Effect of substrates on the yield, yield attribute and dietary values of oyster mushroom (pleurotus ostreatus) in the pastoral regions of Northern Ethiopia

Dry areas are vulnerable to climate change and are commonly hit by drought, which makes the inhabitants to rely on food aid. Mushroom cultivation is a profitable agribusiness that can improve the economic and food status of farmers in dry areas as an alternative technology. Research on the effect of substrates on the yield, yield attributes and dietary values of oyster mushroom (Pleurotus ostreatus) was conducted to identify the best substrates. The experiment included 23 treatments with three replications. The substrates were sawdust, rice straw, cottonseed hull & maize cob with 100%, 75%, 50% and 25% combination ratios. The substrates were chopped, moisturized and filled into 40 cm X 60 cm polyethylene bags and sterilized for one hour at 100 oC. The substrates were cooled and inoculated with 75g mushroom spawn, and were kept in a dark place to enhance mycelium growth. The substrates were transferred to a growing room, with full light, lower temperature and higher relative humidity for fructification after mycelium growth was completed. Data on yield attributes, fresh yield and dietary values were collected and analyzed. The fruiting bodies were picked after 22 - 35 days of inoculation. The treatments had significant effect on the number of days for mushroom growth, stalk length, pileus diameter and number of fruiting body, fresh yield, biological efficiency and dietary values (P < 0.05). All consumers significantly preferred mushroom grown on 100% maize cob substrate. The 100% cottonseed hull substrate gave the highest profit (133.25US$ 100kg-1 substrate). The study concluded that 100% cottonseed hull substrate was the best substrate for oyster mushroom production at small-scale level. It was also the best nutritive source of substrate for oyster mushroom growth. Mushroom grown on a 100% maize cob substrate was a tasty and protein rich mushroom. Therefore, producers should be encouraged to use this substrate for maximizing the yield, for changing the agricultural wastes into food in the form of mushroom and for improving their livelihood. Oyster mushroom could play a pivotal role in supporting the food self-sufficiency, hence it should be included as a component of food security assurance strategy for the country.Key words: mushroom, substrates, yield, pastoral, dietary value, agricultural waste, livelihoo

Pheromone-based mating and aggregation in the Sorghum chafer, Pachnoda interrupta

Adults of the sorghum chafer, Pachnoda interrupta Olivier (Coleoptera: Scarabaeidae: Cetoniinae), form aggregations during the mating period in July, but also in October. The beetles aggregate on food sources, e.g., Acacia spp. trees or sorghum with ripe seeds, to feed and mate. During the mating season, field trapping experiments with live beetles as bait demonstrated attraction of males to unmated females, but not to mated females or males, indicating the presence of a female-emitted sex pheromone. Unmated females combined with banana (food source) attracted significantly more males and females than did unmated females alone. Other combinations of beetles with banana were not more attractive than banana alone. Thus, aggregation behavior appears to be guided by a combination of pheromone and host volatiles. Females and males were extracted with hexane during the mating period, and the extracts were compared by using GC-MS. In a field trapping experiment, 19 compounds found only in females were tested, both singly and in a mixture. Traps baited with one of the female-associated compounds, phenylacetaldehyde, caught significantly more beetles than any other treatment. However, the sex ratio of beetles caught in these traps did not differ from that of control traps and it is possible that other components may be involved in the sex pheromone signal. Furthermore, traps baited with a mixture of all 19 compounds attracted significantly fewer beetles than did phenylacetaldehyde alone

Impact of Climate Change on the Hydrology of the Upper Awash River Basin, Ethiopia

This study investigated the impacts of climate change on the hydrology of the Upper Awash Basin, Ethiopia. A soil and water assessment tool (SWAT) model was calibrated and validated against observed streamflow using SWAT CUP. The Mann–Kendall trend test (MK) was used to assess climate trends. Meteorological drought (SPEI) and hydrological drought (SDI) were also investigated. Based on the ensemble mean of five global climate models (GCMs), projected increases in mean annual maximum temperature over the period 2015–2100 (compared with a 1983–2014 baseline) range from 1.16 to 1.73 °C, while increases in minimum temperature range between 0.79 and 2.53 °C. Increases in mean annual precipitation range from 1.8% at Addis Ababa to 45.5% over the Hombole area. High streamflow (Q5) declines at all stations except Ginchi. Low flows (Q90) also decline with Q90 equaling 0 m3 s−1 (i.e., 100% reduction) at some gauging stations (Akaki and Hombole) for individual GCMs. The SPEI confirmed a significant drought trend in the past, while the frequency and severity of drought will increase in the future. The basin experienced conditions that varied from modest dry periods to a very severe hydrological drought between 1986 and 2005. The projected SDI ranges from modestly dry to modestly wet conditions. Climate change in the basin would enhance seasonal variations in hydrological conditions. Both precipitation and streamflow will decline in the wet seasons and increase in the dry seasons. These changes are likely to have an impact on agricultural activities and other human demands for water resources throughout the basin and will require the implementation of appropriate mitigation measures