro Valley, change to the climate are expected in the coming years, namely an increase in average temperature and a decrease in annual precipitation. Since vine cultivation is extremely vulnerable and influenced by the climate, these changes are likely to have negative effects on the production and quality of wine.
Adaptation is a major challenge facing the viticulture sector where the choice of plant material plays an important role, particularly the rootstock as it is a driver for adaptation with a wide range of effects, the most important being phylloxera, nematode and salt, tolerance to drought and a complex set of interactions in the grafted plant.
In an experimental vineyard, established in the Douro Region in 1997, with four randomized blocs, with five varieties, Touriga Nacional, Tinta Barroca, Touriga Franca and Tinta Roriz, grafted in four rootstocks, Rupestris du Lot, R110, 196-17C, R99 and 1103P, data was collected consecutively over 20 years (2001-2020). Phenological observations were made two to three times a week, following established criteria, to determine the average dates of budbreak, flowering and veraison. During maturation, weekly berry samples were taken to study the dynamics of sugar accumulation, amongst other parameters. Climate data was collected from a weather station located near the vineyard parcel, with data classified through several climatic indices.
The results achieved show a very low coefficient of variations in the average date of the phenophases and an important contribution from the rootstock in the dynamic of the phenology, allowing a delay in the cycle of up to10-12 days for the different combinations. The Principal Component Analysis performed, evaluating trends in the physical-chemical parameters, highlighted the effect of the climate and rootstock on fruit quality by grape varieties.

Soils, climate, nutritive status and production of cv “Palomino fino” in the superior quality area of the Jerez-Xérès-Sherry zone

The Registered Appellation of Origin Mark (RAOM) « Jerez-Xérès-Sherry and Manzanilla Sanlucar de Barrameda » is one of the oldest and more important zone in wine history and production. «Albarizas» unit (white calcareous marls with sea-fossils) is the most representative geological material of the RAOM (75%) and even more in the central-NW area of the RAOM, known as «Jerez Superior» area (Superior Quality Sherry Area). « Albarizas » form undulated hillocks (3-10% slope) and hills (>10% slope), the litologic unit has E-W and S-W direction, and Regosols and Leptosols are the principal soils.