-
Yukiko KAGA
2018 Volume 2018 Issue 69 Pages
10-12
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Makoto KONDO
2018 Volume 2018 Issue 69 Pages
13-19
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Naoya FUJII, Hideki MATSUDA, Tokumitsu NIIYAMA
2018 Volume 2018 Issue 69 Pages
20-24
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Hideki MATSUDA, Naoya FUJII, Takaaki SAITO, Akira SAYAMA
2018 Volume 2018 Issue 69 Pages
25-28
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Toru KOZAWA, Jun SOUMA
2018 Volume 2018 Issue 69 Pages
29-34
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
We examined the deoxynivalenol (DON) accumulation in visually unaffected (normal-looking) kernels of winter wheat during the ripening stage. Normal-looking kernels were collected from diseased heads with Fusarium head blight symptoms and visually symptomless heads (normal-looking heads) at the soft dough, hard dough, and harvest-ripe grain stages, and their Fusarium graminearum isolation freguency and DON levels were analyzed. In the normal-looking kernels obtained from diseased heads, DON levels and isolation frequency increased during the later stages of kernel development, and high levels of DON were detected at the harvest-ripe grain stage. Conversely, in the normal-looking kernels of symptomless heads, F. graminearum and DON were detected at the harvest-ripe grain stage; however, the isolation frequency and DON levels were low compared to those in the diseased heads. The results suggest that the secondary infection in diseased heads is the major cause of DON accumulation in normal-looking kernels.
View full abstract
-
Toru TAKEUCHI
2018 Volume 2018 Issue 69 Pages
35-38
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
We estimated yield and quality losses in winter wheat due to eyespot disease based on field experiments over three years in Hokkaido. The yield and quality of wheat decreased when the stems were completely girdled by lesions but no lodging occurred. Eyespot infection did not affect ear number per m2 and grain number per ear, but reduced 1,000-grain dry weight under severe infection, resulting in a decrease in the yield. The yield did not decrease significantly when less than 90% of stems were covered with lesions and disease severity index was less than 40.
View full abstract
-
Toru TAKEUCHI
2018 Volume 2018 Issue 69 Pages
39-41
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
Crop rotation effects on eyespot disease severity in winter wheat were investigated in Hokkaido. Cultivating non-host crops for one, two and three years reduced disease severity by 22.2%–38.7%, 48.2%–56.3% and 69.0%–73.1%, respectively. This effect was lost after the first cropping of wheat. There was no difference in effects between the tested non-host crop species: potato and adzuki bean.
View full abstract
-
Tomoo MISAWA, Kenichi MINO
2018 Volume 2018 Issue 69 Pages
42-44
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
Leaf sheath rot caused by Rhizoctonia spp. is a widespread disease, and it causes serious damage to Welsh onion fields in Hokkaido, Japan. We evaluated the efficacy of two fungicides, i.e., tolclofos-methyl dust formulation and azoxystrobin flowable, against the disease in the field from 2013 to 2016. The fungicides were applied once or twice a year. Tolclofos-methyl dust formulation exhibited high efficacy with protective values of 100, 100 (in 2013); 85, 74 (in 2014); and 87, 100 (in 2016). Azoxystrobin flowable also exhibited high efficacy with protective values of 100, 100 (in 2013); 80, 88 (in 2014); 85 (in 2015); and 93 (in 2016) with one exception (26 in 2016). Therefore, both fungicides were found to be effective against Rhizoctonia leaf sheath rot in Welsh onion.
View full abstract
-
Nayuka DOUMEN, Takahiro SONODA, Hiromitsu FURUYA, Chiharu NARA, Fujio ...
2018 Volume 2018 Issue 69 Pages
45-49
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
In order to develop appropriate countermeasures against fungal species, the distribution of two Fusarium spps. in Hokkaido, Japan was investigated. Fusarium spps. were isolated from all fields investigated, regardless of cultivar and age. Genetic analyses revealed that F. oxysporum was more abundant than F. proliferatum. However, prevalence of both species was confirmed in a wide range of fields. Pathogenicity was confirmed in all isolates. In addition, no significant differences were found between the pathogenicity of F. oxysporum and the pathogenicity of F. proliferatum. These findings suggest that comprehensive countermeasures could be more effective than individual measures targeting the two Fusarium spps.
