Digital Commons Network^™

Adoption Of Brachiaria Grasses In Mexico And Central America: A Successful Story, F. Holmann, Pedro Argel, C. E. Lascano

IGC Proceedings (1977-2023)

In Latin America and the Caribbean (LAC) there has been a major effort to develop new pastures technologies, to increase livestock productivity for the extensive systems prevailing in the tropical lowlands. This multi-national and inter-institutional effort was initiated through the International Network for the Evaluation of Tropical Pastures (RIEPT, by its name in Spanish), which operated from 1976 to 1996 under CIAT leadership. This network became a platform for institutions to train technicians, share forage material from existing gene banks, study the behaviour of new germplasm under different environments, and established the exchange of scientific information to extrapolate research results …

Improved Livelihoods From Grasslands; The Case Of Napier Grass In Smallholder Dairy Farms In Kenya, David Miano Mwangi, D. Romney, S. Staal, I. Baltenweck, S. Mwendia

IGC Proceedings (1977-2023)

In Kenya, smallholder farmers produce about 80% of the marketed milk. The farming systems vary from mixed farms with up to 10 ha of land and < 10 dairy cows (Gitau et al., 1994; Anon., 1985), to intensive smallholder dairy producers in the high human population central Kenya region with 0.9 to 2 ha of land and 3-4 dairy cows (Staal et al., 2001a). Milk production depends heavily on the cultivation of forages, with Pennisetum purpureum (Napier grass) by far the most important. An estimated 350,000 of the 600,000 smallholder farms in Kenya grow and utilize P. purpureum on their farms.

There are …

Role Of Information And Information Providers In Technology Transfer, D. Undersander

IGC Proceedings (1977-2023)

Technology transfer is an essential component of economic change in society. Developers of new technology often fail to realize that there is a science to technology transfer. This lack of appreciation for the skills involved in information dissemination and in activities necessary to affect a change of action in an audience often severely limits the rate and amount of technology transfer that occurs. Significant differences exist between doing a news release or writing a publication and causing audience acceptance of a new technology. The old standards of expecting adoption of a new technology simply because it “will profit farmers” or …

The Contribution Of Participatory Research: On-Farm Research, P. F. Fennessy, N. J. Daniels, S. A. Chadwick, P. A. Speck

IGC Proceedings (1977-2023)

Participatory research in agriculture may range from research and technology development (R&D), carried out on a research station with some involvement of farmers, through to genuine participatory research involving researchers and farmers working together. The latter involves the end-user in actually carrying out aspects of the research and/or in the development and evaluation of technology that is appropriate to commercial enterprises. Researchers often question the validity of the ‘findings of on-farm participatory research’ as they are more comfortable with the ‘controlled’ environment of the research station. However if research is to be applied appropriately on farms, it must go through …

Participatory Research For Smallholder Livestock Systems: Applying Common Sense To Complex Problems, P. M. Horne, Werner Stür

IGC Proceedings (1977-2023)

Key Points:

1. Participatory approaches to research (PAR) bring researchers closer to farmers, the intended users of research outputs.

2. Active, functional participation of farmers in the evaluation and development of new technologies requires researchers to make an important commitment: respecting the knowledge, skills and opinions of farmers while maintaining confidence in their own scientific knowledge.

3. Farmer experimentation is not usually suitable to provide quantitative biophysical data (this can be achieved more effectively in researcher controlled experiments), but to provide qualitative information and improve understanding. This type of information can be collected systematically to enable rigorous analysis.

