Recent advances in brassica breeding have helped growers reduce harvest costs by, for instance, improving plant uniformity so a crop can be cleared with fewer passes, or tweaking plant habit for quicker cutting. But nothing promises to slash costs in broccoli production so much as the new lines bred by Seminis that, for the first time, offer the prospect of fully automated mechanical harvesting.
The company has trademarked the concept Easy Harvest, and breeder Frans van den Bosch has spent the past 20 years using conventional methods to develop broccoli varieties with an extended stem so that the crown is presented clear of the foliage. Examples were on show at the brassica open days in Lincolnshire last month.
"The main aim has been the Easy Harvest element, but because the head is held above the canopy, stem colour is improved and the yellow halo effect is reduced," says Grainne Meade, technology development representative of Seminis' parent company, Monsanto. "The stem is also sweeter-tasting as a result."
The breeding has been accompanied by Dutch machinery manufacturer Tumoba's design work on a broccoli harvester. Trials of the varieties are still small-scale, but Seminis plans to release the first introductions in 2013.
Uniformity for harvest is a particular feature of Clause's broccoli variety Kuba, which comes in a couple of days earlier than Ironman, the industry standard for Lincolnshire. "You can achieve a 70 per cent cut in one go," says development and product marketing manager John Ward. "It also has good tolerance to bracting, which can be a problem in the summer period. It needs to be planted into a moisture-retentive soil to get the best out of it."
One of Kuba's parents came from the group's breeding programme in Australia, run by breeder Kiang Lee, while the other was sourced from its programme in France. "Kuba is a variety that's easy to clean," says Lee. "It has a straighter stem than Ironman and is more resistant to hollow stem."
While trials have shown Kuba to be flexible in its timing, in a water-stressed season such as this year's, Kechua is best suited to autumn production. "Plant in July to bring in for mid September to the end of October," says Ward.
Pharos, Sakata's second early variety in its first full commercial year, has found a particular slot in floret production, says technical manager Kate Smart. "It has a dense, heavy head with very fine bead that doesn't crumble but does break down into florets easily, so is quick to process," she adds.
SK8-901, currently in pre-commercial trials, has an 80- to 85-day timing to come in between Aquiles and Pharos. SK9-100 is an autumn variety that will be in grower trials next year - it follows Parthenon in maturity.
A new summer range of cauliflowers from Seminis includes RX 5781, which takes 75 to 80 days to mature, and RX 5785, now named Giewont, which is ready in 95 to 100 days. At 100 to 110 days, RX 5710 bridges the gap between summer and early autumn production, coming in just before Aquata and Agenda.
Seminis has also been working on later material. At 120 to 130 days, RX 5965 leads on from Aquata and Agenda, followed by RX 5982, which is ready in 130 to 140 days, a similar timing to Appia. "They make a vigorous upright plant with good curd cover," says Meade. "For winter cutting, RX 5697, maturing in January, and RX 5738, ready in late February to early March, will complement current varieties such as Tintagel, Treknow and Trewint."
Clause's new second early cauliflower, CLX33005, now named Clipper, is an improvement on the company's current varieties in this slot. "It's a bit higher on the leg so harvesters can get through the crop more easily with the knife," says Ward. "It's also got a slightly better colour."
Sakata, meanwhile, has a new early autumn cauliflower, CSX704. "At 95 to 100 days, it follows on from Atalaya," Smart explains.
Whole-head cauliflower may be struggling to keep its market share, but demand for convenience pre-packs is increasing, according to Nickerson-Zwaan senior range manager Nick Bolton. "Most of our cauliflower breeding programme for the past 10 years has been aimed at the whole-head market," he says. "We're now working on the weight of the curd and floret size for mixed pre-packs. For maximum yield, florets should be 40-60mm in length and depth, and firm so they don't bruise."
One new variety that has stood out for its curd density this year is NiZ 10-417. An autumn type at 85 to 95 days, it comes in a few days later than Seoul and Boris.
Sakata is having another look at its newer, 95- to 100-day variety, Karnak, which it believes could have potential for floret production because of the density of its head.
Rijk Zwaan's Romanesco variety, Puntoverde, may have been around for four years or so, but supermarket interest is just beginning to take off, says brassica crop specialist Keith Stephen. "It shows more resistance to leaf diseases and Peronospora in the head," he adds. "Romanesco is traditionally an autumn vegetable, cropping from September to November, but the arrival of Puntoverde gave growers the option of going all the way through the white cauliflower season."
Seed of Romanesco varieties is hard to produce so commercial quantities are still not yet available. The newer 26-851 is targeted as an autumn variety. "It has a slightly more pointed shape and, like Puntoverde, it doesn't get mildew in the head," says Stephen.
Sakata's ballhead cabbage, Sennen, was developed for late April harvesting, ahead of spring-planted Primo, and so occupies a unique position, says Smart. Sown in late July/August, it has to be planted between 1 and 8 October to have enough time to make its frame. "It stood without protection last November and December," she says. "We didn't know it would do it, but it came through the weather absolutely fine."
CB10271 is an improved Sennen type that is more uniform and higher yielding. Seed of WC99042, a medium to large Primo type, will be available from Sakata for grower trials next year.
Clause's new cabbage, CL 7103, can be grown as a late green Primo type or as an early white for July harvesting, with a head around 1.5kg in weight. "It has a nice shape, plenty of vigour and stands tall so you can get the blade under it," says Ward. "It compares to Castello, but is earlier by several days."
Seed of Rijk Zwaan's savoy 29-417 will be available for trials next year. "It's compact, which is what supermarkets are looking for," says Stephen. It is fast growing, at 90 days.
