potatoe scab

[growbag]

Some of my early potatoes have scab on them. I believe this thrives in alkaline soil. As I planted the potatoes after brassicas could it be the lime I put in the planting hole of the brassicas is still there & has caused this scab. If so I need to alter my rotation scheme

[Two_Sheds]

I mulch my spuds with grass clippings, which increases acidity to prevent scab. It also suppresses weeds, conserves moisture, and uses up lawn mowings.

[growbag]

That would save me changing the rotation which I dont really want to do. Dont have access to grass clippings , is there anything else I could use?

[Snadger]

If you already have an alkaline soil you don't need to add lime to the brassica bed.
Normally lime will wash out of the soil quite quickly but if we have dry weather it tends to linger a bit longer.

Sequestrene of iron is used to acidify soil, likewise using the likes of sulphate of Ammonia will acidify soil.

[Snadger]

That would save me changing the rotation which I dont really want to do. Dont have access to grass clippings , is there anything else I could use?

Most of the topdressing are acidic including manure,home made compost,and of course peat and coir! Woodchippings are acidic but would probably deplete the nitro in the soil.

[growbag]

When I planted the brassicas last year I added a bit of lime in the planting hole With a little blood ,fish & bone as we have club root about the place,they grew brilliantly. I added manure before planting the potatoes. May plant scab resistant varieties next year. Thanks for your replies.