This is what can happen in a vineyard when a grower decides to change varieties. The choice for grafting over can be due to poor performance (a red flag) or market value of the variety planted. Anyway, the safest way to graft over a vineyard block is to test the incoming budwood as well as what is in the vineyard. In this case, either the budwood or vineyard vines were infected with a pathogenic strain of Agrobacterium vitis. Gall symptoms generally do no display unless stress is present (grafting is considered stressful to a vine!). The work of grafting over a vineyard block is time consuming and expensive. Why not spend the extra money to do it right?
Material de propagación infectado con bacteria en este caso. Hay que saber elegir el material que se usara para injertar y saber la condición fitosanitaria del material usado para patrón o portainjerto.
Totally agree Judit. As a grafting contractor I recommend selection of budwood from a reputable vine nursery who has a protocol for crown gall. I saw some blocks last season suffer from poor strike rates and poor growth which looks like it was due to crown gall. The AWRI can test for it and is looking to simplify the current pathology technique for a faster turnaround of results. It will likely be recommended to test prior to grafting as currently done for virus.
3rd gen horticultural field grafter. 20+year Aero Engineer
6moIn the 1000's of acers we have field grafted, the grower understands the risk, and they are usually aware that they have cowngall on their site. The main issue is that every state and nursery have different testing requirements, along with the Clean Plant Netowk and Foundation Plant services not enforcing testing standards at G3 sites or on material that's shipped out to different states. FPS protical 2010 is not enough and I believe does not test for crowngall. The cost of grafting is still more advantages than to replanting, usually with a ROI of 3:1.