Why plants grow faster at night-time

QUESTION

Do plants grow faster at night?

IN 1880, Charles Darwin published The Power Of Movement In Plants. In it, he recorded the motions of a tobacco leaf on which he had waxed a pin. He concluded plants grew more at night than in the day, and that they grew in regular spurts, with stems elongating fastest in the hours before dawn.

Plants like sorghum can elongate a centimetre or more each night. Darwin’s theory was that plants grow more suddenly when they get less light.

A seedling growing more slowly than those around it will be blocked from the sun and will grow taller in an attempt to reach it.

His ideas were largely dismissed then but today scientists believe a pronounced rhythmic growth by plants at night, during certain seasons and when shaded by other plants, has a clear survival value.

Plant cells have phytochromes to measure the ratio of colours of light. Plants that detect they are shaded elicit growth hormones.

Scientists found genes in Arabidopsis (mustard) that deal with hormone biosynthesis, signalling and metabolism, which are all correlated with rhythmic growth.

The genes allow a wave of growth hormones in the predawn hours.

Dr Ken Warren, Glasgow. I recently drank a bottle of Ernie Els’s ‘Big Easy’ Shiraz. What other celebrities make wine? FURTHER to earlier answers, there is a Donald Trump winery. Trump Winery is on a 1,300-acre estate in Charlottesville and is Virginia’s largest vineyard. Trump purchased it from his friend Patricia Kluge, former wife of billionaire John Kluge, in 2011. It is currently run by Trump’s son Eric.

On Valentine’s Day of this year a Virginia branch of the National Organization for Women called for a boycott of Wegmans supermarkets for selling Trump’s wine. But the boycott backfired with Trump supporters showing their support for the US president by buying his wine in bulk in Wegmans.

Jackie Richards, Welshpool.