Plant Pathology Commons^™

Anaerobic Soil Disinfestation As A Non-Chemical Management Option Against Fungi And Heterotrophic Bacteria In Organic Sweetpotato Production, Meredith Tucker

All Theses

North Carolina is the largest producer of sweetpotatoes in the United States, with South Carolina increasing farming acreage to 2,501 in 2022 compared to 1,300 in 2017. Growers producing conventional and organic sweetpotatoes are equally challenged with managing fungal pathogens due to fungicide resistance or fungicides being unavailable due to environmental regulations, leading many to shift to growing organic crops. Anaerobic soil disinfestation (ASD) is a non-chemical pre-plant management option that uses a carbon amendment, irrigation, and plasticulture to establish an anaerobic environment in soils, killing soil microbes. A greenhouse study was conducted to assess ASD on fungal pathogens and …

The Impacts Of Management Practices On Industrial Hemp Chemistry, Physiology, And Microbiome Ecology., Allison Marie Rietman

Electronic Theses and Dissertations

Agroecology incorporates ecology and agronomy to inform crop management. Industrial hemp (Cannabis sativa L.) is a prime system to investigate agroecological questions because it has only recently been authorized for commercial cultivation and its sensitivity to biotic and abiotic stressors is unresolved. Here, I investigate how some conventional management choices, including the application of fungicide, plastic mulch, and irrigation, impact the physiology, chemistry, and microbial ecology of industrial hemp. Overall, I found that industrial hemp can be both resilient and resistant to these stressors, an important development for the industry. In Chapter II, I tested the impacts of fungicide application …

Novel Chloroviruses With Unique Glycans On Their Major Capsid Proteins, Cayden J. Homolka

Honors Program: Senior Projects (Public)

Chloroviruses, of the family Phycodnaviridae, are large, dsDNA viruses with a genome of 290 to 410 kb. These virus genomes are so large that they are classified as “giant viruses”. Within this genome, up to 16 tRNAs and 330 to 450 proteins are encoded. Among the massive amounts of genes and proteins are unique carbohydrate synthesis/metabolism genes, which are responsible for the glycosylation of chloroviruses major capsid proteins. In most viruses, these proteins are glycosylated by the host enzymes located in the endoplasmic reticulum. Instead, Chloroviruses encode their own glycosylation machinery; essentially decorating themselves. Furthermore, these chlorovirus glycans are unlike …

Investigate The Use Of Nucleic Acids As Pesticides To Manage Major Pests And Pathogens Of Crops In South Carolina, Prasanna Valavanur Shekar

All Dissertations

The sugarcane aphid (SCA, Melanaphis sorghi), first discovered on grain sorghum in late 2013, has gradually become a major insect pest of sorghum. It inflicts significant damage to the crop year after year, causing millions of dollars in losses throughout the sorghum-producing regions of the United States. Similarly, Armillaria root rot—also referred to as oak root rot—is a major cause of decline in peach (Prunus persica) production in the southeastern United States. This disease is caused by Armillaria mellea and Armillaria tabescens. Current management practices for controlling M. sorghi include the use of synthetic pesticides, resistant varieties, and regular scouting. …

Functional And Comparative Genomics Of The C.Sojina- Soybean Interaction, Alejandra Maria Vargas Oyuela

LSU Master's Theses

Frogeye leaf spot (FLS), caused by Cercospora sojina, is a significant foliar disease of soybean (Glycine max) and is responsible for substantial yield losses worldwide. While management strategies rely on host resistance and fungicide applications, the emergence of new virulent races and fungicide-resistant isolates necessitates a deeper understanding of C. sojina host interactions and genomic variability. Here, we employed comparative and functional genomic approaches to decipher the molecular mechanisms underlying the C. sojina-soybean interaction. A dual RNA sequencing approach was used to identify transcriptomic changes in G. max cultivars Blackhawk (susceptible) and Davis (resistant) across multiple …

Grassland For Our World, F Riveros

IGC Proceedings (1977-2023)

The present-day role of grasslands and fodder is reviewed with respect agriculture, animal production and environmental concerns. The world 's grazing lands are a finite resource nnd, overall, are being badly mnnaEed; in most developing countries action is required now, before it is too lnte. They will continue to be a major source of animal feed for the foreseeable future; encroachment from cropping will con

Human Impact On Terrestrial Ecosytems- What We Know And What We Are Doing About It, H A. Mooney

