Many plant diseases in Japanese flower production have been spread through the global distribution of seeds, cuttings and plantlets, diversification of flower species usage, and inappropriate cultivation environments. Demands for the implementation of technologies developed for reducing the volume of agrochemical applications are increasing. This article reviewed individual techniques of IPM including biological control, resistant varieties and rootstocks, cultural control such as greenhouse environmental control, small-volume soil medium nutriculture, physical control such as hot water soil sterilization, steam sterilization and soil solarization, soil disinfestation using biological functions, and elimination of water-borne diseases in hydroponics. To promote specific technologies for reducing agrochemicals, we need to assemble them into IPM systems and to demonstrate these systems under commercial field conditions by matching them with local cultivation methods for flower production. In addition, for efficient disease control it is essential to expand the registrations of outstanding effective agrochemicals to many flowering crops. It is necessary for the establishment of these technologies and their manuals on disease-free seedling production to positively conduct collaborative research with experiment institutes, national or prefectural plant protection officers, agricultural extension instructors, growers and especially nursery companies. For promoting IPM in flower disease control, “local plant clinics”, the precise “general diagnosis of diseases” by local plant clinics, and “field charts (agro-medical field records)” will be attractive research fields in the future.
Damping-off of wild turmeric (Curcuma aromatica Salisb.) occurred in Tokyo in 2009. A pathogen isolated from the diseased plants was identified as Pythium myriotylum based on cultural characteristics as well as molecular analyses of the ITS region. An inoculation test confirmed that the fungus was the causal agent of the disease. This is the first report of the disease in Japan.
Leaf blight of sultan snapweed (Impatiens walleriana Hook. f.) occurred in Tokyo in 2009. A pathogen isolated from the diseased plants was identified as Rhizoctonia solani AG-1 IB based on morphological characteristics and anastomosis group. An inoculation test confirmed that the fungus was the causal agent of the disease. This is the first report of the disease in Japan.
Anthracnose of swiss cheese plant Monstera deliciosa Liebm. and Phoma rot of leather leaf fern Rumohra adiantiformis (G. Forst. F) Ching occurred on Hachijo Island of Tokyo Metropolis in 2010. The causal fungi isolated from the diseased plants were identified as Colletotrichum gloeosporioides (Penzig) Penzig & Saccardo on swiss cheese plant and Phoma sp. on leather leaf fern. Inoculation tests showed that these fungi were the causal agents of the diseases. This is the first report of these diseases in Japan.
Races of 7 local populations of the soybean cyst nematode, Heterodera glycines on green soybeans crop in Tokyo, Japan were studied under the scheme given by Golden et al. (1970). Six populations were designated as race 3, and one population was designated as race 1.
Percentages of parasitism and species composition of the parasitoids on the larvae of the smaller tea tortrix, Adoxophyes honmai Yasuda, and the oriental tea tortrix, Homona magnanima Diakonoff (Lepidoptera: Tortricidae), in commercial tea fields treated with the mating disruptant (tortorilure) were investigated in Shizuoka Prefecture from 2007 to 2008. The parasitoids species emerged from larvae of A. honmai were Ascogaster reticulata Watanabe, Apanteles adoxophyesi Minamikawa, Campoplex homonae (Sonan) and Temelucha sp. Among the parasitoides A. reticulate was the primary dominant species, and a predaceous gall midge, Lestodiplosis sp. was also found on the fourth generation of hosts. Percentages of parasitism of the parasitoid complex changed from about 30 to 80% and the percentages in fields treated with the mating disruptant showed a higher trend than an insecticide applied field. A few species of parasitoids emerged from the larvae of H. magnanima, the dominant species of them was C. homonae. Percentages of parasitism of these were kept less than about 5% in all of the fields.
Seasonal capture in pheromone traps of summer fruit tortrix moth, Adoxophyes orana fasciata Walsingham was investigated in Japanese pear orchards treated with mating disruptor in Chiba. A. orana population showed two peaks at late May and middle July in 2010, despite the existence of mating disruptor. In order to elucidate the cause of A. orana outbreak, the mating disruptor susceptibility of A. orana was examined. The mating rate in mating disruptor untreated plots ranged from 10.3 to 34.5%, while those in the pheromone treated plots were 0%. This result suggested that A. orana population in Chiba is not resistant to pheromone-based mating disruptor.