Vegetative wine aromas generally reduce quality in red and white wines.  Methoxypyrazines (MP) are a class of chemicals produced in the fruit that are responsible for some of the vegetative aromas in wine.  Producers understand the importance of adjusting the vineyard for appropriate crop levels and fruit temperature to reduce MPs.  In some years however, fruit will reach maturity according to sugar and acid levels but remain high in MPs despite the growers efforts to reduce them using current management techniques.

High MP levels are consistent with vigorous vineyards, unbalanced vines, heavy crop loads and immature fruit.  Adjusting canopy structure to manipulate light penetration into the canopy and the use of vigour reduction techniques can reduce MP content.  High vigour and crop load are often associated with high nitrogen and water availability.  The role of nitrogen fertilization and irrigation strategies in the early development of MPs has not been investigated.