Liming of alfalfa (Medicago sativa L.)

Summary A growth-chamber experiment was conducted to study the effect of liming upon growth of alfalfa. The beneficial effects observed were related to changes in soil properties brought about by lime application. Reductions of aluminum and manganese toxicities were the major factors responsible for the increased yields and the decreased growth period required to reach harvest stage. Significant correlations between plant growth parameters and various measures of extractable aluminum were found.     

The effect of nitrogen fertilizer applied to Euphorbia pulcherrima on the parasitization of Bemisia argentifolii by the parasitoid Encarsia formosa

More wasps of Encarsia formosa Gahan (Hymenoptera: Aphelinidae) were found on fertilized poinsettias, Euphorbia pulcherrima (Willd.) (Euphorbiaceae), than on non-fertilized plants. Parasitization of Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae) by E. formosa was higher on plants treated with calcium nitrate than with ammonium nitrate or on control plants. In a no-choice test, host feeding by E. formosa was higher when hosts were on fertilized plants than when hosts were on control plants. The nitrogen content of whitefly pupae reared on plants treated with ammonium nitrate was higher than those on calcium nitrate-treated plants.Variability in the parasitization of B. argentifolii by E. formosa appears to be due to host plant-mediated differences in the whiteflies. E. formosa may be influenced by the nutritional suitability of the host, which influences whether wasps continue to oviposit, feed, or disperse.     

Immunoreactive α melanocyte stimulating hormone,its distribution in the gastrointestinal tract of intact and hypophysectomized rats

The presence of immunoreactive α melanocyte stimulating hormone (IαMSH) was investigated in both mucosal and muscular layers of the various areas of the gastrointestinal tract. IαMSH was present in both layers in all areas of the gastrointestinal tract but the esophageal mucosa and muscularis in saline extracts. The highest concentrations were found in the duodenum. Hypophysectomized males tended to have higher content than intact males. There was no difference between intact estrogen-primed females and hypophysectomized females up to 1 month post hypophysectomy in any area. The tract of 3 month hypophysectomized females showed lower levels than the intact estrogen-primed females in 5 areas; however, in similar groups of 3 month hypophysectomized females which were estrogen primed, 8 of the 10 areas contained more IαMSH than the intact estrogen-primed females. Acid extracts from female rats during the estrous cycle showed no cycle-dependent differences. Comparison of acid and saline extracts showed an absence of IαMSH in gastric tissues and a decrease in the duodenal muscularis in acid extracts but no consistent differences were found in other areas. These results suggest that the IαMSH found in the gastrointestinal tract is not of pituitary origin but may be produced in the gastrointestinal tract. The induction of increased content by estrogen priming in hypophysectomized rats suggests that estrogen priming may induce production. The absence of IαMSH in acid extracts of the stomach suggests that a difference in distribution of pro-opio-cortin products may exist in the gastrointestinal tract.