EFFECTS OF CONTROLLED-RELEASE FERTILIZER VERSUS FERTIGATION ON CITRUS THOMPSON NAVEL VEGETATIVE GROWTH, YIELD AND NITROGEN STATUS

A field experiment on a commercial citrus orchard was carried out with mature trees of Thompson navel orange [Citrus sinensis (L.) Osb.], grafted on sour orange rootstock [Citrus aurantium (L.) Osb.]). Trees received the same amount of nutrients but in one plot of half an hectare the trees were fertilized with a controlled release fertilizer (17N-12P-18K +2Mg) applied at a depth of 10 cm in the beginning of the spring tree flush growth (first week of April) and again at the beginning of autumn tree flush growth (end of August) with another slow release fertilizer (13N-5P-27K +2Mg). On a second plot with the same area, trees were supplied with N, P, K and Mg by fertigation distributed during all the growth season.
The yield and foliar nitrogen concentration in September were similar in both treatments.
In contrast, the vegetative growth in the spring, summer and autumn flushes and The SPAD readings from May to November were greater in trees supplied with controlled-release fertilizer than with fertigation.

VI International Symposium on Mineral Nutrition of Fruit Crops

N. Bettaga, M. Ben Mimoun

citrus, flushes, SPAD values

https://doi.org/10.17660/ActaHortic.2010.868.44