4. While …

Soil Biology And The Emergence Of Adventive Grassland Ecosystems, T. R. Seastedt

IGC Proceedings (1977-2023)

The last few years have seen an explosion of information on the responses and feedbacks of soil biota to species and environmental changes. Soil biologists, plant ecologists, and biogeochemists have been searching for patterns, generality and predictability in these relationships. A few brave souls have had the courage to assemble comprehensive assessments of soil biology in our rapidly changing world. Several years ago, I reviewed Wardle’s (2002) book emphasising the links between above- and belowground components of ecosystems. That activity – as well as the present one – provided me with the opportunity to survey recent findings in soil biology. …

Computer-Based Forage Management Tools: Historical, Current, And Future Applications, David B. Hannaway, C. Daly, D. F. Chapman, B. B. Baker, A. S. Cooper

IGC Proceedings (1977-2023)

Forage management has been an important human activity since the beginning of civilization. By comparison, the personal computer has been available only in the immediate past. The software developed to deal with the complexity of climate, soil, plant, animal, and socioeconomic factors has seen huge changes in a few decades. Mainframe computers facilitated numerical calculations for exploring relationships among dozens of variables. Personal computers opened the door for more individual scientist creativity and routine communication. Web-based communication globalised the option for multidisciplinary teams to tackle problems. Forage-related computer applications abound, allowing farmers, ranchers, and others to more effectively manage the …

Paying For Our Keep: Grasslands Decision Support In More-Developed Countries, Andrew D. Moore

IGC Proceedings (1977-2023)

“Models in grassland science have come to stay, and so they must be made to pay for their keep. To do that, it will be necessary to improve their scientific sophistication and their management relevance...” (Seligman, 1993).

Decision support (DS) tools in grassland agriculture have also come to stay. This review will examine the ways and means by which DS tools are being made to pay for their keep, with a focus upon DS efforts from the last decade and on the lessons that arise for those who develop DS tools for grasslands. A survey of the present state of …

Decision Support For Grassland Systems In Developing Countries, P. K. Thornton

IGC Proceedings (1977-2023)

Key points

1. Information flows in complex systems are often themselves highly complex, and decision support approaches based on linear input-output processes may have only limited impact.

2. How decisions are made, and how they can be appropriately supported, is often incompletely understood, in part because of inadequate understanding of the objectives and attitudes of all the decision makers involved.

3. Much of the developing world faces daunting problems in the coming 30 years, and appropriate information could play a critical role in dealing with these.

4. System complexity, household variability, and institutional intricacies have to be embraced rather than …

Near-Atomic, Non-Icosahedrally Averaged Structure Of Giant Virus Paramecium Bursaria Chlorella Virus 1, Qianqian Shao, Irina V. Agarkova, Eric A. Noel, David D. Dunigan, Yunshu Liu, Aohan Wang, Mingcheng Guo, Linlin Xie, Xinyue Zhao, Michael G. Rossmann, James L. Van Etten, Thomas Klose, Qianglin Fang

Department of Plant Pathology: Faculty Publications

Giant viruses are a large group of viruses that infect many eukaryotes. Although components that do not obey the overall icosahedral symmetry of their capsids have been observed and found to play critical roles in the viral life cycles, identities and high-resolution structures of these components remain unknown. Here, by determining a near-atomic-resolution, five-fold averaged structure of Parameciumbursaria chlorella virus 1, we unexpectedly found the viral capsid possesses up to five major capsid protein variants and a penton protein variant. These variants create varied capsidmicroenvironments for the associations of fibers, a vesicle, and previously unresolved minor capsid proteins. Our structure …

Genomics And Transcriptomics To Protect Rice (Oryza Sativa L.) From Abiotic Stressors: -Pathways To Achieving Zero Hunger, Mushtaq Ahmad

Center for Plant Science Innovation: Faculty Publications

More over half of the world’s population depends on rice as a major food crop. Rice (Oryza sativa L.) is vulnerable to abiotic challenges including drought, cold, and salinity since it grown in semi-aquatic, tropical, or subtropical settings. Abiotic stress resistance has bred into rice plants since the earliest rice cultivation techniques. Prior to the discovery of the genome, abiotic stressrelated genes were identified using forward genetic methods, and abiotic stress-tolerant lines have developed using traditional breeding methods. Dynamic transcriptome expression represents the degree of gene expression in a specific cell, tissue, or organ of an individual organism at …

Key Issues Generated From The Xi International Rangeland Congress 2021: Summary And Way Forward, D. L. Coppock, A. J. Ash, B. Irving

