WINETECH Technical Yearbook 2019

CONTENTS

Detection and quantification of black foot disease and crown and root rot pathogens in grapevine nurseries.......................................35 Know your seed for cover crop purposes.....38 What was the impact of the 2017-18 drought? – a case study using FruitLook data. ..............................................40 Rugose wood diseases and associated viruses............................................................45 OENOLOGY Organic yeast nutrients and Chardonnay aroma........................................50 Benchmarking of commercial tannins and mannoproteins.......................................53 Big Data and YAN analysis – new developments in A South African context. ...55 Chitin, chitinase, chitosan…. .........................58 Amino acids in South African grape musts (Part 1): Composition and profiles................61

Amino acids in South African grape musts (Part 2): Cultivar classification.......................64 Accumulation of volatile phenol glycoconjugates in grapes after bushfires.....67 Rapid and cost-effective quantification of YAN concentration and composition – vintage and cultivar effect.............................69 Thiol-releasing and low VA-forming hybrid wine yeasts.........................................72 Pectinases improve consistency in winemaking...................................................75 Pectin-lyase – the key wine enzyme?. ..........77 Mixed culture fermentations and Shiraz flavour.................................................79 Nitrogen and sulphur foliar fertilisation (Part 1): Background and context.................82 Nitrogen and sulphur foliar fertilisation (Part 2)...........................................................86 Nitrogen and sulphur foliar fertilisation (Part 3)...........................................................90

VITICULTURE Lessons to be learned from Israel’s

desert agriculture............................................7 Water footprint of grapes and wine. ............10 Strategy for the control of mealybug in South African vineyards and wine.................12 Detection and classification of grapevine stem pitting-associated virus. .......................14 A new era for wine grape yield estimation...17 Management and re-use of treated winery wastewater (Part 1): New Zealand wineries...................................20 Management and re-use of treated winery wastewater (Part 2): Dairy and municipal wastewaters in New Zealand........24 Management and re-use of treated winery wastewater (Part 3): Adelaide, Australia.........................................28 TerraClim – online terrain and climate spatial decision support systems. .................31

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