Someone Grafted Your Groceries

These days, if we hear about two different plants being combined, the first thing we think of is modern biotechnology. But the low-technology process of grafting remains an extremely important form of genetic engineering in agriculture.

Grafting still holds an important place even in an age of high-tech agriculture. Many kinds of plants are grown not from seeds but from pieces cut from existing plants. Farmers cut branches or buds, young growths, from one plant and place them on a related kind of plant.

The branch or bud that is grafted is called a scion [pronounced SY-uhn]. The plant that accepts the graft is called the root stock.

Over time, the parts from the two plants grow together. The grafted plant begins to produce the leaves and fruit of the scion, not the root stock.

A graft can be cut in several ways. A cleft graft, for example, requires a scion with several buds on it. The bottom of the scion is cut in the shape of the letter V. A place is cut in the root stock to accept the scion.

The scion is then securely placed into the cut on the root stock. Material called a growth medium is put on the joint to keep it wet and help the growth.

Grafting can join scions with desirable qualities to root stock that is strong and resists disease and insects. Smaller trees can be grafted with older scions.

The United States Environmental Protection Agency says producing stronger plants by grafting can reduce the need to use pesticides.

Agriculture could not exist as we know it without grafting. Many fruits and nuts have been improved through this method. Some common fruit trees such as sweet cherries and McIntosh apples have to be grafted.

Bing cherries, for example, are one of the most popular kinds of cherries. But a Bing cherry tree is not grown from seed. Branches that produce Bing cherries must be grafted onto root stock. All sweet cherries on the market are grown this way.

And then there are seedless fruits like navel oranges and seedless watermelons. Have you ever wondered how farmers grow them? Through grafting.

The grapefruit tree is another plant that depends on grafting to reproduce. Grapes, apples, pears and also flowers can be improved through grafting.

In an age of high-technology agriculture, grafting still holds an important place.

Source:
VOA News Service

Invasive Insect Damages US Ash Trees

A beetle invasion in the United States has killed at least twenty million ash trees. The invasion of the emerald ash borer was first discovered near Detroit, Michigan, in 2002. Experts believe the small green insects arrived in the 1990s in shipments of goods from China.

The emerald ash borer has destroyed trees in the Midwest and as far east in the United States as Maryland. The insects have also spread as far north as Ontario, Canada. Emerald ash borers are attacking tree farms and can also spread when logs and firewood are transported.

Ash trees are popular. They grow well in heavy clay soils, and they can survive ice storms well. They produce many leaves, so they provide shade protection from the sun. And in the fall the leaves turn a beautiful gold and purple.

Ash trees can resist many diseases. But they cannot resist the emerald ash borer. It lays eggs on the bark. Then the young larvae drill into and feed on the inner bark. This harms the ability of the tree to transport water and nutrients.

The United States Department of Agriculture is working to save the ash tree. So are agriculture departments and university extensions in a number of states.

In some places, farmers are using "detection trees." These have an area where bark has been cut away. The area circles the tree and is called a girdle. The girdling process weakens the trees. It makes them easier targets for borers, and shows if the insects are nearby.

Efforts to stop the spread of the emerald ash borer include cutting down affected trees. A tree farmer in Maryland, for example, recently faced the loss of hundreds of trees.

There are worries that the ash tree might disappear unless the invasion is controlled. To prepare for such a possibility, a government laboratory is collecting seeds from ash trees.

David Burgdorf works in East Lansing, Michigan, for the Natural Resources Conservation Service; the service is part of the United States Department of Agriculture. He is asking people to send in ash seeds. The laboratory examines and x-rays the seeds to make sure there are no living borer embryos.

The best seeds are then sent for storage in a seed bank in Fort Collins, Colorado. There, they are dried and frozen at the National Center for Genetic Resources Preservation. Should the seeds ever be needed, the hope is that scientists might someday develop an ash tree that could resist the little green attackers.

Source:
VOA News Service

United Nations Study Finds Improvements in the World's Forests

The Rome-based United Nations Food and Agriculture Organization (FAO) recently presented its biannual report on the State of the World's Forests, which found that most countries in Europe and North America have reversed centuries of deforestation.

In its March 2007 report, the FAO noted that economic prosperity and careful forest stewardship have had positive effects on the world's forests, with many forests showing a net increase in forest area.

