Chris Cooper and Rob Saunders, vine specialists in the Hutchinsons Horticultural Team, continue their thoughts on vineyard priorities for March.
In March, pruning should be completed, herbicide strips tidied up, nutrition base dressings reviewed and pH ameliorated. If conditions are suitable, cultivations, like sub-soiling, can be undertaken, rotten/damaged posts replaced and wire work replaced or repaired. Thankfully, Hutchinsons expanding sundries team, headed up by Chris Williams can supply many of these materials.
Vines suspected of carrying infection of trunk diseases (GTD) should have been identified and marked, the distinguishing features would include apoplexy, stunted growth or, sometimes, individual vines showing early autumn colours. These should be pruned separately, usually last, with the prunings (or sometimes whole vines) being removed and burnt on the same day. A sensible precaution is to sterilise pruning equipment with a disinfectant material between cuts but definitely at the end of the shift.
For non-infected prunings, burning is best practice and those with burning barrows achieve excellent crop hygiene. Pruning gangs can work steadily through, burning as they go and disinfecting their pruning equipment between cuts or between vines. There is a requirement to hold the relevant Environment Agency exemptions permit to carry out burning of prunings.
Using a mower or pulveriser to chop the prunings into small pieces is acceptable and is the most practical way to dispose of them on larger holdings, reducing the infection bridge provided no corners are cut such as leaving prunings in alleys for weeks. The prunings will break down relatively quickly on healthy soils.
Ideally now is the time to look into frost mitigation by clearing areas that may prevent frost dissipation, clearing the weed free area under the vine allowing bare earth to retain heat. Sharpen mower blades ready for April.
At the WineGB conference the Dr Glen Creasey talk included information on nutrition, advising growers to work from the soil upwards. A recent soil analysis, less than four years old, is required (if unavailable, get one carried out) combined with crop off-take from the previous season. This will give a baseline for macro-element additions. There were some big crops in 2018 so it is likely potash, nitrogen and possibly phosphate will be required. Potash and phosphate take a while to permeate to rooting zones from the soil surface, even longer if a green manure/mulch is being applied, so make potash and phosphate applications in mid to late March.