滋賀県のタマネギ栽培で一般的な秋植作型において，貯蔵施設および出荷先でタマネギりん茎の細菌性腐敗が発生し，加工業者からのクレームやタマネギの廃棄につながることが問題となっている。本研究では，滋賀県の秋植タマネギで防除対象とすべきりん茎腐敗の病原細菌を把握し，その発病適温を明らかにするために，県内各地で細菌性腐敗を生じた生育期間中および収穫後のタマネギ葉身やりん茎から細菌を分離し，種を同定した。さらに，それらのタマネギりん片に対する病斑長径と貯蔵時のりん茎腐敗率（りん茎に腐敗を生じた個数/供試数×100）に及ぼす温度の影響を調査した。葉身・りん茎からは計5種の病原細菌が分離され，りん茎からはBurkholderia cepacia，B. cenocepaciaおよびB. gladioliの3種のみが分離された。特に，調査地点数に占めるB. cepaciaの分離割合は52.6％と最も高かった。3種のBurkholderia属細菌によるりん片の病斑は10°Cでは確認できなかったが，15～20°C以上で病斑の進展が認められ，病斑長径は25～35°Cで最大になった。B. cepaciaによるりん茎腐敗率は貯蔵温度15°Cと20°Cで約10％程度と低かったが，30°Cでは約41％となり，15°Cおよび20°Cよりも有意に高かった。以上のことから，滋賀県の秋植タマネギで防除対象とすべき病原細菌はBurkholderia属の3種であること，これらは15～20°Cでタマネギに発病可能であり，発病適温は25～35°Cの高温であることが示された。また，滋賀県の秋植タマネギ栽培では気温が上昇する4～6月に感染リスクが高くなること，そして貯蔵時には10°C以下の低温で被害を抑制できる可能性が示唆された。

奈良県で2021年にトマト灰色かび病菌83菌株を採取し，その薬剤感受性を調査した。その結果，ジエトフェンカルブ，ペンチオピラド，チオファネートメチル，アゾキシストロビンに対する耐性菌率が高く，それぞれ96.3％，92.8％，79.5％および46.3％であった。一方で，イプロジオン水和剤に対する耐性菌率は低く，20.5％であった。なお，メパニピリムでは，耐性菌は認められなかった。フェンヘキサミドでは感受性低下菌が確認されたが，4.1％のみであった。トマト生産農家の薬剤散布暦を調査した結果，耐性菌率が高いジエトフェンカルブ，ペンチオピラド，チオファネートメチル，アゾキシストロビンの使用頻度が高かった。これらの結果からメパニピリムとフェンヘキサミドが有望な薬剤と考えられた。耐性菌が高頻度で発生していることから，灰色かび病の防除には感受性の評価に基づいた薬剤の選択が必要となる。

The fruiting bodies and plasmodia of slime molds were found on small-flowered chrysanthemums (Chrysanthemum morifolium Ramat.) in an open field in Nara Prefecture, Japan. The damage was limited to the bottom leaves with fruiting bodies. The isolate was identified as Fuligo gyrosa (Rostaf.) E. Jahn based on its morphological characteristics and BLAST analysis. This is the first report of F. gyrosa causing slime mold disease in chrysanthemums.

Fusarium head blight (FHB) is a significant fungal disease of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) that can cause severe crop losses. The causal pathogens also produce toxins. In this study, 1,280 Fusarium graminearum Schwabe species complex (FGSC) isolates were obtained from sporodochia on symptomatic spikelets of wheat and barley in 437 fields in Mie Prefecture, Japan, from 2008 to 2021. The resistance of the FGSC isolates to methyl benzimidazole carbamate fungicides (MBC) was determined using the minimum inhibitory concentration method and testing for the presence of single nucleotide polymorphisms of the β2-tubulin gene coding region related to MBC resistance. The isolates established in this study had multiple amino acid mutations in the β2-tubulin gene-coding region. The F200Y and F167Y mutations were found among the highly resistant isolates, and the E198Q was found among the moderately resistant isolates. This is the first report of the E198Q mutation being detected outside of China. The isolates with the F200Y mutation, which showed high resistance to thiophanate-methyl, were only detected in 2008 and 2018. Additionally, the isolates with the F167Y mutation, which showed high resistance to thiophanate-methyl, were only detected in 2020 and 2021. In Mie Prefecture, which has a pest management system that controls the FHB once a year during the flowering period of wheat and barley, MBC-resistant strains are still low.

