HOW DO APPLE TREES POLLINATE?
If you have been on one of our blossom walks this year you will have seen some trees in bloom, others coming into bloom, and tiny fruitlets forming as the trees turn greener and the orchard floor is delicately covered by fallen white petals. We have 7 apple varieties on the farm and a further 5 “pollinators”. Some of our pollinators are very colourful but do not bear fruit, while others, like Egremont Russet, are wonderful apples. All our pollinators are carefully spaced through the orchard to ensure their pollen is abundant.
Apple trees can be self fertile, but the vast majority need two (diploid) or three types (triploid – like Bramley) of pollen to get a good crop. We need good viable pollen to start with. This means a healthy previous year where the tree has not been under too much stress to lay down bud, a winter with enough cold units and, most of all, the right weather conditions during pollination in Spring. |
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This year has been a genuine struggle for many of our varieties. Once the days become longer and the soil warms up, bud begins to break and bad weather only slows this process but cannot pause it completely. This means we often have trees in full flower exposed to very imperfect weather this year. Firstly it did not warm up and many lower lying areas were exposed to frost, but even the higher areas suffered because much of the pollination workforce were still in their hives. The wind is both your friend and your enemy. Light winds help create a cloud of pollen but strong winds can carry the pollen off before it has had a chance to move from the stamen (the male part of the tree) to the pistil (the female part of the flower). The stamen is made up of the “anther” where the pollen is produced and below this is the “filament” that holds the anther and pollen and allows it to waggle in the wind and stick to bees as they visit the flower and help “cross pollination” between our different apple varieties. Having our varieties out all together really supports pollination so this year the long flowering period with many varieties finished before others have begun has put significant pressure on the viability of the crop.
We rely on the different types of pollen to be out at the same time as the main variety and the pouring heavy rain has also played a role in making pollination harder. The warm weather is very welcome but it is coming rather late for our varieties with the exception of our Bramley. We now have to sit and wait to judge what fruitlets we have and whether they will be viable. There is not much we can do but you will see us out feeding the young leaves so that they have as much strength and resistance to help the apple grow and keep the tree healthy through the summer and autumn.
Alex Charrington |
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