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Re: [nafex] Hand Pollenate Pawpaws.

What a great post.  Have you ever tried Q-tips instead of the capsule
and brush?

"Gordon C. Nofs" wrote:
> Thought that there might be some interest for some out there.
> 1
> Doing what comes unnaturally
> How to hand-pollinate pawpaws
> By Neal Peterson
> Some people find that Pawpaw trees just don't produce fruit. "Why?" they
> ask. The answer usually is, "They need a pollinator." Sometimes this
> means they need a helping hand in their pollination. Literally.
> Hand-pollination. The question then be-comes, "How do you do it if you've
> never done it? When is the pollen ripe? When is a flower in the female
> stage and most receptive? How do you do the act itself - transfer the
> pollen to its appointed spot?" It's all very easy, but - like human sex -
> it ~ isn't necessarily obvious how to do It.'he first time. Here are some
> simple pointers to guide you if you aspire to pollinate pawpaws by hand.
> Pawpaw blossoms begin life as females and later become males. They are
> designed this way to discourage
> self-pollination. In the female stage the petals are held rather tightly
> together, forcing the small flies and beetles that visit the flowers,
> searching for nectar, to brush past the stigmas where the pollen they
> carry on their backs can be deposited. In this stage, the petals will
> have turned color, from green to maroon (although some green may still
> show) but the anthers will be tightly pressed together as a solid green
> ball, and the stigmas will appear green and shiny.
> In the later male stage, the petals darken more, the fetid flower odor
> intensifies, the ball of anthers loosens (no longer solid) and the
> anthers turn from green to brown, shedding the yellow dust-like pollen.
> In this stage, the petals flare back, allowing the visiting insects to
> brush easily past the anthers, thereby collecting pollen on their backs.
> The first trick for the hand pollinator is collecting the pollen. There
> are many ways to do this, but my own
> Preference is to use large empty gelatin capsules (size XXX) that you may
> buy at health food stores. I open
> the capsule and use one end as a cup to scrap the ripe-with-pollen
> anthers, causing them to fall into the capsule. I then close the capsule
> and label the contents with an indelible pen. These capsules, being made
> of gelatin, absorb moisture, promote the anthers to release their pollen,
> which then adheres to the sides of the capsule. I then use a very small
> camel's hair brush to collect the pollen from the sides of the capsule,
> and apply the pollen to the stigmas of the female flower. For the sake of
> thoroughness, and to learn the results of my efforts, I also tag the
> flowers I have pollinated.  The final pointer has to do with picking the
> right time of day and the right type of day for pollinating. I find that
> I get the best results on a perfect spring day, when the sun is bright,
> the air is warm, the breezes gentle or not at all. I don't do it in early
> morning or late in the day. When in doubt about how to do it, think like
> a flower, think like a beetle.
> *************************************************************************
> *************
> My Botanical Rendezvous
> By Colleen Anderson
> I'm an infamously bad gardener, but six years ago I planted a Pawpaw seed
> in my yard, and it grew. I nursed the little sprout along and, about the
> second year, transplanted it to the sunny side of Arlington Court, where
> I live. It thrived. Last year, the first blossoms appeared - only four of
> them, but there was no denying it - my tree was at least a teenager.
> This year, it's an adult. The tree is tall and straight, and the lovely,
> blood-brown, bell-shaped flowers are everywhere - there must be two
> hundred. My tree could be fruitful - but, like people, paw-paws need
> intimate company in order to reproduce - and there isn't another Pawpaw
> within shouting distance.
> So I have been assisting nature. My tree's mate came from a fine stand of
> pawpaws in Kentucky. I carried the precious pollen back in small
> capsules. On a beautiful, warm day last week - the perfect sort of day
> for romance -1 had a go at hand pollinating. It didn't take long, and it
> wasn't very exciting - dipping a small brush into the pollen capsules and
> delivering it to the waiting blossoms - but still, I tried to
> 2
> accomplish it without attracting attention. Plants may not care about who
> watches their sexual encounters, but I couldn't get over the feeling that
> there was something illicit about this endeavor.
> Nevertheless, word got around. By that evening, my neighbors were teasing
> me about my midaftemoon botanical rendezvous. All over the block, they're
> calling me "Madame Pawpaw."
> I feel more like a grandmother-in-waiting. I'm looking forward to the
> story this summer will tell.  Will my lovely young tree be compatible
> with her Kentucky gentleman? Will the blossoms swell into clusters of
> fruit? Will we have Arlington Court paw-paws this fall? Stay tuned. With
> luck, I'll be making a birth announcement.
> This essay was originally broadcast as a commentary on West Virginia
> Public Radio in April 1996. The
> harvest was bountiful.
> *************************************************************************
> *********
> Pawpaws in the Garden
> SITE, SOILS, AND HABITAT. Although the Pawpaw is capable of fruiting in
> the shade, optimum yields are obtained in open exposure, with some
> protection from wind (on account of the large leaves). Germinating
> seedlings, however, will not survive under those conditions because they
> are extremely sensitive to full sunlight, which can kill them. Shading
> for the first year, and sometimes the second, is normally required, and
> it is for this reason that pawpaws are almost always found in nature as
> an understory tree. The soil should be slightly acid (pH 5.5-7), deep,
> fertile, and well-drained. Good drainage is essential to success. Pawpaws
> will not thrive in heavy soil or water-logged soil. In habit it is a
> small tree, seldom taller than 25 feet. Grown in full sun, the Pawpaw
> tree develops a narrowly pyramidal shape with dense, drooping foliage
> down to the ground level. In the shade it has a more open branching habit
> with few lower limbs and horizontally held leaves.
