Control measures

The control of common and netted scab must combine different techniques before or during the crop season:

Before planting:

• try to arrange long rotations to limit the incidence of netted scab;

• limit the introduction of host plants (beet, carrot, radishes, etc.) in crop rotation with the potato;
• evaluate the risk to the crop, in relation to the level of soil infection, with the use of bait plants;
• avoid the use of inadequately decomposed organic matter;
• limit the plantation of potatoes in too light soils or after soil preparation giving light-textured soil;
• limit the application of lime-based soil amendments just prior to the cultivation of the potato.

During the growing season:

• use of cultivars resistant to netted scab and relatively less susceptible to common scab;
• irrigation to saturate the soil during tuber initiation and during the 2-4 weeks after tuberisation is an important means of maintaining the soil moisture near the field capacity and thus limiting the conditions for tuber infection with common scab.