Here’s a tip for dealing with White Rot which I learnt from a local grower. It’s adapted from a recent article I wrote for the Blackmore Vale Magazine. It won’t suit everyone but it is an option…
Many vegetable growers have experienced problems in recent years with their onions. The cause of this anxiety, and failed crops, is a fungal disease called White Rot. The fungal equivalent of seeds, called ‘spores’, can remain viable in the soil for a long time. Symptoms are a white fluffy fungal growth on the bulb and around the roots. The crop turns to a foul smalling mush in the ground or fails to store and must be wasted. The Royal Horticultural Society book Pests & Diseases (greenwood & Halstead, 1997) is to, “Remove and burn infected plants as soon as they are noticed and do not grow onions on the same ground for at least eight years.” So how did one exhibition grower manage to cultivate fantastic bunches of handsome onions which currently hang like trophies in his greenhouse only one year after suffering White Rot in his clayey soil?
“I contacted W. Robinson & Sons up in Preston, Lancashire, where I get my seeds. They’ve grown onions in the same bed for 140 years and I followed their advice,” the onion specialist told me.
It’s a strict regime. Douse the bed with Jeyes Fluid in October (early Nov will do) and let it sit for six weeks. This should kill off unwanted fungi. Then dig a trench where you plan to grow your crops and ‘bottom dress’ this with spent runner bean plants and manure. This involves lining the trench with the naturally nitrogen-rich good stuff then covering it with soil.
You could run a mower over the bean plants with the collecting box on, like my mate. “It doesn’t stick up all over the place,” he tells me, ” and is easier to handle. It’s also important to make sure the manure is within 10cm of the surface so the roots can get down into it.”
Autumnal preparations finish with the application of 140 grams of bone meal and 170 grams of Sulphate of Potash per 3 square metres. Then leave it until March when 2.25 kg of calcified seaweed is forked in prior to planting onions in April.
Copyright, Joe Hashman www.dirtynails.co.uk