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Parthenium is an exotic invasive weed that originated in South America, and has formed severe infestations in Ethiopia. This weed is known to be host to various micro-organisms such as the rust pathogen Puccinia abrupta var. partheniicola that may be used as a component of integrated parthenium weed management. Field surveys were conducted in 2008 and 2009 cropping seasons in eastern Ethiopia to determine distribution, incidence, and severity of the rust (P. abrupta var. partheniicola) on this weed. In addition, the effect of this pathogen on morphological parameters of parthenium was studied both in the field and in the greenhouse at the Plant Protection Research Center, Ambo. A total of 218 fields were surveyed in four districts (Chiro, Gemechis, Kuni and Tullo) of Western Hararghe Zone, eastern Ethiopia. All the fields surveyed were infected with the pathogen, indicating that the disease was widely distributed in the zone. The incidence of rust in the surveyed area ranged from 25 to 74% while severity ranged from 18 to 55%. The highest (74%) and the lowest (25%) disease incidence were recorded in Tullo and Chiro, respectively, while the highest (55%) and the lowest (18%) disease severities were encountered at Gemechis and Chiro, respectively. Altitude had significant effect on both disease parameters (p ≤ 0.05). The effect of this pathogen on morphological parameters of parthenium under field conditions was found to be significant (p ≤ 0.05) at all locations. The effect of the rust on parthenium dry matter and seed production was significant (p ≤ 0.05) at all locations. Also, the effect of the rust on morphological parameters of parthenium in the greenhouse was significant (p ≤ 0.05). In addition, there was significant variation in the number of rust pustules per leaf, leaf senescence, and number of leaves attacked per plant, disease incidence and severity both at 14 and 21 days after inoculation. In the greenhouse, comparison of isolates from Ambo, Kuni, and Tullo showed significant effect while isolates from Chiro and Gemechis performed poorly for all the studied morphological parameters of parthenium. This study indicated that P. abrupta var. partheniicola has the potential to reduce morphological parameters as well as dry matter and seed production capacity of parthenium weed. It also elucidated the presence of variation in aggressiveness of the isolates. However, more extensive studies need to be undertaken at molecular level to utilize this pathogen in combination with other host-specific insects and pathogens after importation and release, as a component of integrated parthenium weed management in Ethiopia.

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An experiment was conducted during the dry seasons in western Hararghe Zone, Eastern Ethiopia at the Haramaya University Chiro Campus to determine the effect of maize stover as soil mulch on yield of Arabica coffee. Five levels of maize stover as soil mulch at a rate of: 0t/ha, 2t/ha, 4t/ha, 6t/ha and 8t/ha were applied in randomized complete block design with four replications from 2008 to 2011. Yield data was recorded during specific phenological stage of the plant. Result from the analysis of variance from the application of maize stover as soil mulch over years showed the presence of significant difference among treatments on bean yield of Arabica coffee. The highest bean yield (1070 kg/ha) and the lowest bean yield (520 kg/ha) were noted at 8 tons/ha and 0 ton/ha, respectively. Similarly, the pooled analysis of variance over seasons corroborated that the effect of maize stover as a soil mulch at a rate of 6t/ha and 8t/ha showed the presence of no significant difference on bean yield of coffee (p<0.05). The result of the present study also elucidated that, the unmulched control plots had the lowest coffee bean yield. While application of 8 tons/ha of maize stover as a soil mulch significantly increased coffee yield both in 2010 and 2011 cropping seasons. Therefore, on the basis of these results, it can be concluded that applying maize stover as soil mulch during the dry seasons at west Hararghe can help to sustain Arabica coffee production. Thus, it is recommended that application of 8tons/ha maize stover as soil mulch can significantly increase the yield of Arabica coffee and sustains its productivity over years.

