Abstract

Urtica simensis (Samma) is among the species of nettle which belongs to the family Urticaceae that is endemic to Ethiopia and consumed as vegetable in some places and traditionally people used in treating different types of diseases including infectious diseases. This study was conducted to evaluate the genetic diversity of Urtica simensis to address and fill the gap on its genetic variability using morphological characters and ISSR DNA markers. A total 133 plant samples were collected from Northern growing areas of Ethiopia (Gondar and Mekelle), based on variability in morphological characters. Morphological characterization was conducted on six morphological traits which demonstrated variation based on PCA and correlation matrix analysis. A total of 5 good amplified ISSR markers were selected out of 16 ISSR primers for molecular characterization. Highest genetic divers6ity (H) was found to be 0.4286 and Shannon Information index (I) was 0.6197 with respect to 100% polymorphism. Dendrogram based on Jaccard’s similarity coefficients generated by UPGMA cluster analysis using morphological and ISSR data shows major and minor clusters with broad distribution of Urtica simensis individuals over the entire tree which indicates the low divergence in morphological appearance among populations of both study areas. Based on the results of this study, morphological and ISSR markers were effective in studying genetic diversity of Urtica simensis since they shows variations in morphological appearances and genetic variability and this have valuable effect on characterization of Urtica simensis genetic resources in different parts of Ethiopia for conservation purposes.

Keywords: Genetic diversity, Urtica simensis, morphological characters and or markers, cluster analysis.

Abstract

We propose the nonparametric two-sided synthetic and side-sensitive synthetic control charts using signed-rank statistic. Performance of the proposed nonparametric control charts is measured using the measure average time to signal. The Markov chain approach is employed to compute average time to signal of the proposed sidesensitive synthetic control chart. The proposed nonparametric side-sensitive synthetic control chart perform significantly better than the two-sided synthetic control chart as well as the two-sided synthetic control chart gives better performance in terms of average time to signal than the nonparametric control chart based on the signed-rank statistic. The usefulness of the proposed control chart is explored by using a numerical example.

Keywords: Nonparametric, Control chart, Signed-rank statistic, Side-sensitive, Average run length.

Abstract

Wheat (Triticum spp.) becomes one of the most important cereal crops in the highland of Ethiopia ranking 2nd in total grain production next to maize. However, weed competition is one of the most important production constraints causing up to 65% reduction in potential yield of wheat. Therefore, this study was conducted in 2018 and 2019 consecutive main cropping season at North Gondar zone, Ethiopia to determine the effect of durum wheat varieties and weeding frequency on weeds, yield and yield components of wheat. The field experiment was comprised 15 treatment combination with two improved durum wheat varieties (namely Mangudo and Utuba) and one local and five weeding frequency (one hand weeding at 20DAE, one hand weeding at 30DAE, two hand weeding at 20 and 50DAE, weed free check and weedy check). The treatment was laid out in Randomized Complete Block Design (RCBD) in a factorial arrangement and replicates three times per treatment. Among both study area, durum wheat varieties and weed frequencies significantly affected weed density, weed dry biomass, weed control efficiency and all yield and yield component parameters. The interaction effect of Mangudo improved durum wheat variety with weed free check treatments reduce the weed density, weed dry biomass and having a good weed control efficiency performance by 22.78%, 3.89% and 84.06% respectively as compared to other treatment combination. However, they didn’t showed significance difference between Utuba improved durum wheat varieties with weed free check treatments. The highest thousand grain weight of 48.66 g and 47.55g were obtained from Mangudo and Utuba improved durum wheat varieties with weed free check treatments, respectively. Significantly maximum grain yield of 39.57q ha-1 and 38.88 q ha-1 were also recorded from Mangudo and Utuba improved durum wheat varieties with complete weed free treatments, respectively while the minimum grain yield of 21.67q was recorded from local wheat with weedy check treatments. It could be conclude that cultivating Mangudo and Utuba improved durum wheat varieties with complete weed free treatments were resulted in optimum growth parameter and yield of wheat as compared to other treatments.

Keywords: Triticum spp., wheat, cropping season, randomized complete block design, weed control.