Earth Wise

A look at our changing environment.

You are here: Home / Archives for fruit

fruit

A New Problem For New York Apples | Earth Wise

By Leave a Comment

New York is the second largest apple-producing state in the country, trailing only Washington state.  New York averages nearly 30 million bushels of apples annually from approximately 600 commercial growers.  The apple industry supports 10,000 direct agricultural jobs as well as 7,500 indirect jobs involved with fruit handling, distribution, marketing and exporting.

Thus, there is considerable concern about the recent discovery by Cornell plant pathologists of a new fungal pathogen that causes bitter rot disease in apples.  They also found a second related fungus that is known to cause rot disease in other fruits but has now been found for the first time in apples.  The study was published in early July in the journal Scientific Reports.

Both of these pathogens belong to the genus Colletotichrum, which contains 189 species of fungi that cause devastating rot diseases in multiple fruit crops, including bananas, strawberries, citrus, avocados, papayas, mangoes and apples.

Unless protective measures are taken in a timely manner, apple losses from bitter rot in New York state can average up to 25% per year.  Some organic farms have lost essentially all of their crop at times.  Bitter rot also can destroy up to 5% of marketable fruit in post-harvest storage.

The Cornell study of samples from eight New York counties found both the Colletotrichum chrysophilum fungus, that had not been found in apples before, and a newly-discovered fungus that they named Colletotrichum noveboracense, after the Latin name for New York State.

The researchers plan to work with other plant pathologists and apple breeders to identify possible genes that confer natural resistance to Colletotrichum fungi that can be bred into apple cultivars.

**********

Web Links

Scientists identify new pathogen in NY apples

Photo, posted October 12, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Narwhal Tusks And Stories Teeth Can Tell | Earth Wise

By Leave a Comment

Teeth and particularly narwhal tusks are getting some unusual press recently when one of them was the weapon of choice to fend off the London Bridge attacker, which was a good choice according to Harvard dental researcher Dr. Martin Nweeia.  Turns out that narwhal tusks have some pretty amazing physical features.  They exhibit both extreme strength and flexibility at the same time.  The narwhal is known as the unicorn of the sea, a pale-colored, medium-sized whale found in Arctic coastal waters and rivers.  In males, the more prominent tooth grows into a sword like, spiral tusk up to 8.8 feet long.

Changes in the shape of teeth over time can tell us about climate change. Adaptations in horse teeth 55 million years ago from North America were observed and caused by changes in climate, favoring different food sources.  The horses changed their diets from fruit to more favorable grasses and their teeth changed in response. For this same reason, the teeth of elephants adapting in different environments of Asia and Africa have different tooth forms.  Both eat plants but Asian elephants, with more ridges on their teeth, eat larger amounts of grasses while African elephants, with wider spread ridges, eat more leaves. 

Teeth have been used to link land mass theories like the Bering Land Strait Theory, hypothesizing that North America and Asia were once one land mass. The teeth shape and form of people on both sides of the Bering Land Bridge shared a common “mongoloid dentition” with unique features. And so, can the narwhal tusk tell us something about a changing Arctic?  Scientists have discovered that the narwhal tusk is a giant sensory organ that is able to continually monitor its environment and has the ability to detect ice formation, and melt, both capabilities helpful for surviving in a changing Arctic.

**********

–Earth Wise acknowledges script contribution from Dr. Martin Nweeia of Harvard University.

Web Links

Fossil teeth reveal new facts about a mass extinction 260 million years ago

From the Horse’s Mouth: Teeth Reveal Evolution

Photo, posted April 3, 2019, courtesy of James St. John via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bananas In Danger

By Leave a Comment

For a few years we have been talking about the precarious position of the global banana crop, which is almost entirely based upon a single cloned cultivar known as the Cavendish banana.  The banana you buy in Rome is identical to the one in Rochester.  And therein lies the danger:  if a fungal blight can kill one banana shrub, it can kill them all.

For decades, a fungal disease known as Panama Disease Tropical Race 4 has been wreaking havoc on banana plantations in the Eastern Hemisphere.   Even though it was first identified in Taiwanese soil samples in the early 1990s, the destructive fungus remained confined to Southeast Asia and Australia until it was confirmed in both the Middle East and Africa in 2013.  Experts continued to fear its eventual appearance in Latin America, which is the epicenter of the global banana export industry.

In August, Colombian agricultural authorities announced that laboratory tests have positively identified the presence of Tropical Race 4 in the Caribbean coastal region and declared a national state of emergency.

The infection of the banana plant does not produce bananas that are unsafe for humans.  What happens is that the infected plants eventually stop bearing fruit.

Cavendish bananas are a prime example of the dangers of growing crops with limited genetic diversity – known as monoculture.  It leaves food systems dangerously vulnerable to disease epidemics.

This has happened to the global banana crop before when the predecessor to the Cavendish banana – the Gros Michel – was mostly eradicated by another fungal outbreak.  At the moment, there is no ready replacement banana to bail out the industry, but scientists are desperately trying to breed one.  In the meantime, the world’s supply of bananas is in real danger.

**********

Web Links

The banana is one step closer to disappearing

Photo, posted July 9, 2009, courtesy of Dabin Lambert via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Produce Stickers

By

The fruit and vegetables in most grocery stores these days come with little stickers on them with a numerical code identifying the produce for the cashier at the checkout counter.  They are quite helpful for the cashier but a real irritation for the customer.  Half the time it is difficult to get the labels off the piece of produce and sometimes we don’t notice them at all and end up with a little paper sticker in our salad.

[Read more…] about Produce Stickers

Light Pollution And Early Spring

By

We have talked about the impact of light pollution on our ability to see stars and the Milky Way.  We have also discussed its impact on our circadian rhythms.   Recently, scientists in Great Britain published a report on the relationship between light pollution and the timing of when trees produce their buds.  The results of the study suggest that light pollution is causing plants to jump the gun on spring.

[Read more…] about Light Pollution And Early Spring

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)