Bees’ value to agriculture underestimated

The economic importance of bees is significantly undervalued, according to a European study released this week.

Strawberries pollinated by bees were of far higher commercial value than fruit that was self-pollinated or pollinated by the wind, researchers in Germany reported Wednesday.

Bee pollination strongly increased the commercial value of strawberries by producing well-shaped fruit of increased weight, according to the study.

In addition, it increased shelf life, enhanced coloring and lowered sugar-acid ratios of most varieties of strawberries.

The study, by a team at the Department of Crop Sciences at the University of Göttingen in Germany, comes on the heels of a 2011 report by the UN Environment Program that showed that pollination by bees and other insects contributed about a little more than $204 billion, or 9.5 percent, of the total global value of food production.

But the most recent analysis offers evidence that the 2011 estimate could have substantially devalued the agricultural impact of the bees.

The Germany team conducted its study by planting nine commercial strawberry varieties in an experimental field. Plants were either covered with special gauze bags to allow pollination by the wind or other parts of the plant, or were left open for visiting by bees.

Fruit was then collected and graded according to standard commercial criteria.

They were then put through a battery of lab tests for objective assessment of color, firmness and resistance to premature softness or fungal spread.

In seven of the 10 varieties, bee-pollinated fruit were more intensely red than their self- and wind-pollinated rivals, according to Agence France-Presse.

They were 11 percent heavier than wind-pollinated and 30.3 percent heavier than self-pollinated fruits, the wire service reported, adding that they were also firmer, which meant their shelf life was about 12 hours longer than that of wind-pollinated strawberries and more than 26 hours longer than self-pollinated ones.

In commercial terms, this is a big deal, the study reported.

“More than 90 percent of strawberries can become non-marketable after only four days in storage. Softer flesh exposes them to accidental bruising and fungus infection,” according to the wire service.

In the 1.5-million-ton European market for strawberries, bee pollination reduces waste by 11 percent, or $320 million, each year, according to the study.

Add in other benefits, and bee pollination accounted for around $1.44 billion of the market’s value of $2.9 billion, the study said.

The benefits of bee pollination may be partly seen by the effects on achenes, the tiny seeds that line the outside of strawberries.

Bee-pollinated strawberries had far more fertilized achenes than other fruit, because the insects, with their typical diligence, pollinated all of the plant, rather than just part of it.

“The achenes are important because they control levels of a plant hormone called auxin, which in turn influences a second hormone called gibberelic acid,” according to Agence France-Presse.

Higher levels of the two hormones delay fruit-softening proteins called expansins.

“Our results showed that crop pollination is of higher economic importance than hitherto thought,” according to the study, published in the British journal Proceedings of the Royal Society B.

“Our comprehensive findings should be transferable to a wide range of crops and demonstrate bee pollination to be a hitherto underestimated but vital and economically important determinant of fruit quality.”