caused by Ganoderma zonatum ) as the two most prominent diseases. However, since the mid-1990s, several new pathogens and diseases have been observed, presenting additional challenges to the successful growth and maintenance of palms. Fusarium oxysporum
Monica L. Elliott
Ju Ding, Kai Shi, Yan-Hong Zhou, and Jing-Quan Yu
Cucumber ( Cucumis sativus L.) is one of the major greenhouse vegetables in the world and is very vulnerable to fusarium wilt caused by Fusarium oxysporum (FO) ( Ahn et al., 1997 ; Ye et al., 2004 ). Fusarium pathogen infects the roots and
A. James Downer, Janice Y. Uchida, Donald R. Hodel, and Monica L. Elliott
Canary island date palm wilt Pathogen and host range. The pathogen Fusarium oxysporum f.sp. canariensis causing date palm wilt has been reported primarily on canary island date palm ( Simone, 2004a ), but wilt symptoms have also been observed on
Inga A. Zasada, Clyde L. Elmore, Lani E. Yakabe, and James D. MacDonald
metam sodium treatment ( Table 2 ). Weeds. In contrast to the citrus nematode and Fusarium , the weed species varied greatly in their susceptibility to propargyl bromide ( Fig. 2 ). These differences were observed both years at all locations and
Samuel F. Hutton, John W. Scott, and Gary E. Vallad
. Fusarium wilt, caused by the soilborne fungus Fusarium oxysporum f. sp. lycopersici , has been a major disease of tomato in Florida and in other warm production regions worldwide. The fungus colonizes the vascular tissue of plants after infecting the
Mark Hoffmann, Husein A. Ajwa, Becky B. Westerdahl, Steven T. Koike, Mike Stanghellini, Cheryl Wilen, and Steven A. Fennimore
species were chosen due to the regional value of the acreage they represent. Fumigant application rates and fumigant application dates are shown in Table 1 . All fumigants were shank-applied. Table 1. Fumigation treatments, methods of fumigant injection
Anas Eranthodi, Mohammad Babadoost, and Bernhard Trierweiler
complex. Three fungal species, V. dahliae, V. longisporum , and Fusarium solani , were identified as the causal agents of the internal root discoloration ( Babadoost et al., 2004 ). Horseradish producers save their horseradish sets from their harvest
Frank A. Buffone and Don R. La Bonte
Chlorotic Leaf Distortion (CLD) is a common disease of sweetpotato caused by Fusarium lateritium. This fungus is unique among Fusarium species in that it grows on the epidermis of leaves and shoot tips of sweetpotato. Fusarium lateritium appears as a white epiphytic material and under bright sunlight causes leaf chlorosis. When cloudy weather persists for several days, all symptoms disappear.
Researchers who use RAPD to examine banding patterns of sweetpotato DNA assume that foreign DNA present in the cTAB extract is quantitatively low and will not appreciably amplify and appear as bands. In this study we found the modified cTAB procedure used to amplify sweetpotato DNA also amplifies DNA of Fusarium lateritium cultures. DNA banding patterns of infected leaves was compared with those free of the disease. No differences in banding patterns were observed in this preliminary study.
Mario Orozco-Santos, Javier Farías-Larios, Jaime Molina-Ochoa, and José Gerardo López-Aguirre
Development of resistance to chemical pesticides has been reported in about 150 plant pathogenic species, mostly fungi. Biocontrol of plant pathogens is an alternative to chemical pesticides. Actually, there are products formulated with beneficial microorganisms, such as mycorrhizal fungi, rhizobacteria, antagonistic fungi, and others. The objective was to evaluate the development of Fusarium oxysporum f. sp. melonis (FOM) on melon plants inoculated with commercial biological formulations based on beneficial microorganisms. Twelve treatments were evaluated: T1) VAM media nursery + FOM; T2) Hortic Plus + FOM; T3) BioPak F + FOM; T4) Glomus intraradices + FOM; T5) FOM; T6) control; T7) VAM media nursery; T8) Hortic Plus; T9) BioPak F; T10) Glomus intraradices; T11) FOM + Mancozeb wp80; and T12) FOM + BioPak F. The melon cultivar used was `Colima' (Peto Seed Co.). Seeds were planted in Styrofoam growing containers containing coconut fiber powder as substrate. One seed was planted per cell and maintained until transplanting. Plants were transplanted to pots containing sterile soils 13 days postemergence. Inoculation of treatments with Fusarium was made with a concentrated suspension at 1 × 106 conidia/mL. For inoculation with beneficial microorganisms, manufacturer specifications were followed. A completely randomized design with 12 treatments and 12 replications was used to estimate the incidence of Fusarium, number of leaves, leaf area, root biomass, and percentage of roots colonized by mycorrhizal fungi. Overall, T10 showed the best behavior in all variables. Inoculation of cantaloupe plants with Fusarium affected their performance, but those treatments including mycorrhizal fungi enhanced their performance withstanding the damage by Fusarium.
Thomas R. Gordon, Dorothy Okamoto, Andrew J. Storer, and David L. Wood
Pitch canker, caused by Fusarium subglutinans f. sp. pini, causes branch dieback and stem cankers in many species of pine. Monterey pine (Pinus radiata D. Don), one of the most widely planted pines in the world, is extremely susceptible to pitch canker. Four other pine species, which might serve as alternatives to Monterey pine in landscape settings, were found to be relatively resistant, based on the size of lesions resulting from branch inoculations under greenhouse conditions. Of these species, Japanese black pine (P. thunbergiana Franco) was the most resistant, followed by Canary Island pine (P. canariensis Sweet ex K. Spreng), Italian stone pine (P. pinea L.), and Aleppo pine (P. halepensis Mill.). Consistent with these findings, a field survey conducted in Alameda County, Calif., revealed Monterey pine to have the highest incidence of infection, with significantly lower levels in Aleppo, Canary Island, and Italian stone pines. Japanese black pine was not observed in the survey area.