They occur as a result of environmental and growth stresses, including nutrition deficiencies. It is most common in watermelon, early on in the season, when conditions quickly alternate between wet and dry, or cold and warm.
Too much nitrogen and excessive moisture during fruit set can encourage hollow heart and lead to a melon with a bland taste. Hollow and white heart, can be minimized by ensuring optimum nutrition and soil moisture management.
Phosphorus is important during flower formation to increase fruit set. It also helps produce thicker skins with well-developed netting. Foliar phosphate can reduce hollow-heart.
Foliar phosphate can reduce melon fruit hollow-heart and white heart. The use of foliar phosphorus prior to harvest has been shown to reduce the incidence of hollow heart in watermelon.
Poor calcium nutrition in melons can also result in hollow heart and white heart. Fruits are distorted with a poor skin finish. Hollow heart is more common when there is a lack of calcium in the plant.
Trials confirm that calcium nitrate is particularly effective at ensuring good fruit quality, also hollow and white heart.