View full abstract
-
Ryo DAIMARUYA, Takahiro SONODA, Hiromitsu FURUYA, Chiharu NARA, Takesh ...
2018 Volume 2018 Issue 69 Pages
50-54
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Yasuya IWADATE, Haruna SASAKI, Hirokazu KAN, Yutaka CHIDA, Chika TATED ...
2018 Volume 2018 Issue 69 Pages
55-59
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
Roots of Aconitum plants (A. japonicum and A. carmichaelii) have been used as traditional Japanese Kampo medicine. They are listed in The Japanese Pharmacopoeia as raw materials of Kampo medicine, “Bushi”. In commercial plantations of A. japonicum in Iwate Prefecture, blighting and wilting symptoms were observed in 2016. Diseased stems were water-soaked, dark brown, and displayed both white mycelium and brown sclerotia on the basal parts of the stems. Based on morphological traits, internal transcribed spacer sequence analysis, and pathogenicity tests, the causative fungus was identified as Sclerotium rolfsii (Sexual morph: Athelia rolfsii). S. rolfsii on A. carmichaelii has been reported in China, but not on A. japonicum. To the best of our knowledge, this is the first report of S. rolfsii causing southern blight disease in A. japonicum in Japan or elsewhere in the world.
View full abstract
-
Taiki NAKAMURA, Mariko USUGI, Jiro OIKAWA, Hirokazu KAN
2018 Volume 2018 Issue 69 Pages
60-62
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Fusaharu NAKATANI
2018 Volume 2018 Issue 69 Pages
63-66
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Tomoya AKAHIRA, Tomoe HANAOKA, Kazuyuki HIRAYAMA
2018 Volume 2018 Issue 69 Pages
67-71
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Syuuichi NEKODUKA, Kazuki NAKUI, Shikiko HIROTA
2018 Volume 2018 Issue 69 Pages
72-76
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Tomoo MISAWA, Akio SUMINO, Motohiko AOKI, Kazuhiro NAKAHO
2018 Volume 2018 Issue 69 Pages
77-84
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Hironori OHTAKE, Yuka YANAI
2018 Volume 2018 Issue 69 Pages
85-87
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Tomoo MISAWA, Yoshie NISHIWAKI, Toyozo SATO
2018 Volume 2018 Issue 69 Pages
88-94
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
We collected 11 Colletotrichum isolates from various horticultural crops, i.e., apple, grape, cherry, blueberry, watermelon and eustoma, exhibiting anthracnose symptoms in central Hokkaido from 2006 to 2016. Species-specific polymerase chain reaction (PCR) analyses revealed that all 11 isolates belonged to the Colletotrichum acutatum species complex (CASC). Based on partial nucleotide sequences of the β-tubulin-2 gene, we identified seven isolates from grape, apple, watermelon, blueberry and cherry, two isolates from eustoma and blueberry and two isolates from apple and cherry as C. nymphaeae, C. fioriniae, and C. godetiae, respectively. In the present study, we described the morphology of the conidia, appressoria and reverse colony colors of the isolates. All of the 11 isolates caused soft rot in apple fruits. The present study reveals that CASC is widespread in central Hokkaido.
