Citrus rootstocks for Western Australia

Page last updated: Tuesday, 24 November 2020 - 8:09am

Please note: This content may be out of date and is currently under review.

C35 citrange

Developed in California, this is a hybrid of trifoliate orange (P. trifoliata) and Ruby Blood sweet orange. It has not been extensively tested under WA conditions. There is some interest in it as an alternative rootstock for navel oranges because it reputedly produces medium-sized trees, around 25% smaller, than those produced by Troyer and Carrizo citrange. Yield and other characteristics are reputedly similar to other citranges.

It is tolerant of Phytophthora spp., citrus nematode and tresteza.

Compatibility

C35 should not be used with Eureka lemon as incompatibility issues have become apparent in both local and eastern states commercial plantings in trees as young as three years old.

Evaluation of a 1997 rootstock trial at Loxton Research Centre in South Australia has revealed C35 citrange also has compatibility issues with Navelina (Navelina 7.5 selection). Trees of this variety/rootstock combination performed adequately up to 10 years of age but significant tree deaths have occurred since then, while no deaths were observed in other variety/rootstock combinations. There is also a risk that C35 citrange will be incompatible with the closely related varieties Navelina 315, M7 and FJ Navel.

Eureka seedless lemon on C35 citrange showing incompatibility line April 2018
Eureka seedless lemon on C35 citrange rootstock showing incompatibility line April 2018

Local experience

Although this stock has been planted in large numbers in recent years, there is very little local information on performance over a longer time period. Evaluation in a Newhall navel rootstock demonstration block in Bindoon showed that trees grew well in the establishment stage, and yields were similar to those achieved by Troyer citrange at the same site. Eureka lemon plantings on C35 in Western Australia have failed and, in most cases, trees have been removed.