But forests in poorer nations, and those embroiled in wars and internal conflicts, still face substantial threats. Around 13 million hectares of forest are still lost annually to other land uses. However, the net deforestation over the last five years has been reduced from nine to seven million hectares. This is mainly due to reforestation and preservation of existing forests.

Africa is one region that faces huge losses. The continent accounts for about 16 percent of the global forests. Between 1990 and 2005, Africa lost over nine percent of its trees.

On the positive side, forest area increased in Asia between 2000 and 2005. While severe deforestation continues in South-East Asia, especially Indonesia, Malaysia, Papua New Guinea, there were tremendous increases in forested areas in China, Vietnam and a number of smaller countries.

One of the principal causes of deforestation is the conversion of land for farming or livestock. Forests currently cover about 30 percent of the world's land area. According to the FAO the world lost three percent of its forests between 1995 and 2000.

Source:
VOA News

Americans Face Higher Food Prices as More Corn is Used for Ethanol Production

The United States Department of Agriculture says high demand for ethanol fuel made from corn will mean higher meat prices. In its monthly crop report on March ninth, 2007, the department said feed costs are rising for cows, pigs and poultry birds. Corn, or maize, is their main feed.

Corn has been selling at more than three dollars a bushel in early 2007. In 2006, the average was two dollars.

The government says ethanol is using twenty percent of the American corn crop from last year. With this year's harvests, the amount is expected to reach twenty-five percent.

The National Chicken Council has objected to Congress about the situation. The council is a trade organization that represents the industry. It says the feed cost of the chicken industry alone has risen by forty percent.

In January, Tyson Foods, the world's biggest meat processor, reported its first profitable three-month period in a year. But the head of the Arkansas company warned that sharply higher corn prices have become a "major issue" for the food industry. Richard Bond says people will have to pay more for food because companies will be forced to pass along rising costs.

But Deputy Agriculture Secretary Chuck Conner says demand for corn will probably get farmers to plant more corn. A University of Missouri Extension official says ethanol could bring the biggest change in American agriculture since farmers began planting soybeans.

Some economists have suggested that land from the Conservation Reserve Program should be used for additional corn production. But the Agriculture Department says only a limited area of land will be released for use over the next four years. The program supports the planting of things like native grasses or trees to reduce the loss of soil from croplands.

The department has appointed a committee to study the needs of biofuel producers. These are fuels like ethanol that are made from renewable resources.

On March ninth, the United States and Brazil signed a cooperation agreement on biofuels technology. The signing took place in Sao Paulo during the first stop on a trip by President Bush to Latin America. Seventy percent of the world's ethanol supply comes from the United States and Brazil. But while most American ethanol is made from corn, most Brazilian ethanol comes from sugar cane.

Source:
VOA News

Benefits of Mulching

Mulch is important to farmers. Mulch is a protective cover of material that is spread on top of soil. It is usually made out of organic material, like crop waste. Farmers may keep the remains of maize or other crops on top of the soil. This creates mulch on the soil surface. The plant remains help protect the soil against wind and water damage. This is called conservation tillage.

Mulching is one of the best things people can do for their plants. Mulch not only protects the soil against wind and water damage. It also helps keep the soil from getting dry, and reduces the need for watering plants. It also limits temperature changes in the soil. And it stops unwanted plants, or weeds, from growing.

Organic mulch improves the condition of soil. As the mulch breaks down, it provides material which keeps the soil from getting hard. This improves the growth of roots and increases the movement of water through the soil. It also improves the ability of the soil to hold water. Organic mulch contains nutrients for plants. It also provides a good environment for earthworms and other helpful organisms in the soil.

The best time to add mulch depends on your goal. Mulch provides a thick barrier between the soil and the air. This helps to reduce temperature changes in the soil. As a result, mulched soil will be cooler than other soil in the summer. Mulched areas usually warm up more slowly in the spring and cool down slowly in autumn. In winter, the mulched soil may not freeze as deeply as other soil.

Mulch used to help moderate the effects of winter weather can be added late in autumn. The best time is after the ground has frozen, but before the coldest weather arrives. Spreading mulch before the ground has frozen may attract small animals searching for a warm place to spend the winter. Delaying the spreading should prevent this problem. The animals will probably find another place to live.

The United States Department of Agriculture says it is easy to find organic mulch materials. Cut-up leaves and small pieces of tree bark can be used. Grass cuttings are also a good mulch for plants. Mulch from newspapers works well in controlling weeds.

Source:
VOA News