Post by murrayc on Jul 21, 2017 14:25:45 GMT
A quick visit to the plot to pick some beans - and courgettes - turned into a much longer stay this morning when my own suspicions were confirmed by the knowledgeable wilbarra. Those blotchy, yellowed haulms on the 3/4 row of Kestrel maincrop potatoes showed that the blight had arrived, and had to be dealt with quickly.
There is dispute about the causes of blight and whether it is entirely air-borne or inherent to the seed potato. Many people think it is the former, and one of the causes is the scale of commercialised agriculture in recent years, and the selectivity of supermarkets on shape and size of what they will buy from the farmer, leading to gigantic spoil heaps in fields and farmyards. In very humid periods, such as we've seen in the last month the virus spreads quickly and a little breeze will carry it miles. Once the visible leaves and stems are infected it is necessary to act quickly to prevent it from travelling down to the tubers and rotting them. In most cases it is sufficient just to crop the haulms right down to ground level and leave the tubers undisturbed. They won't grow any bigger but they can stay underground until it is convenient to lift them.
In this case we tried a sample lift and most of the potatoes were both a very good size and completely disease free. There was one that seemed to have rotted so I decided to cut my losses, so to speak, and dug them all up. The haulms were carefully bagged up and I've taken them from the site and they can go to green waste collection, as the high temperatures used by the waste processing plant at Burgess Hill are sufficient to kill the virus. Do not compost them: it will only spread more quickly and the spores will remain in the compost for a very long time.
It hasn't spread to the Sarpo Miras, which are advertised as disease-resistant, planted along the last 1/4 of the row, but the Charlottes planted alongside don't look too healthy and I will address them next.
Just to underscore what we have been saying about the good yields this year we weighed up all our prizes when we took them home and dried them off: just over 56 lbs for an outlay of about £6.50. No doubt it would have been even more if we had been able to keep them growing for another few weeks, but I'm just glad that we have these stored safe and dry and will be eating them as roast or baked well into the winter.
And now, a little earlier than expected, I have some open soil ready to be tilled and prepared for autumn and winter plantings!
There is dispute about the causes of blight and whether it is entirely air-borne or inherent to the seed potato. Many people think it is the former, and one of the causes is the scale of commercialised agriculture in recent years, and the selectivity of supermarkets on shape and size of what they will buy from the farmer, leading to gigantic spoil heaps in fields and farmyards. In very humid periods, such as we've seen in the last month the virus spreads quickly and a little breeze will carry it miles. Once the visible leaves and stems are infected it is necessary to act quickly to prevent it from travelling down to the tubers and rotting them. In most cases it is sufficient just to crop the haulms right down to ground level and leave the tubers undisturbed. They won't grow any bigger but they can stay underground until it is convenient to lift them.
In this case we tried a sample lift and most of the potatoes were both a very good size and completely disease free. There was one that seemed to have rotted so I decided to cut my losses, so to speak, and dug them all up. The haulms were carefully bagged up and I've taken them from the site and they can go to green waste collection, as the high temperatures used by the waste processing plant at Burgess Hill are sufficient to kill the virus. Do not compost them: it will only spread more quickly and the spores will remain in the compost for a very long time.
It hasn't spread to the Sarpo Miras, which are advertised as disease-resistant, planted along the last 1/4 of the row, but the Charlottes planted alongside don't look too healthy and I will address them next.
Just to underscore what we have been saying about the good yields this year we weighed up all our prizes when we took them home and dried them off: just over 56 lbs for an outlay of about £6.50. No doubt it would have been even more if we had been able to keep them growing for another few weeks, but I'm just glad that we have these stored safe and dry and will be eating them as roast or baked well into the winter.
And now, a little earlier than expected, I have some open soil ready to be tilled and prepared for autumn and winter plantings!
