Seed World

No Tears In Future Of Onions

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 conditions.

“An early maturing variety with long storability attributes would offer major benefits by optimizing flexibility,” explains 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 storability.

“Initially these tests pushed ambient stored samples as far as possible into May and June to see who were the ‘last men standing’,” says De Soyza. “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 De Soyza.

“Encouragingly, in 2017 commercial scale trials showed Fasto F1 to be very high yielding and early maturing.”

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 De Soyza. “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.”

Source: Hazera