Maize (Zea mays L.) is an important food security crop in Ethiopia. However, low soil fertility and the use of haphazard nitrogen (N) fertilizer with little attention to the rate and timing of N application constrain productivity. Therefore, field experiments were conducted during the 2019 and 2020 cropping seasons to investigate the response of maize to different N application rates and timings. The treatments consisted of six N fertilizer rates (0, 23, 46, 69, 92, and 115 kg N ha −1 ) and four application timings (all at vegetative stages; one-half at sowing + one-half at vegetative stages; one-third at sowing + one-third at vegetative stages + one-third at tasseling; one-fourth at sowing + two-fourths at vegetative stages + one-fourth at tasseling). The experiments were a randomized block design in a factorial arrangement with three replications. The results of the study revealed that ears per plant, ear length, grains per row, grains per ear, stover, and grain yield were significantly (p ≤ .001) influenced by the interaction effects of N application rates and timings. The highest stover (9.99 t ha −1 ) and grain yield (9.41 t ha −1 ) were obtained from the application of 92 kg N ha −1 in three split applications of one-fourth at sowing, one-half at vegetative stages, and one-fourth at tasseling. Therefore, it is concluded that 92 kg N ha −1 in three split applications of one-fourth at sowing, two-fourths at vegetative stages, and one-fourth at tasseling was found to be the most economical in the study area.

Application of farmyard manure (FYM) alone or in combination with inorganic fertilizers helps in proper nutrition and maintenance of soil fertility in maize fields when applied at proper doses replenishing the most deficient macro and micro nutrients which in turn help in getting the highest grain yield and harvest index in hybrid maize varieties. The harvest index determines how many photosynthates are transformed into economic yield. It is the ratio of economic yields to biological yield. A study was conducted at the Haramaya University Chiro Campus to determine the effect of enriched FYM and inorganic fertilizers on grain yield of maize and harvest index. FYM was used either alone or in combination with inorganic fertilizers as follows: control (zero fertilizers and FYM), 10 tons/ha FYM, 8 tons/ha FYM and 25 kg/ha of (Nitrogen (N) + 20 kg/ha Potassium (P), 6 tons/ha FYM, 50 kg/ha N + 40 kg/ha P, 4 tons/ha FYM, 75 kg/ha N + 60 kg/ha P, 2t ons/ha FYM , 100 kg/ha N+80 kg/ha P 100 kg/ha N + 100 kg/ha P. The treatments were arranged in randomized complete block design with four replications from 2008 to 2010. Result from the combined analysis of variance on hybrid maize (BH-140) yield and harvest index over years showed the presence of no significant difference among treatments with 10 tons/ha FYM and 100 kg/ha N +100 kg P/ha (p < 0.05). The pooled analysis of variance over years also revealed the existence of no significant differences among Treatments 2, 6, and 7 viz (10 t/ha FYM + 0 N and P, 2 t/ha FYM and 100 kg/ha N + 80 kg/ha P and100 kg/ha N + 100 kg/ha P), respectively at (p < 0.05) on grain yield of hybrid maize (BH-140) and the harvest index. But 4 tons/ha FYM and 75 kg/ha N + 60kg/ha P increased maize yield from 5.1 tons/ha in 2009 to 8.15 tons/ha in 2010. Similarly, the harvest index has increased from 0.33 to 0.58 (33 to 58%) at this rate. From this finding it was noted that, enriching FYM with inorganic fertilizers can boost hybrid maize grain yield significantly through improving the physico-chemical properties of the soil and contribute to the highest value of harvest index. Therefore, on the basis of these results, it can be concluded that, enriched FYM could be used for hybrid maize production at western Hararghe in order to get maximum grain yield and the highest value of the harvest index. Thus, it is recommended that, application of 4 tons/ha FYM incorporated with 75 kg of N and 60 kg of P at Chiro can significantly increase hybrid maize (BH-140) yield and sustain its productivity over years. Besides, it also contributes in reducing the cost of inorganic fertilizers which has been a bottle neck to smallholder farmers of eastern Ethiopia. However, profitability of this technology needs to be tested at different locations and in different seasons.