Diseases

Phytophthora root rot of paradise apple

Malus pumila L. Mill.

Phytophthora root rot of paradise apple (Malus pumila) manifests as root and crown rot caused by the oomycetes Phytophthora cactorum, P. syringae, and P. pseudosyringae. The disease leads to stunted growth, premature leaf drop, and tree death under conditions of excess soil moisture.

In the reference 6 varieties crop Paradise apple, where this is mentioned in the description.

The primary pathogens of the infection in Malus pumila are the oomycetes Phytophthora cactorum, Phytophthora syringae, and Phytophthora pseudosyringae. Symptoms of the disease correspond to the general signs of Phytophthora crown rot and manifest as the destruction of the root system and the root collar zone of the tree.

No specific resistance genes have been identified in the genetic makeup of the species; however, resistance mechanisms to Phytophthora cactorum in apple are associated with quantitative trait loci (QTLs). These include the MdRPc1 loci on chromosome 6, as well as MdRPc2 and MdRPc3 on chromosomes 5 and 15, respectively.

In agronomic practice, the majority of classical clonal rootstocks of the Paradise group are characterized as susceptible to Phytophthora root rot. A high degree of infection is observed under unfavorable growing conditions, particularly with poor drainage and waterlogged soil.

General information about the subject — on the page Late blight.

Sources8

Varieties of Paradise apple mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.