the Mâconnais village of Clessé and sometimes confused with the 'Dijon-166' clone planted in South Africa, which yields Muscat-like aromas. In the 1930s, Chardonnay was crossed with a Seibel grape to create the hybrid grape Ravat blanc. Viticulture Chardonnay has a wide-ranging reputation for relative ease of cultivation and ability to adapt to different conditions. The grape is very "malleable", in that it reflects and takes on the impression of its terroir and winemaker. It is a highly vigorous vine, with extensive leaf cover which can inhibit the energy and nutrient uptake of its grape clusters. Vineyard managers counteract this with aggressive pruning and canopy management. When Chardonnay vines are planted densely, they are forced to compete for resources and funnel energy into their grape clusters. In certain conditions, the vines can be very high-yielding, but the wine produced from such vines suffers a drop in quality if yields go much beyond 80 hl/ha (4.5 tons per acre). Producers of premium Chardonnay limit yields to less than half this amount. Sparkling wine producers tend not to focus as much on limiting yields, since concentrated flavors are not as important as the wine's finesse. Harvesting time is crucial to winemaking, with the grape rapidly losing acidity as soon as it ripens. Some viticultural hazards include the risk of damage from springtime frost, as Chardonnay is an early-budding vine – usually a week after Pinot noir. To combat the threat of frost, a method developed in Burgundy involves aggressive pruning just prior to budburst. This "shocks" the vine and delays budburst up to two weeks, which is often long enough for warmer weather to arrive. Millerandage and coulure can also pose problems, along with powdery mildew attacking the thin skin of the grapes. Because of Chardonnay's early ripening, it can thrive in wine regions with short growing seasons, and in regions such as Burgundy, can be harvested before autumn rain sets in and brings the threat of rot. While Chardonnay can adapt to almost all vineyard soils, the three it seems to like most are chalk, clay, and limestone, all very prevalent throughout Chardonnay's traditional "homeland". The Grand crus of Chablis are planted on hillsides composed of Kimmeridgian marl, limestone, and chalk. The outlying regions, falling under the more basic "Petit Chablis" appellation, are planted on portlandian limestone which produces wines with less finesse. Chalk beds are found throughout the Champagne region,