OiDiag-System Versionen 2.x Dr. Walter K. Kast und Karl Bleyer Weinsberg

Transkript

1 OiDiag-System Versionen 2.x und Karl Bleyer Weinsberg

2 The two OiDiag tools: 1st tool: date for the first application of fungicides 2nd tool: maximal time lag for last applied fungicide

3 The two OiDiag tools: 1st tool: date for the first application of fungicides 2nd tool: maximal time lag for last applied fungicide

4 1st tool: theoretical aspects: epidemic may be described by an exponential function (Vanderpank 1963) low initial inoculum= Exponential phase latent phase

5 1st tool: theoretical aspects: epidemic may be described by an exponential function (Vanderpank 1963) differences on low levels are invisible high initial inoculum= 10 low initial inoculum= flowering

6 1st tool: practical aspects: initial inoculum dictates the the need to start with control high initial inculum - a lot of grape infetions - high initial inoculum in the next year => start earlier to keep epidemic low low initial inculum - no grape infetions - low initial inoculum in the next year => start later because epidemic is delayed

7 Evaluation of the initial inoculum is extremly diffcult survival in infected buds (flag shoots) survival as Cleistothecia)

8 for the initial inoculum no data are available

9 Powdery mildew symptomes observed at Weinsberg since 1953 in 6 classes Note description of symtomes no powdery mildew observed only a few leaves with late season powdery mildew observed late season syptomes in a few vineyards observed late season syptomes in most of the vineyards on leavees and lateral grapes a few vineyards had powdery mildew on grapes more than 5% of the vineyards had damage on grapes

10 Correlations between weather data, the powdery mildew disease indices of the preceeding year and disease indices of the current years source of variation database: (n=54 ) correlation to disease notes minimum of temperature (mean of the two preceeing years) disease index of the preceeding year +0,42** +0,35** coefficient of determination: 32%

11 coefficient of determination: 32% calculations are possible in January the complete epidemic of the relevant year is in the offing => these two values give an exellent estimation for the initial inoculum

12 1st tool: delay on base of stage 3 leaves unfolded disease severity preceeding year 1st spray should start latest : input: input: 0,00 17,50 34,75 mean of the absolute minima of the 2 preceeding winters days after 3 leaves unfolded

13 1st tool: delay on base of stage 3 leaves unfolded disease severity preceeding year 1st spray should start latest : input: input: 5,00 10,30 0,39 mean of the absolute minima of the 2 preceeding winters days after 3 leaves unfolded

14 The two OiDiag tools: 1st tool: date for the first application of fungicides 2nd tool: maximal time lag for last applied fungicide

15 maximal time lag for last applied fungicide depends on: active period of the fungicides climatical effects on the fungus ontogenetics of the vine (relevant: grape)

16 The idea classification of fungicides for their preventive period Calculation of an index value integrating ontogenetics and climate The result:

17

18 befallene Oberfläche in % Stadienspezifische Anfälligkeit Trollinger Lemberger ,

19 befallene Oberfläche in % Stadienspezifische Anfälligkeit Trollinger Lemberger ,

20 Befallststärke % Stadienspezifische Anfälligkeit Trollinger Lemberger ,

21 Mehltaufenster: Zeitraum der Besiedlung der Trauben

22 Standard Oidag 3 x Blüte T Vorblüte Kumulus T letzte Vorblüte Talendo T abgehende Blüte Vivando T Nachblüte Flint T Ende TS Vivando T nach TS Systhane T Abschluss Systhane T Vorblüte Talendo T letzte Vorblüte Vivando T abgehende Blüte Cabrio Top T Nachblüte Discus T Ende TS Systhane T nach TS Systhane T Abschluss Systhane T1 Vorblüte T letzte Vorblüte Talendo T abgehende Blüte Cabrio Top T Nachblüte Talendo T5 Ende TS T6 nach TS T7 Abschluss

23 Mehltauversuch Cabernet Dorsa 2008 Blatt und Traube Traubenbefall Stärke26.6. Blattbefall Stärke % % Kontrolle Bayer Dow Standard OiDiag x "Fenster"

24 Mehltauversuch Cabernet Dorsa Auswertung Mehltauinfektionen erfolgen fast ausschließlich im Mehltaufenster sitzen meist an versteckten Stellen sie 70 werden durch Spritzungen nur unterdrückt werden 60 allmählich (meist Wochen später) sichtbar 94% 99% Traubenbefall Stärke % Blattbefall Stärke % Kontrolle Bayer Dow Standard OiDiag x "Fenster"

