Cultivation of seed potatoes: insolation of infected plants

In 2007 some regions were to a great extent affected by viral diseases. If a greenfly comes to an infected plant, in process of sucking juice it co-opts the virus (for example, the Y-virus) and transmits it to other plants. Therefore, at present there are sources of viral diseases and viral vectors, which can cause new infections of potatoes in 2008.

Thomas BOTTNER, Europlant pflanzenzucht


















 

It is strongly recommended to reduce the risk of spread of viral diseases by means of timely removal of the infected plants, and with that preventing the infection of greenflies attacking the potato. The potato farms should perform negative selection and remove the infected plants as early as possible. If there is a slightest delay – then precious time is lost, as the infected bushes are the source of contagion among other plants, which results in significant loss of quality and crop capacity of potatoes (especially in case of contamination with mixed infections).

High humidity and rains advance the process of the spread of shrubs which to great extent complicates finding viral the diseases, as the healthy plants extend into each other and often totally cover the contaminated ones. The main task of potato enterprises is still the timely detection and careful removal of ALL the infected plants. At many enterprises there is a lack of specialists. Experienced technicians/seed growers retire, and finding new qualified personnel (which should first receive specialized training) for performing negative selection is not easy, as in order to recognize the signs of infection on the affected plants one needs to have a good eye, and this comes only after long experience.

For a hundred years now it is been stressed in books on specialized subjects, that multiple careful cleaning of seeds along with healthy seed materials) is the guarantee for successful potato cultivation:

  1. One should start as early as possible, i.e. from the time when it is already possible to identify the infected plant – approximately in two – the latest – in three weeks after the emergence of seedlings.
  2. Perform cleaning each two – maximum three weeks and
  3. Perform cleanings during the whole potato plants growth period and up to the full ripening.
  4. The more carefully the first cleaning is performed, the quicker and easier it will be to perform the other ones.
  5. Each plant, deviating or lagging from the norm in some way, i.e. looking unhealthy, should be removed. If the new bulbs have already started to form, they are also to be removed.
  6. It is extremely important to carry out staff training and systematically involve them in performing cleanings.
  7. Each technician/seed grower should monitor not more than 2 rows.
  8. The removed shrubs and bulbs must not be piled up on the edge of the field, but should be immediately carried out of the bounds of the field, as they can become the source of new infection.
  9. Soon after the emergence of seedlings the person responsible for the cultivation of potatoes should perform a thorough examination of seeds. He or she should estimate, on which seeds the cleaning should be performed immediately and with all due care, and on which this procedure will not take much time. With that, one should not hold illusions and abandon careful cleaning of seemingly healthy sections, as in reality absolutely healthy seeds do not exist.
 

Not only plants, infected with the virus are subject to negative selection, but also those infected with bacterial disease (for example, the “blackleg”) and Rhizoctonia rot, as well as growths, foreign or uncharacteristic for this plant.

It is not recommended to perform a cleaning of strongly infected seeds, in order not to waste time and not to neglect the other sections.