• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.73-82
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• 1989

The development of eggs and larvae, and minute scale-like tubercles on the skin surface of the larval Acanthorthodeus asmussi from Korea were observed in the laboratory. The egg was nearly ovoid-shaped. The number of egg averaged 195 per an oviposition. The morphological character of larval development was relatively similar to those of Acheilognathus tabira tabira, A. tabira subsp. (a), A. yamatsutae, A. moriokae, A. cyanostigma and A. rhombeus. The larvae of this species had many scale-like tubercles ellipsoided in a diagonal cross section on the skin surface of the body. And also this species moved like incessant wiggly movement pattern as that of fly maggot duing the larval development. As regards the tubercles and larval movement pattern, the larvae of A. asmussi shared similar characters with those of Acheilognathus rhombeus, A. longipinnis and Pseudoperilampus typos. Hence A. asmussi may be closely related to these species. The latter three species are autumn-spawning bitterlings and the larval development always retard in a certain stage, while A. asmussi is a spring-summer spawning species and the larval development never retards. Judging from these facts, it should be considered that there are close relations in evolutionary trend between the two spawning species.

• Korean Journal of Ichthyology
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• v.2 no.2
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• pp.169-181
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• 1990

The development of eggs and larvae, and minute scale-like tubercles on the skin surface of larval Acantlaorhodeus gracilis from Korea were observed. They spawned from late March through the middle of June. A fish spawned at least 5 times and the number of eggs averaged 304 per oviposition. Unfertilized eggs are nearly ovoid-shaped(mean$\pm$SD=$2.09{\pm}0.04\;mm$ in length with range of 2.05 to 2.13 mm and mean$\pm$SD=$1.26{\pm}0.02\;mm$ in breadth with range of 1.24 to 1.30 mm measured for the 50 eggs) and opaque yellow color. The tip of egg membrane at the animal pole side swelled and formed a few hilly projections. The shape of the eggs was just like a loquat. Most of embryos began to hatch out in thirty-eight hours after insemination at $22{\pm}1^{\circ}C$ in water temperature. As regards the morphological characters of the eggs and larval development, Acan. gracilis was similar to Acan. asmussi, Acheilognathus rhombeus, A. longipinnis and Pseudoperilampus typus. The larvae of this species is unique particularly in the following two characters, i.e., 1) scale-like tubercles ellipsoided in a diagonal cross section on the whole body and 2) incessant wiggly movement pattern as that of fly maggot, with the larvae of the above mentioned species. These characters seem to reflect the phylogenetic relationships among acheilognathine fishes. On the other hand, this species and Acan. asmussi are spring-summer spawning bitterlings. And also these species never retard the larval growth in such larval stage as the duration from Stage B to Stage D.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.85-90
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• 1998

A series of experiments were carried out to determine the effect of seed dressing application of chemicals on the early occurring rice insect pests. The number of small brown planthopper adults per 3hills in seed-dressing plot of Imidacloprid WS (Im WS) was 1.6 and its control efficacy was over 90%, compared with that of untreated plot. Rice water weevil was observed in the density of 8.8 larvae per 5 hills seed-dressed Im WS plots(showing 95.5% of control efficacy). Control efficacy of Im WS and Im GR against adult weevils lasted for 26 days after treatment and was higher than that of Carbofuran GR. Rates of injured stems by rice stem maggot and injured leaves by rice leaf miner were 3% and 3.7% in Im WS treatment plot respectively. Seed germination rate after seed dressing with recommended dosage (3 g/seed kg) of Im WS was 71 % on the 1st day and increased on 5th day up to that of untreated seed. The residual amount of Im in seed dressing plot was 0.11 ppm in rice roots and 0.05 ppm in leaves on the 40th day after treatment. Residual effect of Im WSI sustained for 50 days with over 95% insecticidal effect for the rice water weevil and over 90% for the brown planthopper. Quantity of the chemical applied in the field was calculated as 0.084 kg a.i./ha in seed dressing and 0.3 kg a.i./ha in seed box treatment, respectively It took 1 hour to treat insecticide by seed dressing, 2.5 hours by seed box applying, and 3.6 hours by water surface releasing per 990 $m^2$.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.55-64
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• 2011

To investigate a comparison of rice yield and quality by a utilization of green crops using barley and hairyvetch, this study was carried out in rice (Oryza sativa L.) organic cultivation field. Convention barley harvest (CBH), Green barley crop (GBC), Green barley+Green Hairyvetch crop (GB+HVC), and Non-Green crop (NGC) were treated in rice cultivation field. The results obtained as following: 1) Culm length and pancile length in Convention barley harvest (CBH) cultivation were longer than organic cultivation but were not significant difference in all treatments. Yields of milled rice in Green barley crop (GBC) and Green barley+Green Hairyvetch crop (GB+HVC) were by 90.3% and 95.9%, respectively. 2) Protein contents in Green barley crop (GBC) and Green barley+Green Hairyvetch crop (GB+HVC) were by 5.7% lower than 6.6% in Convention barley harvest (CBH) cultivation. Amylose contents in all treatment were similar as range 18.8% to 19.1%. Whiteness contents in Green barley crop (GBC) and Green barley+Green Hairyvetch crop (GB+HVC) were slightly higher by 38.9% and 39.1%, respectively, than 37.7% in Convention barley harvest (CBH) cultivation. 3) Palatability values in Barley harvest (BH) and Non-Green crop (NGC) were slightly higher by 82.0 and 83.8, respectively, than 77.6 in Convention barley harvest (CBH) cultivation. 4) Head rice in Non-Green crop (NGC) was 95.5%, while that of Convention barley harvest (CBH), Green barley crop (GBC), and Green barley+Green Hairy-vetch crop (GB+HVC) were slightly low as range 93.8% to 94.2%. White core and belly rice in Convention barley harvest (CBH) cultivation was the highest level by 1.7%. 5) Leaf blast, neck blast, sheath blight, rice stem maggot, rice leaf roller, rice leaf-tier, and green rice leafhopper were occurred lightly in rice field.