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To screen for potential biocontrol agents against postharvest disease of garlics caused by Penicillium hirsutum, a total of 1292 isolates were isolated from the rhizoshere or rhizoplane of Allium species. Among them, S59-4 isolate was selected as a potential biocontrol agent by in vivo wounded garlic bulb assay. The isolate was identified as Pantoea agglomerans (Pa59-4) through Biolog system. Pa59-4 did not inhibit the mycelial growth of P. hirsutum in dual-culture with P. hirsutum on tryptic soy agar. In order to elucidate mode of action of Pa59-4 on biological control, nutrient competition between Pa59-4 and P. hirsutum was investigated by the simple method using tissue culture plates with cylinder inserts containing defusing membrane reported by Janisiewicz et al. (2000). The results showed that Pa59-4 effectively suppressed spore germination and mycelial growth of blue mold in the low concentration (0.5%) of garlic juice, but it did not suppress those of blue mold in the high concentration (5%) of garlic juice. This result suggests that the mechanism in biocontrol of garlic blue mold by Pa 59-4 may be involved in nutrient competition with P. hirsutum on garlic bulbs.

308 isolates of Ampelomyces quisqualis were isolated from powdery mildew fungi of 73 plant species in Korea from 1994 to 2004. Among them, the new mycohosts and new plant hosts of A. quisqualis were found in 13 species of powdery mildew fungi in 38 species of plant. The new hosts of A. quisqualis were Erysiphe heraclei on Heracleum moellenderfii; E. hommae on Elsholtzia splendins; E. glycines on Glycine max; E. lespedezae on Lespedeza biclor; E. pileae on Pilea mongolica; E. pisi on Phaseolus radiatus; E. polygoni on Rumex aquatica and Rumex crispus; Golovinomyce artemisiae on Artemisia princeps var. orientalis; G. cichoracearum on Rudbeckia laciniata var. hortensis; G. rubiae on Rubia akane; Oidium sp. on Valeriana fauriei, Lactuca indica var. laciniata, Carpesium triste var. manshuricum, Aster ageratoides var. turczaninow, Lufa cylindrica, Ixeris demtats Nakai, Phlox paniculata, Bidens bipinnata and Pathenocissus tricuspidata; Microsphaera alphitoides on Quercus aliema, M. pseudolonicerae on Cocculus trilobos; Podosphaera sp. on Ligustrum obtusifolium; Sphaerotheca aphanisi on Fragaria ananassa; S. balsaminae on Impatiens textori; S. fusca on Cucurbita pepo, Cucurbita maxima, Ligularia fischeri, Solanum melongena, Lagenaria leucantha, Cucumis melo var. makuwa, Acalypha australis, Cosmos bipinnatus and Aster scaber; Uncinuliella simulans on Rosa muliflora and Uncinula australiana on Lagerstroemia indica.

An isolate of Ampelomyces quisqualis 94013(AQ94013) was selected as an effective parasite for biological control of cucumber powdery mildew. In the greenhouse, occurrence of cucumber powdery mildew was significantly suppressed for nine days by pre-treatment with and of conidial suspension of AQ94013. The disease was effectively controlled within three to seven days by post-treatment with the suspension of AQ94013. When AQ94013 was treated at concentration of three times at seven-day interval in the vinylhouse, the control effect was higher than that treated twice at ten-day interval and that treated with fenarimol twice. As the results, Ampelomyces quisqualis 94013 could be a prospective biofungicide for biological control of powdery mildew of cucumber.

An isolate of Ampelomyces quisqualis 94013(AQ94013) was selected as an effective agent for biological control against cucumber powdery mildew. In order to develop mass production technique, six cereal media made with barley, rice, mille and brown rice, sorghumand rice seed were tested. Among them, barley medium was the best for the growth and conidial production of AQ94013. Optimum temperature for the mass production of AQ94013 was and followed by and . Light radiation inhibited conidial production of AQ94013 since number of conidia formed on barely medium under continuous light or 12 hrs alternative light were much less than cultured in darkness. Tthe conidia produced on the medium at maintained the parasitic ability to Sphaerotheca fusca for 30 days. A culture method of AQ94013 in barley liquid medium with adding barely power(40 g/l) in darkness for five days at using a 30 l-fermenter was very effective for mass production of conidia.