IGC Proceedings (1977-2023)

The important issues, knowledge gaps, and evolving research approaches for the global rangelands are summarised in this review of submissions to the Joint XXIV International Grasslands and XI International Rangelands Congress (IGC/IRC). In the big picture, it is concluded that stand-alone studies of livestock production are becoming rare compared to that of the past International Rangelands Congresses (IRC). Rather, added effort is now being directed at understanding the fuller context of social-ecological systems (SESs) on rangelands in a quest to improve the prospects for sustainable resource management as well as the enhancement of human welfare. Although climate change is upon …

Joint International Grassland And International Rangeland Congress Kenya 2021: Grasslands Summary, James L. Klotz, J. H. Bouton

IGC Proceedings (1977-2023)

This summary used as its main sources the plenary and keynote papers and talks in Sub-theme 2: Forage Production and Utilization and Sub-theme 3: Livestock Production Systems as well as a sampling of oral talks presented at the XXIV International Grassland Congress (IGC). This IGC was held virtually and jointly with the International Rangeland Congress and hosted in Nairobi, Kenya during 23-29 October 2021. The XXIV IGC was also the first to be held on the African continent in Congress' 94-year history. The summary is further focused on that information presented under the concept "cultivated grasslands" (e.g., a small number …

Variation In Morpho‑Physiological And Metabolic Responses To Low Nitrogen Stress Across The Sorghum Association Panel, Marcin Grzybowski, Mackenzie Zwiener, Mackenzie Zwiener, Hongyu Jin, Nuwan K. Wijewardane, Abbas Atefi, Michael J. Naldrett, Sophie Alvarez, Yufeng Ge, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

Background: Access to biologically available nitrogen is a key constraint on plant growth in both natural and agricultural settings. Variation in tolerance to nitrogen deficit stress and productivity in nitrogen limited conditions exists both within and between plant species. However, our understanding of changes in different phenotypes under long term low nitrogen stress and their impact on important agronomic traits, such as yield, is still limited.

Results: Here we quantified variation in the metabolic, physiological, and morphological responses of a sorghum association panel assembled to represent global genetic diversity to long term, nitrogen deficit stress and the relationship …

Determination Of Fungicide Resistance In Botrytis Cinerea On Wine Grapes In California's Central Coast Region, Evelyn Alvarez-Mendoza

Master's Theses

Botrytis bunch rot, caused by Botrytis cinerea, is a fungal disease that primarily affects the fruit of wine grapes. Infection of fruit consequently results in reduced yields and wine quality. These factors lead to significant economic losses for growers which prompts the implementation of management practices to control the disease. One objective of this study was to evaluate the level of resistance that populations of B. cinerea in the Central Coast region showed to various chemicals. A fungicide assay was conducted to determine resistant phenotypes to six fungicide active ingredients (pyrimethanil, iprodione, fenhexamid, fludioxonil, trifloxystrobin, boscalid). Thirty-five (2020) and …

Clavibacter Nebraskensis Causing Goss's Wilt Of Maize: Five Decades Of Detaining The Enemy In The New World, Ebrahim Osdaghi, Alison E. Robertson, Tamra Jackson-Ziems, Hamid Abachi, Xiang Li, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

Goss's bacterial wilt and leaf blight of maize (Zea mays) caused by the gram-positive coryneform bacterium Clavibacter nebraskensis is an economically important disease in North America. C. nebraskensis is included within the high-risk list of quarantine pathogens by several plant protection organizations (EPPO code: CORBMI), hence it is under strict quarantine control around the world. The causal agent was reported for the first time on maize in Nebraska (USA) in 1969. After an outbreak during the 1970s, prevalence of the disease decreased in the 1980s to the early 2000s, before the disease resurged causing a serious threat to …

Clavibacter Nebraskensis Causing Goss's Wilt Of Maize: Five Decades Of Detaining The Enemy In The New World, Ebrahim Osdaghi, Alison E. Robertson, Tamra Jackson-Ziems, Hamid Abachi, Xiang Li, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

