​Citrus rind pitting is a rind disorder in grapefruit and oranges. The symptoms occur post-harvest and appear as sunken spots on the rind about 0.3 to m0.6cm in diameter. The disorder is responsible for heavy crop losses. In some seasons large amounts of export fruit are rejected at the ports for rind pitting.

Research conducted by the Post-harvest unit of the ARC-ITSC have clearly shown that over-fertilizing with nitrogen is the most common cause of rind pitting in grapefruit on certain farms in the Mpumalanga area. A subsequent survey further suggested that overfertilizing with nitrogen is a major cause of deep rind pitting in Midknight Oranges. Queries from various other areas regarding this aspect have further served to enforce our opinion regarding this aspect.

In spite of the above, considerable superficial rind pitting still occurs each year in correctly over-fertilized Valencia oranges, especially, in the Benny Valencia variety. Ironically, surveys conducted strongly suggested that nitrogen deficiency during the second half of the growing season contributes towards the problem, particularly in sandy soils.

In this study, we attempt to reduce the incidence of rind pitting in Benny Valencia oranges by applying small rates of nitrogen towards the end of the season. 

Contact Email: infoitsc@arc.agric.za