Wednesday, May 30, 2007


Most bananas grown universal are used for local consumption. In the tropics, bananas, particularly cooking bananas, stand for a major source of food, as well as a major source of income for smallholder farmers. It is in the East African highlands that bananas reach their utmost importance as a staple food crop. In countries such as Uganda, Burundi and Rwanda per capita consumption has been estimated at 450 kg per year, the highest in the world. Ugandans use the same word "matooke" to describe both banana and food.
In the past, the banana was a highly sustainable crop with a long plantation life and stable yields year round. However with the entrance of the Black Sigatoka fungus, banana production in eastern Africa has fallen by over 40%. For example during the 1970s, Uganda produced 15 to 20 tonnes of bananas per hectare. Today production has fallen to only 6 tonnes per hectare.

Monday, May 14, 2007

Synthetic and artificial gemstones

Some gemstones are manufactured to imitate other gemstones. For example, cubic zirconia is a artificial diamond simulant composed of zirconium oxide. The imitations copy the look and color of the actual stone but possess neither their chemical nor physical characteristics. However, true synthetic gemstones are not necessarily imitation. For example, diamonds, ruby, sapphires and emeralds have been manufactured in labs, which possess very nearly the same chemical and physical characteristics to the naturally occurring variety. Synthetic corundums, including ruby and sapphire, are very ordinary and they cost only a fraction of the natural stones. Smaller synthetic diamonds have been manufactured in large quantities as industrial abrasives for many years. Only recently, larger synthetic diamonds of gemstone quality, especially of the colored variety, have been manufactured.