by Deb Robie
This story is just one example of how teachers can use an agricultural theme to teach science, math, geography, or even literature. NH Ag in the Classroom can help you find fun and exciting ways to teach your students in a way that will be engaging and memorable. Isn't that what teaching should be all about?
Somewhere near you, an apple factory is hard at work. We don't think of it as a factory because it's not a big building. No trucks rumble in with supplies. No smokestacks belch out gray clouds, and no whistles blow. Nobody even works there; the factory runs all by itself. Yet it keeps producing tasty little nutritious snacks year after year. It's that plain old apple tree, maybe right out in your backyard.
But it really isn't a "plain old apple tree"; it really is an amazing, efficient factory. Let me show you around.
Around the month of October your apple factory is probably adding a last bit of sugar to this year's crop. Until then the apples (depending on variety) have been quite hard and may have tasted rather tart. Anyone touring the factory before mid-September or October (depending on where in the state you are) may have wanted to stop the assembly line to see what went wrong. But nothing has gone wrong; the visitors just came too early, that's all.
The sugars in the apples, until now, were complex sugars called carbohydrates. Now they're breaking down into simple sugars that taste sweeter to us. This break down of sugars, the last step in the apple assembly line, helps turn hard, tart apples into softer, sweet-tasting ones. The tree factory works this step best in the clear, crisp days of autumn.
If you look around the factory, you'll notice that the apples stored closet to the windows-those on the outer edges of the tree-are the reddest. That's because they get more sunlight than apples stored in the closets-close to the trunk.
This apple factory is far busier than it looks at this time of year. Besides putting the final touches on this year's product, it's also making plans for next year. It's beginning to store supplies so that it will be ready to work next spring.
Look closely at the point where the apple stem is connected to the branch. Nearby you should see a little bud. That's the fruit bud for next year's apple. Everything needed to grow an apple is tightly packed inside. The supplies simply haven't been unpacked yet.
You see, this apple factory usually takes time off in the winter. The machinery needs a rest. But before it closes shop completely, it packs its next-year's supplies into weatherproof containers that we call buds. They won't be damaged when the heat is turned down. Buds on the apple tree have scales wrapped tightly around them to protect them from snow and ice. Deep within the buds lay all the apple-flower and leaf parts, just waiting for spring.
When spring warms the apple factory, the machinery turns on once more. Sap begins to flow inside the tree. Then supplies are unpacked; flower buds and their leaves begin to swell open. We know that the factory is working because small green leaves and clusters of apple blossoms dot the tree.
If you'd tour your apple factory in the spring, you'd be amazed at how efficient it is. Nothing is wasted. Every supply is there for a purpose.
First, a little cluster of leaves opens up. These are needed to make food for the tree, using sunlight.
As the leaves spread, little blossom buds appear. Each bud is enclosed by five tiny, green, leaf-like things called sepals. They protect the precious inner package. Soon the sepals push back, and you can see scarlet petals that quickly turn pink or almost white as they grow.
Petals help make the apple flowers noticeable and attractive to bees. Apple flowers also produce a sweet juice called nectar to help attract bees. You'll see later where bees fit into the plans.
At the center of each apple blossom grow the supplies for making apples. Twenty little stalks grow in a ring around the base of the petals. On top of each stalk is a little, two-sectioned bag. These stalks-with-bags are called stamens. The bags hold pollen.
Right in the middle of the stamens grows a part called the pistil. The thick bottom part of the pistil, the ovary, will become the apple. Inside it are ten ovules, or seeds-to-be. The top part of the pistil is divided into five little tubes called styles. Each style has a sticky top called a stigma. The sticky stigma must be brushed with pollen. The pollen then travels down a tube to the ovary and join the ovules to make apple seeds. The fruit grows around the seeds.
Sounds complicated, doesn't it? But then most factories are.
Anyway, this is where the bees come in. By springtime their winter supply of honey is used up, so they're eagerly looking for more food. They visit the apple blossom to collect the nectar and to gather pollen to feed their little bees. As they move from flower to flower, their bodies become dusted with pollen. They brush against the sticky tips of the pistils, and some pollen rubs off. This is the process of pollination and it is essential for the development of apples.
If the pollen is from different varieties of apple blossoms, cross-pollination has taken place. Most apple flowers must be cross-pollinated, so the bees are really important. I suppose that you could say the apple factory does have a few workers-the bees.