For now, the turkey feather pollinating brush can take a rest in the kitchen, job done on the nectarines and apricots for this year. But as the blossom faded and there was that expectant wait to see whether any fruit had set from my tickling of these very appealing seasonal flowers, I was struck by an obvious difference between these 2 fruit trees.
The white flowers of the tomcot apricot, develop about 10 days before those of the first nectarine (Lord Napier), and this year as they emerged in waves along the different branches, I had a strategy of pollinating every couple of days, always after morning condensation had dissipated. But after about a week, I was aware that some of the flowers I must have already pollinated were dropping off completely with the slight disturbance from the feather. So, I tried to concentrate on just the fresher looking, and presumably more recently opened flowers, though this is quite a difficult visual task to achieve, particularly at the greenhouse apex. Undisturbed, the pollinated flowers eventually seem to wilt after several days and the petals fall, and it’s then that you notice the tiny green swelling which will develop into the apricot.
Once the gorgeous pink nectarine blossom opened, I noticed that something quite different happened. Within just a couple of days of pollination with the feather, the whole appearance of the flower, particularly at its centre, changed. A wonderful deep red/pink suffused the area round the stamens. Clearly this was a visual cue for me, the pollinator, to avoid these flowers with subsequent feather flourishes.
By now I can start to gauge the success of my handiwork with the tomcots, with clusters of acorn sized fruits already forming.
Since then, we have suffered one of the hardest (minus 4 degrees C) frosts of this non winter, before a gorgeous tree fringed sunrise.And with the greenhouse glazing condensation freezing internally, I was pleased that the extra heat from the reactor compost heating system (which is still significant this year, after regular top ups and turning of the compost bed), seems to have been sufficient to avoid any frost damage to these fruitlets.
About the same time, I’d had a go pollinating a few of the fabulous flowers of the Cymbidium Orchid ‘Ice Cascade’, once I’d worked out exactly where the pollen and stigma were located! In fact, on orchids, both male and female organs are located on the underside of the obvious upper ‘lip’ of the flower. Little is apparently known about natural orchid flower pollination in Cymbidiums, but some have been observed to be pollinated by bumblebees, which land on the lower lip, and after being guided down the flower throat, will sometimes dislodge one of the 2 pollen containing ‘pollinia’, which having a sticky base can become fixed to the bumblebees back. On visiting another flower, with luck the whole structure will rub against and perhaps adhere to the stigma, which is a sticky pit like structure located just behind the 2 pollinia. One of the features of Cymbidiums which appeals to me is that their spectacular flower spikes last for a good 6 to 8 weeks, so when I got round to moving a few pollinia from another cultivar onto the general area of the pollinia using an old pair of forceps, I wasn’t expecting to see quite such a rapid clue that I had indeed hit the right spot. Within barely 36 hours, there was obvious colour change in the throat of the flower, and about 10 days later you can see that the petals of the single pollinated flower in this spike are shrivelling and the flower stem is also changing colour. In fact all the flowers I’d pollinated then dried up and dropped off completely, so I guess that no viable seed were going to be produced, but the stigma still gave the message out, that the flower had been ‘pollinated’, so it was time to end its existence
Such colour change is apparently very common in orchid flowers, and not surprisingly it’s thought to be a powerful signal to pollinating insects that there’s no point in visiting this particular flower again. It seems to be controlled by ethylene, which is also used by plants (and commercially) as a chemical trigger to promote fruit ripening. Orchid flowers are particularly sensitive to ethylene, which is why we now keep our fruit bowl in a different room, when we have in-flower orchids in the kitchen!
But researching such clever colour cues employed by flowers to communicate their pollination status threw up several interesting ideas. A very good review article by Van Doorn on the effects of pollination on floral attraction and longevity can be accessed by clicking here. This confirms that other cues such as flower closure, or petal withering or abscission (falling off), are also used by many flowers (as with the tomcot). But the article makes the point that any pollination induced reduction in flower appeal to pollinators, doesn’t always coincide with an overall reduction in the lifespan of the individual flower.
This conclusion links to another interesting research article by Oberrath, who studied the floral appeal of the different coloured (red and blue) flowers on a species of Pulmonaria – P. collina.
We don’t grow P. collina, but many of the Pulmonaria varieties we do grow show similar flower colour changes.Oberrath makes a point which stupidly has never occurred to me before.
For any flowering plant relying on the visual attraction of pollinators to its flowers, there’s a dilemma. On the one hand the plant wants to attract many different pollinators to its flowers; on the other hand, to reduce the chances of self-pollination and to encourage out crossing, it wants an individual pollinator to only visit a few of its flowers, before moving on to another plant, hopefully of the same type.
Oberrath discovered that the young red flowers contain significantly more nectar and pollen than the older blue ones, and that pollinators quickly learnt this by experience. But by retaining the older blue flowers, the size of the overall floral display, (i.e. the number of open flowers) which is critical to grabbing the attention of an insect from a distance, is maximised. When the insect is closer, the colour difference between flowers should minimise wasted effort by the insect, by using the colour cue to direct it to the newest, unpollinated and most food rich flowers.
