No tears in future of onions

Onion breeders are making headway in improved storability and
resistance to key diseases. Sue Jupe reports.

Post Brexit there is likely to be significant potential for UK onion growers to
increase their share of the UK onion market, writes Sue Jupe. Particularly thanks
to recent advances in onion storage technology together with new genetics
optimizing flexibility.

Currently around 50% of bulb onions consumed in the UK are imported. A
surprisingly high figure considering the suitability of our climate, soils and
varieties and the commodity nature of the crop – with low margins making
operating at scale essential.

Match funding through the Fruit and Veg Aid Scheme has supported major
development by producer organisations in onion storage systems. Reliance on
imports has been reduced thanks to innovations in high quality onion storage
technology extending the marketing period of home grown onions to 49 weeks,
while reducing wastage and increasing marketed volumes. Since 1990 the UK
industry has seen a 30%+ increase in the five-year average onion yield.
Alongside advances in storage, onion breeding is also playing a significant role.
Ten years ago downy mildew resistance in onions was aspirational while more
recently resistance to fusarium has become increasing desirable, due to higher
disease pressures.

“Progressive forward thinking onion breeding companies see such absolutes as a
challenge to be met and matched,” says John De Soyza, market development
manager for root and salad crops at Hazera Seeds UK. “We became one of the
first companies to launch a downy mildew resistant onion. The launch of our
mildew resistant ‘Santero’ variety is proving revolution, helping change what is
possible in the European organic onion market.

“More recently, through work in collaboration with Warwick University, we have
identified high resistance to Fusarium within the allium genome. This
fundamental research is set to create greater security against Fusarium attack in
the future.”

Another major challenge remains flexibility in changing seasons and market

“An early maturing variety with long storability attributes would offer major
benefits by optimizing flexibility,” explains John De Soyza. “However, until now
early maturing varieties have failed to offer the long term storability attributes
generally associated with some mid and late season varieties.”
Facing up to the challenge, over several years Hazera has subjected onions in
screening trials to extreme storage tests in order to select for improved

“Initially these tests pushed ambient stored samples as far as possible into May
and June to see who were the ‘last men standing’,” says John.
“Although the ambient test gave good comparative data, we set out to push the
onions further developing an accelerated deterioration test. This creates high
pressure conditions for rotting and sprouting using elevated temperatures over
a ten week period.”

These more extreme tests put additional pressure on the onions and one variety
stood out – Fasto F1. “In recent testing this variety achieved an astonishing
100% marketable yield ex store, despite the extreme storage environment, and
the test bulbs remained highly dormant,” says John. “Encouragingly, in 2017
commercial scale trials showed Fasto F1 to be very high yielding and early

In this year’s NIAB trials, on average Fasto F1 reached 80% fall over 1-4 days
ahead of the first early reference variety.
“Such a variety represents ‘the Holy Grail’ of onion breeding – offering complete
flexibility to the grower through early maturity and long term storage,” says
John. “Widely tested and put through it paces this year in the main UK onion
production areas, Fasto F1 has consistently demonstrated strong early
establishment and vigour – despite some very challenging spring conditions. It
also appears to withstand herbicide applications better.

“Maturity has been very early on all locations comparing well to the earliest UK
standards. Bulb size and uniformity have been excellent leading to high yields
and little waste or undersized bulbs.
“While breeding revolutions are rare, Fasto F1 has so far show itself to be a
groundbreaking variety. Together with improvements in storage technology, this
timely new introduction is poised to benefit the UK onion industry by helping to
stem the tide of onion imports.”