Guidance for farmers

FOR DECISION – MAKING PROTOCOL FOR CROPPING SYSTEMS IN ORDER TO
MINIMIZE THE RISK OF STOLBUR PHYTOPLASMA OUTBREAKS

1. Chose the crops of interest for breeding.
2. Browse the data from the Stolbur phytoplasma Compendium:
   • check if the crops of interest are susceptible to stolbur phytoplasma infection
   • check if the crops share the same vector(s)
   • check what weeds are hosts of Stolbur phytoplasma and the vector(s)
3. Consult the tables for recognized potential risks, risk ranking and proposed risk mitigation tools:
   • Table 1 – potential risks if susceptible crop is grown in monoculture
   • Table 2 – potential risks if susceptible and non-susceptible crops are grown together in allotment
   • Table 3 – potential risks if two susceptible crops are grown together in allotment.
4. Get introduced with stolbur phytoplasma outbreak risk assessment matrix, ranks and numerical scores of the ranks.
5. Conduct the risk analysis using the risk assessment framework for stolbur phytoplasma outbreaks:
   • Risk analysis for allotment of susceptible and non-susceptible crops, on the same land, without rotation
   • Risk analysis for allotment of susceptible and non-susceptible crops, on the same land with rotation
   • Example of risk analysis for crop allotment without rotation
   • Example of risk analysis for crop allotment with rotation.
6. Make a final choice of crops and allotment over space and time.
   Examples of decision making models of land use with fixed and flexible, repetitive and non-repetitive rotation sequences and utilization of 3 plots over a 5-year period.
7. Apply risk management strategies proposed in Table 1, 2 or 3.
   The risks of growing susceptible crops in the same allotment could be minimized by:
   • using a certified healthy planting material
   • eradication of symptomatic crop plants, weeds and surrounding vegetation
   • surveillance on introduction of weeds and vectors into the crop field
   • monitoring the vectors aggregation on crops and host-shifts
   • modification of rotation sequences or crop allotment to disrupt vector’s life cycle
   • attract and kill strategy or creation of buffer zone to exclude vectors from crop field
   • chemical control of vectors if adequate insecticides are registered
   • spatial isolation by soil resting or weed-free fallows
   • breeding non-susceptible crop(s) separating two susceptible crops within the allotment
   • rotating a non-susceptible crop between two susceptible crops.
8. Examples of decision-making schemes for crops allocation based on risk assessment of stolbur phytoplasma disease outbreaks:
   • fixed repetitive rotation sequences
   • flexible non-repetitive rotation sequences
   • flexible temporal and spatial crop allotment within plots
   • examples of land use with partially fixed and/or flexible, repetitive and/or non- repetitive rotation sequences.