There is however a problem with this elegant hypothesis, (and Oberrath does indeed list a number of other species of flowers where independent studies have confirmed a similar strategy of pollinator induced flower colour changes take place).
Which is that our Welsh bumblebees don’t seem to have read his paper!
(More recent work has shown that insect scents and electrical charge on individual flowers may all play a role in influencing which flowers are actually visited when a bee gets really close to them).
Whilst our Pulmonarias show flower colour change consistent with flower ageing, the bumblebees are usually unbelievably efficient visitors to every flower, whether red or blue. Or at least they were this morning when I nipped out to get a few contemporary photos. Notwithstanding this annoying discrepancy, the need to maximise a single type of floral display is surely a critical one if trying to appeal to, and help the work of, a garden’s insect visitors.Perhaps this is in contrast to the ‘plantsman’s/woman’s/collector’s approach of great cultivar variety, and limited numbers of any particular plant.
Repeated swathes or block plantings of selected insect friendly flowers, even if intermingled, are likely to result in a more diverse and numerous garden insect fauna, because at a distance of more than about 0.3 metres, the insects will tend to perceive such block plantings as a single massive floral attraction, worth visiting.One of the inevitable beneficiaries of the very wet winter has been our diverse indigenous collection of mosses which carpet much of the garden and form a cushioned green mulch, and weed suppressing mat, over many areas. There’s just no point fighting it, and even now as the early spring bulbs fade, there’s still real charm in its huge range of colours green. And perhaps because there is more food elsewhere this year, the blackbirds haven’t (yet?) torn sections of it up in their usual fashion.Even our mossy crazy croquet lawn looks mossier than ever.
As I write, we’ve celebrated our first lamb of the season. ‘Del Boy’ arriving to first time mother ‘Babs’ just before 11 pm on Thursday, and justifying me dragging Fiona out of a very hot soak bath to witness the scene. We were beginning to wonder whether any of the ewes would lamb this year. In the end their slow start has been a real blessing, as the ground has dried up a lot, and warmer weather is forecast for the weekend.
Whilst waiting for this always special seasonal event, the turkeys have slotted into breeding mode. Dirk the tom/stag turkey, has been noticeably active in mating with all 4 hens on quite a regular basis.And with much less distress to his harem than we observed with last year’s efforts from Bernie the bronze. And what autonomic (?) co-ordination to get all those feathers moving, to create such a fantastic puffed up display, whether directed at his hens, or Cyril the cockerel next door. This poor camcorder screen captured image shows an actual mating at dusk. The best guide to whether fertile eggs are likely to be produced if you don’t see such mating, is the dirty backs of the submissive hens, who lie on the ground as the much larger stag literally stands on top of them.
Here the other 3 hens watch me, whilst mating with the fourth happens to the rear. I’d gone inside to grab the camera after watching one hen ‘attend’ to Dirk’s nether regions, whilst he was proudly standing on the back of a different prostrate hen. Needless to say this moment had passed when I returned, but it does serve to illustrate the interesting social interactions and cohesion of a group of domestic turkeys.
Fortunately with our heritage Ronquières turkeys, their size is such that natural mating is feasible without injury. Most commercial turkey breeding requires A.I. because the stags have been bred to be double breasted, and are so heavy that they would damage the hen’s backs, even if they were capable of mounting them.
In a 3 pronged bid to ensure we end up with more than the 1 viable poult from all the eggs laid last year during the freeze drying conditions of March, we have acquired an incubator from the splendid Somerset (UK) based firm of Brinsea. Click here for link.
We are incubating some eggs, as will a friend, and then we plan to leave some with the hens to have a go brooding remaining eggs in their 2014 nesting area, to the rear of their shelter.In spite of being a typical jerry built structure of to-hand materials, the turkeys seem to enjoy it, and are now slotted into a routine of each laying about an egg every other day.
The set up ensures reasonable privacy and shelter from elements, with good ventilation, whilst minimising the visibility from the watchful eyes of all the potential and regularly present predators (squirrels/magpies/carrion crows and rats). It also allows me to remove eggs with little disturbance, by approaching from the far side. But whereas I’d hoped to be able to lean through the gap at the top of the metal sheet, I’ve found that my arms aren’t quite long enough, so a pair of old barbecue tongs have been modified to form a perfect egg grabbing tool. Once turkey hens start sitting in earnest, they will hiss aggressively at any such intervention, so the tongs are definitely a safer bet than a bare hand.
Since the incubation period is 28 days, it should mean that any poults will start to hatch in the kitchen on Easter Monday, but this picture illustrates just how sophisticated a set up is available, to compete with the task performed by a hen turkey sitting on a clutch of eggs in a nest.
There is an excellent guide to critical factors in optimising hatch rates which you can read by clicking here. But the incubator display hints that a very tightly controlled temperature around the 37.8 degree C mark, together with adequate humidity (around 50-55%) to prevent too much weight loss during the egg incubation period, (and this being raised to more like 65% in the 2 days before hatching, to aid the poults escaping from the egg membranes), are all important. Actually the Brinsea holds temperatures with 0.1 degree C accuracy, but I was experimenting with humidity levels when I took the above image.
