PRUNE (DRIED PLUM): FUNGICIDE EFFICACY - CONVENTIONAL

Rating: 5 = excellent and consistent, 4 = good and reliable, 3 = moderate and variable, 2 = limited and/or erratic, 1 = minimal and often ineffective, 0 = ineffective, NL = not on label, and ND = no data. NR=not registered after bloom.

* Registration pending in California.

**Not registered, label withdrawn or inactive in California

¹ Code numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions (for more information, see http://www.frac.info/). Fungicides with a different Code number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode-of-actions (MOA) with high resistance risk before rotating to a fungicide with a different MOA (Code number); for other fungicides, make no more than two consecutive applications before rotating to fungicide with a different MOA (Code number).

² Fruit brown rot treatments for fungicides in FRAC Codes 1,2, 3, 17, 7/11 are improved with the addition of 2% light summer oil. The oil is "light" summer oil (1-2% vol/vol). If applied in summer, fruit will lose their waxy bloom and look red. They will dry to normal color.

³ Strains of Monilinia fructicola and M. laxa resistant to Topsin-M and T-Methyl have been reported in some California prune orchards. No more than two applications of Topsin-M or T-Methyl should be made each year. Resistant strains of the jacket rot fungus, Botrytis cinerea, and powdery mildew fungi have been reported in California on crops other than almond and stone fruits and may have the potential to develop in prune with overuse of fungicides with similar chemistry. Subpopulations of both Monilinia spp. have been shown to be resistant to AP (FRAC 9) fungicides on prune in CA.

⁴ To reduce the risk of resistance development, start treatments with a fungicide with a multi-site mode of action; rotate or mix fungicides with different mode-of-action FRAC numbers for subsequent applications, use labeled rates (preferably the upper range), and limit the total number of applications per season.

⁵ Blossom blight only; not registered for use after petal fall.

⁶ High summer temperatures and relative humidity reduce efficacy.

⁷ Registered for use on fresh prunes only.

⁸ Do not use in combination with or shortly before or after oil treatment.

⁹ Do not use after jacket (shuck) split.

¹⁰ Do not use sulfur, captan, or chlorothalonil in combination with or shortly before or after oil treatment.

PRUNE - FUNGICIDE EFFICACY - BIOCONTROLS AND NATURAL PRODUCTS

Rating: 5 = excellent and consistent, 4 = good and reliable, 3 = moderate and variable, 2 = limited and/or erratic, 1 = minimal and often ineffective, 0 = ineffective, NL = not on label, and ND = no data. NR=not registered after bloom.

* Registration pending in California.

¹ Organic treatments arranged by performance on brown rot.

² FRAC Codes are also provided as BM- or P-number codes. In general, sulfur compounds are fungicidal and may affect applications of fungal biocontrols (e.g., Botector); whereas copper may affect applications of bacterial biocontrols (e.g., Actinovate, Double Nickel 55, and Serenade). Rotations must consider these factors.

PRUNE (DRIED PLUM): TREATMENT TIMING

Note: Timings listed are effective but not all may be required for disease control. Timings used will depend upon orchard history of disease, length of bloom, and weather conditions each year.

Rating: 3 = most effective, 2 = moderately effective, 1 = least effective, and 0 = ineffective

¹ Flowers are susceptible beginning with the emergence of the sepals (green bud) until the petals fall but are most susceptible when open.

² A physiological disorder; no pathogens involved.

³ More severe when late spring rains occur.