THESES OF DOCTORAL (PhD) DISSERTATION Takács József KESZTHELY 2009 0
THESES OF DOCTORAL (PhD) DISSERTATION PANNON UNIVERSITY GEORGIKON FACULTY OF AGRICULTURE Institute of Plant Protection Department of Agricultural Entomology DOCTORAL SCHOOL OF ANIMAL- AND ANGRAR- ENVIROMENTAL SCIENCES Science: Plant Cultivation and Horticultural Sciences Supervisor: Dr. ANDA ANGÉLA doctor of HAS Dissertation advisor: Dr. NÁDASY MIKLÓS candidate of agricultural science FORECASTING OF THE WESTERN CORN ROOTWORM AND ALTERNATIVE CONTROL METHODS OF THE PEST Written by: TAKÁCS JÓZSEF KESZTHELY 2009 1
1. SCIENTIFIC PRELIMINARIES Western Corn Rootworm (Diabrotica virgifera virgifera LECONTE, 1868) and its control have the same importance as potato beetle dragged earlier from the US in Europe. First goal of integrated pest management is to collect all the scientific results, cropping and plant protection technologies to manage economic pest management of newly appeared invasive pests. Biological and ecological specialties of WCR give us the chance to do the integrated control of the pest based on long term forecast. 2
2. OBJECTIVES Doing reliable forecast plant protection experts have to find typical field parameter to define solid areas in plots can be treated by the same technology. Handling all the known forecast methods, biological/ecological specialties of the pest and sampling techniques as a dynamic system our main goal was to develop a reliable forecast tool of WCR. Knowing egg laying behavior of the pest a multidimensional model based on field-relieves were started to develop, to do plant protection forecast much easier and less expensive. The model can be used directly by the farmer. The forecast system based on the fieldrelief of the maize plot can defines imperiled zones of the field are represent the possible larval damage of WCR. 3
3. MATERIALS AND METHODS 3.1 Sampling Known methods of Diabrotica egg/larvae counting were compared to find the most effective technique to forecast predicted larval damage of WCR. Soil samples were taken from different maize fields of Hungary. Sampling was based on field-relief of the plots. Representative sample was made from 3 partial samples to minimize sampling error. 3.2 Soil water potential studies Water potential of maize fields was examined by fixed tensiometers. Suction tensiometers were placed in a square grid pattern on fields to find changes in soil water content after precipitation. 3.3 Studies of egg laying behavior Egg laying behavior was examined in an isolated plastic tunnel (10x4m). Intensity of egg laying was studied in 10 treatments of different host plant species and untreated field. Experimental plots were placed in random order in 3 repetitions. Climate conditions and development of plants were controlled continuously under season. About 4
3500 gravid females of WCR were settled in tunnel under August October. Soil samples were taken from plots after the season and were examined in laboratory by the method of egg washing. 3.4 Thermal requirements of WCR Thermal requirements of the pest were examined in climate chambers. Soil samples containing WCR eggs were placed in climate chambers on 3 different temperature levels. Soil and air moisture level were controlled continuously. Larvae ran out from samples were collected by germinating corn seeds. Corn sprouts were placed in scouting funnels to count the number of larvae. Results of thermal requirements issues were used for checking reliability of other forecasting methods of the pest. 3.5 Egg washing studies Gravid females of WCR were collected from the field to develop the egg washing technique. Insects were placed in plastic buckets with an aeration hole at the top of the pots covered by insect screen. Every pot was filled with moisturized soil from the field. Immature florescence and 5