I baulked at a separate humidity pump to alter humidity, so trial experiments with strips of cloth dipped into the sub egg water reservoirs can be made to alter the humidity inside the incubator.
Regular egg turning as well is necessary throughout the incubation period, but stopping completely, in the last 48 hours. The Brinsea does this simply with an external cradle which moves the upper incubator frame and eggs through 90 degrees, back and forth, at an imperceptible rate. Fiona quite rightly decided there was no way I would remember to do this on a regular basis for 4 weeks. In researching the Brinsea products I also really liked the way that their electricity consumption is a lot lower than most of their rivals.
Quite a lot to take in, but the incubator is pretty simple to set up and operate with comprehensive instructions. I’ll update on how things are going, since it’s advisable to ‘candle’ eggs by shining a bright light through them, to detect any non viable ones early in the process and remove them from the incubator to prevent explosion and contamination of the remaining eggs. The 38 degrees C inside the incubator being a great temperature for encouraging bacterial growth.
All these thoughts about eggs at Easter made me think about the culture of giving eggs as Easter gifts. Like many traditions, recent commercial efforts have muddied, or should that be chocolated, the origins of why eggs are given – other than as a fix for chocaholics, and a boost to chocolatier’s incomes.
Certainly, I had no idea of when or why it began, but it seems that in many parts of the world with a Christian tradition, decorated eggs have been offered as gifts, in part because they signify the end of a Lent fast which began with Shrove Tuesday (so the last chance to use eggs in a meal, was with your pancakes) or indeed the French ‘Mardi Gras’ – Fat Tuesday.
Egg eating could begin again, once the Easter weekend arrived, and the fast was completed. Some think that the shape of the egg mirrors the stone placed over Christ’s tomb, or that the emergence of the chick from the egg captures the Easter message of the resurrection, with new life emerging from within a tomb like structure. Click here for more information on Easter egg traditions around the world.
I’m guessing that few folk now complete a Lent fast, but certainly there will be heightened excitement this year in the Gelli kitchen, as Easter approaches. In this strange season, how many times before, have I seen a bumblebee working Narcissus ‘Jetfire’ flowers? None.
And if you think turkey eggs are big, how about this egg, presumably from a visiting Canada goose which appeared, under water, in the margins of our upper pond 10 days ago. Finally a few more scenes from the garden as the daffodil season passes the third-of-all cultivars-open stage.
I don’t know if it’s relevant but some pulmonaria don’t undergo the colour change and as far as I know the bees like them.
Thanks for the comment, which made me look for a bit more definitive information on Pulmonaria species and cultivars. P.rubra ( which we don’t grow since I’m not keen on too much red in the garden in spring!) seems to have just red flowers, not changing to blue, but the most helpful review article I could find was from the Chicago Botanic Gardens …
Click to access no17_pulmonaria.pdf
which rates many cultivars for their garden worthiness. The point is also made that Pulmonaria are very promiscuous, so will throw up lots of variants around a garden in time ….which confirms I suppose that the bees are doing a good outcrossing job. Interestingly they also rate the often praised dark blue flowered ‘Blue Ensign’ as being a poor doer – an observation we would agree with. Our favourite is one of those shown, which we think is called ‘Trevi Fountain’, and which consistently flowers well and over a long period for us,
Thanks, Julian, that’s very interesting
Fascinating as always and I will go away and muse on the flower pollination colour change hypotheses.
Amazing how far garden is advanced compared to mine – my pulsatilla (yes I only have one survivor – natural selection is tough here) is just producing leaves. As for the bumblebees, I had the first one in the garden on Saturday – cold and wet it had to be rescued and dried out in the polytunnel.
Thanks for the comment. But I bet from your single Pulsatilla you’ll be able to breed a strain that will cope better with the Hebridean climate? Anyway a look back to my post from April 1st last year reminds me how very fortunate we are to have enjoyed a milder start to the year ….no apple blossom out before May last year, and still in the grip of the deep freeze through most of April,
Hopefully the lengthening days will soon bring the insects out in force ( and not the midges?),
Del boy is beautiful complete with his baby curls on his back. Wonderful photographs as usual and lots to think about pollination. I had never noticed any colour change so it is something for me to keep an eye on as all our fruit trees have started to flower. Your apricot is a lot more successful than ours but we do have fruit set but it is still early days yet to count our apricots. We have very little moss usually but this year because of the rain and high temperatures, the rocks are covered and I love it. Your mossy paths look very appealing.
Thanks for the comment. We had a scare with DB after 36 hours with serious breathing issues, but he seems to have turned a corner now, so today we shall let him out. All the gingery curls are hairy ‘kemp’, which in this breed are valued as aiding water shedding and warmth.
The apricots are still looking good, but I’m now fretting that I can’t see any nectarines setting … maybe they are more sensitive to the low temperatures we experienced on the one night, and have all fallen off. Time will tell. ‘Tomcot’ is supposed to be quite cold tolerant.