IGC Proceedings (1977-2023)

At present the impact of humankind on the Barth System is substantial mul will become greater as we continue to add over 80 million people to the global population each year. Collectively the human species utilises over a third of the total fresh water that is available, as well as an equivalent amount of tho total terrestrial productivity. Possil energy is being consumed at a prodigious rnte and fuels, among other things, over a half a billion vehicles. To support the large human population the Earth has been greatly reconfigured with much of the land utilised for grazing and agriculture. …

Grasslands For Sustainable Ecosystems, Malcolm Hadley

IGC Proceedings (1977-2023)

Grasslnnds present many advantages for examining issues related to sustainability. Grasslands include planted pastures as well as a variety of natural rangelands in situations ranging from semi-arid to subhumid. Diversity is also reflected in the spectrum of grassland users and uses, for example, nomadic pastoralism, extensive ranches, intensive pastures, wildlife tourism, game hunting. And in terms of sustainability of resource management, grasslands encompass a wide range of contrasting situations and conflicts in resource use. Heavy grazing pressure associated with increasing human populations in certain tropical savannas, the implications of rural depopulation to traditional pasture management in alpine regions, and the …

Red Clover Hybrid Ryegrass Associations Results Obtained From 1984 To 1987 In Four French Regions, C Pfitzenmeyer, C Longueval

IGC Proceedings (1977-2023)

In France, red clover is often grown in association with a grass in order, if not to increase the yield of forage, at least to improve its quality by having a larger protein content in the harvested product. Among the grass species associated to red clover, Italian ryegrass, too aggressive a competitor, is replaced more and more by hybrid ryegrass. The aims of the present work were the following

1% to obtain quantitative references on the behaviour o[ hybrid ryegrass/red clover associations in four contrasting regions of France ;

2% to check that the presence of clover, through the transfer …

Potentials Of Summer Fodders Under Intensive Cropping System In India, M S. Tiwana, Thakur Singh

IGC Proceedings (1977-2023)

One of the reasons for low milk production in India is the non-availability of good quality fodders in sufficient quantity. Therefore, it is necessary to bridge the gap of this acute short­age of fodder for increasing the milk production. There seems to be no possibility of increasing area under fodders and the only alternative looks to be the ulilization of vacant land (70 days) after harvesting wheat and before the sowing of main summer season crops. However, the growing of these crops may have some effect on the yield of succeeding crops by depleting or replenishing the nutrient status of …

Competitive Effects On Production Of Lolium Perenne L. And Trifolium Alexandrinum L. In Mixture And Mono-Culture, M S. Tiwana, K P. Puri, I S. Thind

IGC Proceedings (1977-2023)

Berscem (Trifolium alexandrinum L.) is grown as a fodder crop by every farmer of north India. Though it is a very good multi-cul legume fodder, yet its dry matter percentage is low which indirectly affects the total dry matter production over a period of 6 to 7 months. Presently no suitable multicut grass for the same period is available which may be grown separately or in mixture with berseem to produce high dry matter yield. The first successful planting of ryegrass in research trials was made in 1976 (Tiwana and Puri, 1984) in India. After that, we became interested …

Herbage Yield Of Annual Ryegrass (Lolium Multiflorium Lam.) And Common Vetch (Vicia Sativa L.) At Different Seeding Rates, M A. Jimenez, O L. Gallegos, M.J L. Castrellon

IGC Proceedings (1977-2023)

Most of the dairy farms in the Central Valley of Mexico have alfalfa and corn silage as major forages. Winters are mild, how­ever, yield of alfalfa is reduced and no corn can be grown. For­age crops as oats, annual ryegrass and common vetch have been grown successfully to supply winter forage (Avendano, 1978; Victoria, 1981). Annual rycgrass generally outyields oats, but a high input of nitrogen is required by annual rye grass (Ciane, 1978). The high cost of N fertilizers prevents their use and cheaper N sources should be sought. Legumes as common vetch grown with annual ryegrass can be …

Performance Of White Clover Cultivars In Mixtures With Orchardgrass In Atlantic Canada, Joanna Fraser, H T. Kunelius

IGC Proceedings (1977-2023)

