葡萄酒社

World of Wine——Vineyard management practices

DR CASSANDRA CLARE:
 


Vineyard management practices are directed primarily toward obtaining the maximum fruit yield of the desired quality.
 These practices modify the light and temperature conditions in the canopy either directly or indirectly.
 Examples of practices such as pruning, leaf removal in the bunch zone, shoot thinning, irrigation, and shoot positioning in combination with the trellis system.
 To discuss vine management, it is necessary to define several commonly used terms.
 For example, training refers to the development of a permanent vine structure and the location of renewal wood.
 This is done to ensure that shoot and hence, fruit growth occurs in the desired locations of the vine framework.
 Training is usually associated with a support, such as a trellis.
 It takes into consideration environmental factors, such as climate and soil, harvest practices, in particular, if fruit is harvested mechanically, and the fruit characteristics of the vine.
 The development of training systems, based partially on achieving an optimal ratio between vegetative growth -- so that's the shoots and leaves, etc -- and reproductive growth, which is the bunches and berries, is one of the success stories in modern viticulture.
 Examples of this include the vertical shoot position trellis, Geneva double curtain, the Scott Henry and Smart-Dyson trellises, and the Lyre trellis.
 These training systems, in addition to achieving an optimal growth ratio, provide better fruit exposure to light and air, resulting in good berry colour, flavour development, less disease, and better inflorescence initiation for future seasons.
 Pruning is a big part of our management strategy in the vineyard.
 It is defined as the partial selective removal of canes, shoots, wood, and leaves, or the severing of roots to obtain the goals of training and canopy management.
 However, pruning most commonly refers to the removal of excessive growth before the beginning of the next season.
 This type of pruning is conducted when the vine is dormant in winter, and the absence of foliage makes it easier to select the parts of the vine to be removed for a particular training system, and/or to regulate the crop.
 Pruning allows the selection of bearing wood, so spurs and canes, and thereby influences the location and development of canopy growth.
 This, in turn, can affect grape yield, health, and maturation, as well as pruning and harvesting costs.
 Later in the course, we will describe the different types of pruning systems we use in the vineyard.
 Canopy management is generally viewed as positioning and maintaining growing shoots and their fruit in a microclimate that is optimal for grape quality, inflorescence initiation, and cane maturation.
 Controlling shoot vigour is an important aspect of canopy management, and there's a number of canopy management practices used in the vineyard.
 An example is what we call leaf removal, which is used in many vineyards around the world to modify bunch microclimate.
 Leaf removal has an impact on berry and wine composition, and the resultant wine style as it improves cane and fruit exposure to light and air.
 As a consequence, the canopy is more open, which can mean better spray penetration when applying things like fungicides to control diseases.
 One limitation of using leaf removal is that in some vineyards, it can increase the risk of heat damage and sunburn.
 For this reason, leaf removal is more common in vineyards growing in cooler climates.
 Another commonly used practice is shoot thinning.
 Shoots are often removed in situations where two shoots have burst from a single bud or when shoots have burst from basal buds.
 This can result in a very dense canopy with excessive leaf and bunch shading.
 Shoot thinning normally results in some yield loss, because bunches are lost when shoots are removed, but to manage this, we try to selectively remove shoots when the shoots are long enough that the inflorescences are clearly visible.
 Bunch thinning in vineyards is also performed if the fruit yield appears excessive.
 This practice can be done early in the season before flowering or later in the season.
 When it's performed around veraison, there is some evidence that it may increase the uniformity of berry composition by selectively removing fruit that's undesirable.
 Many of the practices that we use in the vineyard are aimed at improving vine balance.
 We define vine balance as the equilibrium between vegetative vigour, root growth, and fruit load, which is consistent with high quality fruit of a targeted style.
 To assess vine balance, the two most common ways are to look at the ratio between the yield and pruning weight or the ratio of leaf area to the fruit yield.
 It is also believed that these ratios give an indicator of vine balance that has a direct relationship to wine quality.
 However, the routine measurement of these ratios has been limited by the absence of a rapid and simple measure of leaf area and pruning weight.
 Recently, our research team at the University of Adelaide has developed a mobile application that uses image analysis to estimate leaf area index, and is currently working on a similar application to estimate pruning weight.
 The first app is called LAI Canopy, and is available for use on Apple products.
 As you can see, we use many different management approaches in the vineyard to improve and achieve vine performance to obtain our desired wine quality.
 
已邀请:

要回复帖子请先登录注册