The Off-Season Flowering Induction of „Keprok‟ Citrus Tree (Citrus reticulata).

Abstract

The purposes of this study were to study (1) the effectiveness of flowering induction treatments (Prohexadion-Ca, Paclobutrazol, and strangulation) toward Keprok, (2) the effectiveness of dormancy-breaking substance treatments (etephon, BAP, and KNO3) on the flowering of Keprok, and (3) the interaction effect between flowering induction treatment and dormancy-breaking substances on the flowering of Keprok. This research was conducted at orange farm in Tangkil, Caringin Bogor Sub-district which lasted from November 2012 until July 2013. This experiment used a separated block design (Split Block Design) which consisted of two factors. The first factor is the flowering induction consists of four levels i.e. control, Prohexadion-Ca, Paclobutrazol, and strangulation. Whereas, the second factor was the provision of dormancy -breaking substances consisted of four levels i.e. control, etephon, BAP and KNO3. From treatment combination, there were 16 trial units and 4 replications. As a result 64 plants were used. Young citrus tres used in this research have similarity of age (5 years). Flowering induction treatment, namely, Prohexadion-Ca, was applied to the leaves twice. The first application after flush getting mature and the second was one week after the first application was done, with a concentration of 500 ppm/ plant in a liter of water. Paclobutrazol was applied to the soil once after flush getting mature with of 2 g/plant in a liter of water. Strangulation was done by a wire twist with diameter of 2 mm. The wire was twisted at a height of 30 cm. The wire twist was made after trubus getting mature. Dormancy-breaking substance treatment was applied 45 (HSA) flowering induction. Each dormancy-breaking substance was in liter of water added with 200 ppm ethepon, 200 ppm BAP, and 40 g KNO3 for each tree. The results showed that the flowering induction treatments (Prohexadion-Ca, Paclobutrazol, strangulation) gives the significant effect to accelerate of flowering and increase the number of flower and fruit on keprok tree. Prohexadion-Ca treatment has ability to accelerate of flowering time better than Paclobutrazol. Paclobutrazol, Prohexadion-Ca and strangulation gives the effects to increase the number of fruit due to these treatments are able to increase the C/N rasio in the leaves tissue. Dormantion breaking treatments doesn‟t gives the significant effect to accelerate of flowering time and increase the number of flower and fruit.