Broomrape Resurgence: a Weed of Concern

Gene Miyao, Farm Advisor, UCCE, Yolo, Solano & Sacramento counties Yaakov (Coby) Goldwasser, Newe Yaar Research Center, Israel Radi Aly and Hanan Eizenberg, visiting scientists, Volcani Institute, Israel Branched Broomrape X x ( ramosa)

x x x xx

xxx Egyptian Broomrape xX x (Orobanche aegyptiaca)

O. ramosa O. aegyptiaca minor cernua crenata

Strigolactone is a stimulant for the parasite seed germination

arbuscular mycorrhizal Once conditions are optimal, the parasite seeds will germinate

Seed setting

Inflorescence germination

Life cycle Spider like tubercle Tubercles P. aegyptiaca reduced quality and yield quantity in fields Cabbage highly infested with P. aegyptiaca

Novel control strategy

Approaches

Plant arming by Gene silencing and editing toxic compounds

Non-transgenic Transgenic

(Aly et al., 2006); (Hamamouch et al., 2005) Non-transgenic Transgenic

(Aly et al., 2006); (Hamamouch et al., 2005) Broomrape: Egyptian species an introduction into U.S. Sample by 25’ x ~25’ grid presence/absence 1. √ Limit spread (quarantine) 2. Reduce seed production √ 1. Kill host 2. Hand Remove weed 3. Flame-kill seed 4. Fumigation 3. Post: scout for escapes 4. SANITATION (in general) Glyphosate-kill host to reduce seed production Bag shoots to reduce seeds

1. √ Limit spread (quarantine) Problem: 2. Reduce seed production Incomplete as 1. Kill host 88 hours/acre 2. Hand Remove weed 3. Flame-kill seed many seeds have 4. Fumigation 3. Post: scout for escapes already shed. 4. SANITATION (in √ general) Seeds are: Tiny Abundant Long-lived

Seeds: Dispersal Intense heat kills exposed seed

1. Limit spread (quarantine) …but not when 2. Reduce seed production protected under: 1. Kill host 2. Hand Remove weed fruit √ 3. Flame-kill seed ~ $200 per acre 4. Fumigation 3. Post: scout for escapes vines 4. SANITATION (in general) soil & clods CA Tomato Processors 1. Limit spread (quarantine) 2. Reduce seed production 1. Kill host 2. Hand Remove weed 3. Flame-kill seed √ 4. Fumigation ~ $4K per acre 3. √ Post: scout for escapes 4. SANITATION (in general) Application of sulfonylurea herbicides directly to the soil, pre-broomrape attachment, controlled Egyptian broomrape in tomato (Solanum lycopersicum) and

NOTE: Not Registered for use in California

Broomrape Control Choices: $pend lots early to eradicate vs. $pend continuously to routinely manage??