Goss's bacterial wilt and leaf blight of maize (Zea mays) caused by the gram-positive coryneform bacterium Clavibacter nebraskensis is an economically important disease in North America. C. nebraskensis is included within the high-risk list of quarantine pathogens by several plant protection organizations (EPPO code: CORBMI), hence it is under strict quarantine control around the world. The causal agent was reported for the first time on maize in Nebraska (USA) in 1969. After an outbreak during the 1970s, prevalence of the disease decreased in the 1980s to the early 2000s, before the disease resurged causing a serious threat to …

Clavibacter Nebraskensis Causing Goss's Wilt Of Maize: Five Decades Of Detaining The Enemy In The New World, Ebrahim Osdaghi, Alison E. Robertson, Tamra A. Jackson-Ziems, Hamid Abachi, Xiang Li, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

Goss's bacterial wilt and leaf blight of maize (Zea mays) caused by the gram-positive coryneform bacterium Clavibacter nebraskensis is an economically important disease in North America. C. nebraskensis is included within the high-risk list of quarantine pathogens by several plant protection organizations (EPPO code: CORBMI), hence it is under strict quarantine control around the world. The causal agent was reported for the first time on maize in Nebraska (USA) in 1969. After an outbreak during the 1970s, prevalence of the disease decreased in the 1980s to the early 2000s, before the disease resurged causing a serious threat to maize production …

Effects Of Pesticides On Red Rot Of Sugarcane, Kezia Cristina Da Silva Reis

LSU Master's Theses

Red rot disease of sugarcane, caused by Colletotrichum falcatum, can be an important constraint to crop production. In Louisiana, red rot primarily affects seed-cane and is more severe when billets (stalk sections) are planted rather than whole-stalks. At planting application of seed-treatment chemicals, particularly a combination of fungicide and thiamethoxam insecticide, has improved stand establishment and increased yields in billet plantings in Louisiana. However, information has been lacking on the effect of the treatments on disease development. Greenhouse experiments were conducted in 2020 and 2021 to evaluate stalk rot symptom severity and initial plant growth for billets dip-treated with …

Comparative Genomics And Virulence Studies Of Streptomyces Soil Rot And Scab Pathogen Species, Natasha Soares

LSU Doctoral Dissertations

Comparative genomic analyses were performed to gain insights into the organization and content of the genome of Streptomyces ipomoeae, the soil rot pathogen that infects sweetpotatoes. Unlike Streptomyces scab pathogens, the thaxtomin phytotoxin gene cluster (txt) in S. ipomoeae does not appear to reside within a genomic island and has diverged from its scab pathogen counterparts. Increased usage of the rare TTA codon, particularly for the txt cluster, suggests greater translational control by the bldA tRNA in S. ipomoeae. Orthologous gene searches and secondary metabolite profiling yielded ortholog groups and metabolite gene clusters that were exclusive …

Pengendalian Penyakit Busuk Buah Kakao Menggunakan Trichoderma Dan Pupuk Kalium, Sunjaya Putra, Yulius Ferry, Rita Harni

Jurnal Kultivasi

Kerugian akibat serangan penyakit busuk buah kakao (BBK) mencapai 40-100%, produktivitas hanya 669,9 kg/ha/tahun. Upaya pengendalian dapat dilakukan melalui penggunaan cendawan antagonis Trichoderma dan peningkatan dosis pupuk Kalium. Penelitian bertujuan menguji efektivitas Trichoderma viride dan pupuk K dalam mengendalikan penyakit BBK. Penelitian dilakukan pada Januari sampai Desember 2019 di kebun kakao rakyat (Klon CSA 6) berumur 10 tahun dengan tanaman pelindung Gliricidia sp. Desa Suka Bandung, Kecamatan Natar, Kabupaten Lampung Selatan. Penelitian menggunakan rancangan acak kelompok dengan 12 perlakuan dan 3 ulangan. Macam perlakuan yaitu fungisida Trichoderma viride, fungisida kimia (mancozeb), pupuk KCl 100 g/phn, dosis KCl 110 g/phn, dosis …

