White Rot on alliums

[plot22]

I am in the UK and last week I watched Monty Don on Gardener's World on tv. Monty is a famous gardener and his programme is well viewed. Monty has white rot on his garlic in one of his raised beds he had it in a different bed last year. I tried to contact the programme to tell them how I combatted this disease on my allotment but without success. I first had it in onions then garlic with nearly 60% losses. I tried everything but to no avail. Then I tried garlic powder bought from horse supplier but I now buy it from an Indian supermarket. I spread it out in September and rake it in. It tricks the white rot to thinking alliums are growing but because there is not any it dies. The first year I tried it I probably lost 25% the second year perhaps 15% last year probably no more than a dozen out of 200 onions. I must add that I followed in my late dad's footsteps and keep the same onion bed year after year. I set up a new garlic and over wintering bed of onions and using the same method I have just harvested 110 elephant garlic and 80 odd over winter onions and I have lost 2 garlic and 4 onions so the system is working for me. I think the super dry spring may have helped but as I type this letter my garlic and onions are drying attached to our trees at home.