Foliar urea (low biuret) after fruit set, in low nitrogen regime can be used to improve table grape colour. However, too much nitrogen can reduce colour. This can be minimised by leaf pruning just after veraison.
Influencing Table Grape Colour
Most consumers seek a large, evenly sized grape bunch of consistent appearance. Colour is important, with green, red or black grapes favoured over those of more intermediate colours. The correct crop nutrition will also affect table grape colour.
Crop Nutrition and Table Grape Colour
Potassium
Potassium plays the central role during transportation of photosynthetic products to support growth and development processes. It is common field practice to use potassium to improve table grape skin colour. High potassium on the other side will reduce skin colour, so balanced nutrition is important.
Iron
Related articles
Increasing Table Grape Yield
High yield of table grape is obtained on the most freely drained soils where nutrients and water are sufficiently available. Table grape grows across a wide range of soils, from sands to clays, that can be of high or low fertility.
Influencing Table Grape Quality
Table grape quality standards vary between countries. Many have been established as a result of local preference, taste and tradition. Maintaining high sugars and a juicy berry by manipulating the time of maturity is important for marketability.
Influencing Table Grape Health
Deficiency of any essential nutrient can hinder growth and development of a crop. Well-nourished crops are generally more tolerant of diseases compared with sub-optimally nourished crops.
Preventing Bunch Stem Necrosis in Table Grapes
Bunch stem necrosis is a disorder known under many different names. It can occur around flowering or at veraison, sometimes even later in the season.
