Vol. 101, No. 6 (Supplement), 2011 S47 Potato IPM program: Taking the research to the farm J. D. DWYER (1), J. F. Dill (2), S. B. Johnson (1), G. M. Dill (2) (1) University of Maine Cooperative Extension, Presque Isle, ME, U.S.A.; (2) University of Maine Cooperative Extension, Orono, ME, U.S.A. Phytopathology 101:S47 Potatoes are the largest agricultural commodity in the State of Maine, generating a total economic value of over $500 million, and producing employment for over 6,000 individuals. The University of Maine Cooperative Extension Potato IPM program is a multidisciplinary program that assists growers in the management of potato pests by providing specific and timely scientific information. Information gathered through multiple sources, including direct observation, traps, weather data, and prediction models, is delivered to potato growers in Maine and around the globe through electronic and standard newsletters, websites, and via telephone message centers. The Potato IPM program impacts approximately 56,000 acres of commercial potatoes and employs 18 program aids who assist in producing over 1.5 million data points that help IPM scientists track potential pest outbreaks and provides potato growers and industry professionals with current information on specific and timely treatments, which can be used to minimize pesticide applications and maximize potato yield and quality. In 2009, the UMaine Cooperative Extension Potato IPM Program produced an estimated $26 million positive impact on the Maine potato industry. Coat protein expression strategy of oat blue dwarf virus M. C. EDWARDS (1), J. J. Weiland (1) (1) USDA ARS, Fargo, ND, U.S.A. Phytopathology 101:S47 Oat blue dwarf virus (OBDV) was the first marafivirus (family Tymoviridae) to be sequenced and for which an infectious clone has been reported. Although sequence data are now available for multiple marafiviruses, precise details of the expression strategy of these viruses remain undocumented. Translation experiments with OBDV suggest that a large 224-240 kDa polyprotein encoded by much of the genome is post-translationally processed into its functional components, in agreement with its tymoviral lineage. ORFs for two 21-25 kDa coat proteins (CP) are encoded near the 3c terminus and are coterminal with the large polyprotein ORF. By analogy with tymoviruses, a marafibox is presumed to serve as a promoter for a subgenomic RNA encoding the CP, yet the expression strategy for the CPs has to date been poorly investigated. The smaller (major) CP appears to be the product of direct translation of a subgenomic RNA, while the larger (minor) CP may be a cleavage product derived from a larger precursor or also may be expressed directly from a subgenomic RNA. Using an infectious clone of OBDV, we have developed a series of mutants to dissect and analyze the OBDV CP expression strategy. Preliminary results from protoplast experiments are consistent with a coat protein expression strategy involving proteolytic cleavage to produce the minor CP and direct translation of a subgenomic RNA to produce the major CP. Field application of asafoetida and seaweed for the management of root diseases of watermelon and eggplant S. EHTESHAMUL-HAQUE (1), G. N. Baloch (1), V. Sultana (2), J. Ara (3) (1) Department of Botany, University of Karachi, Karachi, PAKISTAN; (2) Department of Biochemistry, University of Karachi, Karachi, PAKISTAN; (3) Department of Food Science & Technology, University of Karachi, Karachi, PAKISTAN Phytopathology 101:S47 Water melon (Citrullus lanatus (Thunb.) Matsum. & Nakai) and eggplant (Solanum melongena L.) are highly susceptible to root rotting fungi Fusarium solani, F. oxysporum, Macrophomina phaseolina and root knot nematode (Meloidogyne spp.) causing huge losses each year in Pakistan. In field experiments, application of asafoetida, a medicinal gum from Ferula assafoetida and seaweeds Spatoglossum variabile, Stokeyia indica and Melanothamnus afaqhusainii showed significant suppressive effect on root rotting fungi Fusarium solani, Macrophomina phaseolina and root knot nematode Meloidogyne incognita) attacking watermelon and eggplant and improved plant growth in soil naturally infested with root rotting fungi and artificially infested with root knot nematode. Length of vine of watermelon, shoot length of eggplant and fresh shoot weight were higher in seaweed and asafoetida treated plants as compared to control or Topsin-M, a fungicide, treated plants. Seaweed and asafoetida treated plants also showed earlier fruiting than control or fungicide treated plants. At farmer’s field seaweed showed similar suppressive effect on F. solani and M. phaseolina and root knot nematode on water melon in soil naturally infested by these pathogens. Application of seaweed produced healthy plants and number of fruits and weight were significantly higher in seaweed and asafoetida treated plants. Asafoetida and seaweeds offer a non-chemical means of disease management. A non-structural, p17 protein of Potato leafroll virus co-localizes in plant