Editing Fruit tree pollination (section)

==Temperate nuts==

===Almonds===

The blossoms of most California [Almond] varieties are self-incompatible, requiring cross-pollination with other varieties to produce a crop. The single most important factor determining a good yield is pollination during the bloom period. More than a million colonies of honey bees are placed in California Almond orchards at the beginning of the bloom period to pollinate the crop. California beekeepers alone cannot supply this critical need, which is why honey bees travel across the country to the San Joaqin Valley each year. Although the recommended number of hives per acre is 2 to 3, due to the high demand in conjunction with the reduced availability of commercial beehives, many almond growers have to make do with a lower hive density during pollination. These growers started using semiochemical formulations, like SPLAT Bloom,<ref name="ISCA Technologies">{{cite web |url=http://www.iscatech.com/exec/index.html |title=Slideshow |website=ISCA Technologies |url-status=dead |archive-url=https://web.archive.org/web/20140410230851/http://www.iscatech.com/exec/index.html |archive-date=2014-04-10}}</ref> to compensate for the low hive density. SPLAT Bloom manipulates the behavior of the bees, inciting them to spend more time foraging, and thus pollinating flowers in the entire almond orchard (increasing pollination and fruit set), not only close to the hive.

Research into self-fertile almonds has led to the development of several almond varieties that do not need a pollinator tree. Working from an old Spanish variety, "Tuono", researchers in 2008 started making available new self-fertile varieties that more closely match the qualities of the popular "Nonpareil" almond—including varieties "Lone Star" and "Independence".<ref>{{cite web |url=https://www.ars.usda.gov/news-events/news/research-news/2010/ars-scientists-develop-self-pollinating-almond-trees/ |title=ARS Scientists Develop Self-pollinating Almond Trees |author=Alfredo Flores |date=April 6, 2010 |publisher=USDA}}</ref>  While self-fertile trees do not require pollen from a second tree variety for fruit / nut set, they still depend upon insect pollination for good production. Almond growers with self-fertile almonds report excellent nut set with half (or less) the number of bees in the field.<ref>{{cite web |author=Don Studinski |date=February 6, 2015 |title=Almonds without Honeybees? |url=https://www.seleneriverpress.com/almonds-without-honeybees/ |website=seleneriverpress}}</ref><ref>{{cite web |author=Ezra David Romero |date=March 23, 2016 |title=With Bees In Trouble, Almond Farmers Try Trees That Don't Need 'Em |url=https://www.npr.org/sections/thesalt/2016/03/23/471437025/with-bees-in-trouble-almond-farmers-try-trees-that-dont-need-em |publisher=NPR}}</ref><ref>{{cite web |author=Burchell Nursery |date=May 22, 2014 |title=A Star Is Born, Introducing LONE STAR Self-Fertile Almonds |url=http://www.prnewswire.com/news-releases/a-star-is-born-introducing-lone-star-self-fertile-almonds-260240461.html |website=Cision PR Newswire}}</ref>

===Wind-pollinated nuts===

Hazelnuts (filberts), walnuts, pecans, and chestnuts are all wind-pollinated temperate-zone nuts. Mostly these wind-pollinated nuts are selected varieties that need two different varieties (and favorable winds) for cross-pollination. Insects and birds may visit and consume the pollen, but are not a factor in pollination.

Edible seeds from wind-pollinated coniferous trees such as pine, ginkgo, and monkey-puzzle trees are also harvested and the seeds are colloquially called nuts.