View full abstract
-
Erika TAMURA, Syuuichi NEKODUKA, Makoto TAKADA
2018 Volume 2018 Issue 69 Pages
95-97
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Tokumitsu NIIYAMA, Naoya FUJII, Hideki MATSUDA
2018 Volume 2018 Issue 69 Pages
98-104
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Tohru ONO, Joji KASHIN, Takaho OE, Aya YOKOBORI
2018 Volume 2018 Issue 69 Pages
105-114
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Nobuhiro MATSUKI, Tomoaki NEMOTO
2018 Volume 2018 Issue 69 Pages
115-118
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Yuji KIMURA, Yusuke TSUSHIMA
2018 Volume 2018 Issue 69 Pages
119-124
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Motohiko AOKI
2018 Volume 2018 Issue 69 Pages
125-127
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Yusuke TSUSHIMA, Yuji KIMURA, Takehiko FUJIMURA
2018 Volume 2018 Issue 69 Pages
128-131
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Hideki KIKUCHI, Tokumitsu NIIYAMA
2018 Volume 2018 Issue 69 Pages
132-135
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Takaho OE
2018 Volume 2018 Issue 69 Pages
136-139
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Iori MATSUHASHI
2018 Volume 2018 Issue 69 Pages
140-145
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Iori MATSUHASHI, Reishi OHTOMO, Hiroshi YOKOTA, Hatsumi KUMAGAI
2018 Volume 2018 Issue 69 Pages
146-153
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Iori MATSUHASHI, Reishi OHTOMO
2018 Volume 2018 Issue 69 Pages
154-158
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Takayuki SEKINE, Shota INAWASHIRO, Kafuka SUZUKI, Tomio YAMAZAWA, Isam ...
2018 Volume 2018 Issue 69 Pages
159-163
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Motohiko AOKI
2018 Volume 2018 Issue 69 Pages
164-167
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Shota INAWASHIRO, Takayuki SEKINE, Takeru ITABASHI
2018 Volume 2018 Issue 69 Pages
168-172
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Hiroshi YOKOTA, Hatsumi KUMAGAI, Masaru SASAKI
2018 Volume 2018 Issue 69 Pages
173-176
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Yoshiko KIMURA, Yoichi ISHIGURI, Yoshinori KAWAGUCHI, Shigemitsu ARAI
2018 Volume 2018 Issue 69 Pages
177-182
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
Bioassays have been conducted since 2003 to assess the efficacy of acaricides against the two-spotted spider mite Tetranychus urticae, collected from apple orchards in Aomori Prefecture. The current status of acaricide efficacy was evaluated and compared with its efficacy in the past. Milbemectin, bifenazate and propargite maintained high efficacy in most populations. The efficacy of cyflumetofen, cyenopyrafen and pyflubumide has reduced in recent years in some populations, and the data suggested that T. urticae exhibited cross resistance to these three acaricides. The efficacy of spiromesifen has become insufficient in most populations. Spirodiclofen, a new acaricide, demonstrated high efficacy against T. urticae eggs.
View full abstract
-
Kazuyuki HIRAYAMA
2018 Volume 2018 Issue 69 Pages
183-185
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
-
Yoichi ISHIGURI
2018 Volume 2018 Issue 69 Pages
186-190
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
The present study investigated the effects of temperature on the development of immature stages of Grapholita molesta at five constant temperatures between 14 °C and 26 °C under a photoperiodic condition of 16L8D. The lower threshold temperature for development (LT) and the thermal constant (K) were 10.4 °C and 59.3 DD for eggs, 7.9 °C and 215.1 DD for larvae, and 9.6 °C and 167.7 DD for pupae, respectively. For total immature development (oviposition to adult emergence), LT and K were estimated to be 9.1 °C and 436.8 DD. Because egg development is relatively fast in G. molesta and insecticide is not effective after neonate larval entry into fruits, the interval between insecticide sprays needs to be short, especially in high temperature conditions in the summer. It is preferable to adopt a mating disruption strategy to control G. molesta to avoid increasing the number of sprays.
View full abstract
-
Kouki YOSHIDA, Takamori KANNO, Etsushi KAWAGUCHI, Akihiro ARAKAWA
2018 Volume 2018 Issue 69 Pages
191-194
Published: 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS
Supplementary material
-
Reishi OHTOMO, Hideki KIKUCHI, Tokumitsu NIIYAMA
2018 Volume 2018 Issue 69 Pages
195-198
Published: December 21, 2018
Released on J-STAGE: December 21, 2019
JOURNAL
FREE ACCESS