18s-Nemabase: Curated 18s Rrna Database Of Nematode Sequences, Kaitlin Gattoni, Eli M. S. Gendron, Rebeca Sandoval- Ruiz, Abigail Borgemeier, J. Parr Mcqueen, Rachel M. Shepherd, Dieter Slos, Tom Powers, Dorota L. Porazinska

Department of Plant Pathology: Faculty Publications

Nematodes are the most abundant and diverse animals on the planet but lack representation in biodiversity research. This presents a problem for studying nematode diversity, particularly when molecular tools (i.e., barcoding and metabarcoding) rely on well-populated and curated reference databases, which are absent for nematodes. To improve molecular identification and the assessment of nematode diversity, we created and curated an 18S rRNA database specific to nematodes (18S-NemaBase) using sequences sourced from the most recent publicly available 18S rRNA SILVA v138 database. As part of the curation process, taxonomic strings were standardized to contain a fixed number of taxonomic ranks relevant …

Distribution And Management Of Phytophthora Species On Lavender In The United States, Daniel Dlugos

All Dissertations

Phytophthora root and crown rot (PRCR) is currently the most important disease on lavender (Lavandula spp.) in the United States. The disease was first described on English lavender (L. angustifolia) in a Maryland nursery in 1991, with Phytophthora nicotianae as the causal agent. Since that time, the disease has been reported on multiple continents and as caused by several species of Phytophthora. This study examined the distribution and pathogenicity of Phytophthora species on lavender in the United States, requested lavender grower feedback regarding their production and concerns, and examined efficacy of selected management options. Lavender …

Using Condensed Tannin To Mitigate Tall Fescue Toxicosis, Ally Jo Grote

Graduate Theses and Dissertations

Endophyte-infected (Neotyphodium coenophialum) tall fescue, [Schedonorus arundinaceus (Shreb.)] produces ergot alkaloids. Condensed tannins could bind to ergot alkaloids and render them ineffective. The first objective was to improve the health of sheep offered endophyte-infected tall fescue by binding toxins in the rumen with condensed tannins. Non-toxic novel-endophyte infected tall fescue (NE) or toxic endophyte-infected tall fescue forage was harvested, baled at targeted moisture of 55%, wrapped within 8 hours of baling with 2 layers of net wrap and 20 layers of plastic, and ensiled for at least 60 days. Prior to feeding, forages were chopped and packed into plastic trash …

18s-Nemabase: Curated 18s Rrna Database Of Nematode Sequences, Kaitlin Gattoni, Eli M. S. Gendron, Rebeca Sandoval- Ruiz, Abigail Borgemeier, J. Parr Mcqueen, Rachel M. Shepherd, Dieter Slos, Tom Powers, Dorota L. Porazinska

Department of Plant Pathology: Faculty Publications

Nematodes are the most abundant and diverse animals on the planet but lack representation in biodiversity research. This presents a problem for studying nematode diversity, particularly when molecular tools (i.e., barcoding and metabarcoding) rely on well-populated and curated reference databases, which are absent for nematodes. To improve molecular identification and the assessment of nematode diversity, we created and curated an 18S rRNA database specific to nematodes (18S-NemaBase) using sequences sourced from the most recent publicly available 18S rRNA SILVA v138 database. As part of the curation process, taxonomic strings were standardized to contain a fixed number of taxonomic ranks relevant …

Evaluation Of Factors That Contribute To Injury To Quizalofop-Resistant Rice From Quizalofop Applied Postemergence, Navdeep Godara

