can be accomplished by gardeners as they hand pollinate vegetables to promote a better yield.
For the same reason, the treatment of open-pollination
, which promotes cross-pollination, was also superior to others and was not different from that of hand crosspollination (Table 2).
It may be that sense of community that keeps open-pollination
efforts alive despite the economic odds against it.
COUNTRYSIDE: An article by Jean Smith in the March/April issue of COUNTRYSIDE explores the question of heirloom vegetables, hybridization, and open-pollination
. Her article, whose discussion of heirlooms appears on Wikipedia, suggests that the question of what constitutes a genuine heirloom vegetable rests not on objective standards but on which of several definitions you choose.
Ten trees were selected for manual crosspollination and open-pollination
. One hundred and twenty five flowers were used per each tree for manual cross-pollination.
The trees were subjected to open-pollination
caninus were reported to be mostly self-fertile with stainable pollen ranging from 5 to 25% and seed yield ranging from 2 to 600 seeds per plant under open-pollination
The calculation of both inbreeding depression due to open-pollination
and the proportion of out-crosses in the OP families assumed that (1) selfing is the only form of inbreeding; and (2) the controlled outcrosses are genetically equivalent to the outcrossing that occurs under natural open-pollination
within each population.
During May 1998, once a flower opened, it was randomly assigned to one of the following treatments: (1) Automatic self-pollination: bagged flowers with no further manipulation,(2) Forced self-pollination: flowers manually self-pollinated, (3) Cross-pollination: pollen from ten plants was applied to previously emasculated flowers, the average distance of pollen source was approximately 50 m and none of the 31 plants (block) were included and (4) Open-pollination
(control): mature flowers left open and bagged at the end of the day.
A sample set often tagged inflorescences consisting of 2987 flowers from 5 trees was used for assessing fruit set in open-pollination
Bulked [F.sub.3] seed (derived by open-pollination
of eight [F.sub.2] plants in the greenhouse) was grown in bulk progeny yield trials in 1994.
When heirloom gardeners refer to open-pollination
, they mean that a particular cultivar can be grown from seed and will come back "true to type." In other words, the next generation will look just like its parent.