-
Takashi NAIKI, Yasuhito HATTORI, Hatiro IKEGAMI
1985 Volume 27 Pages
1-5
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
Vertical distribution of the clubroot pathogen, Plasmodiophora brassciae, in 7 heavily infested fields in Gifu Prefecture, was determined by the use of a susceptible plant, Chinese cabbage (Brassica campestris ssp pekinesis), as an indicator plant. Soil was sampled at every 5 cm depth from the soil surface to the subsoil. The pathogen sufficient to cause the disease was detected in soil above 5 cm deep, but not in soil below 40 cm deep in every field tested irrespective of their soil types and cropping histories. The disease severity was greatest in soil 0-15 cm deep, but varied among the fields. It decreased gradually with the depth of soil. In sandy loam, alluvial soil, with a deeper low layer, the pathogen was detected even at depths of 30-40 cm. In the field with shallow plowed layer above 30 cm deep, the disease occurred even in the subsoil layer where the pathogen might be distributed by direct tillage. The disease incidence and the vertical distribution of the pathogen in heavily infested fields seem not to be affected by once cropping with sweet corn (Zea mays var. saccharata),taro ( Colocasia esculenta) and eggplant ( Solanum melongena) or even by soil pH, differed slightly at depths of soil.
View full abstract
-
Tomohiro HORIKAWA
1985 Volume 27 Pages
7-14
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
(1) Recent epidemics of bacterial shoot blight of tea caused by Pseudomonas syringae pv. theae have been recorded in Shizuoka Prefecture since 1979. The most serious damage was observed in Haibara-gun and Ogasa-gun located in the central part of the prefecture.
(2) The disease occurred both on young and mature tea plants, although the serious damage was observed mostly on the former. The first symptom of the disease appeared as small, water-soaked and dark greenish-brown spots on the leaf-blades and leaf-petioles of matured leaves. These spots gradually enlarged and often coalesced with each other. Where veins or midribs were attacked, the spots enlarged along them forming elongated lesions. Water-soaked, dark-green and narrow areas were formed along edges of the lesions. Although shoots were also attacked, direct infection was rare (i. e., shoots were usually infected through expansion of the leaf lesions). The diseased leaves defoliated easily, but the new shoots of first flush were scarcely infected.
(3) The outbreak of the disease occurred in early spring and autumn. In early spring, infection seemed to occur in February through April, and the symptoms to appeared from March through May. The infection could not be established by artificial inoculation on May 25.
(4) The varieties SURUGAWASE and OOIWASE were most susceptible to the disease, and KANAYAMIDORI and YAEHO were most resistant. The variety YABUKITA was somewhat in between in this respect.
View full abstract
-
Kimiharu INAGAKI, Katsuhiro ITO
1985 Volume 27 Pages
15-19
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
Outbreaks of rice sclerotial diseases caused by Rhizoctonia oryzae RYKER et GOOCH, R. solani KUHN (IIIB, AG2 Type 2) and Sclerotium hydrophilum SACC. in the paddy fields were not as frequent as those of diseases caused by S. oryzae-sativae SAW. and S. fumigatum NAKATA et KAWAMURA. Diseases caused by S. oryzae-sativae and S. fumigatum proved to be ones occurring all over the field, but those caused by R. solani and S. hydrophilum tended to occur only in a few limited sections of the field. The former diseases, when they occurred in a confined part of the field, were similar in outbreak tendency to the latter diseases. A mixture of diseases caused by S. oryzae-sativae, S. fumigatum and the other one or two species of Rhizoctonia and Sclerotium were more frequently found in the same field.
View full abstract
-
Susumu TAKEDA, Eriko SAKKA, Hironori SAKURAI
1985 Volume 27 Pages
21-25
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
The common bimaculated field-cricket, Gryllus bimaculatus DEGEER, is a sort of nondiapause gryllid. Its northern limit of distribution in Japan is located at Kikai-Cho, Ohshima-Gun, Kagoshima Prefecture (MATSUURA, 1979). Recently this cricket was reared under indoor conditions for frog food (NISHIOKA, 1975) and as a teaching material for scientific education in the elementary school, junior and senior high school (NOMURA and KAWASAKI, 1977 ; TOMIDA et al., 1984). Physiological investigations on the behavior and habits of this cricket had been carried out by some research institute (TOMIOKA and CHIBA, 1982), yet there is still insufficient knowledge about its life cycle.
From 1982 to 1983, the Laboratory of Entomology, Faculty of Agriculture, Gifu University, conducted an investigation on the development of this cricket at the larval stage. The specimens were collected from Maisaka-Cho, Hamana-Gun, Shizuoka Prefecture and were reared at 4 different temperature: 32°C, 28°C, 22°C, and 18°C.
It was found that in the plots under 32°C about 80% of the larvae emerged after the 8th larval stage, a duration of about 35 days. In the plots under 28 t treatment, about 30% of the larvae emerged after the 8th and 9th larval stage, a duration of about 50 days. The development of the larvae decreased at 22°C and 18°C. About7% of the larvae under 22°C treatment plots emerged at 110 days, and not a single larvae emerged under 18°C treatment plots. The developmental zero points of 1st and 2nd to 4th instars were 10.7°C and about 15°C, respectively. These findings suggest that this cricket is a species that developed well in a higher temperature zone.
View full abstract
-
Masateru INOUE, Tetsuya SUGIURA
1985 Volume 27 Pages
27-30
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
Variously sized mite-infested spot, called “tsubo?”, were made in a vinyl greenhouse for strawberry cultivation for testing, and the “tsubo?” size index of each spot was determined as follow; _??_ where Pn means the number of plants in the spot and S(max)means the largest symptom index of the spot.
When the Sp reached 12, about 80% of the observers could find the “tsubo?” spot by only walking observation of symptom formed on the upper surface of leaves. This result shows that the grower can control pests by partial application on the infested area. Since the ratio of symptom formation on the upper surface of leaves is highly correlated with infestation in January and February, this method is more effective in these two months.
View full abstract
-
[in Japanese], [in Japanese]
1985 Volume 27 Pages
31-34
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese]
1985 Volume 27 Pages
35-40
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
41
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
42
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
43
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
44
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
45
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
46
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese]
1985 Volume 27 Pages
47-48
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese]
1985 Volume 27 Pages
49
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
50
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
51
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese]
1985 Volume 27 Pages
52
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese]
1985 Volume 27 Pages
53-54
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese]
1985 Volume 27 Pages
55
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese]
1985 Volume 27 Pages
56
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
57
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
58
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
59-60
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese]
1985 Volume 27 Pages
61-62
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
1985 Volume 27 Pages
63
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
64
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
65-66
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
67-68
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese]
1985 Volume 27 Pages
69
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
1985 Volume 27 Pages
70-78
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
1985 Volume 27 Pages
79-85
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
1985 Volume 27 Pages
86-91
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese]
1985 Volume 27 Pages
92-96
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese]
1985 Volume 27 Pages
97-102
Published: May 01, 1985
Released on J-STAGE: October 29, 2012
JOURNAL
FREE ACCESS