Field Evaluation of 64 Apple Rootstocks for Orchard Performance and Fire Blight Resistance

Abstract

<jats:p>In 2002, apple rootstock trials using three scion cultivars were established at Geneva, NY, to evaluate 64 apple (<jats:italic>Malus</jats:italic> ×<jats:italic>domestica</jats:italic> Borkh.) rootstocks for horticultural performance and fire blight resistance. Field trials compared several elite Geneva® apple rootstocks, which were bred for tolerance to fire blight and <jats:italic>Phytophthora</jats:italic> root rot, to both commercial standards and elite rootstock clones from around the world. Three rootstocks performed well with all scion cultivars: ‘B.9’, ‘Geneva® 935’, and ‘Geneva® 41’. All three rootstocks were similar in size to ‘M.9’ clones but with elevated yield efficiency and superior resistance to fire blight. ‘Geneva® 11’ also performed very well with ‘Golden Delicious’ and ‘Honeycrisp’ with regard to yield efficiency and disease resistance. Resistant rootstocks greatly enhanced the survival of young trees, particularly with the susceptible scion cultivars ‘Gala’ and ‘Honeycrisp’. Results demonstrate the ability of new rootstock clones to perform better than current commercial standards, reducing financial risk to producers while promoting orchard health with enhanced disease resistance.</jats:p>

Rootstock scion somatogenetic interactions in perennial composite plants

“…In contrast, Russo et al (2007) demonstrated that the tested apple rootstocks significantly controlled fruit weight and yield though fruit number were not reported. Similar to this result, peach fruit weight and total yield were controlled by the rootstock and fruit number were not shown (Tsipouridis and Thomidis 2005).…”

“…While Russo et al (2007) were unable to show a root-stock effect on fireblight resistance, Jensen et al (2003) report a difference in ‘Gala’ apples on several rootstocks. The difference is noticed only when the canker length is expressed as a percentage of the shoot length.…”

“…While resistance and tolerance to these diseases is critical, it does not depend on the interplay between the rootstock and scion and are therefore not covered in detail in this review. This includes the reported fire blight resistance in apple (Russo et al 2007) where the resistance prevents the rootstock from dying but does not aid the scion’s resistance, and pear decline (Seemüller et al 2009) where the rootstock genotypes varied in amount of symptoms but did not prevent scions from obtaining the causal bacteria. Still, there are a couple of examples where the rootstock influences the disease characteristics of the scion.…”

A Phenotyping Protocol for Detailed Evaluation of Apple Root Resistance Responses Utilizing Tissue Culture Micropropagated Apple Plants

“…Continuing supply of genetically uniform apple plants with functional and non-contaminated root systems overcame this long-standing barrier. This micropropagation procedure avoided several limitations associated with stool-bed produced one-year old bare root trees, or "rootstock sticks" [28]. Restricted availability on genotypes and time window, roots with unintended exposure to biotic and abiotic stresses, and uneven root system between individual trees are a few known factors which can severely impact the expression of genotype-specific root resistance phenotype.…”

Field Evaluation of 64 Rootstocks for Growth and Yield of ‘Kensington Pride’ Mango

“…High costs and the length of time needed are significant obstacles to large-scale field evaluations and point to early screening techniques as a possible way of improving the efficiency of mango rootstock research. The lack of large-scale rootstock experiments may partly explain why the modern mango industry lags behind crops such as apple, in which selection of an appropriate rootstock is as important to the success of a new orchard as the choice of the scion variety (Russo et al, 2007).…”