1. The fruit paper bags which have been treated with Uspulun are quite effective for the prevention of pear black spot disease not only in the year of this preparation but also in the following year.
2. Bordeaux mixture sprayed on pear leaves shows such an effect that germinating percentage of spores of
Alternaria kikuchiana was 40∼50% after 11∼12 days. And effects of the following chemicals were as follows: SR-406 after 8∼10 days, Manzate 5∼7 days, OB-21 and Dithane about 5 days after had a germinating percentage of 50%. Uspulun had a remarkable inhibiting power on germination on the day spray was executed, but the effect will be los markedly aftter two days from spray.
3. Great differences couldn't be seen among 800:1, 1000:1, 3000:1 Uspuluns, concerning rapid decreasing tendency of the inhibition of the spore germination after spraying of Uspulun on leaves.
4. Decreasing of the inhibition of spore germination on slide glass are similar to the case of leaves. However, the decreasing tendency is by far the more remarkable under the direct sunlight than in the shade. The decreasing tendency on a slide or a leaf is in proportion to the lapse of time, say 6, 8 or 30 hours.
5. Uspulun and Ceresan emulsion (experimental spray) will lose almost all their inhibiting power to spore germination in 4 hours after spray under the direct sunlight, but wettable Ceresan (experimental spray) won't lose the power even after 24 hours.
6. After dipping in Uspulun liquid, unhulled rice seed were inoculated with such fungi as
Alternaria kikuchiana and
Ophiobolus miyabeanus and then the inhibition of conidia germination investigated. It was clarified that the inhibiting power on the surface rapidly decreased as the time goes on after dipping. In this case mercury itself was clearly demonstrated even after 144 days.
7. Spray effect was similar in both cases of pot and field experiments, and the mixture of Bordeaux and Uspulnn was best, and the alternately sprayed plot of the both liquids, Uspulun calcium stand in order of efficacy.
8. According to inoculating test of
Alternaria kikuchiana upon a young shoot, Uspulun liquid was most effective, and SR-406, Bordeaux, OB-21, Dithane, Manzate, etc. came next in efficacy. And a special relation wasn't discovered between the time elapsed after the Uspulun spray was practised and degree of infection.
9. Not with standing the rapid decrease of inhibition of spore germination on leaves, it may be said many interesting problems still remain in the future in relation to Uspulun which has a remarkable control against infection in the final stage.
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