A decision support system for

Transcription

1 A decision support system for Fusarium head blight on wheat V. Rossi, S. Giosuè, Istituto di Entomologia e Patologia vegetale Università Cattolica S. Cuore Piacenza EPPO Conference on Computer Aids for Plant Protection Wageningen 7 9 October 006

2 Fusarium head blight (FHB) is a serious disease of cereals in many areas of the world, including Europe and Italy, caused by several Fusarium species. Under favourable conditions, FHB causes severe epidemics, heavy yield losses and reduces grain quality due to the presence of mycotoxins. Mycotoxin contamination occur mainly in the field. Field contamination depends on environmental factors and cultural practices favouring the development of toxigenic Fusaria, as well as the level of resistance of the host. Introduction A DSS was developed to aid people working along the cereal production chain in making decisions about the management of FHB risk, both in field and during postharvest.

3 Influencing variables Weather X Growing area X Host species X Cultivar X4 Previous crop X5 Soil tillage X6 Groups of increasing proneness to FHB Risk (R) = X + X + X + X4 + X5 + X6 R Very low DSSFHB Discriminant analysis <R <R..<R R> Low Intermediate High Very high

4 Data base: monitoring FHB and Don in EmiliaRomagna Discriminant analysis N. cases Total Bread wheat Durum wheat Barley Total Distribution and abundance of the monitored fields

5 Discriminant analysis Campione N PCFT.. Data del prelievo Azienda: Struttura (es. Cons. Agrario di ): Comune.. Provincia. Coordinate catastali dell appezzamento oggetto del campionamento. Specie: Varietà. Precessione colturale Tecnica colturale adottata Preparazione del terreno. Data di semina:. Concimazione in copertura: Azoto Seme conciato: si no se si, p.a... Quantità di seme ad ha: kg.. Data Quantità, kg/ha Concimazione pre semina kg/ha: Azoto Fosforo. Potassio. Diserbo: data p.a... Data di spigatura: Trattamento di difesa: data.. p.a. Osservazioni (segnalare la presenza di eventuali attacchi parassitari e/o di ogni altro evento che possa aver condizionato la resa finale della coltura): Data di accolta Produzione ha: Umidità alla raccolta Peso ettolitrico. For each field: v information sheet v sampling of kernels incidence of Fusaria level of mycotoxins

6 40% 40% F. culmorum F. graminearum 00 0% F. poae 9% 66% 00 5% Year Don >0 (%) Don Median (ppb) Zea >0 (%) Zea Median (ppb) Discriminant analysis 68% 004 4% 8% % 6% 9% % 0% 0%.5 0% 0%

7 Independent variables Year Growing area Host species Cultivar Groups 5 4 Don group Don ppb >500 Procedure: stepwise selection of independent variables Previous crop Soil tillage Sowing time Fungicides (seed) 6 4 Don group Estimated Discriminant analysis Nitrogen manuring Heading time Fungicides (heads) Harvest time Humidity Original Right Over estimated Under estimated % 0% %

8 Autovalues FD Autovalue % variance % cumulated canonic correlation Coefficients of discriminant canonic functions Discriminant analysis Independent variables Year Growing area Host species Cultivar Previous crop Soil tillage Constant DF DF % relative weight Year Area Species Cultivar Previous crop Soil tillage

9 .0 P DON= (0 ppb) P DON= ( 500 ppb) P DON= (>500 ppb) 0.8 R Very low Propability <R <R..<R Low Intermediate High 0. R> Very high Discriminant analysis Risk (R)

10 Influencing variables Weather (FHBwheat) Growing area (Map) Host species (FHB rating) Cultivar (FHB rating) Previous crop (Table) Soil tillage (Table) X X X X4 X5 X6 tox 0 green barley resistant vegetables ploughing multitillage Groups of increasing proneness to FHB 5 yellow bread wheat med resistant renewals others milling etc 0 red durum wheat med susceptible cereals no tillage minimum 4 5 susceptible 5 >5 DSSFHB

11 Weather Epidemiological model: FHBwheat (acronym of Fusarium Head Blight on wheat) mechanistic and dynamic systems analysis v Input: meteo data from heading (T, RH, Rainfall, LW) v Output: risk indexes, daily and cumulated over the season 4 Index of infection (FHBinf) for each Fusarium species 4 Index of mycotaxin accumulation in kernels by F. graminearum e F. culmorum (FHBtox) SHT Sintomi sulle spighe MAH Micotossinenelle cariossidi Specie fungina SPOR: Sporulaszione T, a W T INC: Incubazione MAC: Tossinogenesi MIS Micelio nelle fonti d inoculo SIS Spore sulle fonti di inoculo SHS Spore sulle spighe HIH Micelio nelle spighe HIS Micelio nelle cariossidi Stadio fenologico SPOR: Sporulazione DIS: Dispersione INF: Infezione INV: Invasione Specie fungina T R, T, RH Stadio fenologico T, LW, RH Specie fungina T, a W

12 FHBtox daily sample 8 sample FHBtox cumulated F. culmorum F. graminearum 8 7 sample sample Don (ln) 4 Weather 0/5 5/5 0/5 5/5 0/5 4/6 Date 9/6 4/6 9/6 4/6 9/ Samples

13 ln mycotoxin Don Group 4 5 Weather tox 0 0<tox 5 5<tox 0 0<tox 5 tox>5 Zea FHBtox Weather

14 Semivariogram Nugget Sill Nugget/Sill Range R / / / / / / /. Group Area Green Yellow Red Maps Relative content of Don

15 Relative susceptibility of species and cultivars Group Species Barley Bread wheat Durum wheat. FHB assessments under natural conditions Group 4 Cultivars Resistant Med Resistant Med Susceptible Susceptible. Susceptibility to Fusarium infection in bioassays. Don production with artificial inoculation FHB rating

16 Relative Don Legend:. Cereals. Renewals: beet, tomato, sunflower, etc.. Vegetables 4. Grasses and/or alfalfa 5. Others: fruit trees, vine, etc Previous crop Experiments with different kinds of previous crops Dendrogram using Average Linkage (Between Groups) Group Previous crop Previous crop Rescaled Distance Cluster Combine Vegetables Renewals or others Cereals

17 Relative Don Soil tillage Legend:. Ploughing. No or minimum tillage. Milling, harrowing, digging 4. Multitillage Experiments with different kinds of soil tillage Soil tillage Dendrogram using Average Linkage (Between Groups) Rescaled Distance Cluster Combine Group Soil tillage ploughing or multitillage milling or harrowing or digging no or minimum tillage

18 Influencing variables Weather (FHBwheat) Growing area (Map) Host species (FHB rating) Cultivar (FHB rating) Previous crop (Table) Soil tillage (Table) X X X X4 X5 X6 tox 0 green barley resistant vegetables ploughing multitillage Groups of increasing proneness to FHB 5 yellow bread wheat med resistant renewals others milling etc 0 red durum wheat med susceptible cereals no tillage minimum 4 5 susceptible 5 > 5 DSSFHB R = =. R = =.

19 Risk (R) Level Fungicide application Don analyses Postharvest management Problems in relation to products R Very low No No No problem No <R 0.44 Low No Random No problem No Information form DSSFHB 0.44<R..<R R> Intermediate High Very high Suggested Necessary Necessary Random Systematic Systematic Under proper conditions Short under proper conditions Short under proper conditions Possible Probable Probable

20 Conclusion The DSSFHB is an useful tool in making decisions about the management of FHB risk along the cereal production chain.