Pollen_Collection_in_Pines_-_revised_dlf_1-18-18.pdf

Last Update 1/18/18 DLF

Pollen Collection in Pines - revised 1-18-18 Page 1 of 2

Pine Pollen Collection and Handling

1). Locate trees and assess for pollen development. Flag elite trees ahead of time to facilitate relocation before actual pollen collections take place. Tape the seams of the paper bags to prevent pollen leakage and record the pollen identification information on the outside of the bags ahead of time, to speed up actual field collections.

2). If you are collecting pollen from the same trees or same locations in different years, when to monitor for ripeness can be based on past experience with adjustments made for that year’s climate. An

“indicator” tree close to your office can also be used, based on past experience with that tree’s ripeness relative to target trees in the field. It is always better to be a little early and have to make a second visit than too late and have to wait until next year.

3). Hopkin’s Bioclimatic Law1 can be used to estimate pollen ripeness dates for trees in new locations relative to locations where ripeness dates are known. For the Northern Rockies, pollen ripens:

4 days later for each 1o latitude northward and 4 days earlier for each 1o latitude southward

4 days later for each 5o longitude eastward and 4 days earlier for each 5o longitude westward

4 days later for each 400 ft. increase in elevation and 4 days earlier for each 400 ft. elev. decrease

This should be used as a general guideline only. Ripeness is also affected by microsite differences such as aspect, cold air drainage, and the genetics of the tree (early ripeners vs. late ripeners).

4). Monitor catkins for ripening. You have 24-36 hours to collect mature pollen before pollen flight.

Catkins turn from green to yellow in white pine and from reddish-purple to yellow in ponderosa pine

Trees ripen from the bottom up, unless there are cold air drainage problems like at Hog Meadows .

Need to perform squeeze test (squeeze a catkin between thumb and finger, if liquid is yellow and/or cloudy, the pollen is not ripe. If the liquid is clear, pick the catkins).

If near neighbor trees are shedding pollen, and there is a risk of pollen contamination at the target elite tree due to air movement, do not collect pollen.

5). The size of the brown paper bags is important. Avoid using large, thick papered, grocery bags.

Pollen catkins in the center of a large volume of pollen retain moisture even when catkins at the top or edges of the bag appear dry. It is best to use a standard brown paper lunch bag or lunch sack which is approximately 10 5/8 inches tall with a flat bottom that is approx. 5 1/8 x 3 1/8 inches. Fill bags with pollen so they are no more than half full when folded and stapled at the top. This allows bags to be rotated and shaken twice a day to facilitate even, uniform drying of the catkins throughout the bag. This helps prevent mold from growing in the bags.

6). To prevent leakage, seams of the bags must be taped before placing pollen in the bag. It is best to collect complete, intact clusters of pollen catkins rather than individual catkins. A half-full bag of catkin clusters has more air space to facilitate drying versus a half-full bag of individual catkins which settle and pack more tightly together in the bottom of the bag. To reduce moisture going into the bag, green needles at the terminal end of the branch must be clipped off immediately above the catkin clusters. Also, clip the base of the branch immediately below the clusters. When the bag is no more than half full, double fold the top of the bag and staple 4 or 5 times across the width of the bag. Place tape over the staples so pollen doesn’t leak out of the staple holes!

1A.D. Hopkins (1918) Periodical events and natural law as guides to agricultural research and practice.

Last Update 1/18/18 DLF

Pollen Collection in Pines - revised 1-18-18 Page 2 of 2

7). To avoid pollen contamination when moving from one elite tree to the next, sterilize all collection tools (snippers) and hands with rubbing alcohol and allow sufficient drying time before proceeding with the next collection. A new pair of disposable Surgical gloves are recommended for hands in lieu of repeated skin contact with alcohol.

7). Do not collect pollen in the rain or in wet, extremely humid conditions. This greatly increases the chances of mold growing on the catkins before the pollen can be processed at the Nursery.

Mold decreases pollen yield and viability.

8). Use red tape or staple red flagging to the top of the bag to indicate “red tag” pollen lots that need to be processed for use that same field season. Also, write “red tag” on the bag.

9). Record collection and identification information with a waterproof marker.

a. Plantation Collections (PP) record the following information on the bag:

Indicate if this is a “red tag” lot.

Collection Date _____/_____/_____

Species Code _________________ (2 alpha, PP )

Plantation Code________________ (4 alpha, e.g., LONE, COND, LUBR)

Breeding Zone_________________

Family Number________________

Pedigree Number_______________

Collected by_______________________________

b. Single-tree collections in stands (WP) record the following information on the bag:

Indicate if this is a “red tag” lot.

Collection Date _____/_____/_____

Species Code _________________ (2 alpha, WP )

TWN______ RNG______ SEC______ ELEV________

Cycle Number_________________

Family Number________________

Collected by_____________________________________

10).Temporary storage. Keep bags cool and dry, out of direct sunlight while in the field. If unable to ship pollen within 24 hours, hang bags on a clothes line in a garage or warehouse, with clothes pins, and be sure to shake the bags twice a day to ensure air circulation and minimize mold formation.

Ship bags within 48 hours of collection.

11).Ship pollen by priority overnight delivery. Pack bags of pollen loosely in a cardboard box that is loosely packed with crumpled newspaper. Cut 2" diameter holes around the sides of the box for aeration. Tomato or apple boxes work well.

12).Ship pollen to the Coeur d'Alene Nursery. Notify David Foushee (dfoushee@fs.fed.us or (208)

765-7394) prior to shipment. Ship to arrive during posted business hours, 7:30am to 4:00pm M-F.

Shipping address:

David Foushee

USDA Forest Service

Coeur d’Alene Nursery

3600 Nursery Rd.

Coeur d’Alene, ID 83815 mailto:dfoushee@fs.fed.us