An isolate of Ampelomyces quisqualis 94013 was selected as an effective parasite for biological control against cucumber powdery mildew. Temperature range for the parasitism of A. quisqualis 94013 against cucumber powdery mildew was , and optimal temperature for that . In humidity of the greenhouse, parasitic ability of A. quisqualis 94013 against Sphaerotheca fusca was not good. Inoculation tests revealed that A. quisqualis 94013 can parasitize on six species of Sphaerotheca in the 12 crops and Ersiphe cichoracerum in tomato. As host rang of A. quisqualis 94013 was broad and it may be used effectively as a biocontrol agent for powdery mildew of 13 crops.

Ampelomyces quisqualis 94013 (AQ94013), a hyperparasite, was selected as an effective biological control agent against cucumber powdery mildew. Optimal temperature for mycelial growth of AQ94013 was , and the optimal pH was 6.5. Conidia of AQ94013 were more Produced on potato dextrose agar (PDA) in darkness than under alternating cycles of 12 hr fluorescent light and 12 hr darkness. Temperature range for spore germination of the fungus was , and optimal temperature was . Conidial germination of the fungus began 8 hr after incubation at . Germination rate of conidia at concentration of was higher than at concentration of . The best source of carbon and nitrogen for mycelial growth of the fungus were dextrin and neopeptone, respectively.

Internal fruit rot of cucumber was observed in several locations in Korea. Incidence of the disease reached up to 21.5% and averaged 4.2% in the fields surveyed. The disease started at blossom ends of cucumber fruits. Internal tissues of infected fruit tips showed brown discoloration over 2 cm in length and 2 mm in diameter. Subsequently, the brown discoloration was extended into the carpels, and the surface of the infected fruit tips was rugged. Fungal isolates from the internal tissues of diseased fruits were identified as Didymella bryoniae based on mycological characteristics. Temperature for mycelial growth of isolates ranged with optimal temperature between . Similar symptoms were developed in the internal part of the cucumber fruit when conidial suspensions of the isolates were inoculated to the flower of cucumber. Furthermore, Didymella bryoniae isolates from other plant parts of cucumber, watermelon, oriental melon, melon and pumpkin also showed the similar symptoms in the internal part of cucumber fruits by inoculation tests. Temperature range for occurrence of internal fruit rot of cucumber was with optimal temperature of .

Powdery mildew of eggp1ant was found in Yeoiu, Korea in autumn 2000. Many white and Powdery mycelial colonies appeared on leaves, petioles and branches of the plants. Conidia with fibrosin bodies were ellipsoid to elongate-ellipsoid, 25~4015~22 in size and formed in chains with crenate edge. Conidiophores were erect on superfical mycelium, 47~100 in length. Germ tubes from conidia were simple and unbranched. No cleistoth-ecia were observed. On the basis of morphological characters of the conidial stage, the fungus was identified as Sphaerotheca fusca.

Powdery mildew of mug bean was found in Suwon on September 2000. Many white and powdery mycelial colonies appeared on leaves of the plants. Conidia with fibrosin bodies were ellipsoid to elongate-ellipsoid, 25~3816~22 in size and farmed in chains. Conidiophores were erect on superfical mycelium, 67~100 in length. Foot cells were cylindric with 37~6510~11 in size. Appressoria were indisdinct. Germ tubes from conidia were simple, not branched. Dark brown cleistothecia were observed on the leaves of mung bean. Cleisto-thecia were globose or subglobose, 85~1130 in size. Wall cells were irregularly polygonal with 15~457~26 . Appendages were mycelioid, 6-11 per ascocarp, coloured, throught when mature or paler upwards, 1~7 septa, 192~2235~7 in size. A single sun had in a cleistothecium and was ovoid or subglobose with 62~9550~67 in size. Ascusspore had 8 spores in an ascus and rarely developed, mostly imatuna ellipsoid-ovoid with 16~2412~16 . On the basis of morphological characters of the conidial stage and teleo-morph, the fungus was identified as Sphaerotheca phaseoli.