25 Spritzungen während des Mehltaufensters im Vergleich zu 7 Routinespritzungen (Freilandversuche) Unbehandelt 42 7x Discus 4 % befallene Beerenoberfläche 3x Discus 9

26 Spritzungen während des Mehltaufensters im Vergleich zu 7 Routinespritzungen (Freilandversuche) % befallene Beerenoberfläche Unbehandelt 7x Vento 4 3 xvento

27 Spritzungen während des Mehltaufensters im Vergleich zu 7 Routinespritzungen (Freilandversuche) % befallene Beerenoberfläche Unbehandelt 7x Flint 3x Flint

28 Spritzungen während des Mehltaufensters im Vergleich zu 7 Routinespritzungen (Freilandversuche) % befallene Beerenoberfläche 7 Unbehandelt totaler Fehlschlag 3x Vento

29 Spritzungen während des Mehltaufensters im Vergleich zu 7 Routinespritzungen (Freilandversuche) % befallene Beerenoberfläche 7 7 Unbehandelt 7x Vento 3x Vento

30 Ursache der schlechten Wirkung Ausfall der Parzellenspritze Spritzintervall 18 Tage vor und während der Rebblüte

31 Calculation of OiDiag-2.X Index Values Input values needed 1. Actual number of leaves developed (stage) 2. Precipitation sum/day 3. Daily mean of temperature 4. Daily Leaf-wetness (hours) 5. Humidity: hours with humidity>65< =80 and hours with humidity>80

32 Ontogenetical-Index (ONT) ONT = {(0.0007*N³)+(84*Ln(N)-(9.4*N)-0.67)}/100 N= number of days after three leaves unfolded N = IF(N<3;=3,=N2) IF(N>30;=30,=N) [set limits:] ONT=IF(ONT<0.2;0.2;ONT)

33 Ontogenetical-Index (ONT) 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,

34 Ontogenetical-Index (ONT) ONT = {(0.0007*N³)+(84*Ln(N)-(9.4*N)-0.67)}/100 N= number of days after three leaves unfolded N = IF(N<3;=3,=N2) IF(N>30;=30,=N) [set limits:] I2=IF(I1<0.1;0.1;I1) fixed function with maximum at beginning of flowering period (independent from weather-conditions) Works well in Weinsberg and Freiburg but transfer is limited in other regions Vitimeteo: Leaves according to the model of Schultz/Geisenheim are going to be used in 2010 Vitimeteo allows to set own values for each number of leaves separately

35 Index based on climatical conditions (CLI): Contribution of temperature (TEM) TEM=(((0.11*T)-(0.0025*T*T))-0.6)*1,63 T = daily mean of temperature a similar formula was used in OiDiag1.0

36 Contribution of temperature (TEM)

37 Contribution for humidity (HUM) HUM=(H80+(H65*0.7))/24 H65 = hours with humidity>65< =80 H80 = hours with humidity >80 The same function was used in OiDiag1.0 OiDiag1.0 was criticized heavily for the integration of humidity to the index

38 Contribution of rainfall and leaf wetness (RAI): R=IF(PREC<2.5; =0; =LWET*1.5) R=IF(PREC>10; =LWET*3.0; =LWET) RAI=R/24 PREC = rainfall/day [mm] LWET = Leaf-wetness [hours/day]

39 Index based on climatical conditions (CLI): CLI=(TEM*HUM)*2-(1.1*RAI) [set limits:] CLI=IF(CLI<0;0;I1) CLI=IF(CLI>1.1;1,1;I1)

40 Index for the relevant day (IND) [combine CLI and ONT] IND=CLI*ONT [set limits:] IND=IF(IND>1.02;1;I4)

41 OiDiag2.2-Index (final result) [calculate sliding means over the last 7 days (%)] Mean((IND (day-6), IND (day-5)), IND (day-4), IND (day-3), IND (day-2), IND (day-1), IND (actual day) )*100)

42 Exsamples of OiDiag Index-values 2008/ flowerung 2008 flowering

43 Danke für Ihre Aufmerksamkeit Bilder Obstbau Staatliche Dr. Lehr- Walter und Versuchsanstalt K. Kast für Wein- FDW und AK Obstbau Rebschutz Weinsberg