Wheat blast caused by the Triticum pathotype of Pyricularia oryzae was first reported in 1985 in Brazil and recently spread to Bangladesh. We tested whether Rmg8 and RmgGR119, recently identified resistance genes, were effective against Bangladeshi isolates of the pathogen. Common wheat accessions carrying Rmg8 alone (IL191) or both Rmg8 and RmgGR119 (GR119) were inoculated with Brazilian isolates (Br48, Br5, and Br116.5) and Bangladeshi isolates (T-108 and T-109). Br48, T-108, and T-109 carried the eI type of AVR-Rmg8 (the avirulence gene corresponding to Rmg8) while Br5 and Br116.5 carried its variants, eII and eII’ types, respectively. Detached primary leaves of IL191 and GR119 were resistant to all isolates at 25°C. At a higher temperature (28°C), their resistance was still effective against the eI carriers but was reduced to a low level against the eII/eII’ carriers. A survey of databases and sequence analyses revealed that all Bangladeshi isolates carried the eI type which induced a higher level of resistance than the eII/eII’ types. The resistance of IL191 (Rmg8/−) to the eI carriers was maintained even at the heading stage and at the higher temperature. In addition, GR119 (Rmg8/RmgGR119) displayed higher levels of resistance than IL191 at this stage. These results suggest that Rmg8 combined with RmgGR119 will be useful in breeding for resistance against wheat blast in Bangladesh.

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Parthenium hysterophorus L. is a harmful invasive weed to plant biodiversity and human health. It is native to American tropics and first introduced to Ethiopia in the 1970s. Today, it is widely distributed across the country and severely affecting the biodiversity, crop, and animal production in the country. In the Metekel Zone, there was no report on its distribution and impacts so far. Therefore, this study was aimed to assess the distribution and abundance of the plant in the zone. The distribution and abundance data of the weed were recorded at five km intervals following all accessible roads of the zone. The result reveals that P. hysterophorus L. was less distributed in the area with a 4.95% frequency. However, it was found abundantly growing at roadsides, wastelands, around habitation, market place, and around Zeghibridge where it can rapidly spread to most economical lands like the arable and grazing lands. Moreover, it has aggressively invaded a nursery site, which enables the weed to enter agricultural fields directly. This suggests that the weed is on a fast move to agricultural lands in the zone. The regular active development activities such as agricultural investment, construction of roads, and factories are presumed to promote its spread. Therefore, a decisive and timely decision is needed to mitigate the weed when it is still sparse and small.

Rice blast disease caused by Pyricularia oryzae Cavara is the most destructive rice disease worldwide. Among the disease management options, the use of a fungicide is suitable for immediate action and remained an exclusive management method in the continents like Africa where agricultural technologies are not well advanced. The present study aimed to evaluate the effectiveness of seven chemical fungicides viz., Amistar Xtra 280 SC, Artea 330 EC, Contaf Max 350 SC, Fungozeb 80 WP, Matco, Rex® Deo and Tilt 250 EC for the control of rice blast disease under field condition at Pawe, northwest Ethiopia. The result revealed that all the test fungicides have significantly suppressed the disease development with 11.1 – 51.5% suppression of panicle blast severity and 18.9 – 67% suppression of neck blast severity compared to the control (Untreated plot). However, Contaf Max 350 SC had superior disease reduction by more than 60% and gave the maximum grain yield (5617.06 kg ha-1) among the fungicides while the lowest yield was obtained from the control (4324.73 kg ha-1) followed by Artea 330 EC (4639.35 kg ha-1). Therefore, the present results suggest that twice application of Contaf Max 350 SC fungicide at 1 Lha-1 is effective for managing rice blast disease in Pawe and other places with a similar condition.

The rice blast control efficacy of three genes-complete resistance gene Pib in isogenic line 'Koshihikari Toyama BL 3' and partial resistance genes Pb1 in near-isogenic line 'Koshihikari Aichi SBL' and pi21 in a variety 'Tomohonami'-was evaluated in pot and upland trials with spray inoculation of the blast isolate Ina 86-137 (Japanese race 007.0) or Ao 92-06-2 (Japanese race 337.1). The evaluation was conducted by assessing their leaf and panicle blast severity, and then comparing their severity with that of blasticide (probenazole or tricyclazole) applied 'Koshihikari' and three control varieties with different levels of partial resistance to blast, including 'Koshihikari'. 'Koshihikari Toyama BL3' harboring Pib showed very high levels of efficacy with few leaf and panicle blast lesions in both trials. The efficacy of 'Tomohonami' having pi21 to leaf blast was also high and equal to or higher than that of the blasticide-applied 'Koshihikari' in both trials. However, 'Tomohonami' had no panicle blast control efficacy in the pot trial, although it showed high panicle blast reduction in the upland trial. The panicle blast control efficacy of 'Koshihikari Aichi SBL' with Pb1 was moderate, while its leaf blast reduction was low to moderate in both trials. For expansion of the leaf blast lesions with punch inoculation on the uppermost leaves of rice plants in the booting stage of the pot trial, the areas (length x width) of the lesions on 'Koshihikari Toyama BL 3' with Pib were the smallest and significantly different from those of all oth er lines and varieties, including probenazole-applied 'Koshihikari'. The results showed the blast control efficacy of the three resistance genes Pib, Pb1, and pi21, and confirmed a quantitative reduction of blast severity with partial resistance genes Pb1 and pi21.