What is in this article?:
- Almond checklist: bloom, pollination and harvest timing
- Growers consider a checklist of issues when choosing almond varieties in terms of bloom, pollination and harvest timing. At the 2009 Almond Industry Conference, a panel of experts gave growers assistance in this choice by reviewing variety development, evaluation and selection, balancing both field and market considerations.
As a rule, the better the variety bloom overlap, the better opportunity for cross pollination. Poor bloom overlap is demonstrated in this photo.
This article is the second in a series on choosing almond varieties.
This second article looks at the “checklist” of issues to consider when choosing almond varieties in terms of bloom, pollination and harvest timing. At the 2009 Almond Industry Conference, a panel of experts gave growers assistance in this choice by reviewing variety development, evaluation and selection, balancing both field and market considerations. The panel included Tom Gradziel (UC Davis almond breeder), Joe Connell (UC farm advisor, Butte County), Bruce Lampinen (UC Pomology Extension specialist), Ned Ryan (past Almond Board chair and almond industry consultant) and Roger Duncan (UC Davis farm advisor, Stanislaus County).
Almond varieties are grouped by approximate peak bloom periods, based on days before or after peak Nonpareil bloom. They are classified as:
- Early: six days or earlier before Nonpareil peak
- Early-mid: five days to one day before Nonpareil peak
- Mid-late: coincides with two days after Nonpareil peak
- Late-mid: three to four days after Nonpareil peak
- Late: five to seven days after Nonpareil peak
- Very late: eight days or more after Nonpareil peak
An updated listing of varieties in each bloom group is included in farm advisor Joe Connell’s presentation (see link to all presentations in last paragraph).
As a rule, the better the variety bloom overlap, the better opportunity for cross pollination. It is best to choose varieties in the same group or adjacent groups, said farm advisor Roger Duncan in his presentation. Good bloom options for Nonpareil also include those in the mid groups: Aldrich, Price, Fritz, Solano, Carmel and Wood Colony. Other options are those that have a peak bloom just before or after Nonpareil peak. These include Winters and Peerless in the early-mid group (just before Nonpareil peak), and Monterey in the mid-late group (just after Nonpareil peak).
Duncan added that to maximize yield potential, it is best to have two pollinizer varieties in addition to the main variety, such as Nonpareil, for a total of three. This is based on results of separate field tests he and Connell are conducting. Smaller operations that rely on custom harvest may want to consider just two varieties — the main variety and a pollinizer. For this scenario, Duncan advised, good matches for Nonpareil include Winters, Aldrich, Price, Carmel, Wood Colony and Fritz. Another option for smaller growers without harvest equipment is to grow varieties that can be harvested at the same time but not necessarily mixed. These include plantings with Aldrich, Winters, and Carmel or a Butte/Padre combination.
Another bloom consideration is the order of bloom time between varieties. A variety that blooms early will inherently have a higher set than a later bloom variety. For instance, if Nonpareil is the main variety, then a variety that blooms just ahead of or at the same time as the Nonpareil peak is much better than a variety that blooms later.