Minimising blossom end rot (BER) in melon

Blossom end rot (BER) is a physiological disorder in melon fruits.

As a result of blossom end rot, young melon fruit may be lost. Older fruit develop brown crust-like lesions at the blossom end of the fruit.

Crop Nutrition and Blossom End Rot in Melon

Calcium has a major role to play in maximizing fruit quality by strengthening rind cell walls and maintaining good fruit condition, shape and storage characteristics. It also plays a major role in minimising Blossom End Rot (BER).

Blossom end rot is often caused by lack of calcium in the flower-end of the fruit. Low calcium levels in the fruits can result in a significant loss in marketable yield.

Calcium and Blossom End Rot Watermelon
Calcium and Blossom End Rot Watermelon
Calcium and Nitrogen Type

A cationic competition, as a result of over-use of ammonium as the main source of nitrogen, significantly increases the incidence of BER. Trials confirm that calcium nitrate is particularly effective at ensuring good fruit quality, also in minimizing blossom end rot.

One of the most common inducing factors for blossom end rot is water stress, either due to a deficiency or excess. Under high humidity conditions, transpiration slows and uptake of calcium – which is solely transported within the transpiration stream – is limited. Thus, calcium management and supply is key.