ears of corn were placed on the top of the soil as nourishment of the adults. Egg washing from soil was made by a three level laboratory screen under tap water spout. Residues were washed in Petri-dishes with 80 g/g concentration solution of NaCl. Eggs were counted under binocular microscope after 12 hours. 3.6 Alternative control of the pest Main lines of sight were the cellulose based binding material tests and indirect protection by microbiological fermentative manures. 3.6.1 Mavicell binding material tests Searching for environmental friendly and low cost protection method against larval damage of Diabrotica many active insecticide ingredients bind in cellulose based carrier pearl were tested to elongate efficacy period of insecticide in soil. These combinations of insecticides and carrier were tested in glasshouse screening on corn weevils (Tanymecus dilaticollis GYLL. 1834). After screening the product was tested in field trials directly with WCR. 6
3.6.2 Microbial manure tests Farmers can also use root development increasing products to control rootworms because this way the relative damage can be decreased. Zinc and microbiological fertilizers can be suitable to increase root weight. In laboratory and field trials we found that microbiological fertilizers can relatively decrease larval damage by turning soil-water supply feasible for plants. This way plants can survive root-chewing of WCR larvae. Root increasing relative decreasing of root losses - effect of microbiological fertilizers were compared with root protection of teflutrin soil decontamination product. 7
4. RESULTS 4.1 Sampling Our sampling development results were used for build up a multidimensional forecasting system based on finding optimal plots for Diabrotica females to lay eggs..a Microsoft Excel based sampling tool was developed as part of the multidimensional forecast system to define imperiled zones inside the plot. This tool can be useful to give correction support to different observations of forecast. The model is based on a partial system creating field relief maps of the plot. Sampling tool creates visual view of the potential imperiled zones of the field by the geo-coordinates and ecological characteristics of the pest. 4.2 Soil water potential studies By the help of water potential changes season term moisture dynamics of the field can be forecastable. Imperiled zones turn to be definable where water content of soil is sufficient for laying eggs for WCR. On lower parts of the field females can find sufficient place to lay eggs. It makes these plots imperiled by plant lodging. 8
4.3 Studies of egg laying behavior Diabrotica adults feed mostly on pollen of weeds in T4 group of living as alternative nourishment. On plots of alternative food sources it was found that Diabrotica eggs were placed in soil close to the stems of weed plants. In glasshouse experiment lots of new information was collected about egg laying behavior of WCR adults. Weeds can generally colonize moisturized plots of the field what Diabrotica females also prefer to lay eggs. Females lay eggs on these plots not because of pollen sources of plants but the soil s water content. Gravid females move to those wet parts of the field to lay eggs in quantities. Examined larval feeding in climate chambers it was found that larvae of WCR can survive for more than two weeks on roots of different weeds - even on jimsonweed (Datura stramonium L.) - but they cannot change development stage. According to our results it is clearly seen that larvae of WCR can survive for long on roots of alternative host plants while they are seeking of roots of corn. With this capability of alternative feeding they can take more than 0,9 m mentioned in literature. 9
4.4 Thermal requirements of WCR In climate chambers exact thermal requirements were searched of the pest in larval stage. Minimum temperature of development of WCR is 10,1 o C and the effective cumulated heat amount in egg stage is 268 day o C. These thermal constants help us to plan control of the pest. 4.5 Egg washing studies Searching for the most effective technique to forecast predicted larval damage of WCR all known methods of Diabrotica egg/larvae counting were compared. 85-93% reliability to find eggs in general sample was reached to determine expected larval damage with précised eggwashing technique. Egg washing technique is a quick and reliable forecasting method to find expected larval damage of WCR on the field. Results imported into the multidimensional forecasting system can help us to esteem the potential economical damages. 10
