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1.
Diversity, density and species composition of naturally regenerated woody plants under Eucalyptus grandis plantation and the adjacent natural forest were investigated and compared. Twenty plots, with an area of 20 m × 20 m for each, were established in both of E. grandis plantation and adjacent natural forest, independently. In each plot, species name, abundance, diameter and height were recorded. Numbers of seedling were collected in five sub-plots (4 m2) within each major plot. A total of 46 species in the plantation, and 52 species in the natural forest, which belongs to 36 families were recorded. The diversity of species (H′) is 2.19 in the plantation and 2.74 in the natural forest. The density of understory woody plant was 3842 stems/ha in the plantation and 4122 stems/ha in the natural forest. The densities of seedlings in the natural forest and the plantation were 8101 stems/ha and 4151 stems/ha, respectively. High similarity of woody species composition was found between the natural forest and the plantation. The E. grandis plantation was found favoring the regeneration and growth of Millitia ferruginia and Coffea arabica in a much better way than other underneath woody species.  相似文献   
2.
Journal of Crop Science and Biotechnology - Abiotic stress, especially drought and heat, affects cereal yields and wheat production worldwide, more particularly in West and South Asia, North...  相似文献   
3.
W. Tadesse    S. L. K. Hsam    F. J. Zeller 《Plant Breeding》2006,125(4):318-322
A total of 50 wheat (Triticum aestivum L.) cultivars were evaluated for resistance to tan spot, using Pyrenophora tritici‐repentis race 1 and race 5 isolates. The cultivars ‘Salamouni’, ‘Red Chief’, ‘Dashen’, ‘Empire’ and ‘Armada’ were resistant to isolate ASC1a (race 1), whereas 76% of the cultivars were susceptible. Chi‐squared analysis of the F2 segregation data of hybrids between 20 monosomic lines of the wheat cultivar ‘Chinese Spring’ and the resistant cultivar ‘Salamouni’ revealed that tan spot resistance in ‘Salamouni’ was controlled by a single recessive gene located on chromosome 3A. This gene is designated tsn4. The resistant cultivars identified in this study are recommended for use in breeding programmes to improve tan spot resistance in common wheat.  相似文献   
4.
Journal of Crop Science and Biotechnology - Fusarium head blight (FHB) is one of the destructive diseases in wheat-producing areas of the world. Field experiments were conducted during the 2019...  相似文献   
5.
The uniqueness of purslane (Portulaca spp.) asthe richest vegetable source of omega-3 (-3)fatty acids is well documented. However, purslane hasnot been domesticated or fully evaluated for itsnutritive value. The objective of this study was todetermine the influence of planting date on chemicalcomposition of purslane accessions. Eight accessionsfrom different geographical locations were planted 12days apart, and whole plants harvested at full bloom. Chemical analysis (DM basis) of leaves showedsignificant differences among varieties for all thecharacteristics measured. Accession by planting dateinteraction influenced (p < 0.05) levels of crudeprotein, total lipids, and carbohydrate contents. Wild Greek accession had the highest, while aBeltsville (Maryland) wild type had the lowest crudeprotein content (27.1 vs 20.5%) at the secondplanting date. Crude protein, lipid and ash levelswere most influenced (p < 0.05) by planting date. Total lipids varied from 4.0–5.8% and 3.7–5.1% forthe first and second planting dates, respectively. Selected fatty acid content indicated significantly(p < 0.05) higher levels of 18: 26, and18: 33 in the Dutch Garden accession comparedwith other varieties. The Egyptian wild accession hadthe lowest level of 18: 33. The ratio of 3 to 6 acids, which ranged from 5.5 to22.3 indicated a highnutritive value of purslane compared to other oilcrops such as soybeans and perrilla. The high levelsof protein in purslane compete with those of othercommercially important vegetable crops. The studyshows that, in spite of its genetic diversity, purslaneremains one of the most abundant terrestrial vegetablesources of Omega-3 fatty acids and other essentialnutrients potentially beneficial for humans as well asanimals.  相似文献   
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7.
This study was carried out to better understand non-adoption of improved varieties of potato (Solanum tuberosum) and associated technologies by smallholder farmers in Chencha, Ethiopia. Data were collected through a survey (n = 47) and in-depth interviews (n = 20). It shows how wealth status was a factor of major importance. Most wealthy and some medium-wealthy farmers adopted improved potato varieties and many of the improved production practices; they had access to seed, associated knowledge and support, and sufficient resources that were necessary to apply the improved practices. Non-adoption was common among many medium-wealthy and most poor farmers: they lacked—next to access to the technologies and knowledge—cash, land, and labor. Results indicated the need to rethink research and intervention efforts. Next to paying attention to differences in the access to technology and the related knowledge, there is a need to consider the variation in technology needs, supporting microcredit services, and room to experiment. As a result, different combinations of improved production practices may be adopted.  相似文献   
8.
Abstract

Two sets of field experiments under seedling transplanting and drill row seed planting methods were conducted side by side for two years during the main cropping seasons of 2017 and 2018 in Fogera Plain of northwest Ethiopia to study the effect of different sources, application methods and time of nitrogen fertilizer on growth and yield of rain-fed lowland rice. Three N sources of fertilizers (conventional Urea, Urea super-granule, and slow-release Urea) with six, one, and three application methods and times, respectively were laid out in a randomized complete block design (RCBD) in three replicates. These treatments and design were equally applied for two sets of experiments under both planting methods. Results revealed that soil-plant analysis development (SPAD) value, LAI, and biomass and grain yields of rain-fed lowland rice were highest with Urea supergranule N fertilizer sources followed by slow-release Urea and conventional Urea applications in both planting methods. Average grain yields of 3.7 and 3.8 tons ha?1 of rain-fed lowland rice were recorded with the application of Urea supergranule N source fertilizer under seedling transplanting and drill row seed planting methods, respectively. Hence, using Urea supergranule tablet is recommendable for getting better grain yield of rain-fed lowland rice without yield penalty in both planting methods.  相似文献   
9.
Cotton crop Ethiopia is a high-value crop and the strategy for pest control is insecticide-dependent with no consideration of beneficial insects. We carried out a study in 2013 and 2014 to determine the effectiveness of a food spray product developed with local ingredients from Benin (BFP), a food spray product developed from Ethiopian ingredients (EFP), and mixtures of the individual food spray products with and without neem extracts. Applications of BFP and of EFP alone attracted and retained beneficial insects and significantly reduced the number of pests, and increased cotton yields and profitability. The net margins of 18,418 and 18,642 Ethiopian birr (ETB)/ha were achieved from the plots treated with BFP and EFP, respectively, and 13,000 ETB (US$1 = 19 ETB) was achieved from the unsprayed plots. Addition of neem extract to the food spray products decreased the number of beneficial insects attracted to the food spray plots. In conclusion, food sprays can be used as part of integrated pest management (IPM) for managing cotton pests and can result in significant increases in crop yields and profitability.  相似文献   
10.
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