Hand-Pollination of Corn: PART 1 of 2
This season, I have planted 5 different varieties of especially large corn, in a search for a specific variety that would be best suited for making corncob pipes. Since corn is wind-pollinated, the multiple varieties would cross extensively, if no pollination protection measures are taken. With multiple varieties, the only way to produce seed (kernels) that are true to the parent corn plant is to bag both the tassels and the ear shoots, then hand-pollinate them.
[If you grow a large plot of corn for eating, bagging is not a practical approach to avoiding cross-pollination. An example would be "super-sweet" corn planted in proximity (in your yard or the neighbor's) to any other corn variety. "Super-sweet" varieties produce kernels (seed) that are not super-sweet, if they are pollinated by other varieties, since the kernel is the offspring of the cross. The only preventive remedy is providing the recommended separation.
If your goal is simply to assure full ears of corn, then you can just select a mature tassel, cut it off after the dew has dried, and use it to "bless" the silks of each of the forming ears.]
The cob itself would seem to be a genetic product of only the plant on which the ear grows, even if the seed it produces is hybridized. But I'm not certain that the growth of the cob is unaffected by crossing.
If you plan to intentionally cross two different varieties of corn, this bagging method is how you would go about it. But plan on 5 or more years of planting, crossing, perhaps back-crossing, and selfing, to get a stable, new variety that meets your expectations.
The specific bags (one type for the tassel and a different type for the ear shoot) are available at a modest cost. They are designed to be weather resistant, and are sized to best fit this use.
Resources:
Ear shoots emerge at one or more leaf axils on the stalk. This happens shortly after the tassel appears. I wait for the tassel to mature and appear somewhat ragged (a sign that it can release pollen). The tassel must not be bagged earlier than this, or it will never produce pollen.
So, once a tassel appears somewhat ragged, and an ear shoot is visible, I carry out these steps during the late afternoon on the day prior to hand-pollinating.
Identify the ear shoot.
Remove the leaf by pulling it downward.
Cut a slot, using the shoot bag.
Cut the tip of the shoot down to a pea-sized core of silks.
Wedge shoot bag in place.
Identify the mature tassel.
Fold the branches upward, and cover with a tassel bag. The bag should be labeled with a Sharpie.
Fold the bag in half lengthwise. Wrap bottom corners around the stalk.
Fold corners together and fix with a paper clip.
Bags will remain in place until the next morning, waiting for all dew and the tassel bag to dry first.
CONTINUED...
This season, I have planted 5 different varieties of especially large corn, in a search for a specific variety that would be best suited for making corncob pipes. Since corn is wind-pollinated, the multiple varieties would cross extensively, if no pollination protection measures are taken. With multiple varieties, the only way to produce seed (kernels) that are true to the parent corn plant is to bag both the tassels and the ear shoots, then hand-pollinate them.
[If you grow a large plot of corn for eating, bagging is not a practical approach to avoiding cross-pollination. An example would be "super-sweet" corn planted in proximity (in your yard or the neighbor's) to any other corn variety. "Super-sweet" varieties produce kernels (seed) that are not super-sweet, if they are pollinated by other varieties, since the kernel is the offspring of the cross. The only preventive remedy is providing the recommended separation.
If your goal is simply to assure full ears of corn, then you can just select a mature tassel, cut it off after the dew has dried, and use it to "bless" the silks of each of the forming ears.]
The cob itself would seem to be a genetic product of only the plant on which the ear grows, even if the seed it produces is hybridized. But I'm not certain that the growth of the cob is unaffected by crossing.
If you plan to intentionally cross two different varieties of corn, this bagging method is how you would go about it. But plan on 5 or more years of planting, crossing, perhaps back-crossing, and selfing, to get a stable, new variety that meets your expectations.
The specific bags (one type for the tassel and a different type for the ear shoot) are available at a modest cost. They are designed to be weather resistant, and are sized to best fit this use.
Resources:
- Corn Ear Shoot Bags 200 ($11.50): http://www.southernexposure.com/corn-ear-shoot-bags-200-p-1162.html
- Corn Tassel Bags 50 ($11.25): http://www.southernexposure.com/corn-tassel-bags-50-p-1143.html
- Hand-Pollination: Corn: http://www.seedsavers.org/site/pdf/corn-hp.pdf (a 6 page instruction sheet from Seedsavers.org)
Ear shoots emerge at one or more leaf axils on the stalk. This happens shortly after the tassel appears. I wait for the tassel to mature and appear somewhat ragged (a sign that it can release pollen). The tassel must not be bagged earlier than this, or it will never produce pollen.
So, once a tassel appears somewhat ragged, and an ear shoot is visible, I carry out these steps during the late afternoon on the day prior to hand-pollinating.
Identify the ear shoot.
Remove the leaf by pulling it downward.
Cut a slot, using the shoot bag.
Cut the tip of the shoot down to a pea-sized core of silks.
Wedge shoot bag in place.
Identify the mature tassel.
Fold the branches upward, and cover with a tassel bag. The bag should be labeled with a Sharpie.
Fold the bag in half lengthwise. Wrap bottom corners around the stalk.
Fold corners together and fix with a paper clip.
Bags will remain in place until the next morning, waiting for all dew and the tassel bag to dry first.
CONTINUED...
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