Graduate Theses and Dissertations

Quizalofop-resistant rice technology allows for over-the-top applications of quizalofop, an acetyl-coenzyme A carboxylase-inhibiting herbicide. However, quizalofop caused significant injury to quizalofop-resistant rice in some Arkansas fields during the first year of commercialization. Experiments evaluated the effect of early-season soil moisture and nitrogen availability; pre-exposure to low rates of glyphosate and imazethapyr; planting date; and environmental conditions including, soil moisture content, air temperature, and light intensity on quizalofop-resistant rice tolerance to quizalofop applications. All experiments assessed sequential quizalofop applications made to 2-leaf followed by 5-leaf stage of rice. Sequential quizalofop applications alone and with surface irrigation or nitrogen application at the …

B.R. Wells Arkansas Rice Research Studies 2021, J. Hardke, X. Sha, N. Bateman

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading rice producer in the United States. The state represents 47.5% of total U.S. rice production and 47.8% of the total acres planted to rice in 2021. Rice cultural practices vary across the state and across the U.S. However, these practices are also dynamic and continue to evolve in response to changing political, environmental, and economic times. This survey was initiated in 2002 to monitor and record changes in the way Arkansas rice producers approach their livelihood. The survey was conducted by polling county extension agents in each of the counties in Arkansas that produce rice. Questions …

Screening Soybean Cultivars For Resistance To Aerial Blight Caused By Rhizoctonia Solani Ag1-Ia, Kensy D. Rodriguez-Herrera

LSU Master's Theses

Aerial blight, caused by the fungus Rhizoctonia solani AG1-IA, is an economically important soybean disease in the mid-South. The same pathogen also infects other crops commonly rotated with soybeans like rice, corn, and grain sorghum. Rhizoctonia solani AG1-IA is difficult to manage because of its soilborne nature and the production of long-term survival structures, sclerotia. Management has relied on fungicide applications during the season. Still, there is an increasing prevalence of resistance to commonly used strobilurin fungicides and an urgent need to identify soybean cultivars resistant to aerial blight. Since the patchy distribution of the pathogen complicates field cultivar screening, …

Genetic And Biochemical Investigation Of Seed Fatty Acid Accumulation In Arabidopsis, Chinedu Charles Nwafor, Delin Li, Ping Qin, Long Li, Wei Zhang, Yuanwei Zhou, Jingjing Xu, Yongtai Yin, Jianbo Cao, Limin He, Fu Xiang, Chao Liu, Liang Guo, Yongming Zhou, Edgar B. Cahoon, Chunyu Zhang

Center for Plant Science Innovation: Faculty Publications

As a vegetable oil, consisting principally of triacylglycerols, is the major storage form of photosynthetically-fixed carbon in oilseeds which are of significant agricultural and industrial value. Photosynthesis in chlorophyll-containing green seeds, along with photosynthesis in leaves and other green organs, generates ATP and reductant (NADPH and NADH) needed for seed fatty acid production. However, contribution of seed photosynthesis to fatty acid accumulation in seeds have not been well-defined. Here, we report the contribution of seed-photosynthesis to fatty acid production by probing segregating green (photosynthetically-competent) and non-green or yellow (photosynthetically-non-competent) seeds in siliques of an Arabidopsis chlorophyll synthase mutant. Using this …

Insect Pest Management With Sex Pheromone Precursors From Engineered Oilseed Plants, Hong-Lei Wang, Bao-Jian Ding, Jian-Qing Dai, Tara J. Nazarenus, Rafael Borges, Agenor Mafra-Neto, Edgar B. Cahoon, Per Hofvander, Sten Stymne, Christer Löfstedt

Center for Plant Science Innovation: Faculty Publications

Pheromones have become an environmentally friendly alternative to conventional insecticides for pest control. Most current pheromone-based pest control products target lepidopteran pests of high-value crops, as today’s manufacturing processes cannot yet produce pheromones at low enough costs to enable their use for lower-value crops, especially commodity crops. Camelina sativa seeds genetically modified to express (Z)-11-hexadecenoic acid, a sex pheromone precursor of several moth species, provided the oil from which the precursor was isolated, purified and transformed into the final pheromone. Trap lures containing this pheromone were then assessed for their capacity to manage moth pests in the field. Plant-derived pheromone …