Oldtimers input on strange things re vegetation requested

Our mangos trees usually drop some immature fruit, but the trees are full, just like always. Knock wood. We're in the rain forest on STX.

Don't know a thing about genip or papaya trees, but this is often a sign of a lack of water. How's the rainfall this year?

I'd thought of the same thing too as we're going through a very dry spell. It could be an unusual combination of too much rain when the blossoms were forming and then a very dry spell. Not an unusual weather pattern, but maybe this year all at the "wrong" time.

Likewise my passion fruit blossoms were prolific and then I lost them all during heavy rains the middle of May, then blossoms came again but fruit isn't forming.

It's certainly of note that the Trade Winds have been dying down earlier each year in recent years. Last year it was unusually hot starting in June and this year it started in May. Not a good omen for hurricane season, particularly in light of the past few years of such devastating hurricanes which have fortunately bypassed us but have hit the mainland with such intensity.

Thanks for your input!

Hello!

My lime tree is not producing, I wondered if it was because I lack some bees? Our papaya trees are drying out and falling over. The ones down hill from our 'grey' water are doing fine.

We really could use some rain. My cistern is low.

Teresa

It could be the sahara dust. Article in todays paper---

Researchers say Sahara dust could carry danger
Microbiologists have discovered bacteria and fungi in the African dust
By PATRICK JOY
Thursday, June 8th 2006

ST. CROIX - Traveling thousands of miles across the Atlantic Ocean, the hazy clouds of African dust that drift into the territory every summer have long been assumed sterile - any live organisms burned off by intense solar radiation on the long, high-altitude journey to the Caribbean.

Microbiologists at the United States Geological Survey, however, have recently discovered some worrisome hitchhikers.

A team of USGS researchers, including former St. Thomas resident and All Saints School graduate Christina Kellogg, have isolated bacteria and fungi in the dust that could be harmful to plants, animals and humans. While the exact impact these particular strains might have is still being researched, the species have been associated with diseases that cause blights on fruits, soft wood in trees, blood poisoning in green turtles and wound infections in humans.

The findings are the latest in a field of expanding research on the global transport system that carries billions of tons of dust around the world every year. Storms lift the dust off Africa's deserts and the trade winds carry the dust across the Atlantic and into the Caribbean.

The climate factor of the equation involves a complex pressure system known as the North Atlantic Oscillation. The oscillation is a combination of high and low pressure systems in the Atlantic that influences the strength of the trade winds blowing east to west across the ocean. When the oscillation is in its "positive" phase - with pressure near the Azores abnormally strong and low pressure over Iceland abnormally low - the strength of the trade winds that transport dust from Africa to the Caribbean increases. The oscillation has been in a lengthy positive stage for the past few decades.

Regional conditions also play a role. Sea surface temperatures on the east and west coasts of the continent seem to influence the number and strength of storms that pick up the dust. In recent years, those temperatures have been helping to create the ideal conditions for dust transport.

Western Africa also has seen increasingly arid conditions in recent decades, with a massive drought gripping the region two years ago. The result has been more dust on the ground and more in the air, leading last year to the largest recorded dust cloud that the USGS has seen since it began studying the phenomenon in 1997.

Another factor is human land use in western Africa. With cattle, goats and other livestock roaming the borders between arable land and desert, desertification began to rise in the 1960s and peaked in the 1970s and 1980s before declining in the 1990s. Research also shows that human off-road vehicle traffic has had an impact, crushing the mineral and microbial rich crust and releasing it into the air.

Kellogg says growing and modernizing African populations also are changing the composition of the dust.

"The pulses contain different qualities and quantities than it used to. There's not a lot of sanitation, so you have sewage being disposed of in the river," she said. Sewage contains a large number of bacterial organisms. "Then when the river floods it is carried out on to the plain, where it dries out and is aerosolized."

Kellogg said that everything from burnt garbage to personal care products and antibiotics could be making their way into the dust and stowing away to the Caribbean.

While Kellogg has been studying microbes, fellow USGS researcher Ginger Garrison has been investigating the chemical side of the dust, collecting air samples from sites on St. John, St. Croix, Trinidad and even Mali. Garrison's and colleagues' research suggests that much more than benign soil is being carried across the ocean - that metals, chemicals and even pesticides used on crops in Africa are making the long trip.

Kellogg said her research should not cause panic but people should be aware that long-distance transport of potentially troublesome bacteria, fungi and chemicals is possible.

"The intent is not to scare people but to understand what is going on," she said. "This could be having an effect, but until we understand the system we don't know if there are precautions we should be taking."