Millerandage (or shot berries, hens and chicks and pumpkins and peas) is a potential viticultural hazard in which grape bunches contain berries that differ greatly in size and, most importantly, maturity. Its most common cause is cold, rainy or otherwise bad weather during the flowering stage of the vines though other factors, such as boron deficiency or fanleaf degeneration, may also play a role. [1]
While millerandage always causes a drop in yield, its impact on wine quality varies, particularly by grape variety. For some varieties that are prone to uneven ripeness within a cluster, such as Sangiovese, Zinfandel and Gewürztraminer, the development of millerandage may be unfavorable due to "green flavors" from the potentially unripe grapes hidden within the cluster. For other varieties, such as Pinot noir or the Mendoza clone of Chardonnay, wine quality could be improved due to the reduced overall berry size and higher skin to juice ratio. [1]
The root cause of millerandage is the poor fertilization of grape flowers during the growing season. While this is most often attributed to bad weather, other factors such as nutritional deficiencies (particularly of the mineral boron which is needed to synthesis the growth hormone auxin and facilitate the movement of sugars in the vine) or viral infections can play a role. [1]
For grapevines, flowering occurs usually 8 weeks after the beginning of bud break when the mean daily temperatures hit around 20 °C (68 °F). Usually flowering begins at the base of the inflorescence (cluster of flowers) and moves its way to the top. Following the apical dominance of grape vines, the uppermost shoots of the vine will begin flowering first with complete blooming taking place over 7 to 10 days. Ideally the temperature and weather condition for this period should be warm, sunny and dry to insure optimal flowering. For some varieties, such as Zinfandel and Merlot, flowering may be more staggered which poses a greater risk for inclement weather disrupting the process and encouraging millerandage. Some growers may try to encourage more synchronized flowering with the use of chemical treatments, such as cyanamide. [2]
Following flowering, the flowers of the grape vine go through pollination and fertilization over the next 2 to 3 days. Here is another opportunity where incremental weather can influence the outcome with temperature drops below 10 °C (50 °F) potentially damaging the ovules of the flowers before they can be fertilized. Since grapevines are hermaphroditic (containing both male and female parts) and usually rely on self-pollination, the presence of wind to circulate pollen or insects usually doesn't influence the success or failure of the pollination stage. [2] While not as influential as temperature, the presence of rain can "wash off" the pollen from the stigma or greatly dilute the stigmatic fluid, causing the pollen to absorb too much water, swelling and bursting before it reaches the ovules. [3]
Even in the most ideal conditions, usually only 20–30% of flowers develop into mature fruit with fully developed seeds and auxin production. [2] If even fewer berries develop, the condition of coulure emerges while for developed berries, the number of seeds (or their absence) will influence the resulting size of the berries. Millerandge most often occurs when the partially fertilized grapes do not develop any seeds, leaving small (and potentially immature) berries present in a cluster of larger, otherwise mature berries. [1]
While millerandage will always have an economic impact in reduced harvest yields, it may not always have a negative impact on the resulting quality of the wine. In some areas, such as the New World wine regions of Australia, California and New Zealand, the presence of millerandage in the a vineyard can be seen as a positive quality for a vintage due to the reduced average berry-size. [1] Some growers will even use chemical sprays to deliberately encourage millerandage. [4]
However, the small, seedless berries may never fully ripen and stay hard and green (with high acid) throughout the growing season. Some growers may choose to remove clusters with high preponderance of millerandge through green harvesting or choose to harvest the entirety of the crop later at higher ripeness levels to balance the high acid and potentially "green flavors" of the shot berries. Other growers will remove the grape post-harvest at a sorting table along with other MOG. [5]
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
A vineyard is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes, and non-alcoholic grape juice. The science, practice and study of vineyard production is known as viticulture. Vineyards are often characterised by their terroir, a French term loosely translating as "a sense of place" that refers to the specific geographical and geological characteristics of grapevine plantations, which may be imparted to the wine itself.
