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This study was designed to evaluate selected physiological responses of Salvinia minima to copper (Cu^^) concentrations of 0.06 (control), 1.0, 2.0, 2.5, and 3.0 mg r\ The plants were grown under laboratory conditions of 25 ± 2''C, a light intensity of 120 |.imol m"^ s^\ and a 14h photoperiod. After seven days of exposure to the Cu, Salvinio growth decreased gradually with an increase in Cu concentration resulting in a significant decline at 3.0 mg I'^Cu. Similar results were obtained after 14 days of exposure. However, calculating growth using fresh weight shouted a significant decline at 2.5 and 3.0 mg I"^. After 14 days exposure, CO^ assimilation decreased as the Cu concentration increased in the growth media. This decrease in CO2 assimilation coincided with a similar decrease in photosynthetic pigments. Uptake of Cu significantly increased with the increase of Cu concentration in the growth media. This study demonstrated the potential of Salvinia to remediate Cu in concentrations 100 times what is currently found in freshwater environments.

t\L-HnvoeNr, S. AND TOoo, G. W. 1990. Effects of temperatufe on photosynthate partitioning in alfalfa. llhis study was conducted to examine the effects of three temperature regimes (1212"C, tl.l18"C, and 34125'C day/night) on photosynthate partitioning in alfalfa (Medicago s:ativaL. (lna6tudi6 leseffetsdetroisr6gimesdetemp6rature (1212,2118 et34125"C jourinuit) sur la r6partition du photosynthdtat chez la luzerne (Medicago sativaL.). Aprds avoir r:ultiv6 les plantes en serre pendant environ trois mois, on les a rabattues. Lorsque lla repousse a atteint le stade du bouton, on a plac6 les plantes dans des chambres de ,:roisiance r6gl6es aux trois tempdrature de I'exp6rience, pour une photop6riode de 14 h. Le second jour, deux heures aprEs le d6but de la photop6rio9e, on a appliqu6 rje l,ur6e marqu6e au t*C sur une feuille de chaque plante et le '"CO2 a permis de suivre le d6placement du photosynth6tat vers les diff6rents organes v6g6taux. Aprds i24 h, les plantes ont 6t6 r6coltdes et r6parties en 6 portions, d savoir: la feuille source, ta partie sup6rieure de la tige trait6e, la panie infdrieure de la tige trait6e, les tiges non trait6es, la collerette et les racines. Les mesures de radioactivit6 ont montrd que le pourcentage total de raC export6 par la feuille source augmente avec la temp6rature.Plus la temp6rature 6tait 61ev6e, plus le taux de radioactivit6 mesur6 dans la partie sup6rieure de la tige traitde, les tiges non trait6es et les racines 6tait 6lev6. Par contre, au niveau de la collerette, la teieur en 'ac d 2ll8"c 6tait la plus 6lev6e, suivie respectivement par les teneurs observ6es b, l2l2 et d 34125'C. Dans la partie inf6rieurede ia tige trait6^e, la teneur en 'tC di*inue avec l'6l6vation de temp6rature.Mots c16s: Activit6 sp6cifique relative; radioactivit6. totale de la plante; translocation;Medicago sativa L.;'"C.

No abstract

The nutritional value of kudzu (Pueraria lobata) was evaluated as a potential animal feed. Randomly selected samples from natural habitats with Jacksonville area (Alabama, USA) were utilized in the study. Kudzu leaves showed significantly higher dry matter and crude protein content than the stems; whereas, ADF fiber was significantly lower in the leaves. However, NDF and total digestible nutrients (TDN) were similar in the leaves and the stems. The leaf part of kudzu was especially rich in CP (24.46%) and met the requirements and recommendations for most ruminants. The TDN value for kudzu stem is 55.99%, which falls below but within the recommended range. Macronutrients concentration between the stem and leaf of kudzu, nitrogen, calcium, and magnesium showed a significantly higher in the leaf than the stem. However, phosphorous was similar in concentration in the stem and the leaf, and potassium was higher in the stem. In regard to the micronutrients, the only significant difference between the leaf and the stem was iron. However, iron, manganese, zinc, and copper were all above the recommended concentrations by the National Research Council. In general, kudzu can be considered a good source for animal feed, especially the leaf, which shows a higher value in most of the determined criteria in comparison to what was recommended by the National Research Council. This should provide a new outlook to kudzu, which has been considered a noxious weed and help in the utilization of kudzu in a positive way in the southern region of the US.

This greenhouse study was carried out to determine the impact of drought on plant growth, photosynthetic rate and the recovery of photosynthesis after drought relief. Twenty four Roselle plants were equally divided between the control and the treatment groups, which received 100% and 25% soil saturation respectively. The plants were grown under greenhouse conditions with the temperature averaging 27 ± 2ºC. The treatments were applied with seven cycles of watering until the plants reached the anthesis stage. The drought influence caused a significant reduction in the plant height, flower number, and photosynthetic rate. Re-watering the plants growing under drought to 100% water saturation resulted in complete recovery of photosynthetic rate within forty-eight hours. However, rewatering to 25% showed only 30% recovery in photosynthetic rate after forty-eight hours. Photosynthetic pigments including chlorophyll a, b and carotenoid were not significantly influenced by the drought. Similarly, total phenolic compound concentration of the calyx was insignificant between the treatments. However, Anthocyanin concentration of the calyx was significantly higher under the drought treatment.

This study was designed to evaluate the effectiveness of salvinia [Salvinia minima) in accumulating nitrogen and phosphorus under different imitating eutrophic environments. Nitrogen concentrations of 1.0 (control), 10.0, and 100 mg/1 and phosphorus concentrations of 0.1 (control), 1.0, and 10.0 mg/1 were used in this study. Plants were grown under laboratory conditions at 25 ± 2 C with a light intensity of 120 umol/m 2 /s, and a 14 hr photoperiod. Salvinia's growth, expressed as frond production and plant fresh weight doubling time, was significantly increased with increasing nitrogen concentration from 1.0 mg/1 to 100.0 mg/1 in the growth media. The increase in growth rate was independent from the variation in phosphorus concentrations. However, the highest growth rate was obtained for days 1 through 7 when the levels of both nitrogen and phosphorus were elevated 100 fold (100 mg/1 N and 10.0 mg/1 P) from that of control

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