A G R I C U L T U R A L U N I V E R S I T Y O F A T H E N S 2nd International Conference on «Novel and Sustainable Weed Management in arid and semi-arid agro-ecosystems» 7-10 September Santorini Hellas Could marine algae consist an auxilliary tool for Orobanche management ?

Unusual life cycle High potential of broomrape seeds in the soil seed bank Total dependence on the host Almost all control methods for broomrape have not proven to be as effective economical and applicable as desired

Urgent need for effective control methods……

Urgent need for effective control methods………… O r o b a n c h e s p e c i e s I n v a d e N e w A r e a s p r o b a b l y d u e t o G l o b a l E f f e c t R e s t r u c t u r I n g o f c r o p s Cost Action 849 “Parasitic Plant Management in Sustainable Agriculture”

Urgent need for effective control methods………… P P L I C A B L E A R G E T E D H E A P A C T

B I O L O G I C A L C O N T R O L I n s e c t s ( i.e. Phytomyza orobanchia ) P a t h o g e n s ( i.e. fungi ) S t i m u l a n t s (Trenchev, 1981) (Boari and Vurro, 2004) (Wegmann, 2006)

“ S u i c i d a l G e r m i n a t i o n” S t i m u l a n t s I n d u c t i o n I n h i b i t i o n

N a t u r a l (plant origin) Strigolactones S t i m u l a n t s S y n t h e t i c Strigolactones GR N e w s o u r c e s a l g a e

Seaweeds : Treasure from the sea Wallenkemp, J. O. Treasure from the sea. Organic Gard. and F. 2(3) :52-53 P l a n t g r o w t h r e g u l a t o r s M a j o r a n d m I n o r e l e m e n t s P r o t e I n s C a r b o h y d r a t e s A m I n o a c I d s V i t a m I n s a n d A n t I o x I d a n t s o Increased nutrient uptake o Greater resistance to diseases, frost o Higher yields o Better quality product o Reduction of storage loss Seaweeds are excellent sources of: Beneficial effects on plants

H y p o t h e s i s M a r i n e a l g a e could have b e n e f i c i a l effects for O r o b a n c h e control

A s c o p h y l l u m n o d o s u m (An)

An- information An is a member of the order Fucales (apical cell group). It generally grows upward in the water column anchoring to hard substrates using a holdfast. Upward growth promotes the maximum absorption of sunlight for photosynthesis (Lobban 1985). Geographical distribution

An formulations

Suicidal Germination (Economou et al. 2007) Systemic Acquired Resistance (S.A.R.) (Gonsior et al. 2004) A. nodosum effect on O r o b a n c h e control

Steps of our research activity Steps of our research activity

G. Economou et al. (2007) Phytoparasitica 35(4): Step 1: Evaluation of effective dose of Algit Super ® (an An extract) V/V Germination (%) Log [Algit Super®]

GR A. nodosum Longer radicle

Plant hormones Cytokinines Giberellins Auxines Betaines (Crouch, I. J. and van Staden, J. 1993) (Stirk, W.A. and van Staden, J. 1997) Plant regulating role Step 2: Evaluation of A. nodosum components

…..growth regulators effect….. “ …plant growth regulators have a stimulatory effect on Orobanche seeds…” (Batchvarova et al. )  Analysis of variance among the growth regulators showed differences not statistically significant (F-value: 4,13 p: ).  Beatine appeared to be the best seed stimulant relative to Kinetin, IAA and GA3, with higher mean values of germinability.

Step 3: Identifying the factors involved in An efficacy  Orobanche species (Ph. ramosa, Ph. aegyptiaca, O. crenata)  Temperature effect (18, 20, 23 ο C)  Population variability (18 Ph. ramosa, 16 Ph. aegyptiaca, 10 O. crenata) Statistical analysis  Response to stimulants best fit with Boltzmann function (GraphPad Prism 4.03)  Kruskal – Wallis test / Nemenyi test/ Box-Whisker plot

Orobanche species – Temperature - Germination (1) GR 24 Algit Super  GR 24 Algit Super  Ph. aegyptiaca Ph. ramosa

GR 24 Algit Super  O. crenata Orobanche species – Temperature - Germination (2)

Orobanche species – Temperature - Radicle length (1) Ph. aegyptiaca Ph. ramosa GR 24 Algit Super  GR 24 Algit Super 

Orobanche species – Temperature - Radicle length (2) O. crenata GR 24 Algit Super 

Population variability – Ph. aegyptiaca GerminationRadicle length

Population variability - Ph. ramosa GerminationRadicle length

Population variability – O. crenata GerminationRadicle length

Key message (1) An stimulating effect An components are under investigation

? Key message (2)

The higher radicle elongation Catch crops ?

A ctive A ctive Environmenta L benign Environmenta L benign Natural a G ent Natural a G ent Economic A l feasible Economic A l feasible Commercializ E d Commercializ E d

Seaweed extracts have a place in Orobanche management as a part of an integrated approach ……the findings would corroborate the claims….