タバココナジラミによって媒介されるウイルスの感染で引き起こされるトマト黄化葉巻病やトマト黄化病の発生地域である熊本県の冬春トマトにおいて，捕食性天敵であるタバコカスミカメによる春期のタバココナジラミ密度に対する抑制効果を2020～2021年の作期に検証した。隣接する2つの生産者施設をそれぞれ天敵導入区・対照区とし，天敵導入区では連棟間の天井谷間の天窓で0.4 mm，側窓で0.3 mmの目合いの防虫ネットを展張し，対照区では天窓で1.0 mm，側窓で0.4 mmとした。野外のタバココナジラミの発生量が多い定植初期（9，10月）は，天敵導入区・対照区ともに非選択性殺虫剤とコナジラミ類成虫忌避剤を中心とした慣行防除を行い，10月下旬から天敵導入区にタバコカスミカメおよびバンカー植物を導入した。バンカー植物としてクレオメとバーベナを用いた。その結果，天敵導入区では対照区と比較して5月以降のタバココナジラミ密度の上昇ペースが抑えられ，間接的にTYLCVおよびToCVの感染株率も対照区と同等もしくはそれ以下に抑えられた。これらの結果から，トマト黄化葉巻病およびトマト黄化病の発生地域において，0.3～0.4 mm目合い防虫ネットの組み合わせたタバコカスミカメ利用は，タバココナジラミの防除に有効であることが示された。

愛知県内のトマト，イチゴ等から2021年から2022年に採取した灰色かび病菌54菌株に対し，QoI剤・SDHI剤等を含む殺菌剤16剤について，インゲンマメ初生葉を用いた感受性検定を行った。生物検定の結果，QoI剤のアゾキシストロビンの耐性菌株数は22菌株（41％）で，ピリベンカルブは17菌株（31％）であった。SDHI剤は，ペンチオピラドが3菌株（6％），イソフェタミドが2菌株（4％），ピラジフルミドで同じく2菌株（4％）が耐性菌であった。QoI剤とSDHI剤の混合剤であるピラクロストロビン・ボスカリドは23菌株（43％）と最も耐性菌株の割合が高かった。このほか，ジエトフェンカルブ・チオファネートメチルで8菌株（15％）が耐性菌であることが判明した。また，病斑形成抑制率を用いた相関解析（スピアマンのρ）の結果，QoI剤ではピラクロストロビン・ボスカリドはアゾキシストロビン（ρ＝0.68）とピリベンカルブ（ρ＝0.62）と相関があった。SDHI剤ではペンチオピラドとイソフェタミド（ρ＝0.5）で相関があった。これらにより，同一系統間の薬剤間において，本県での交叉耐性の発生が示唆された。

Strains of satsuma dwarf virus (SDV) occurring in Mie Prefecture were examined, and at the same time, the disease symptoms on the rind of citrus mosaic virus (CiMV) sub-strain were also examined. SDV-free trifoliate orange (Poncirus trifoliata (L.) Raf.) rootstocks were planted in plots where the SDV strain, the CiMV sub-strain, and the navel orange infectious mottling virus (NIMV) strain occur. The relationship between the SDV strain and the infection rate was determined. The CiMV sub-strain occurred most frequently in Mie Prefecture, followed by the SDV strain. An isolate of the NIMV strain was detected in two orchards in Mie Prefecture. This is the second occurrence of the NIMV strain recorded in a field outside of the original field in Wakayama Prefecture, following an occurrence in Ehime Prefecture. This is also the first report of mixed CiMV sub-strain and NIMV strain infection in citrus. The results indicate that the CiMV sub-strain is widely distributed outside Wakayama Prefecture. Moreover, isolates of the CiMV sub-strain, which hardly induce mosaic symptoms in the fruit rind, were widely distributed. Trifoliate orange seedlings were planted near infected citrus trees growing on trifoliate orange rootstocks. SDV infection occurred within one year of planting. Whether the difference in infection rate was caused by differences in viral strains or by environmental factors in the field remains unknown.

