Help Please!!! on pollinating Cherimoya flowers

I'm new at trying my hand at Cherimoyas and was worried a month ago that my 4 year seedling would not flower at all. Well, it now has more than 30 flower buds and the 1st could be within a week of blooming. Its about 1/2 inch long. From what I've read, female stage occurs 1st for about 36 hrs, but should be pollinated within 1st 4 hours. The male stage then appears for the next 36 hours. How do I collect the pollen? Do I use a que tip, brush, or what. How long can I store the pollen and should it be in the refrigerator? The article says collect the pollen in a small bag. Are they kidding? Do the flowers put out that much pollen? I haven't even seen pollen other than what seems to be on the anthers, let alone collect it in a bag. There's something here (probably a lot) that I'm missing. From reading this message board for the last few months, there seems to be a lot of knowledge floating around out there. I would sure appreciate some guidance before its too late.

The following thread was started by Don on May 17, 2005 at 1:01 pm PST

Don,

First, no worries on the timing. Cherimoyas bloom for a long period from about April to October. The earliest flowers are known to produce infertile pollen. You're best off to start hand pollination at least a couple of weeks after the first bloom shows up.

The way it works is simple. First, you need to understand how the flower works. A flower starts in the female stage when it's slightly open. At that point, the round thing in the middle is wet and sticky, and can receive any pollen.

Then, the flower switches from the female stage to the male stage - it opens wide, and there are pollen covered starch granules right where the green petal looking things join up with the main part of the flower. The pollen is dust, you can't see it with the naked eye. All you can see are the starch granules.

Trouble is that the female part dries up by the time the pollen ripens, and the flower is then no longer receptive.

There are two ways to get around this problem and get fruit set.

1) Hand pollinate: get a black film canister and a small painters brush. Look for all the male flowers, and collect the starch granules by using the paint prush and brushing the granules off into the film canister. If the petals are drooping, it's too late, but it never hurts to collect the granules anyway. If you look in the canister, you will see granules and, if any of the pollen is ripe, you will also see dust. The dust is the pollen.

Then, find any flowers in the female stage, and use the paint brush to brush the pollen against the sticky female parts. The commercial growers use a little blow gun to blow the pollen onto the fruit. The female stage flowers are the ones that are only slightly open.

The cycle is different depending on temperatures that particular day, so it's good to do this once in the morning and once in the evening. The pollen remains viable at least for 12 hours, so you can apply what you collected your previous runs.

2) Another yet unproven method is to keep the female part from drying up by wrappping some plastic cellophane wrap over the flower in female stage and sealing tightly. Then, when the flower is in the male stage, just tap the bag slightly to get the pollen to drop onto the still sticky female part.

I will try 2) this Summer. Other methods include misting. I have noticed my cherimoyas set fruits by themselves when we get night and Morning fog and drizzle and sun during the day. So ideally, fog at around 55-70F with daytime warm up is best.

Axel

The above followup was added by Axel on May 17, 2005 at 2:26 pm PST.

Cherimoya pollination is not a science. Forget all the specific hourly cycle of the flower. Just pollinate twice a day, and you should get lots of fruits. Pollinate once a day, and you will still get plenty of fruits. I pollinate about twice a week at most and still get many fruits.

FYI, if you have a seedling, you won't know if you can get fruits.

Axel

The above followup was added by Axel on May 17, 2005 at 2:28 pm PST.

Don,
I sounded like you last year. At first the instructions sounded confusing.
It turned out very simple and I did manage to get 30 fruits the first year.

1st. You can smell when the flowers are in the male stage. Get inside the canopy and look for the open wide flowers. Here in Modesto the male stage is generally in the early evening. Take a brush and swirl it around the center... lotz of pollen will fall out. I catch it in a film canister. Save the brush and pollenin the fridge over night as the next morning is the female stage. The flowers will be somewhat closed but not droopy. Shove the brush laden with pollen into the female flower... give the brush a few spins... thats it.

You just had Cherimoya sex!

Jeff

The above followup was added by Jeff on May 17, 2005 at 3:37 pm PST.

The local Guru's suggest that you can create an environment that helps natural pollination (and saves police visits courtesy of nosey nieghbours reporting rustling in the trees at dusk as you collect pollen).
One expert suggests planting impatiens plants under the canopy around the trunk. These keep the air humid and attracts some sort of insects that assist the pollination. Its also suggested that pruning is kept to a minimum allowing the canopy to form a dense closed 'umbrella' further helping humidity - Still, what do I know? Mine haven't flowered yet.

The above followup was added by Nigel(NZ) on May 18, 2005 at 2:56 am PST.

Nigel,
Your canopy idea might help a few pollenate naturally, but around here we are so dry during flowering that most pollen, doesn't remain viable for long.... except this year! We have been very wet this month.

Jeff

The above followup was added by Jeff on May 18, 2005 at 9:01 am PST.

I would be over-joyed if I could get 5 fruit this year. Any more would be a big bonus.

The above followup was added by Don on May 18, 2005 at 3:03 pm PST.

I highly recommend the pollen gun (pollinator) imported by Brokaw Nursery, costs about $80.
http://brokawnursery.com/polingun.html
I also recommend the book "Custard Apples" published in Australia if you can find it, edited by Garth Sanewski published by Queensland Dept of Primary Industries, Brisbane.
Pollen will keep for a day or two, so I collect in late afternoon, and pollinate the next morning. Male stage flowers seem more common in afternoon, and female stage in the morning. But if you see a male stage flower in the morning, that's OK, go for it. Female flowers are receptive when moist, so if you are in a very dry climate your window for pollination may be smaller. You might try gently misting the female flowers just before you pollinate, this will help the pollen cling. But do NOT get pollen moist, it will ball up and become difficult to handle.
Cherimoyas love moisture, some experts advise using mister type sprinklers around trees for hours each day: not a rainbird blast, just a mist.
Natural pollination occurs in my area, but it is my hope to extend the season with hand pollination. There is some discussion of what critters may be pollinating. Some say it is nitidulidae family, around here we call them "pineapple bugs", but I actually do NOT see any in my flowers. I have heard some say it is staphylinidae (rove beatles), but I cannot confirm this either. Other suspects I have heard mentioned are moths and bats. In my own very preliminary research I have come to suspect a very tiny spider, Thomasidae family, sometimes called flower spiders or crab spiders.
They are hard to see, about 1/8-1/4 inch long. Under a miscroscope I have seen 30 pollen grains on one segment of a front leg (forearm?). I suspect it is a female, and it hides at the entrance of the flower, and preys upon insects that are attracted to the flower scent. It may prey on thrips which I commonly see in the flowers (but which are too small to carry much pollen around). It may prey upon flies, upon aphids, upon moths or a species of tiny wasp. But then again, my study is very preliminary, I have not even watched the flowers at night. Perhaps there are moths which are pollinating, and this spider is only killing the moths.
But I do believe there is a complex situation going on. It may be that by poisoning insects thought to be harmful (like thrips and aphids) you could also eliminate the spiders which might be helping you pollinate.

The above followup was added by mauisurfer on July 10, 2005 at 8:14 pm PST.