Allelopathic influence ofSorghum bicolor on weeds during germination and early development of seedlings.

The allelopathic interaction between sorghum [Sorghum bicolor (L.) Moench] and 10 species of grass and broadleaf weeds was investigated. Germination of weed seeds was slightly inhibited or stimulated, depending on species, when incubated in closed Petri dishes with germinating sorghum. Subsequent radicle and hypocotyl or coleoptile elongation of weeds was significantly inhibited by the germinating sorghum. For weeds interplanted with sorghum and grown under greenhouse conditions. The inhibitory effect on some weed species was still evident after 2 months of growth. Significant differences were found in the dry matter per weed plant grown in pots in proximity to sorghum vs. weeds grown in monoculture. Aqueous leachates from pots planted with sorghum alone or from a system in which sorghum roots protruded into water had strong allelopathic activity. These results indicate that water-soluble allelochemicals are produced by germinating sorghum seeds and that production of these substances continues during seedling growth.

Mass spectrometric 13C/12C determinations to detect high fructose corn syrup in orange juice: collaborative study.

The 13C/12C ratios in orange juice are sufficiently uniform and different from those in high fructose corn syrup (HFCS) so that the addition of HFCS to orange juice can be detected. HFCS averages -9.7% (parts per thousand) delta 13C, orange juice averages -24.5%, and mixtures of HFCS and orange juice possess intermediate values. One pure orange juice and 4 orange juice -HFCS mixtures containing from 25 to 70% orange juice were properly classified by 7 collaborators. Samples with delta 13C values less negative than -22.1%, 4 standard deviations from the mean of pure juices, can, with a high degree of confidence, be classified as adulterated. Samples with values more negative than -22.1% must be considered unadulterated with HFCS, because pure orange juices possess a range of delta 13C values. The 13C/12C mass spectrometric method was adopted official first action for detecting HFCS in orange juice.

Disappearance of patulin during alcoholic fermentation of apple juice.

Eight yeast strains were used in three typical American processes to ferment apple juice containing 15 mg of added patulin per liter. Patulin was reduced to less than the minimum detectable level of 50 microgram/liter in all but two cases; in all cases, the level of patulin was reduced by over 99% during alcoholic fermentation. In unfermented samples of apple juice, the concentration of added patulin declined by only 10% when the juice was held for 2 weeks, a period equivalent to the time required for fermentation.

Inhibitory effect of a polychlorinated biphenyl (Aroclor 1254) on aflatoxin B1 carcinogenesis in rainbow trout (Salmo gairdneri).

Duplicate lots of 120 rainbow trout (Salmo gairdneri) fingerlings were fed for 1 year semipurified diets containing 6 ppb aflatoxin B1 (AFB1), 100 ppm Aroclor 1254 (a polychlorinated biphenyl), and 6 ppb AFB1 plus 100 ppm Aroclor 1254. Appropriate controls were also maintained. Samples were taken at 1, 2, 4, 6, 9, and 12 months to monitor tumor incidence, Aroclor 1254 accumulation, and histopathology of liver, spleen, and kidney tissues. At the end of the year, 26 of 37 (70.3%) trout fed 6 ppb AFB1 had hepatocellular carcinomas, compared to 14 of 46 (30.4%) trout fed 6 ppb AFB1 plus 100 ppm Aroclor 1254, a highly significant reduction in tumor incidence in the trout on the Aroclor 1254-containing diet. None of the control or Aroclor 1254-fed fish had liver tumors. Levels of Aroclor 1254 increased rapidly during the first 6 months, then plateaued at approximately 80 ppm on a whole-fish basis. AFB1 inhibited growth but Aroclor 1254 did not. Glycogen depletion of hepatocytes and hyperemia, and white pulp depletion of the spleen were the only changes induced by Aroclor 1254.

Effect of toxaphene on the performance of White Leghorn layers and their progeny.

An experiment involving 48 white leghorn layers fed 0, 10 and 100 p.p.m. of toxaphene has been conducted. Except for a slight decrease in egg production, no adverse effects on various performance parameters including fertility, hatchability and survival of progeny were observed. A significant increase (P less than .05) in average 7-day weights of progeny was noted.