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. Crop nutrition is an important factor influencing bunch Stem Necrosis in table grape.

Crop Nutrition and Bunch Stem Necrosis in Table Grapes

Nitrogen 

Too much nitrogen causes excessive vigor which again causes primary bud-axis necrosis, restricting table grape yields. Over-use of nitrogen has been implicated in the physiological disorder, bunch stem necrosis.

Magnesium

Magnesium deficiency is also associated with bunch stem necrosis. The disorder affects table grape fruit set and fruit ripening. 2-3 foliar applications of magnesium starting just before veraison minimizes the problem. Bunch stem necrosis is also linked to an imbalance of magnesium with potassium and nitrogen. 

Research suggests that low levels of sugars in storage organs and table grape fruit lead to nitrogen accumulation, particularly during cold weather at maturation. In this situation, magnesium sprays can help reduce bunch stem necrosis.

In a similar fashion , a foliar spray with magnesium helps correct the imbalance of too much Potassium-uptake again preventing bunch stem necrosis. However, while foliar sprays can help, long-term magnesium shortages should be corrected using soil applied or fertigated magnesium fertilizer in a standard maintenance programme.

Related articles

Increasing the Number of Bunch/Berry Weight in Table Grape

Increasing the Number of Bunch/Berry Weight in Table Grape

In order to influence the production of higher table grape yields the farmer will need to control the number of grape bunches and grape berry weight.
Influencing Table Grape Size and Shape

Influencing Table Grape Size and Shape

Physical or chemical crop manipulation is important to ensure an even berry size and consistent maturity in order to meet the markets requirements. The use of the growth hormone Gibberellic acid (GA) at flowering can reduce table grape berry set by around...
Influencing Table Grape Color

Influencing Table Grape Color

Most consumers seek a large, evenly sized grape bunch of consistent appearance.
Improving Storage Quality of Table Grapes

Improving Storage Quality of Table Grapes

It is important to prevent deterioration of fruit quality after harvesting and assure long shelf life of the crop.

See all table grape nutrition advice