Of a colourful 'superbloom'

SNIPPETS

Of a colourful ‘superbloom’

Death Valley, one of the hottest places on Earth, is currently a riot of colour: More than 20 kinds of desert wildflowers are in bloom there after record-breaking rains last October. It’s the best bloom there since 2005, according to Abby Wines, a spokeswoman for Death Valley National Park, and “it just keeps getting better and better.”

The flowers started poking up in November, but the particularly colourful display emerged late last month in the park, which is mainly in California but stretches across the Nevada border. On Twitter and Instagram, park visitors have taken to calling it a “superbloom.”
The park gets about two inches of rain annually, so it always sees some wildflowers, though not as many or as varied. But it doesn’t take much more rain than that to completely dye the desert, Abby said, making last fall’s unusually heavy rains particularly effective.

Over the past couple of years, as much of California has been in a state of exceptional drought, in Death Valley, where dry is the norm, rainfall has hovered around the average, Abby said.

The primary threads in the floral carpet are yellow — the most common flower is called Desert Gold, which looks like yellow daisy.

But there are also strands of purple, pink and white. One of Abby’s favourites is the “Gravel Ghost,” a white flower that appears to float above the ground. The flowers are expected to stick around until mid-March, unless it gets too hot or windy.

 Wild tomatoes repel whiteflies, study says

Whiteflies are the scourge of many farms, damaging tomatoes, peppers, eggplants and other crops. Now, researchers in Britain report that a species of wild tomato is more resistant to the pest than its commercial counterparts.

The wild type, the currant tomato, is closely related to domestic varieties, “so we could crossbreed to introduce the resistance,” said Thomas McDaniel, a biologist and doctoral student at Newcastle University in England and co-author of the study. The study was published in the journal Agronomy for Sustainable Development. “Another method would be genetic engineering, if we identified the genes.”

The researchers studied Trialeurodes vaporariorum, a species of whitefly that often attacks tomatoes grown in greenhouses. Whiteflies damage tomato plants by extracting the plant’s sap, which contains vital nutrients; by leaving a sticky substance on the plant’s surface that attracts mould; and by transmitting viruses through their saliva.

But currant tomatoes have some sort of mechanism, yet to be understood, that repels whiteflies. “They seemed to move away every time they tried to sample the sap,” Thomas said. The wild plants also produce a chemical reaction that causes the plant sap to gum up the whitefly’s feeding tube. Growers use a parasitic wasp to control whiteflies. The wasp lays its eggs on young whiteflies, which are eaten by hatching larvae. The treatment is expensive and laborious. As an alternative, farmers use chemical pesticides, but some have been linked to declines in bee populations.

“Genetic diversity is very, very low in domestic crops, so introducing these genes that we’ve lost along the way is probably quite important,” Thomas said.

Sindya N Bhanoo