Propagação por estaquia de porta-enxerto de pessegueiro e ameixeira

Abstract

The cultivation of peach fruit is a major activity in Southern Brazil, RS being the main producing state. The propagation is traditionally performed by grafting on rootstocks obtained from seeds from canneries and have no guarantee of genetic and sanitary quality. Due to the problems of genetic segregation of the seeds of this kind of material used, the multiplication of rootstocks for stone fruit trees for cutting is the most appropriate because it allows the production of plants with the same genetic characteristics of the parent plant, and ensure greater uniformity of the orchard. However, the propagation of these species by cuttings, requires control of several factors (exogenous application of growth regulators, appropriate time to make cuttings, rooting environment, etc.). To improve the formation of adventitious roots, as this has been a major problem of the technique in several species of Prunus. Therefore, the work was divided into two experiments. At first, we evaluated the ontogeny of branches (herbaceous and semi-hardwood) and the position of the cutting (basal and apex) on the adventitious rooting peach rootstock cv. Okinawa and Tsukuba 1 and plum cv. Julior Mirabolano and 29-C. Cuttings were prepared with 15 cm and keeping two pairs of leaves after were placed in fine vermiculite and kept under intermittent fog for 50 days. It was observed that in both herbaceous and semihardwood cutting as the rooting of the cultivars Mirabolano 29-C, Tsukuba-1 and Okinawa were greater than 80% in the apex cuttings, but is always greater cv. Mirabolano C-29, which also had the greatest number and dry weight of roots. Regarding the shoot, 'Mirabolano 29-C' had 96.65% of sprouting, with more and greater dry mass of shoots. In the second experiment. It was evaluated the nutritional status of the parental plants, the influence of IBA on rooting of cuttings derived from herbaceous and semi-hardwood peach cv. Flordaguard and plum cv. Genoese and Marianna in 2624.The preparation of cuttings and the conditioning was the same as described above with the difference that applied two treatments: control without use of AIB, AIB and using (2.000 mg L-1). The rooting of softwood cuttings treated with IBA was above 80% for all cultivars, while in semi-hardwood was 90% for 'Genovese' and 'Marianna 2624', and only 30% for 'Flordaguard'. 'Genovese' presented the highest number, length and dry weight of roots in all treatments and in both sampling times, different rooting cultivars may be related to different levels of some nutrients such as phosphorus and iron. The results of this study suggest that research the physiological responses and seedling development by cuttings of peach rootstocks are important because, knowledge about changes in root development through the use of different techniques and information here generated, can be used in selecting the most suitable for this type of propagation and purpose genotypes, well as to stimulate vegetative propagation of selected commercially for use as rootstock genotypes.