Jakkie Stander
Citrus Research International (CRI)
Citrus orchards are experiencing an intense blossom period, especially in the cooler production regions in the Eastern and Western Cape. Producers are reminded of the importance of the following cultural practices to manipulate the crop to ensure acceptable fruit size and quality.
The period during and immediately after flowering (September to December) is the cell division stage of fruit development. It is the period in which most cells of the fruit are formed. Flowers and fruit are particularly sensitive to water stress, carbohydrate depletion, and mineral nutrient deficiency during this period.
The tree needs water, light energy and CO2 to synthesize sugars, which are used in the growth of the roots, shoots, flowers and fruitlets. In the process, sunlight drives water transport through the plant, which carries all the soil-applied mineral nutrients to where they are required. Any water stress, lack of sunlight, or mineral nutrient stress will negatively affect the cell division period, the fruit yield, and most of the fruit quality attributes, i.e. small fruit, thin rinds, creased/split fruit. Too high or low temperatures and/or strong, dry winds will have the same negative impact.