薬剤散布を行った際のイチゴうどんこ病菌（Podosphaera aphanis var. aphanis）分生子の動態について調査した。分生子は薬剤散布を行なっても，ハウス内で捕捉されたが，その飛散量は処理薬剤によって異なっていた。脂肪酸グリセリド乳剤300倍＋炭酸水素Na・銅水和剤750倍散布は3日後，ペンチオピラド水和剤2,000倍散布およびピリオフェノン水和剤3,000倍は散布4日後まで分生子飛散量を抑えた。脂肪酸グリセリド乳剤600倍＋炭酸水素Na・銅水和剤1,000倍1回処理で分生子柄の再生を完全に抑えた。脂肪酸グリセリド乳剤300倍＋炭酸水素Na・銅水和剤750倍を10日よりも短い間隔で300 L/10 aの割合で散布すると無散布と比較して発病率が有意に低かった。

In this study, we evaluated the efficacy of anaerobic soil disinfestation with incorporation of a vegetable oil refining byproduct (VORB) and sugar-containing diatomite (SCD). It was found that incorporation of VORB alone at a dose of 0.4 to 1.0 t/10 a could reduce the soil layer (0–30 cm depth) where VORB had been mixed, thereby disinfecting Ralstonia solanacearum. It was also found that incorporation of SCD at 0.5 t/10 a in combination with VORB at 0.7 t/10 a could effectively reduce the deeper layer (30–50 cm depth) of soil and suppress the development of tomato bacterial wilt.

The resistance of commercial sweet basil cultivars against basil downy mildew (BDM) caused by Peronospora belbahrii was assessed during pot and field experiments. In all experiments, var. “Campione” exhibited high resistance with no disease symptoms. In contrast, “Devotion” exhibited moderate resistance, and “TSGI-208” and “Obsession” exhibited low resistance. Furthermore, “Basil” was susceptible to the highest disease severity. According to these results, the combination of resistant cultivars and fungicide application could effectively control basil downy mildew.

The causal fungus of gray blight on tea [Camellia sinensis (L.) Kuntze] collected in Shiga Prefecture in 2019 and strains registered in the NARO Genebank as Pseudopestalotiopsis theae (Sawada) Maharachch., K. D. Hyde & Crous were reexamined. Phylogenetic and morphological examinations revealed that all strains were Pseudopestalotiopsis chinensis F. Liu & L. Cai.

To establish biological control for cucumber mosaic disease, we evaluated control effect of attenuated isolates of cucumber mosaic virus (CMV) and watermelon mosaic virus (WMV). In 2015 and 2017, cucumber seedlings were inoculated with the attenuated CMV-CM14 and WMV-WM14 isolates, and grown in greenhouses. When mosaic disease severity in the control plots increased to as much as 93.3–100%, the protective inoculation with the two attenuated isolates significantly suppressed cucumber mosaic disease. In 2023, the control of mosaic disease was evaluated in production fields using the CMV-CM14- and WMV-WM14-inoculated cucumber seedlings. The results showed that protective inoculation with the two attenuated isolates was effective to control the disease even under medium occurrence conditions. Our results suggest that protective inoculation with the two attenuated isolates can be effective to suppress the infections of CMV and WMV strains occurring in Kyoto Prefecture.

