Crop Protection Online - now also including maize Per Rydahl Danish Institute of Agricultural Sciences

Contents Status Introduction to model Prototypes in maize User interfaces

Status

Status (1) Crops: –3 spring cereal crops –4 winter cereal crops –spring- and winter oilseed rape –field pea –sugar beet

Status (2) Herbicides: –all registered and marketed products Weeds: –75 species Subscribers in Denmark: –1000 farmers –300 consultants –200 schools, companies etc. System export: –Estonia, Latvia, Lithuania, Poland and Norway

Introduction to model

Model function 1.assesses the level of weed control needed 2.selects single herbicides and calculates doses needed 3.calculates tank-mixtures, optimised for cost or TFI 4.strategy-module for multiple treatments

Step 1: The level of control needed Includes aspects on yield, quality and crop rotation Based on expert knowledge Input: –Crop name –Season –Expected yield –Weed name –Weed density Output: –level of control needed on weed biomass, 4-6 weeks after a herbicide application (0-97%)

Step 2: dose-response function 1 herbicide, 1 weed 1/4 N 1/2 N 1/1 N 2/1 N

Step 2: dose-response function Integration

Step 2: dose-response function 1 herbicide, 3 weed species Actual doseEfficacy target level

Step 3: ‘Tankmixtures’ Additive Dose Model (ADM) Herbicide A: ADM (70%) Synergism Antagonism ED 70 Herbicide A ED 70 Herbicide B Herbicide B:

Sp 1 Dose Herbicide A Dose Herbicide B Sp 2 Sp 3 Sp 4 a b c d Line (a,b),(b,c),(c,d) = ’Border isobole’ Step 3: ‘Tankmixtures’ Optimization

Prototypes in maize

Tasks to develop and validate DSS models for weed control in maize to achieve sufficient and safe control of weeds to quantify potentials

Reuse of components from cereals target effect levels: –expert model dose/response functions: –weed species (field data) –weed growth stages (semifield data) –temperature, relative air humidity and water stress (semifield data) ADM(semifield data)

Reuse of components from sugar beet strategy: –spray subsequent flushes of emerged weeds repeated: –field inspections –consultations of model –sprayings, as recommend by model dose/response functions: –data from ’genuine’ split-applications of single herbicides

Prototypes 3 prototypes with 3 levels of aimed efficacy: –’90%-version’ –’85%-version’ –’80%-version’ questions to answer in field validation tests: –can treatment options be recommended by model? –is yield and weed control at satisfactory levels? –can input of herbicides be reduced?

Efficacy 4-6 weeks after treatment Efficacy on weed density (%) YearNo. of trials Un- treated (no./m 2 ) 2 x Calaris 0,75 l/ha 90%85%80% W.m

Efficacy at harvest (1) Total weed cover (%) YearNo. of trials Un- treated 2 x Calaris 0,75 l/ha 90%85%80% W.m

Efficacy at harvest (2) No. of trials with >15% total weed cover YearNo. of trials Un- treated Ref. 2 x Calaris 0,75 l/ha 90%85%80% W.m

Yields *) No significant differences between treatments Hkg dry matter per hectare YearNo. of trilas Un- treated 2 x Calaris 0,75 l/ha 90%85%80% *) 450,359,6-58,256,

Treatment Frequency Index (TFI) TFI YearNo. of trials 2 x Calaris 0,75 l/ha 90%85%80% ,130,970, ,13-1,030, ,13-1,221,13 W.m.141,130,971,041,01

Costs of herbicides DKK per hectare YearNo. of trials 2 x Calaris 0,75 l/ha 90%85%80% W.m

Conclusions on prototypes in maize considerable variation in weed infestations in validation test plots satisfactory weed control was achieved by all prototypes in all tests input of herbicides by 85%-version and 80%-version: –about 10% reduction of TFI –about 20% reduction of cost (about 160 DKK/ha) slightly revised 80%-version will be integrated in the official version of CPO in 2006

User interfaces

User interface - input

User interface - output