Sweet Cherries: High-Density Planting Grafted onto Invigorating and Semi-dwarfing Rootstocks. A 13-Year Field Study
摘要
The impact of Mazzard seedlings and Colt rootstock on tree growth, precocity, yield attributes, financial results and main fruit quality traits of eight commercial sweet cherry cultivars was studied over a period of 13 years after planting 1250 trees ha−1. The experiment was performed in the Prislonica village (Čačak, Serbia) on shallow, heavy and acidic soil without irrigation. Significant differences in parameters such as trunk cross-sectional area (TCSA), yield components, gross profit, fruit weight (FW) and fruit equatorial diameter (T) were examined between rootstocks. Effect of rootstocks on soluble solids content (SSC) and titratable acidity (TA) in fruits was not significant, whereas influence on ripening index (RI) only occurred in the second year of the trial. Significant differences were observed among cultivars within same rootstock. Year-by-year variations of examined properties were also observed in most cases. Mazzard rootstock induced higher TCSA, yield parameters, financial results, FW in 2014, 2016 and 2018, and T in 2016 and 2018. ‘Summit’ and ‘New Star’ grafted on Mazzard in general promoted the highest vegetative growth, yield components and gross profit, whereas ‘Hedelfinger’, ‘New Star’, ‘Summit’ and ‘Germersdorfer’ grafted on Colt were similar and had the highest yield (Y), cumulative yield (CY), yield efficiency (YE) and gross profit. Generally, ‘Summit’ and ‘New Star’ had the largest fruit size, whereas ‘Summit’ and ‘Lapins’ had better values for SSC, TA and RI. A high correlation was found among some tree and fruit quality attributes. The principal component analysis (PCA) made it possible to establish similar groups of cultivars depending on their tree performances and fruit quality properties as well as to study relationships among examined traits.