Seed producers and merchants have averted a possible shortage of kale seed for this sowing season after a frost late last year decimated Mid Canterbury seed crops.
Seed has been imported and stocks drawn down, but suppliers say supplies of Gruner, Sovereign and Regal kale varieties could be short.
Melissa Sowden, PGG Wrightson Seed's Otago Southland area manager, said there was sufficient kale seed available for farmers in her area and imported varieties that were comparable in quality and yield would cover those in short supply.
However, there has been a large swing to growing fodder beet for winter feed, but not out of concern at the shortage of kale seed, merchants say.
Agricom product development specialist Allister Moorhead said the shift to fodder beet was because of farmers seeing the success others had growing the crop, and the ability of farmers to grow a crop which had little room for error but potentially offered high yields.
Between five or six years ago, just 50ha of fodder beet was grown, all of that in Canterbury for pig and stud stock farmers.
Word spread and the area grown had doubled or trebled every year since, Mr Moorhead said.
While not revealing the area to be sown this spring, he said farmers from the middle of the North Island and throughout the South Island were growing it.
While yields of 20 tonnes a ha were achievable, growing it required precise management.
The earlier the crops were sown in spring, the better the yields, but that was dependent on the weather.
Management in the first six weeks was crucial, Mr Moorhead said, and he urged farmers to get and follow advice.
The seedbed had to be prepared correctly, the seed sown by a precision drill and weeds sprayed early.
Establishment costs were about $2000 a ha, and there was the potential for farmers to end up with nothing if the crop was not established correctly, he said.
"Farmers have to realise that is what fodder beet requires."
There were two varieties - a low dry-matter type which grew upright and another low dry-matter type which grew similarly to swedes.
Farmers favoured the low dry-matter varieties, which were break-fed in the same way as kale.
Fodder beet was one of three closely related varieties - sugar beet which grew in the ground and was a high dry-matter plant; fodder beet which was a cross between sugar beet and mangels; and mangels which were very low in dry matter.
He said farmers needed to understand the implications of growing a plant which was high in sugar, as cows could suffer from acidosis or metabolism problems unless it was managed correctly.
Initially, deer farmers led the interest in fodder beet, but Mr Moorhead said use by dairy farmers had eclipsed them this year, while sheep and beef farmers were "watching with interest".