> PROPAGATION BY GERMINATION. Pawpaw seed is slow to germinate but not
> difficult if certain procedures are followed. Do not allow the seed to
> dry for long periods (ie., months) because this can destroy the immature,
> dormant embryo. To break dormancy, the seed must receive a period of
> stratification (exposure to cold temperatures) for 90-120 days. this may
> be accomplished by sowing the seed late in the fall and letting it
> overwinter; the seed will germinate the following year in late July to
> late August. Another way is to stratify the seed in the refrigerator
> (32-40F/0-5C). In this case the seed should be stored in a plastic
> ziplock bag with a little moist sphagnum moss to keep the seed moist and
> suppress fungal/bacterial growth. After stratification the seed should be
> sown in a well-aerated soil mix, pH 5.5-7, with an optimum temperature of
> 75-85F (25-30C). The root will normally emerge from the seed coat on the
> 18th day, develop into a taproot about 10 inches deep, and then send up a
> shoot on day number 64. Germination is hypogeal: the shoot emerges
> without any cotyledons. For the first two years growth is slow as the
> root system establishes itself, but thereafter it accelerates.
> Fruitbearing normally begins when the sapling reaches 6 feet, which
> usually requires six to eight years.
> PROPAGATION BY VEGETATIVE MEANS. Pawpaw clones are easily propagated by a
> number of grafting and budding techniques, such as whip-and-tongue,
> cleft, bark inlay, and chip budding. The only method that does not
> produce good results is T-budding. Shoot cuttings have proved virtually
> impossible to root, while root cuttings are usually successful. Although
> it is common for a Pawpaw to sucker from the roots, and would therefore
> seem a natural way to propagate a clone through transplanting root
> suckers, in practice this is extremely difficult. Pawpaws are ordinarily
> quite difficult to transplant. They have fleshy, brittle roots with very
> few fine hairs. Experimentation has shown that, to be successful,
> transplantation should be done in the spring at the time that new growth
> commences, or soon after. (This is basically the same as for magnolia.)
> If many roots are lost, it may be desirable to prune the top to bring it
> into balance with the remaining roots.
> 3
> Pollination is the major limitation to Pawpaw fruit set.  The flowers are
> protogynous, meaning that the stigma (the female receptive organ) ripens
> before the pollen, and is no longer receptive when the pollen is shed.
> Thus the flower is designed not to be self-pollinated. In addition,
> Pawpaw trees are self-incompatible, requiring pollen from a genetically
> different tree in order to be fertilized.  Finally, the natural
> pollinators of the Pawpaw-various species of flies and beetles-are not
> efficient or dependable. Although it requires a little extra labor, hand
> pollination can be well worth the effort and can be done as follows:
> Using a small, flexible artist's brush, transfer a quantity of fresh
> pollen from the anthers of the flower of one clone to the ripe stigma of
> the flower of another clone. Pollen is ripe when the little ball of
> anthers is brown in color, loose and friable; pollen grains appear as
> yellow dust on the brush hairs. The stigma is ripe when the tips of the
> pistils are green and glossy, and the anther ball is still hard and
> green. Do not overburden the tree with fruit, as this will stress the
> tree, resulting in smaller than normal fruit, and may cause limbs to
> break under excessive weight.
> PESTS. In its native habitat the Pawpaw has few pests of any importance.
> The worst pest is Talponia plummeriana, the Pawpaw peduncle borer, a
> small moth larva (about 5 mm long) that burrows in the fleshy tissues of
> the flower, causing the flower to wither and drop. In some years this
> borer is capable of destroying the majority of blossoms.  Another pest is
> Eurytides marcellus, whose larvae feed exclusively on young Pawpaw
> foliage, but never in great numbers. The adult butterfly is of such great
> beauty that this should be thought more a blessing than a curse.
> Sometimes the fruit surface may be covered with patches that are hard and
> black; this is a fungus infection, but it seldom has any effect on flavor
> or edibility. Deer will not eat the leaves, twigs, or fruit. Outside its
> native region, the Pawpaw is sometimes reported to be plagued by pests,
> but this may be because of poor health resulting from improper soils and
> an unsuitable climate.
> The Pawpaw Foundation, August 1990
> Bees show no interest in Pawpaw flowers. The task of pollination is left
> to unenthustic species of flies and beetles. A better solution for the
> home gardener is to hand pollinate. Using a small soft artist's brush to
> transfer pollen to the Stigma (Female part of the blossom)  Pollen is
> ripe for gathering when the ball of anthers is brownish in color loose
> and friable. (Male part of blossom, up to top inside flower above the
> female part)  Pollen grains should appear as small beige colored
> particles on the brush hairs. The stigma (female part) is receptive when
> the tips of the pistils are green, glossy, and sticky,  and the anther
> (male part) is firm and greenish to light yellow in color.
>      So the female part is ready when the male part is not in the same
> blossom.
> Gordon C. Nofs
> Flint, Michigan
> gcnofs@hotmail.com
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