Zinfandel is a variety of black-skinned wine grape. The variety is grown in over 10 percent of California vineyards. DNA analysis has revealed that it is genetically equivalent to the Croatian grapes Crljenak Kaštelanski and Tribidrag, as well as to the Primitivo variety traditionally grown in Apulia, Italy, where it was introduced in the 18th century, and Kratošija in Montenegro. The grape found its way to the United States in the mid-19th century, where it became known by variations of a name applied to a different grape, likely "Zierfandler" from Austria.
Viticulture, viniculture, or winegrowing is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of Vitis vinifera, the common grape vine, ranges from Western Europe to the Persian shores of the Caspian Sea, the vine has demonstrated high levels of adaptability to new environments, hence viticulture can be found on every continent except Antarctica.
Durif is a variety of red wine grape primarily grown in Australia, California, France, and Israel. Since the end of the 20th century, wineries located in Washington's Yakima River Valley, Maryland, Arizona, Texas, West Virginia, Chile, Mexico's Baja California Peninsula, and Ontario's Niagara Peninsula have also produced wines from Durif grapes. It is the main grape known in the U.S. and Israel as Petite Sirah, with over 90% of the California plantings labeled "Petite Sirah" being Durif grapes; the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) recognizes "Durif" and "Petite Sirah" as synonyms for the same grape. It produces tannic wines with a spicy, plummy flavour. The grape originated as a cross of Syrah pollen germinating a Peloursin plant. On some occasions, Peloursin and Syrah vines may be called Petite Sirah, usually because the varieties are extremely difficult to distinguish in old age.
Mourvèdre is a red wine grape variety grown in many regions around the world including the Rhône and Provence regions of France, the Valencia and Jumilla, Bullas and Yecla denominaciones de origen (DOs) of Spain, as well as the Balearic Islands, California and Washington and the Australian regions of South Australia and New South Wales, plus South Africa. In addition to making red varietal wines, Mourvèdre is a prominent component in "GSM" blends. The variety is also used to make rosé and port-style fortified wines.
Agiorgitiko is a red Greek wine grape variety that, as of 2012, was the most widely planted red grape variety in Greece, ahead of Xynomavro. The grape has traditionally been grown in the Nemea region of the Peloponnese but can be found throughout the country including Attikí (Attica) and Makedonía (Macedonia).
Schisandra chinensis, whose fruit is called magnolia berry or five-flavor fruit, is a vine plant native to forests of Northern China, the Russian Far East and Korea. Wild varieties are also found in Japan. It is hardy in USDA Zone 4. The fruits are red berries in dense clusters around 10 centimetres (3.9 in) long.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.
Coulure is a viticultural hazard that is the result of metabolic reactions to weather conditions that causes a failure of grapes to develop after flowering. In English the word shatter is sometimes used. Coulure is triggered by periods of cold, cloudy, rainy weather or very high out-of-season temperatures. The condition is most often manifested in the spring. It also occurs in vines that have little sugar content in their tissue. Flowers stay closed and are not fertilized. Thus the vines are not pollinated as the grape fails to develop and falls off. Coulure can also cause irregular bunches of grapes which are less compact than normal. These bunches are more sensitive to developing various grape diseases. The yield of a vine with coulure will decrease substantially. Grape varieties with high proclivity to coulure are Grenache, Malbec, Merlot, and Muscat Ottonel. Other causes of coulure may be vineyard conditions and practices, pruning too early or too severely, excessively fertile soils or overuse of fertilizers, and improper selection of rootstocks or clones.
The annual growth cycle of grapevines is the process that takes place in the vineyard each year, beginning with bud break in the spring and culminating in leaf fall in autumn followed by winter dormancy. From a winemaking perspective, each step in the process plays a vital role in the development of grapes with ideal characteristics for making wine. Viticulturalists and vineyard managers monitor the effect of climate, vine disease and pests in facilitating or impeding the vine's progression from bud break, flowering, fruit set, veraison, harvesting, leaf fall and dormancy – reacting if need be with the use of viticultural practices like canopy management, irrigation, vine training and the use of agrochemicals. The stages of the annual growth cycle usually become observable within the first year of a vine's life. The amount of time spent at each stage of the growth cycle depends on a number of factors – most notably the type of climate and the characteristics of the grape variety.
