Agronomic performance of ‘BRS Kampai’ peach on 15 clonal rootstocks and own-rooted trees in Pelotas-RS, Brazil

Abstract The clonal rootstocks allows preservation of mother tree genetic characteristics, such as vigor and produce a fasciculated root system, with an abundant thin roots. The objective of this research was to determine the effect of fifteen clonal genotypes as rootstocks on the agronomic performance of ‘BRS Kampai’ peach, as well as the technical feasibility of own-rooted trees (without rootstock) in a no-irrigated field condictions, in Pelotas-RS, Brazil. Bagged nursery trees were planted at the field in August, 2014, under a randomized block design with four replications of one tree per plot, and evaluations of trunk diameter, trunk cross-sectional area (TCSA), yield efficiency, annual and accumulated fruit yield per tree and per hectare were carried out until 2019. In the adopted experimental conditions, we conclude that ‘Barrier’ (P. persica x P. davidiana), ‘Cadaman’ (P. persica x P. davidiana), G x N.9 (P. persica x P. dulcis), ‘Ishtara’ [(P. cerasifera x P. salicina) x (P. cerasifera x P. persica)] and ‘Santa Rosa’ (P. salicina) do not have potential as a rootstock of ‘BRS Kampai’ peach due irregular bud breaking of scion, small fruits and/or low fruit yield. Clone 15 (P. mume) stands out for increasing fruit weight and maintaining satisfactory fruit yield per tree. ‘Flordaguard’ (P. persica) is the best rootstock tested, which is vigorous, do not present any undesirable agronomic characteristics and induce the highest yields per tree and per hectare, exceeding 50 t ha-1 in accumulated yield. Own-rooted trees of ‘BRS-Kampai’ peach have technical feasibility, as long as pruning is properly carried out.

克隆砧木（clonal rootstocks）能够保留母本树的遗传特性，如树势，并可形成具丰富细根的簇生根系统。本研究旨在巴西里约格兰德州佩洛塔斯（Pelotas-RS）的非灌溉田间条件下，探究15种克隆基因型砧木对‘BRS Kampai’桃农艺表现的影响，以及自根苗（无砧木）的技术可行性。2014年8月将装袋育苗的苗木定植于田间，采用随机区组设计，每小区1株树，共4次重复。于2019年前持续测定树干直径、树干横截面积（trunk cross-sectional area, TCSA）、产量效率、单株及单位面积的年度与累计果实产量。在本实验条件下，可得出如下结论：‘Barrier’（P. persica x P. davidiana）、‘Cadaman’（P. persica x P. davidiana）、G x N.9（P. persica x P. dulcis）、‘Ishtara’[(P. cerasifera x P. salicina) x (P. cerasifera x P. persica)]以及‘Santa Rosa’（P. salicina）不适宜作为‘BRS Kampai’桃的砧木，原因在于接芽萌发不整齐、果实偏小及/或果实产量较低。15号克隆（P. mume）可显著提升单果重，并维持令人满意的单株果实产量。‘Flordaguard’（P. persica）为本次试验中最优砧木，其树势强健，无任何不良农艺性状，可诱导最高的单株及单位面积产量，累计产量超过50 t·ha⁻¹。‘BRS-Kampai’桃自根苗具备技术可行性，前提是需进行合理修剪。