SOW PineIslandGraftingProject.pdf

Statement of Work for SHRS Avocado Clonal Collection Regeneration Project

Scope: The USDA-Agricultural Research Service National Plant Germplasm System maintains collections of economically important crop accessions. The clonal collection of Persea americana, avocado, is held at the Subtropical Horticulture Research Station (SHRS) in Miami, Florida. The collection contains 168 cultivars representing the diversity of the species with representatives from each of the three avocado races Guatemalan, Mexican, and West Indian. The collection is utilized by avocado researchers and breeders worldwide through distributions of budwood and seed as well as phenotypical and genetic information accessible through the Germplasm Resource Information Network (GRIN Global). The SHRS avocado collection consists of trees varying in age from 90 to 3 years of age located in three field blocks with miscellaneous accessions scattered throughout the 220-acre site. In the collection there are 69 cultivars with only one representative. The objective of this project is to have each accession cloned into three representatives and plant out the entire collection into one field block for more consistent and efficient execution of cultural practices such as irrigation, fertilization, pathogen control, and data collection. The SHRS avocado collection eradicated the ASBVd viroid that was found in the collection in the early 1990s by removing all infected trees in 2015. Researchers are aware this pathogen is found throughout the South Florida avocado growing area.

Project Requirements: The project would be contracted to a local reputable nursery with extensive experience in commercial avocado propagation, consistent labeling protocols, extremely high sanitation standards, facilities required to irrigate and apply chemical fertilizers and pesticides, as well as proficiency working with research staff. A local nursery is required to minimize the amount of possible damage in transport. To minimize the potential of using ASBVd infected rootstock, SHRS will test a sample of rootstock. The seed will be from the cultivar ‘Lula’ or ‘Waldin’ from the SHRS collection as well as from the ARS-Ft. Pierce station or a local nursery. Using openly pollinated seed from a single cultivar will allow more uniformity in the new collection planting for data collection and grove maintenance.

SHRS staff will work with the nursery on budwood collection, planting seeds and raising plants, and clarification on any labeling issues. The SHRS has the genetic database to verify the identification of individual clones if required. The vendor will be required to do the grafting and labeling, as well as communicate any needs such as additional budwood material of clones that were not successfully grafted and communicate the ongoing inventory of successful grafts. There is less than 5% grafting failure rate, in which case at least two additional attempts will be made to graft the failed accessions either on the same rootstock or on a different rootstock.

Deliverables:

Number of different avocado cultivars/accessions: 150

Number of grafts per cultivar/accession: 3

Total number of grafted trees: 450

Rootstock: ‘Lula’ or ‘Waldin’ with a complete set of avocado accessions grafted on either of these two rootstocks.