Grape – Downy mildew

Crop(s):          Grape

Disease(s):     Downy mildew

Resistance management strategy for:

Guidelines:

1. Start preventative disease control sprays using non-Group 4 protectant fungicides, typically when shoots are 10-20cm long. Continue spraying at intervals of 7-21 days depending on disease pressure, label directions and rate of vine growth.
2. Group 4 fungicides should be applied as soon as possible after an infection period, and before the first sign of oilspots. Limit the use of Group 4 fungicides to periods when conditions favour disease development. Always apply Group 4 fungicides in mixtures.
3. Group 49 fungicides should be applied prior to infection and only in mixtures with effective fungicides applied at an effective rate from a different cross resistance group. The mixing partner should give effective control of downy mildew at the rate and interval selected. A maximum of two Group 49 applications may be made per season. Only apply Group 49 for a maximum of one in every three sprays of the total number of downy mildew sprays. A Group 49 application must be followed by at least two applications of a different group(s) before being reapplied.
4. Fungicide mixtures are defined as co-formulations, or tank mixes at label rate of an alternative mode of action.
5. Apply a maximum of two consecutive applications of Group 4, 21, or 40 containing fungicides.
6. Do not apply Group 11 (including Group 11+3) consecutively when applying alone.
7. 1. Apply a maximum of two sprays per season of Group 11 (including mixtures) Group 45+40 and Group 49.
   2. Do not apply a spray containing Group 40 as the last spray of the season. Only apply a spray containing Group 40 a maximum of 50% of the total number of downy mildew sprays.
   3. Apply a maximum of three Group 21 containing sprays per season, and a maximum of two consecutive sprays

   	Group
   	4	11, 11+ 3	21+M1	40, 45+40 & 40+M3	49
   Maximum number of consecutive applications	2	none	2	2	none
   Maximum number of solo sprays	None	2	3	2 (50%)	None
   Maximum number of sprays per season	4-mix	2	3	4-mix (50%)*	2-mix
   Areas of higher agronomic risk	mix	mix	N/A	mix	mix

   * Refer to points 7 &8
   N.B. Consecutive sprays include mixture formulations