The ability to regenerate plants from tissue cultures of Arachis has been limited to a few species and, in most cases, to short‐term cultures. Tissue cultures of peanut (A. hypogaea L.) usually are derived from seedling explants and regenerate by organogenesis. This study evaluated the potential to induce somatic embryogenesis in peanut (‘NC‐7’, ‘Comet’, and ‘McRan’) and A. paraguariensis Chod. & Hassel., in comparison to a similar regeneration system in soybean [Glycine max (L.) Merr. ‘Forrest’] and G. canescens F.J. Herm. Intact, immature zygotic embryos were cultured on L2 media with various hormonal treatments. Adventitious somatic embryogenesis was induced from 53% of the cultured immature zygotic embryos of McRan, Comet, NC‐7, and A. paraguariensis, compared to 29% for Forrest and G. canescens, scored after 30 d incubation. By the end of the test period (150 d of culture), Arachis formed an average of 29 somatic embryos per explant compared to 16 for Glycine. An average of 77% of the peanut somatic embryos formed shoots and 61% formed roots compared to 30% shoots and 33% roots for soybean. This regeneration system offers an additional and more efficient tool for peanut biotechnology research programs.

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Medium wool ewes were injected with vitamin E and(or) Se over a 2-yr period to evaluate the influence of these treatments on reproduction. Ewes were divided randomly into four groups, consisting of a control, plus groups receiving monthly sc injections of either 272 iu vitamin E, 4 mg Se or 272 IU vitamin E plus 4 mg Se during pregnancy. Selenium administration increased (P less than .05) ewe blood Se concentrations, but had no effect (P greater than .10) on fertility (number of ewes lambing of ewes bred), prolificacy (number of lambs born/ewe lambing) or lamb sex ratio. Preweaning survival of lambs was increased (P less than .05) by ewe treatments with either Se or vitamin E and thus, treated ewes weaned approximately 20% more lambs/ewe mated than did control ewes.

We examined two methods of combining catch-and-effort data from small geographic regions into large regulatory areas to estimate catch-per-unit-effort (CPUE): (1) weighting regional CPUE by bottom area occupied by the population; (2) weighting by fishing effort. Variance estimates and other statistical properties are presented for CPUE estimates by region and for the two methods, for the type of fishery where total catch is known. The CPUE estimator from area-weighting is approximately unbiased as an index of population density; the CPUE estimator from effort-weighting is biased but less variable than the former. Conditions of similarity are derived for estimators from the two methods to be identical, or, less restrictively, to show the same trend over time. In general, the area-weighted method is preferred, if sufficient samples are taken from all pertinent regions in the regulatory area. However, the effort-weighted method may be used with a gain in precision and no substantial bias, if there are no substantial changes in relative CPUE and effort among regions, or if relative CPUE and effort are inversely related. The two methods applied to catch and effort data for Pacific halibut (Hippoglossus stenolepis) and to produce highly similar CPUE estimates over time, despite large relative changes in both CPUE and effort among regions. The reasons for the similarity are traced back to conditions in the fishery.Key words: catch-per-unit-effort, combining data, sampling commercial fisheries, variance estimation, comparison of methods

To help local Niger government authorities and donor countries ameliorate conditions in the advent of drought, a rapid yet simple means to assess annual herbrceous production at the end of the rainy season is needed. Several rainfall variables were tested as estimators of herbaceous production using weighted and logarithmic transformation in regression analysis. A computer program was developed in Basic to generate rainfall parameters from daily rainfall data. Input parameters used to calculate the rainfall variables were varied to minimize the regression standard error of the estimates. Selected regression models were compared using 80% confidence levels for mean values for each rainfall treatment class using logarithmic and weighted regressions. The selected weighted model involved the number of moist days and consecutive dry days as independent variables. The selected logarithmic model used total rainfall as the only independent variable. These models were tested by comparing an independent data set with the 95% confidence hrtervals for observations. Selected models separated rangeland production classes of 200 kg l ha-r confidence liiits for mean values. The logarithmic model could only do so when biomass levels were less than 800 l ha'*. Thus, these models only have application for predicting herbage biomass within rather large classes.