Distribution, Severity Status, Farmers Knowledge and Management Practices of Wild Radish (Raphanus raphanistrum L.) in Horro Guduru Wollega Zone, Western Ethiopia

The objective of the study was to study the distribution, severity status, farmers’ knowledge, impacts and management practices of Wild Radish (Raphanus raphanistrum L.) in Horro Guduru Wollega Zone, Western Ethiopia. The collected data were analyzed by using descriptive statistics. The Shannon Diversity Index (SDI), the evenness, species richness and Jaccards Similarity Index (JSI) was calculated from the recorded weed samples. Correlation of vegetation variables among and between sampled Administrative Kebeles’ was analyzed by SPSSv20 software. The result of the study indicates that out of the sampled 160 respondents 92 (57.5%) of them heard about wild radish plant as a weed and the rest of 68 (42.5%) of the respondents did not know this plant as a weed. Among the respondents 88 (55%) of them identify R.raphanistrum plant as a weed. There was high negative correlation between mean R. raphanistrium density and Shannon diversity index with R2 = 0.642, p<0.001. This study showed that high infestation level of R. raphanistrum was observed in Horro district followed by Abayi Chomen, Amuru and Jima Rare districts. The highest and lowest mean population (±SD) of R. raphanistrum per quadrate was recorded at Horo (249.82 ± 34.67) and Jima Rare (13.72 ± 14.16), respectively. The biodiversity impact of R. raphanistrium at highly infested areas were more visible than the moderately infested areas. Horro and Abayi Chomen districts showed the lowest Shannon Diversity Index value of 1.78 and 2.12, respectively, due to the fact that, their species diversity was highly affected by the high population density of R. raphanistrium. Moreover, the standing herbaceous vegetation from the sampled sites of Horo district (Doyo Bariso and Gudina Abuna administrative kebeles) showed higher Jaccards Similarity coefficient (0.84), where there was high R.raphanistrium infestation level. The study proved that R. raphanistrum was emerged as invasive weed and have been disseminated into neighbor districts’ and zones. Therefore, further research should be conducted to quantify the distribution, increases in species abundance as well as its impact on biodiversity and socio-economic aspects, which may support to contain R. raphanistrum distribution and planning on its prevention and management. Keywords: Abundance, distribution, invasive, Raphanus raphanistrum, severity, wald radish DOI: 10.7176/JBAH/10-24-02 Publication date: December 31st 202

Efficacy of Azadirachta indica (A. Juss) seed powder water extract against Aulacuspis tubercularis newsteed (homoptera: diaspididae) on mango (Mangifera indica l.) In East Wollega, Ethiopia

Mango (Mangifera indica L.) is a fleshy stone fruit belonging to the genus Mangifera. Among the many tropical fruits, mango has been identified as the most important and considered to be the king of fruits from a socio-cultural, commercial and environmental point of view and grown in over 100 countries including Ethiopia. However, many biotic and abiotic factors limit its production and productivity across the globe. Aulacuspis tubercularis Newsteed (Homoptera: Diaspididae) commonly known as white mango scale is a serious insect pest of mango in Ethiopia. Though A. tubercularis introduced to Ethiopia almost a decade ago, technologies towards its control is almost nil or few which enabled the pest to invade the whole country where mango is grown to the extent of causing 50-100% crop losses. The current study was conducted to know the efficacy of Azadirachta indica (A. Juss) seed powder water extract in the management of A. tubercularis under field condition. Field experiments were conducted at Uke and Arjo Gudetu in western Ethiopia. The treatments were different spray concentrations. (0.05, 0.1 and 0.15mg/ml of water). The treatments were applied 3 times at 10 days interval after complete infestation was observed. The experiment was laid out in a randomized complete block design in four replications. Mortality count was done 10 days after 1st, 2nd and 3rd treatment applications. The results obtained revealed that water extracts of A. indica seed powder at 0.15 concentration significantly (p<0.05) reduced the population of A. tubercularis at both experimental sites. Crawlers and males were more affected than the females. Hence, the use of A. indica seed water extract can be recommended for the management of A. tubercularis. &nbsp

Potency of Neem, <em>Azadirachta indica</em> L. (A. Juss) Leaf Aqueous Extract Insecticide against White Mango Scale, <em>Aulacuspis tubercularis</em> Newstead (Homoptera: Diaspididae) Infesting Mango (<em>Mangifera indica</em> L.)

This study was conducted to evaluate the potency of aqueous A. indica leaf powder extract (LPWE) against A. tubercularis infesting mango. Field experiments were conducted in Ethiopia at two experimental sites, western Oromia. Randomized Complete Block design was laid in four replications with four blocks consisting of sixteen treatment plots. The treatments were 0.05, 0.1 and 0.15 mg/ml spray concentrations made from A. indica LPWE. The treatments were applied 3 times at 10-day interval and the mortality count was carried out 10 days after 1st, 2nd and 3rd treatment applications. The results of the study confirmed that among the tested three different concentration of A. indica LPWE 0.15 mg/ml concentration significantly (p < 0.05) reduced the population of sessile A. tubercularis at both experimental sites. The results also indicated that male adults and nymphs were more affected than females. The population of sessile A. tubercularis significantly decreased as the concentration of A. indica LPWE increased in comparison with the check plots. Thus, the use of A. indica LPWE at high concentrations led to a notable population reduction of sessile A. tubercularis and its effects. Hence, the use of A. indica LPWE can be recommended for A. tubercularis management as part of integrated pest management