4.6 Alternative control of the pest 4.6.1 Mavicell binding material tests The carrier material emitted the active ingredients permanently but we could not solve to take up insecticides in whole volume of the pearl. The pearl is not able to saw with sawing machines and it is not useful to control the pest. In general it is necessary to find the way to elongate efficacy of soil insecticides.. 4.6.2 Microbial manure tests Farmers can also use root development increasing products to control rootworms because this way the relative damage can be decreased. Zinc and microbiological fertilizers can be suitable to increase root weight. In laboratory and field trials it was found that microbiological fertilizers can relatively decrease larval damage by turning soil-water supply feasible for plants. This way plants can survive root-chewing of WCR larvae. In large field trial microbial fertilizers reached the same effect as the teflutrin based soil decontamination product and additionally it caused 0,5t/ha yield development in average of 5 hectares. 11
5. NEW SCIENTIFIC RESULTS First in Hungary we were determined the thermal requirements of Western Corn Rootworm in climate chambers to find effective heat-amount of larval stage under Hungarian thermal conditions. In glasshouse experiments we were determined the preferences of Diabrotica adults on alternative host plants and weeds where egg laying is conceivable near plants. Field-relief based multidimensional model was worked up on winter forecast of WCR. We were improved reliability of egg washing winter forecast method. With the précised method we can increase solidity of the predictable damage of Diabrotica larvae on 80% level. We were built a dynamic forecasting model based on MS Office Excel useful for every farmer to forecast the predictable larval damage on an inexpensive way. Larval damage estimation formula was worked out to find the predictable numeric value of WCR larval damage. 12
PUBLICATIONS HUNGARIAN PUBLICATIONS Lectures TAKÁCS J., TAKÁCS A., NÁDASY M. (2004): Hatékony védekezési módszer az amerikai kukoricabogár (Diabrotica virgifera virgifera LeConte) lárvái ellen. XLVI. Georgikon Napok, Keszthely. TAKÁCS J., NÁDASY M., BAKOS GY., VASS B., ÁCS O., TAKÁCS A. (2004): Hatékony védekezési módszer az amerikai kukoricabogár (Diabrotica virgifera virgifera LeConte) lárvái ellen. Integrált termesztés a kertészeti és szántóföldi kultúrákban tanácskozás, Budapest. TAKÁCS, J., BALOGH, P., KUTAS, J., NÁDASY, M., TAKÁCS, A. (2004): Effective control method of larvae of Diabrotica virgifera virgifera Leconte. 56 th International Symposium on Crop Protection, Ghent. TAKÁCS J. (2005): A kukoricabogár (Diabrotica virgifera virgifera LeConte, 1868) téli előrejelzése tojáskimosással. XI. Ifjúsági Tudományos Fórum, Keszthely. TAKÁCS J., NÁDASY M. (2005): A kukoricabogár tojásainak és lárváinak talajból való kimutatásának lehetőségei, előnyei és nehézségei. Növényvédelmi Tudományos Napok, Budapest. 13
TAKÁCS J., NÁDASY M., PIRGI Z., NÉMETH T., MILEVOJ, L., TRDAN, S. (2005): A kukoricabogár (Diabrotica virgifera virgifera LeConte, 1868) téli előrejelzése és annak felhasználhatósága a precíziós növényvédelemben. Tiszántúli Növényvédelmi Fórum, Debrecen. TAKÁCS J., NÁDASY M. (2005): A kukoricabogár tojásai és lárvái talajból való kimutatásának lehetőségei. Magyar Rovartani Társaság 738. ülés, Budapest. TAKÁCS J., NÁDASY M., PIRGI Z., NÉMETH T.(2006): Mavicell-el a kukoricabogár (Diabrotica virgifera virgifera LeConte, 1868) ellen Tegyünk pontot a végére! Keszthelyi Növényvédelmi Fórum, Keszthely. NÉMETH T., TAKÁCS J., NÁDASY M., (2006): Módszerfejlesztés az amerikai kukoricabogár (Diabrotica virgifera virgifera LeConte, 1868) téli előrejelzéséhez, és annak alkalmazása a precíziós mezőgazdaságban. Növényvédelmi Tudományos Napok, Budapest. TAKÁCS J., NÁDASY M., NÉMETH T. (2007) Módszertani vizsgálatok az amerikai kukoricabogár (Diabrotica virgifera virgifera) téli felvételezéséhez. 53. Növényvédelmi Tudományos Napok, Budapest, 5. CSERÉNYI J., SZABÓ M., NÁDASY M., TAKÁCS J., NÉMETH T., POLGÁR Z. (2007): A kukoricabogár (Diabrotica virgifera virgifera LeConte, 1868) elleni védekezés entomopatogén nematódák és baktericid készítmények alkalmazásával. XVII. Keszthelyi Növényvédelmi Fórum, Keszthely, 2008 január 31.- február 2., 76. 14
