Showing papers in "Plant Disease in 1986"

Physiologic Specialization of Pyricularia oryzae in the Philippines

Abstract: equivalent for the purposes of this study. Bonman, J. M., Vergel de Dios, T. I., and Khin, M. M. 1986. Physiologic specialization of All cultures were maintained initially Pyricularia oryzae in the Philippines. Plant Disease 70:767-769. in prune agar slants. For long-term The rice blast pathogen, Pyricularia oryzae, was collected from various regions in the Philippines storage, sorghum grains were used as a and tested on widely grown Philippine cultivars and the International, Japanese, and Korean substrate. The grains were steeped, differential cultivar sets. Isolates with virulence to Philippine IR cultivars were common in samples boiled, and autoclaved on two consecutive from lowland areas, where such cultivars are widely grown, but virulence was rare among isolates days. The grains were seeded with the from Zamboanga del Sur, where upland rice is cultivated. Virulence to C22 was most frequent fungus and incubated at 25-28 C until all among Zamboanga del Sur isolates. Virulence to IR56, UPLRi3, and UPLRi5 was rare. Virulence grains were colonized. The colonized to the newly released cultivars IR58, IR60, and IR62 was present in the fungus population. IR60 grains were dried at 40 C for 24 hr, and IR62 showed a higher frequency of intermediate reaction types than other IR cultivars. None transferred to a vial of silica gel, and of the three differential sets could adequately differentiate agriculturally important isolates. stored at 4 C. These colonized grains Differential sets using established cultivars grown within a geographic region are recommended for were used as stock cultures for all retested practical use in describing the virulence of a blast pathogen population. isolates.

Fusarial wilt of Cavendish bananas in Taiwan.

Abstract: Historical account of the outbreak of Fusarial wilt on Cavendish bananas since 1967; race identification; disease control measures; and progress and prospects.

Resistance in Aegilops squarrosa to wheat leaf rust, wheat powdery mildew, greenbug, and Hessian fly

Abstract: Gill, B. S., Raupp, W J , Sharma, H. C., Browder, L. E., Hatchett, J. H., Harvey, T. L., Moseman, J. G., and Waines, J G 1986. Resistance in Aegilops squarrosato wheat leafrust, wheat powdery mildew, greenbug, and Hessian fly. Plant Disease 70:553-556. Sixty accessions of Aegilops squarrosa (= Triticum tauschii Schmal) were evaluated for resistance to leaf rust (Paccinia reconditaf. sp. lrirlci) culture PRTUS6; powdery mildew (Erysiphe graminis f. sp. tritici),composite cultures ABK, 127, YUMA CC, and Asosan; greenbug (Schizaphis graminum) biotype E; and Hessian fly (Mayetiola destructor) biotype D. Thirty-two accessrons were resistant to the leaf rust pathogen, 3l to the powdery mildew pathogen, and 34 to the greenbug; 24 were homozygous and I 6 were segregating for resistance to the Hessian fly. Multiple resistance was widespread and six accessions were resistant to both pathogens and both insects Resistance varied from immune to moderate reactions. Because A. squarrosaisthe donor ofthe D genome in common wheat, this species can be readily exploited in breeding wheats for pest resrstance Common or bread wheat (Triticum aestivum L. emend. Thell) is an allohexaploid (AABBDD) of recent origin (about 8,000 yr) between a tetraploid wheat ?i turgidum L. (AABB) and Aegilops squarrosa L. e f. Muschii [DD]) (14). Presumably, initial hybridization was restricted to a narrow range of genotypes of each species, thus the genetic diversity of today's wheats primarily accumulated during the culture and spread of bread wheat into the Mediterranean region, Africa, India, China, and elsewhere. During this expansion. further introgression may have occurred with il, turgidum but not with A. squarrosa because of the latter's strong cross-incompatibility with bread wheat.

Compatibility of Bacillus subtilis for postharvest control of peach brown rot with commercial fruit waxes, dicloran, and cold-storage conditions

Abstract: Etude de l'interaction entre les differentes techniques physiques (cires, entreposage frigorifique), chimiques (fongicide) et biologiques (Bacillus subtilis) de lutte contre Monilinia fructicola. La lutte biologique semble efficace

Dispersal of Verticillium albo-atrum by the fungus gnat (Bradysia impatiens).

Abstract: Adult flies of Bradysia impatiens collected from a greenhouse or growth chamber that contained 0.5% NaOCn for 2 mi, and plating analfalfa plants affected with Verticillium wilt were contaminated 79% with propagules of the alfalfa section from the base on ethao strain of Verticillium albo-atrum. Individual flies washed in 1 ml of sterile distilled water yielded streptomycin agar (ESA) (11). The plates 0-> 100 colony-forming-units of V. albo-atrum on ethanol-streptomycin agar. When Bradysia flies were kept at 21-25 C and observed for either naturally or artificially infested with V. albo-atrum were caged on clipped, 10to 12-wk-old growth of V. albo-atrum. plants of Iroquois alfalfa for 5-7 days, the incidence of Verticillium-infected plants ranged from 31 to 41%. Plants caged with Trichoderma-infested flies or with uninfested flies did not become RESULTS infected. Natural infestation of flies. In a

Disorders in citrus shipments to the New York market, 1972-1984

Abstract: Mise au point concernant les principales maladies et alterations et leurs frequences d'apparition au cours du dechargement des oranges, pamplemousses et citrons au niveau des ports maritimes fournissant les marches de New York. Elaboration d'une base de donnees regroupant ces resultats

Decay and acceptability of mangos treated with combination of hot water, imazalil and gamma radiation

Abstract: La combinaison binaire des 3 types de traitements s'avere beaucoup plus efficace que chacun d'eux applique individuellement