phloem tissue with virus capsid protein S. EID (1), J. S. Durrin (1), O. V. Nikolaeva (1), A. Karasev (1) (1) University of Idaho, Moscow, ID, U.S.A. Phytopathology 101:S47 Potato leafroll virus (PLRV) is a phloem-limited, positive-strand RNA virus. The ca. 6-kb PLRV genome encodes eight open reading frames (ORFs), of which ORFs 0-2 encode proteins involved in genome replication and silencing suppression, and ORFs 3-5 encode proteins involved in particle assembly, systemic movement, and aphid transmission. A non-structural, p17 protein encoded by the ORF 4 was previously identified as a host-dependent movement protein of PLRV. The two structural proteins, capsid protein (CP, ORF 3) and p80 (ORF 5), were known to be indispensable for the PLRV transmission by aphids. In a phloem-limited virus, systemic movement is a pre-requisite for a successful acquisition of the virus by its aphid vector from the vascular system, and recently p17 was suspected to be involved in aphid transmission of PLRV. Here, we have studied tissue localization of the p17 protein in Nicotiana benthamiana plants infected with wild-type PLRV and a series of p17 mutants. Tissue localization was determined using p17-specific antibodies in a tissue immuno-binding assay. In plants infected with PLRV, p17 was found exclusively in the phloem, co-localizing in the same vascular tissue stained with antibodies specific to the PLRV capsid protein. Implications of p17 tissue localization for its possible role in PLRV aphid transmission will be discussed. New method for establishing a network of operational warning of Septoria leaf blotch disease in winter wheat M. EL JARROUDI (1), F. Giraud (2), P. Delfosse (3), L. Kouadio (1), L. Hoffmann (3), H. Maraite (4), B. Tychon (1) (1) Univ of Liege, Arlon, BELGIUM; (2) Staphyt/BIORIZON, MARTILLAC, FRANCE; (3) Centre de Recherches Public Gabriel Lippmann, Belvaux, LUXEMBOURG; (4) Earth & Life Institute, Université catholique de Louvain (UCL), Louvain-la-Neuve, BELGIUM Phytopathology 101:S47 A mechanistic model, PROCULTURE, based on commonly available meteorological data and assessing in real time the risk of progression of septoria leaf blotch disease on winter wheat has been developed in Belgium and the Grand-Duchy of Luxemburg (GDL) to limit fungicide use. However, the reliability of meteorological stations used for the warning system varies according to the distance to the fields. A weather analysis based on the Fourier transform highlighted a great difference in the intraday variation between two sites in the GDL (Everlange and Reuland). The correlation between these two sites is very high for the hourly temperature (R = 0.96), and for the hourly relative humidity (RH) (R = 0.86), (P < 0.05). However, the intraday variation (<11 hours) highlights contrasts for a given meteorological parameter. Hence, the correlation between temperature or RH decreased respectively from 0.96 to 0.43 and from 0.86 to 0.30. The comparison between infection conditions given by PROCULTURE using the Fourier transform, shows: (i) a positive but weak correlation between temperature at Reuland and Everlange (R = 0.64), (ii) a good correlation between RH for these two sites (R = 0.86), and (iii) a contrasted difference for rain (R = 0.27), (P < 0.05). This Fourier transform based method enables to take into account the RH and temperature variation related to topography levels in the warning system and to understand and explain the variation in disease expression between a plateau and a valley bottom or between North and South slopes. Regional-based typology of the main fungal diseases affecting winter wheat in the Grand-Duchy of Luxembourg M. EL JARROUDI (1), F. Giraud (2), P. Delfosse (3), L. Kouadio (1), L. Hoffmann (3), H. Maraite (4), B. Tychon (1) (1) Univ of Liege, Arlon, BELGIUM; (2) Staphyt/BIORIZON, MARTILLAC, FRANCE; (3) Centre de Recherches Public Gabriel Lippmann, Belvaux, LUXEMBOURG; (4) Earth & Life Institute, Université catholique de Louvain (UCL), Louvain-la-Neuve, BELGIUM Phytopathology 101:S47 Despite its small territory size, the Grand-Duchy of Luxembourg (GDL) has several microclimates that result in a variability of disease severity between the South (Gutland) and the North (Oesling). Septoria leaf blotch disease of wheat is an important disease in the GDL. Over 2003–2009, the severity was strong in Gutland (51% on average over the last two upper leaves at the late milk growth stage) and low in the Oesling (16% for the same leaves). For the years 2006, 2008 and 2009, the disease severity was less than 6% in the Oesling while it exceeded 40% in the Gutland. The second fungal disease that has become economically important is the wheat leaf rust. Over the same period, the Gutland and the Oesling showed consistently the highest and lowest disease severity respectively. In 2003 and 2007, the Gutland showed the highest disease severity with 66% and 57% respectively, whereas the lowest severity (<1%) was observed in the Oesling. Another important disease View publication stats View publication stats