NÉMETH T., NÁDASY M., TAKÁCS J. (2008): Az EM-1 baktéruimtrágya kukoricabogár kártételre gyakorolt hatása 2006-ban és 2007-ben. XVIII. Keszthelyi Növényvédelmi Fórum, Keszthely, 2008 január 30.- február 1., 60. Articles VÖRÖS G., SZENTKIRÁLYI F., TAKÁCS J. (2002): A kukoricabogár (Diabrotica virgifera virgifera) rajzásásnak észlelése fénycsapdával. Gyakorlati Agrofórum, Fórum az amerikai kukoricabogár elleni védekezésről, 20-21. TAKÁCS J., BALOGH P., NÁDASY M. (2004): A kukoricabogár tojásszámának gyors meghatározása talajból. 9. Tiszántúli Növényvédelmi Fórum, Debrecen, 277-281. TAKÁCS J., BALOGH P., NÁDASY M. (2004): Hatékonyan a kukoricabogár lárvái ellen. 9. Tiszántúli Növényvédelmi Fórum, Debrecen, 291-296. TAKÁCS J., PIRGI Z., NÉMETH T., (2006): Kukoricabogár - Mi lesz, ha idén nem esik? Gyakorlati Agrofórum, 4 (17): 31-32. NÉMETH T., NÁDASY M., MARCZALI ZS., SIMON F., TAKÁCS J. (2007): A kukoricabogár (Diabrotica virgifera virgifera LeConte, 1868) téli előrejelzése GPS technológia segítségével. INTEGRÁLT TERMESZTÉS a kertészeti és szántóföldi kultúrákban XXVIII., Budapest, 39-43. 15
Refered journals VÖRÖS G., SZENTKIRÁLYI F., TAKÁCS J. (2002): A kukoricabogár (Diabrotica virgifera virgifera) rajzásásnak észlelése fénycsapdával. Növényvédelem 38 (10): 539-541. NÉMETH T., NÁDASY M., TAKÁCS J. (2008): Az amerikai kukoricabogár (Diabrotica virgifera virgifera LeConte, 1868) téli előrejelzése, és annak felhasználhatósága a precíziós mezőgazdaságban. Növényvédelem 45 (2): 69-72. NÉMETH T., NÁDASY M., TAKÁCS J. (2008): Nagyszámú kukoricabogár tojást tartalmazó talaj létrehozása, növényházi és laboratóriumi kísérletekhez. Növényvédelem 45 (2): 91-93. FOREIGN PUBLICATIONS Refered articles NÁDASY, M., TAKÁCS, A., BUDAI, CS., TAKÁCS, J., BALOGH, P., KOCSIS, E., KUTAS, J. (2004): Effect of the global warming on the insect pests of Hungary. 3 rd Alps- Adria Scientific Workshop, Dubrovnik, Croatia, 224-227. TAKÁCS, J., NÁDASY, M., BALOGH, P. (2005): Quick scouting of eggs of Western Corn Rootworm (Diabrotica virgifera virgifera LeConte, 1868) from soil. 57 th International Symposium on Crop Science, Ghent, Belgium. 16
TAKÁCS J., BALOGH, P., NÁDASY, M. (2006): Quick forecasting of the Western Corn Rootworm (Diabrotica virgifera virgifera LeConte), a pest of sweet corn in Hungary, IOBC/WPRS Working group, Ljubljana, Slovenia. NÁDASY M., NÉMETH T., MARCZALI ZS., SIMON F., HORN A., JÁGER F., TAKÁCS J. (2007): Winter forecasting of Western Corn Rootworm, Diabrotica virgifera virgifera (LeConte, 1868) and monitoring of damage by the insect after Sunflower as the preceding crop. IOBC Working Group on Integrated Protection in Field Vegetables Porto, Portugália, 23-28. September, 2007 TAKÁCS, J., NÁDASY, M., S. TRDAN, KUTAS, J. (2005): Effective control method of larvae of the Western Corn Rootworm (Diabrotica virgifera virgifera LeConte). Cereal Research Communications. 33.1 423-425. TAKÁCS, J., BALOGH, P., NÁDASY, M., L. MILEVOJ, MÁRTON, L. (2005): Larval feeding of the Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) on roots of several weeds and its effect on crop tillage. Cereal Research Communications. 33.1 419-421.) TAKÁCS J., NÁDASY M. (2006): Usability of a cellulose base binding material in control of WCR (Diabrotica virgifera virgifera LeConte, 1868). Cereal Research Communications. 34.1. 759-762. NÉMETH T., TAKÁCS J., SIMON F., KESZHELYI S. (2007): Forecasting of WCR on the base of GPS technology. VI Alps-Adria Scientific Workshop Obervellach, Ausztria, 30.April-5.May, 2007. Cereal Res. Comm. Vol. 35. No. 2.: 833-836. 17
NÉMETH T., NÁDASY M., MARCZALI ZS., SIMON F., NÁDASYNÉ I.E., TAKÁCS J. (2008) Effect of a soil microbe preparation (EM-1) on the damage of western corn rootworm (Diabrotica virgifera virgifera LeConte). VII Alps-Adria Scientific Workshop, Stará Lesná, Szlovákia, 28. April-3.May, 2008 Cereal Res. Comm. Vol. 36. No. 2.: 843-846. 18