Seed potato harvest on the Yorkshire Wolds has finished, with crops safely in store. Yields seem to be very good, which is just as well as I understand that yields north of the border are a little more variable. Harvest of ware continues, again yields seem to be very good, although the wait for skin set has been a drawn out affair.

Dry matter of processing crops has been variable, but chitting of late maturing varieties such as Markies and Pentland Dell has resulted in marketable yield and quality being achieved to allow timely desiccation. On the packing front, variability also seems to be the name of the game. Maris Piper has had lots of tubers, but few bakers, common scab, particularly on un-irrigated crops and judging by the amount of Black Dot on stems, long term storage of susceptible varieties could be challenging.

My thoughts are now focussing on next season and the challenges that little or no Vydate (oxamyl) will bring. I have already had a number of calls from concerned clients. Field and variety selection will be even more important, identifying previous problems with free living nematode (FLN) feeding damage and spraing is a good start. However, this can be an issue with the amount of rented land in the mix.

I am not a fan of the over wintered stubble scheme where potatoes are concerned. Allowing stubbles to green up after harvest with weeds and volunteers just allows pest and disease life cycles to continue. Tobacco rattle virus (TRV) which causes spraing symptoms in susceptible varieties is known to survive on weeds such as groundsel and chickweed. In the spring when the soil starts to warm, FLN will start to migrate up the soil profile to feed and if infected weeds are present, they will pick up the virus. However, if stubbles are clean the virus reservoir is reduced, if not eliminated. It is also worth remembering that feeding damage on potato roots can result in increased problems with rhizoctonia.