For the second time in as many years, there has been a stumble along the road to bringing the new Geneva rootstock, G.214, to growers’ orchards.

Cornell University horticulturist Dr. Terence Robinson confirmed that a mixup in rootstock material will mean a delay of about one year in the introduction of this new apple rootstock, which is being billed as a disease-resistant replacement for Malling 9.

The source of the mixup has not been identified. Material was sent to Prosser, Washington, for virus testing and then on to two laboratories for tissue culture ­propagation. What is now in those laboratories is not G.214; it is not even a Cornell rootstock, Robinson said.

The two tissue culture labs are North American Plant in Oregon and ProTree in California.

Because of liability issues, not much is being said about how or where the mixup occurred.

The much-awaited, fireblight- and replant-disease-resistant dwarfing rootstocks from Cornell have been slowed in their introduction by difficulties in propagating them and also by mixups along the production chain from research plots to nurseries.

In 2011, Richard Adams at Willow Drive Nursery in Ephrata, Washington, noticed that plants in the nursery’s new stoolbed, which were supposed to be G.214, didn’t look right. Genetic testing proved that the rootstocks were actually G.222, a more ­vigorous rootstock. At least three other nurseries also had the misidentified ­rootstocks.

On the bright side, Robinson said, this year has been one of great success. More than 2.2 million rootstock liners of G.11, G.41, and G.935 were harvested last fall, to which scions will be budded this spring.