Collection season and auxin treatment in the propagation by cuttings of mandarin hybrids

Abstract

Propagation by cuttings is an alternative for obtaining citrus rootstocks. The exogenous application of indolebutyric acid (IBA), cutting collection season and genotypes used may affect the rooting and vegetative growth of citrus rootstocks cuttings. Two experiments were conducted to study the influence of these factors. In the first one, semi-hardwood cuttings from the ‘Sunki’ mandarin hybrids H49 and H77 were collected in the fall and late spring of 2013 and treated with IBA (0 mg L^-1, 1,500 mg L^-1 and 3,000 mg L^-1). For each collection season, a 2 x 3 (two genotypes x three IBA concentrations) factorial scheme was adopted, in a randomized blocks design. In the second experiment, the development of cuttings that rooted in the late spring was evaluated until grafting. In this case, a completely randomized experimental design was adopted, with the hybrids H49 and H77. The IBA treatments positively influenced rooting and number of roots only in the fall collection, peaking at 23.3 % of rooted cuttings. In the late spring collection, rooting was close to 100 %, with the IBA treatment being unnecessary. Around 50 % of cuttings from the ‘Sunki’ mandarin hybrids were ready for grafting at 14 months after cutting.