We investigated the effectiveness of Ultra violet B (UV-B) irradiation on controlling powdery mildew (Oidium matthiolae Rayss) and white rust (Albugo wasabiae Hara) of wasabi seedlings. The seedlings were irradiated with UV-B for 1 h from 23:00 to midnight at a distance of 100 to 200 cm from the irradiation source. The irradiance ranged from 2.4 to 40.8 μW·cm^–2. High efficacy was observed in this irradiance range for control of powdery mildew and not for the control of white rust. Furthermore, reduction of seed germination, growth inhibition or leaf damages of seedlings were not observed in this study.

Strawberry gray mold disease is one of the important diseases of strawberry caused by Botrytis cinerea. In this study, we examined the susceptibility of sixty-four isolates of this pathogen, collected from fifteen commercial strawberry fields in Osaka prefecture, Japan, to Qo inhibitor (QoI) fungicides (azoxystrobin and pyribencarb), succinate dehydrogenase inhibitor (SDHI) fungicides (penthiopyrad and pyraziflumid), methyl benzimidazole carbamate (MBC) fungicide (benomyl), dicarboximide fungicide (procymidone), phenylpyrrole fungicide (fludioxonil), and anilinopyrimidine fungicide (mepanipyrim).

Most of the isolates were resistant to azoxystrobin, while being susceptible to the QoI fungicide, pyribencarb. Additionally, most isolates showed a low sensitivity to SDHI fungicides and procymidone.

Effects of phosphite fertilizers and picarbutrazoxon on tomato root rot caused by Pythium cryptoirregulare Garzón, Yánez & G. W. Moorman and P. recalcitrans Belbahri & E. Moralejo were tested under pot condition. Soil drench of the phosphite liquid fertilizer at 100–1,000 ppm concentrations and picarbutrazox wettable powder at 500-fold dilution showed suppressive effects on root rot. However, the number of chemically damaged plants increased with increasing concentration and frequency of application of the phosphite liquid fertilizer, indicating that phosphite liquid fertilizer at a concentration of 100 ppm was considered suitable for the control of tomato root rot.

The two-spotted spider mite, Tetranychus urticae Koch, poses a critical challenge in rose cultivation owing to its reduced susceptibility to acaricides. Therefore, this study aimed to assess the efficacy of five distinct acaricides against adult female T. urticae inhabiting rose plants in 13 greenhouses located in the central region of Shizuoka Prefecture, Japan. The findings revealed substantial variations in the adjusted mortality rate of T. urticae, contingent upon the specific acaricides examined and the respective greenhouses from which they were sampled. The acaricides effectuating lower standardized fatality in T. urticae differed across the surveyed greenhouses. This observation suggested that the susceptibility of T. urticae to acarides is influenced not only by the type of acaricide used but also by the specific greenhouse environment, despite being confined to the same area.

In Japan, there is a cultural practice of consuming salted cherry leaves (Prunus speciosa), and edible cherry leaves are intentionally cultivated for this purpose. Synanthedon hector Butler, also referred to as the Japanese cherry tree borer, is a known pest of cherry trees. Its larvae feed on the tree trunks and cause serious damage. Hence, we investigated the disruptive effect on communication by employing mating disruptants using synthetic sex pheromones (synanthelure) and assessed the seasonal prevalence of S. hector adults in edible cherry leaf fields. In the fields treated with a mating disruptant, no S. hector male adults were attracted. In contrast, in untreated fields, S. hector male adults were attracted from late April to October, with peak attraction being observed in May, July, and September (multimodal type of occurrence). These results suggest that the communication disruption effect of pheromones on S. hector is extremely high. Moreover, this high communication disruption effect could continue until autumn if pheromones are installed by late April.

We investigated the chemical susceptibility of Kanzawa spider mites (Tetranychus kanzawai Kishida) and colonized exotic predatory mites (Phytoseiulus persimilis Athias-Henriot) collected from tea fields in Shizuoka Prefecture from 2019 to 2021.

The chemicals that caused in a corrected mortality rate of ≥90% in adult females and eggs of T. kanzawai across all populations were abamectin, milbemectin, acequinocyl, bifenazate, ethoxazole-pyrimidiphene, cyenopyrafen, cyflumetofen, and acynonapyr, out of the 16 chemicals tested.

