Toxicities of cadmium (Cd) and ethylenediamine-tetra acetic acid (EDTA) on Bombyx mori larvae fed on artificial food under the aseptic conditions were examined.
A summary of the results is shown below.
1) Death of the larvae caused by Cd was shown in the concentration of 50 ppm when they were administrated during the first to the third instar and that of 100 ppm when administrated at the fifth instar.
2) Death of the larvae caused by EDTA was shown in the concentration of 0.08 mol when they were administrated during the first to the third instar and that of 0.16 mol when administrated at the fifth instar.
The lethal doses of EDTA in the larvae was shown in 0.1 mol during the first to the third instar and in 0.2 mol at the fifth instar, respectively.
Cd-or EDTA intoxication was confirmed with the dead larvae, but not observed any infectious diseases by microbes.

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Toxicities of the mixture of cadmium (Cd) and ethylenediaminetetra acetate (EDTA) on the Bombyx mori larvae fed on artificial food in aseptic conditions was investigated. The mixture was given to the various developmental stages of larvae and the rates of growth or mortality of the larvae were examined after 10 days of administration.
1) When the 200 ppm Cd was given, the mortality rate of larvae approached 100% on each stage.
2) When a mixture of 200 ppm Cd with 0.04 M of EDTA was given, the development of larvae was almost usual and no dead larva was observed.
3) When a mixture of 320 ppm Cd with 250 ppm Zinc (Zn) was given, still dead larvae were observed. When a mixture of 5, 000 ppm Cd with 0.04 M of EDTA was given, all tested larvae in the first instar were dead, but the survival rate of 10% in the third instar and of 40% in the fifth instar larvae were observed respectively. It was confirmed that a mixture of Cd-EDTA is more effective to decrease on the toxicity of Cd than that of Cd-Zn.

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These experiments were carried out to clarify the relations between meteorological elements and growth parameters in young plants of several vegetables grown in a heated plastic house. The solar radiation transmittance of the house was about 58%. Growth analyses were performed 29 times on eggplant (Solanum melongena cv. Nagaokanaga), 30 times on cucumber (Cucumis sativus cv. Kurumeochiai H), lettuce (Lactuca sativa var, capitata cv. Great Lakes 366 and cv. Okayama salad), radish (Raphanus sativus var. vadicula cv. Comet), 31 times on mitsuba (Cryptotaenia japonica cv. Shirokuki), and 32 times on cabbage (Brassica oleracea var, capitata cv. Sazanami) .
1. The mean values of RGR, NAR and ULWR in radish and of LAR and SLA in lettuce were larger, while those of NAR in lettuce and of RGR, LAR LWR and RLGR in mitsuba were smaller than the rest. The highest values of RGR in the vegetables tested were 0.253-0.297, except 0.130 for mitsuba which is one of shade plants originated in Japan.
2. The followings are considered from the standardized partial regression coefficient in the multiple regression model of growth parameters composed of mean day temperature (DT), mean night temperature (NT), mean daily solar radiation (S), and mean daily maximum saturation deficit (SD) .
RGR: DT has highest positive correlation in vegetables favoring warm season, and NT in those favoring cool season.
NAR: S has highest positive correlation in all vegetables used except mitsuba, in which SD is the most positive factor.
LAR: DT has positive correlation, while S and SD have negative one.
LWR: none of meteorological elements has a close relation.
SLA : SLA is affected by meteological elements similarily to LAR.
RLGR : both temperature and radiation have positive correlation, the former being stronger.
ULWR: either DT or NT has highest positive correlation except lettuce (crisphead) and mitsuba, in which SD is the strongest factor.
3. Coefficient of determination (R²) in the multiple regression model was very small in every growth parameter of mitsuba. From R² for each growth parameter of all vegetables, it is considered that the values of RGR, RLGR and ULWR are more strongly affected by the meteorological element.

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Fourteen-day-old sunflower plants (Helianthus annuus L. cv. Russian Mammoth) were exposed to 0.1 or 0.2 ppm ozone (O₃) for 12 days in an artificially-lighted growth cabinet. Plants were harvested 0, 6 and 12 days after the start of exposure, and the growth analysis was performed. White fleck of injury developed on many leaves after the exposure to 0.1 or 0.2 ppm O₃ for 1-2 days, and subsequently withering of old leaves was accelerated. Twelve days after the start of exposure, the dry weight of whole plant was reduced by 11 % and 32% of the control by 0.1 and 0.2 ppm O₃, respectively. Root growth was markedly inhibited by O₃, while leaf growth was slightly inhibited. Relative growth rate (RGR) and net assimilation rate (NAR) were reduced by 0.1 ppm O₃ for the first 6 days, but were not affected for the following 6 days. The RGR and the NAR were reduced by 0.2 ppm O₃ throughout the exposure period. For the last 6 days, the RGR was less affected by 0.2 ppm O₃ than the NAR, owing to the increase in leaf area ratio (LAR) . Leaf weight ratio (LWR) was also increased by O₃ exposure, whereas stem weight ratio (SWR) and root weight ratio (RWR) were reduced. These changes in growth parameters suggest that the chronic exposures to low concentrations of O₃ should affect the net photosynthesis and the partitioning ratio of photosynthates in sunflower plants.

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