In viticulture, the canopy of a grapevine includes the parts of the vine visible aboveground - the trunk, cordon, stems, leaves, flowers, and fruit. The canopy plays a key role in light energy capture via photosynthesis, water use as regulated by transpiration, and microclimate of ripening grapes. Canopy management is an important aspect of viticulture due to its effect on grape yields, quality, vigor, and the prevention of grape diseases. Various viticulture problems, such as uneven grape ripening, sunburn, and frost damage, can be addressed by skillful canopy management. In addition to pruning and leaf trim, the canopy is often trained on trellis systems to guide its growth and assist in access for ongoing management and harvest.
This glossary of viticultural terms list some of terms and definitions involved in growing grapes for use in winemaking.
In viticulture, ripeness is the completion of the ripening process of wine grapes on the vine which signals the beginning of harvest. What exactly constitutes ripeness will vary depending on what style of wine is being produced and what the winemaker and viticulturist personally believe constitutes ripeness. Once the grapes are harvested, the physical and chemical components of the grape which will influence a wine's quality are essentially set so determining the optimal moment of ripeness for harvest may be considered the most crucial decision in winemaking.
Irrigation in viticulture is the process of applying extra water in the cultivation of grapevines. It is considered both controversial and essential to wine production. In the physiology of the grapevine, the amount of available water affects photosynthesis and hence growth, as well as the development of grape berries. While climate and humidity play important roles, a typical grape vine needs 25-35 inches of water a year, occurring during the spring and summer months of the growing season, to avoid stress. A vine that does not receive the necessary amount of water will have its growth altered in a number of ways; some effects of water stress are considered desirable by wine grape growers.
The use of vine training systems in viticulture is aimed primarily to assist in canopy management with finding the balance in enough foliage to facilitate photosynthesis without excessive shading that could impede grape ripening or promote grape diseases. Additional benefits of utilizing particular training systems could be to control potential yields and to facilitate mechanization of certain vineyard tasks such as pruning, irrigation, applying pesticide or fertilizing sprays as well as harvesting the grapes.
Cascade is a red complex hybrid grape variety that was created by French viticulturist Albert Seibel in the early 20th century in Aubenas, Ardèche, in the Rhône Valley. It has been commercially available in North America since 1938 and has since been planted in Canada and the United States. However, in warmer climates, the grape is highly susceptible to a number of grapevine viruses, which has discouraged plantings of the variety.
Cabernet blanc is a white German and Swiss wine grape variety that is a crossing of the French wine grape Cabernet Sauvignon and the hybrid grape Regent. The grape was bred by Swiss grape breeder Valentin Blattner in 1991. Cabernet blanc has strong resistance to most grape disease including botrytis bunch rot, downy and powdery mildew and tends to produce loose clusters of small, thick-skinned grape berries which can hang on the vine late into the harvest season to produce dessert wines. Today the grape is found primarily in the Palatinate wine region of Germany with some experimental plantings in Spain and the Netherlands. In France, in the Languedoc, Domaine La Colombette is heavily investing in PIWI grapes. Amongst others the Cabernet Blanc in their cuvée "Au Creux du Nid", is gaining wide acclaim.
The propagation of grapevines is an important consideration in commercial viticulture and winemaking. Grapevines, most of which belong to the Vitis vinifera family, produce one crop of fruit each growing season with a limited life span for individual vines. While some centenarian old vine examples of grape varieties exist, most grapevines are between the ages of 10 and 30 years. As vineyard owners seek to replant their vines, a number of techniques are available which may include planting a new cutting that has been selected by either clonal or mass (massal) selection. Vines can also be propagated by grafting a new plant vine upon existing rootstock or by layering one of the canes of an existing vine into the ground next to the vine and severing the connection when the new vine develops its own root system.
In viticulture, the grape cluster is a fertilized inflorescence of the grapevine, the only part of this plant used for food.