Site-specific Wild Oat Operation Program (SWOOP) C Fernandez-Quintanilla, J Barroso, D Ruiz Centre for Environmental Studies, CSIC A Ribeiro, B Diaz, MC Garcia Alegre, D Guinea Institute of Automatics, CSIC

1. Associations among site properties and abundance of wild oats

Soil types Wild oat density 1 2 3

2. Detection systems for wild oat patches

Counting contacts

Visual assesment / walk

Visual assesment / combine

Economic comparison (C/ha) between the three assessment methods Method Contacts Visual/walk Visual/combine Sampling cost Herbicide cost Fixed costs Yield benefit NET RETURN

3. Testing the SWOOP concept

Infestation level 0(<0,1 panícules/m2) 1(0,1-1 panícules/m2) 2(1-10 panícules/m2) 3(> 10 panícules/m2) Infestation map

Treatments: None 28 Assert 0.6 l/ha 43 Assert 1.25 l/ha 22 Assert 2.5 l/ha 7 % of area: % of area: Treatment map

Effects on barley yields

4. Studying the spatial stability of wild oat patches

Relationship between: - panicle density (at harvest time) and - seedling density (at treatment time, next year) R2 = 0,59 Presence Abundance From season to season

N STABILITY IN LOCATION Among various seasons

STABILITY IN LOCATION Test for stability of spatial distribution (Syrjala, 1996)

STABILITY IN DENSITY Seedlings/m 2

STABILITY IN DENSITY y = -1,0424x R 2 = 0,81 y = -0,9756x ,9 R 2 = 0,69 y = -0,587x ,5 R 2 = 0, Years log seedlings/m2