Clause is finding rejuvenated interest in its two savoy varieties, Traviata and Capriccio. "Capriccio keeps a clean leaf," says Ward. "It's less prone to getting Xanthomonas. For that reason, it's a much better variety than we originally thought. We find you can use Capriccio from the end of July to November, while Traviata takes you from the end of September to early January."
Tozer Seeds is trialling two new savoys, TZB 0269 and 6115. "They have been bred for earliness and to keep longer in the field," says retail sales manager Robin Bartels.
New in savoys from Elsoms Seeds are Sabrosa and the coded 2875, which so far has only been trialled on Elsoms' site. Sabrosa has a compact frame, maturing about 97 days from planting.
Sakata has also been looking at its savoy Caserta as a baby vegetable. "Most savoys stay 'fluffy' early on, but Caserta firms up early," says Smart.
Nickerson's pointed cabbage, Dutchman, is well suited to baby-vegetable production, according to Bolton. "It's more uniform to mature than Duchy," he says, "so you get a high class 1 cut-out. And it's even sweeter with higher Brix levels."
Rijk Zwaan's processing cabbage, Oriema, is a 90-day green-white type. It makes a slightly larger, more robust head that Stephen says makes it resistant to the pinking that can occur at maturity in some varieties if plants come under stress.
The secret of breeding white storage cabbage is to combine high yield and good internal colour and structure with the ability to store for at least nine months. With NiZ 17-1265, Nickerson breeders have come up with a variety that seems to show some resistance to the aphid-transmitted viruses that are the cause of cigar burn and internal tipburn, says Bolton. "A lot of crop was lost last year by internal blackening, which develops in store," he adds. "NiZ 17-1265 came out of store with no symptoms at all and virus tests by the University of Warwick found heads to be clear."
Storage cabbage is a relatively new focus for Sakata's breeders. Two white types were in the company's trials - Arcticus, which can make 4kg and is suitable for long-term storage, and Fighter, which is slightly earlier at 135 to 140 days. Varna is a new red variety, for 1.5-2.5kg heads. "Field holding has been good in first commercial trials," says Smart.
Mucsuma, the most recent white processing variety from Rijk Zwaan, has the speed of Ancoma but stores longer, to mid-March. "It's well layered and has a relatively short core," says Stephen.
In red cabbage, Elsoms is trialling a variety resistant to several races of clubroot. Maturing 121 days from planting, BJ 2819 is ready to cut from October and stores to February/March.
Clause's red storage cabbage, Redguard, has the deep colour that processors demand. It makes 1.5-2kg heads and stores to March/April. "It's got an erect leaf and plenty of air gets around the plant so it stays clean," says Ward.
Rodima, Rijk Zwaan's most recent red pre-pack cabbage, has a rounder head and stores well. "It was found to withstand last year's frosts better than some varieties," says Stephen.
Elsoms' joint Brussels sprout breeding programme with Dutch company Bejo has been concentrating on new varieties that have the same quality as December-maturing Doric but that offer a full range of maturities.
Davlin is the earliest, followed by Irene and BE 2807, which both have a rounder button shape. "BE 2807 has good general disease resistance," says crop specialist Keely Watson. "Buttons are a nice size with a small attachment to the stem." BE 2808 is three weeks earlier than Doric, for harvesting from early November, while BE 2776 is two weeks later. Foliage of BE 2776 is on the pale side, but buttons are mid-green in colour.
Nickerson's late-season sprout, Brenden, has the resistance to lodging and uniformity of buttons that growers need in the frantic harvesting period for Christmas. "Every plant produces the maximum number of marketable sprouts," says Bolton. "The number of buttons it develops per stem also makes it suited to sprout 'trees'."
He adds that it is noticeable how Brenden seems to be untroubled by pests, particularly aphids. "If it's a variety that you could use with a reduced pesticide programme, that will be important in the long term."
Flower sprout, Tozer's Brussels sprout and kale cross, continues to be grown exclusively for Marks & Spencer. The original variety is a bicolour, producing purple-stemmed rosettes, but the company has developed all-green and all-purple types, currently marketed as a mix to the retail seed trade. "We are looking to extend the season with earlier varieties," says Bartels.
Another of Tozer's Brussels sprouts hit the headlines last Christmas when Asda took up Red Ball, an old, open-pollinated red variety. As a result of this, the company is now working on several hybrid lines.
Kales, leaves and pak choi
Black Magic is the name Tozer has given to its selected form of cavalo nero, previously coded TZC 9096, which it says could have a role as a baby leaf as well as a cabbage. "It has improved uniformity, a more savoy look to its early leaves and is more winter-hardy," says Bartels. Plant habit is also a little more upright. Black Magic is open-pollinated, but hybrids are in the pipeline. Seed is available for next year's commercial crop.
Tozer's curly kale, TZB 9339, which is in small-scale screening trials, will be trademarked "seaweed kale" because of its appearance after cooking. The company continues to trial speciality brassicas for their potential to inject colour, flavour and texture into salad or stir-fry packs, or more traditional cooking uses depending on the size of leaf harvested. Some lines are more upright in habit as young plants, which could make them suitable for machine harvesting, although depth of leaf colour and contrast is better developed in mature plants.
Sakata's new pak choi, PC10266, is the first to show high tolerance to clubroot. "It was important to find some tolerance, particularly for glasshouse production," says Smart. The variety is a Shanghai type, maturing two to three days earlier than Mei Qing, and has a darker leaf.
Sakata's salad turnip, which has exceptional flavour, has attracted a "phenomenal" uptake, according to the company's technical manager Kate Smart. "We know seed supply for 2012 will be limited," she says. Newly named Sweetbell, the variety is also smooth-leaved so is ideal for selling bunched.