When green pepper seedlings were transplanted to soil mixed with roots infected with pepper mild mottle virus (PMMoV), the mosaic disease developed. This suggested that infection by PMMoV occurred at the time of transplanting. Green pepper seedlings were transplanted to infested soil by several methods to investigate the possibility of preventing soil transmission. Consequently, removing seedlings from their pots and transplanting to soil had an incidence of approximately 80% diseased plants. Plants removed from the seedling pots had exposed roots that were easily contacted by infested soil when transplanted. On the other hand, molded peat-moss pot seedlings transplanted to soil had an incidence of 0-14% diseased plants. The reduction in disease incidence is attributed to the peat-moss pot preventing contact of seedling roots with infested soil at the time of transplanting. Since the molded peat-moss pots had no adverse influence on the growth of green pepper seedlings after transplanting, it appears to be an effective method for preventing soil transmission of PMNIoV.
Stem rot of soybean Glycine max (L.) Merr. occurred in Tokyo Metropolis in 2002. The causal fungus isolated from diseased plants was identified as Phoma exigua Desmazieres by morphological observations, colour reaction test with N-NaOH on MA medium and inoculation tests. This is the first report on stem rot of soybean by P. exigua in Japan.
Gray mold and leaf blight of wasabi, Eutrema japonica (Miq.) Koidz. occurred in the town of Okutama, Tokyo Metropolis in 2002. A Botrytis species isolated from plants infected with gray mold was identified as Botrytis cinerea Persoon: Fries, while a Rhizoctonia species isolated from plants infected with leaf blight was identified as Rhizoctonia solani Kühn AG1 IB. Inoculation tests showed that these fungi were causal agents of the respective diseases. This is the first report on these diseases in Japan.
Stem rot of Lilium ‘casablanca’ occurred at Hachijo-island of Tokyo Metropolis in 2001. The pathogen from the diseased plant was identified as a species of Rhizopus sp. An inoculation test confirmed that this fungus was the causual agent of the disease.
Differences in resistance of statice varieties to Bacterial wilt were evaluated among 32 commercial cultivars. Although all tested cultivars showed symptoms, disease severity differed in each cultivar. The severity in cultivars with yellow or white calyxes was lower than in those with another color calyxes.
Anthracnose of Shibataea kumasaca (Zollinger) Makino occurred in Tokyo Metropolis in 2002. The pathogen isolated from the diseased plant was identified as a species of Colletotrichum. An inoculation test showed that this fungus was the causal agent of the disease. This is the first report of this disease in Japan.
Southern Blight of Achillea milleforium L., Atractylodes lancea var, chinensis Kitam., Corydalis heterocarpa Shieb. et Zucc. var. japonica Ohwi, Lycopus maackianus (Maxim.) Makino, Patrinia villosa Juss., Petentilla fragarioides L. var. major Maxim. and Plantago lanceolata L. occurred at the Tokyo Metropolitan Medicinal Plant Garden. The causal fungus isolated from each diseased plant was identified as Sclerotium rolfsii Saccardo by morphological observations and inoculation tests. This is the first report this disease on these plants in Japan.
We developed a bioassay method using a two-choice test to assess the response of Leptocorisa chinensis (Dallas), rice bug, nymphs, to olfactory stimuli. Two plastic cups were placed on a board covered with wet quartz sand. Each of the cups was covered with mesh cloth in order to prevent visual stimuli of the odor sources tested. At the center of the board, a stick was erected to function as the releasing point for bugs tested. This two-choice test bioassay method was used to demonstrate the responses of L. chinensis nymphs to olfactory stimuli.
Four types of traps baited with synthetic aggregation pheromone were tested in fields to catch the bean bug, Riptortus clavatus (Thunberg). Among them, a fence-like trap using a plastic net (W240×H100cm) with a water-pan caught the bugs much more effectively than a conventional water-pan trap (40cm in diameter). A simple ‘light trap’ made by replacing the light source with the pheromone, caught the bugs as well as the water-pan trap. The other two types might not be useful because few or no bugs were caught.
Of 35 species of ornamental plants and vegetables tested, 30 species were attacked by the banded greenhouse thrips, Hercinothrips femoralis, under laboratory conditions. Of these, dumb cane (Dieffenbachia sp.), beach lily (Crinum asiaticum var. japonica), turmeric (Curcuma longa), plantain lily (Hosta sp.), prairie gentian (Eustoma grandiflorum), common cockscomb (Celosia argentea), pink (Dianthus hybridus), brazilian skyflower (Duranta repens), sultan snapweed (Impatiens wallerana), cucumber (Cucumis sativus), egg plant (Solanum melongena), kidney bean (Phaseolus vulgaris) were most susceptible to damage by the thrips. Malathion 50EC, acephate 50WP and 5G, etofenprox 20EC, spinosad 25SG, emamectin-benzoate 1EC, methidathion 40EC and nitenpyram 10G gave 100% control of the thrips in a glasshouse test.
The olfactory responses of the big-eyed bugs Piocoris varius and Geocoris proteus towards kidney bean leaves infested with Tetranychus urticae were observed in an olfactometer. Adult females of P. varius showed a significant preference for T. urticae-infested leaves over clean air. Neither predator showed any significant preference for uninfested leaves, artificially damaged leaves or spider mites plus their products over clean air. Second-instar nymphs of P. varius and adult females of G. proteus did not discriminate between T. urticae-infested leaves and clean air, irrespective of previous exposure to odors from T. urticae-infested leaves. These results indicated that adult females of P. varius exploit herbivore-induced plant volatiles in their search for prey, whereas this was not true for 2nd-instar nymphs of P. varius or adult females of G. proteus.
Effects of granulated sugar on the longevity and fecundity of Orius strigicollis were examined under laboratory conditions. The 50% survival duration of adult female O. strigicollis fed with 3-5% glucose was 9-10 days and survival of those fed with solid granulated sugar was more than 25 days. The latter result was not different from that of females fed with Ephestia kuehniella eggs. The total number of eggs laid per female with a diet of both solid granulated sugar and yeast was twice as many as that with solid granulated sugar alone. Under weak starvation (fed 3 eggs of E. kuehniella per day), longevity of O. strigicollis females with solid granulated sugar was about five times as long as that of the control and fecundity was about three times greater. There were a few nymphs with mixed artificial diet (solid granulated sugar, trehalose, yeast and casein) that grew to adult stage and laid eggs.
The objective of this report is to evaluate the effectiveness of the immunoassay method as an alternative to the gas chromatographic analytical method for rapid screening of dieldrin residues in soils and cucumbers. The values obtained by analysis with both methods were very similar. There was a high correlation of values obtained by both methods in the range of 0.08-0.3ppm from soil samples. A correlation in the values of both methods did not occur in the range of 0.03-0.08ppm. As for the values from cucumber analysis, there was a correlation in the values for the two methods in the range of 0.01-0.05ppm. However, the immunoassay method tended to have larger values than the chromatographic method with substantial variation. Samples with low levels of residues of must be concentrated for accurate analysis with the immunoassay method. It is necessary to include a procedure to remove impurities when the sample is concentrated. Impurities will affect the analysis values.