What's the Hottest Hot Pepper?

Varieties of the pepper species Capsicum chinense, such as 'Habanero', are generally the hottest peppers with Scotch Bonnet, Thai, and Cayenne cultivars falling in behind.

Heat intensity of peppers is most commonly measured in Scoville Units, with Sweet Bell Peppers measuring in at zero Scoville Units. For comparison, Habanero peppers range from 100,000 - 300,000+ Scoville Units, while pure capsaicin--the chemical that causes the burning sensation--registers at a whopping 15,000,000 - 16,000,000 Scoville Units!

If you are looking to grow really hot peppers, try to pick those cultivars which register higher on the Scoville scale. Just remember that capsaicin does not dissolve in water, so make sure to keep milk or yogurt nearby to help quench the burn!

Source:
U.S. National Arboretum

Controlling Algae in Your Pond or Water Garden

Algae is present because the nutrients are available to support its growth. A small amount of algae is good for the aquatic garden since it absorbs excess nutrients in the water, helping to keep it pure. Uncontrolled algal growth depletes oxygen in the water and makes the water inhospitable for the fish.

Make sure that you have not overstocked your pond with fish. Also make sure that you are not overfeeding your fish. Uneaten food is source of nutrients that translates into algal growth, and a large population of fish produces a large amount of nutrients when they excrete waste products. A pond biofilter can help remove excess nutrients and keep the water clear. You can also add water to the pond periodically to dilute nutrients if you have an overflow system that can drain excess water out of the pond. Barley straw discourages the growth of certain types of algae. Pond supply firms sell barley straw products that can be submerged in your pond. Dyes are available that can be added to the water. The black material absorbs the sun's light energy and deprives the algae of the light it needs to carry out photosynthesis and survive. Dye products have the added advantages of protecting your fish from predators and concealing plumbing and pots in your pond.

Many aquatic plant gardeners are tempted to drain the pond, clean it, and start over with fresh water when confronted with algae. This is usually counterproductive since the excess nutrients that cause algae to grow build rapidly in the fresh water. Frequent water changes and cleaning can make for drastic changes in pond pH and are stressful for fish and other aquatic life. Only drain and clean your pond when a substantial layer of decaying organic matter has accumulated at the bottom.

Source:
U.S. National Arboretum

Global Warming Could Decrease Crop Yields

If there is any good to come from global warming, it is the notion that plants would thrive on the rising emissions of carbon dioxide in the atmosphere, the leading greenhouse gas that helps trap heat. Carbon dioxide is as vital to plant breathing as oxygen is to us. Biologists say that for most vegetation, the more carbon dioxide there is in the air, the more they grow.

At the same time, they point out that extra CO-2 also hurts plants. They say plant growth is slowed by higher temperatures and lower soil moisture caused by faster evaporation.

The United Nations Intergovernmental Panel on Climate Change, the world's leading authority on global warming, has concluded that these two trends balance each other, so global warming was not expected to hurt agriculture overall.

U.S. government and university experiments carried out in greenhouses have supported this view.

"What they do is put one kind of plant in two different greenhouses that are right next to each other and then they put higher CO-2 levels in one of the greenhouses and have regular atmospheric level of CO-2 in the other greenhouse," said Myron Ebell from the Competitive Enterprise Institute in Washington, a pro-business group that opposes government efforts to limit greenhouse gas emissions.

He says more carbon dioxide is good for farming.

"The results of these studies going back half a century or more are stunning because almost every single study show not only do all kinds of plants grow more quickly with higher levels of CO-2, but they are also much hardier," he said. "They are more resistant to things like drought."

But a new study shows differently when crops are grown outdoors. University of Illinois agriculture expert Stephen Long and colleagues report in the journal "Science" that the benefits of raised CO-2 levels in global warming do not balance the harmful effects.

"The two things were very roughly thought to counteract each other," he said. "However, the CO-2 fertilization until recently has been studied only in greenhouses and other enclosed environments. If you raise the CO-2 level under fully open conditions, do you see this large fertilization of crop yield? Roughly what we found was that under open air conditions, that increase appears only to be half of what was expected."

The experiments were carried out using five different crops around the world. All showed considerable growth reductions outdoors. Long says that in the tropics, carbon dioxide increases may not help the growth of crops like corn and sorghum at all.

The findings suggest that without changes in the way crops are planted, future yields will drop with increasing carbon dioxide levels.

"We also simulated that rise in our experiment," he said. "That reduces the yield of soybean by about 20 percent, which is a very large yield decrease, and this has not been taken account in future projections on food supply."

But Myron Ebell of the Competitive Enterprise Institute maintains that higher carbon dioxide concentrations benefit agriculture.

"There is a lot of satellite evidence that the Earth is in a period of rapid greening right now and that is probably due to higher CO-2 levels," he said.

Researchers on both sides of the debate agree that more studies are needed to understand the effects of climate change and greenhouse gases on crops.

Source:
VOA News Service
Author: Frank Ling
First published: June 30, 2006

Jojoba - An Unusual Oilseed Crop

Jojoba is a woody plant that grows in the southwestern United States and northwestern Mexico. It needs dry weather and cannot survive low temperatures.

The jojoba plant produces a high quality oil. In fact, more than half of the seed can be oil. This liquid wax does not spoil easily. And it keeps its chemical qualities at temperatures up to three hundred degrees Celsius.

Jojoba oil is mainly used in skin care and beauty products. Scientists say the oil is chemically similar to the oil produced by human skin.

But jojoba oil can also be used to control insects on crops. It was approved in the United States as a pesticide in nineteen ninety-six.

It can be sprayed on all crops to fight white flies. It is also used to control mildew on grapes and on non-food plants. Jojoba-based pesticides work mainly by forming a barrier between a plant leaf and pests.

The Environmental Protection Agency says jojoba oil is not a risk to non-target organisms. And it says it does not know of any harmful effects to humans even if the oil is eaten. But farmers should not release jojoba products into waterways. Oils are generally dangerous to water life.

Many industrial uses for jojoba oil are being studied. It can be used as a lubricant for machines or electronic parts. It has even been considered as a low-calorie food additive because the body cannot break down jojoba oil.

Large plantings of jojoba in the United States are said to date back to the late nineteen seventies. The export market started to grow in the middle of the nineties. By two thousand, the Agriculture Department found that about ninety percent of American jojoba oil was exported. France, Switzerland and Japan are major importers.

The International Jojoba Export Council has members in Mexico and the United States. It also includes companies and universities in Australia, Argentina, Chile, Peru, Egypt and Israel.

A limited number of producers, and changing harvest conditions, mean that prices for jojoba oil can change sharply.

Source:
VOA News Service