Out of the 32 chemicals tested, profenofos, emamectin, abamectin, milbemectin, tebufenpyrad, pyridaben, tolfenpyrad, etoxazole, pyrimidifen, and fluxametamide were highly toxic to P. persimilis. In contrast, dinotefuran, clothiazinine, pyrifluquinazone, etoxazole, BPPS, chlorfenapyr, lufenuron, methoxyfenozide, acequinocyl, bifenazate, cyenopyrafen, cyflumetofen, pyflubumide, cyantraniliprole, chlorantraniliprole, cyclaniliprole, flubendiamide, flonicamide, and acinonapyr were less toxic to P. persimilis.

Moreover, acequinocyl, bifenazate, cyenopyrafen, cyflumetofen, and acinonapyr were highly effective against adult females and eggs of T. kanzawai, while having little negative effects on adult females P. persimilis. In contrast, spraying the three chemicals, emamectin, tolfenpyrad, and fluxamethamide, that are not applicable to T. kanzawai and highly toxic to P. persimilis in tea fields may lead P. persimilis population decreasing, while T. kanzawai increasing.

In a test cultivation of fig (Ficus carica L.) conducted in a closed-type plant cultivation room with artificial lighting, the damage of fruit pulp caused by thrips and eriophyid mites was investigated. Fig (cv. Masui Dauphine) trees were planted in plastic pots and continuously cultivated five times due to the renewal of bearing shoot. Pulp damage occurred in the fig fruits harvested from fourth and fifth cultivation. The overall incidence was 72% in the fourth cultivation and 85% in the fifth cultivation. The intrusion of onion thrips (Thrips tabaci Lindeman) into the fruit was detected as the cause. Many such infested fruits were observed where the adults and larvae of thrips co-existed, suggesting a high possibility of thrips generation alternation occurring inside the fruit. As thrips were hiding in the cracks of buds or in the soil, it was found that the thrips could not be eliminated from the cultivation environment by spraying pesticides and removing branches, which are the usual methods of pest management. Many cases were also observed where pulp damage occurred even though no thrips were present inside the fruit. Eriophyid mites were thought to be the main cause in this case. Eriophyid mites have been observed sporadically on the leaves, stems and surface of fruits since the first cultivation. In the fourth and fifth cultivation, many of them intruded inside the fruit and caused pulp damage similar to thrips. Thus, it can be concluded that the fate of these two types of pests in fig cultivation differs in a closed environment from that in open field cultivation; therefore it is necessary to develop new countermeasures to eliminate them.

We determined the toxicity of 10 insecticides on adult western flower thrips, Frankliniella occidentalis (Pergande) using the leaf-dipping method. Two different populations of the thrips were collected from an eggplant greenhouse in Kaizuka City and one from Habikino City in Osaka Prefecture. Flometoquin achieved more than 90% mortality while acetamiprid, tolfenpyrad, and cyantraniliprole showed low corrected mortality in all populations.

Conventional application of insecticides cannot successfully control loquat infection with the loquat psyllid, Cacopsylla biwa Inoue, because nymphs inhabit the crowded young fruit of loquat after flowering. We adopted insecticide application with a hand-held sprayer for each fruit at the time between the two cultivation practices: fruit thinning and bagging. Although this method requires more working time than the conventional treatment, it exhibits a higher control effect on the psyllids, resulting in less damaged fruits.

We investigated the susceptibility of second instar larvae and adult flower thrips (Frankliniella intonsa [Trybom]) collected from flat areas of Gifu Prefecture to 12 insecticides. Among the insecticides registered for controlling “thrips” on strawberries, spinosad, spinetoram, and fluxametamide demonstrated the highest efficacy against flower thrips. Conversely, spirotetramat and flometoquine were the least effective among the tested insecticides. Furthermore, among the insecticides not registered for thrips control on strawberries, emamectinbenzoate and chlorfenapyr show potential efficacy against flower thrips.