The climate in the Atlantic Provinces of Canada is ideally suited to pasture production, with up to seven months of grow­ing season in some areas. Moreover, many of the soils are too shallow to support deep-rooted and highly valued forages such as alfalfa (Medicago sativa L.) and corn (Zea mays L.). How­ever, the main limiting factor to pasture production occurs in spring where there are frequent freeze-thaw cycles, which reduce the dependability of snow cover for insulation, and this results in winter injury (Dzikowski et al., 1984). The interest in white clover (Trifolium repens L.) as a …

Comparison Of Ryegrass-White Clover And Competitive Interactions In New Zealand And Wales, W Harris, I Rhodes

IGC Proceedings (1977-2023)

New Zealand and Wales have temperate climates suitable for ryegrass (Lolium species) and white clover (Trifolium repens) pasture. However, pasture management in New Zealand and Wales in fundamentally different. New Zealand pastures are grazed all year, whereas in Wales pastures are mostly not grazed in winter. Moreover New Zealand pastures mostly rely on nitrogen fixed by legumes, whereas nitrogen fertiliser is com­monly applied to Welsh pastures. To consider the basis of differences of pasture management in New Zealand and Wales, data from field experiments at Aberystwyth, Wales (Lat. 52°25'N) and Palmerston North, New Zealand (Lat. 40°20'S) are …

Forage Contribution Of Overseeded Cool-Season Clovers, G D. Mooso

IGC Proceedings (1977-2023)

Warm-season perennial grasses are the foundation of pasture systems in the southeastern U.S. Though well adapted, these species require significant amounts of nitrogen (N) fertilizers to maintain forage production. Nitrogen fertilizers are widely used to improve the yield and quality of grass pastures because it was less expensive and easier to manage than grass-legume mixtures. Cool-season clovers overseeded into dormant peren­nial warm-season swards offer a practical method to extend the grazing season and improve forage quality while capitalizing on the ability of inoculated clovers to supply nitrogen to pro­duction systems thus decreasing production costs (Burton, 1976 ; Hoveland et al., …

Effect Of Irrigation On Vegetation Succession And Forage Regerneration, Fu Jing-Yan

IGC Proceedings (1977-2023)

No abstract provided.

Reponse Du Brome Cathartique A L’Irrigation Premiers Resultats, C Longueval

IGC Proceedings (1977-2023)

L'interet de J'irrigation des graminees prairiales est unc ques­tion souvent debattue dans le sud de la France ou la secheresse estivalc ct frequemment automnale limite considerablement la production de fourrage vert durant cette deuxiemc moitie de l'annee. Dans la region toulousaine, les travaux de l'INRA a Tou­louse (Marty et al., 1977) ct de la Compagnic d'Amenagemenl des Coteaux de Gascogne ont montre, pour la fetuque et le dac­tyle notamment, que si !'irrigation pcrrnet de doubler la pro­duction estivale et automnale. le niveau attcint sans restriction hydrique reste globalement rr{odcstc puisque inferieur a 5 t/ha M.S. a partir du debut de …

Drought Stress And Alfalfa Production In A Mediterranean Environment, T Kipnis, I Vaisman, I Granoth

IGC Proceedings (1977-2023)

Many experimental results have shown a close relationship between total dry matter (DM) yield of alfalfa and annual evapotranspiration (ET). However, this relationship may differ from harvest to harvest (Metochis and Orphanos, 1981), indicating that water use efficiency (WUE) may vary during the growing season, particulary as it is adversely affected by high temperature (Sammis, 1981). Water for irrigating alfalfa is often scarce during the dry Mediterranean summer in Israel. Under such conditions, water is withheld for approximately two months, at a relatively advanced stage of maturity, and the crop is allowed to go to seed, after which irrigation is …

On The Cultivation And Utilization Of Floret Silvergrass (Miscanthus Floridulus) In The Southern Area Of China, Zhu Bangchang

IGC Proceedings (1977-2023)

The plant genus Miscanthus (silvergrass) includes eight species and one variety in China. In the tropical and subtropi­cal area of south China, the silvergrass distributed widely includes the following seven species : Floret silvergrass ( Miscanthus floridulus), Chinese silvergrass ( M. sinensis), Sugary silvergrass ( M. sacchariflorus), Short-hair silvergrass ( M. brevipilus j, Eulalia silver grass ( M. eulalioides), Szechuan silvcrgrass ( M. szechuanensis), Nepal silvergrass ( M. nepalen�� sis). One of them, Floret silvergrass, is the widest in distri­bution and the highest in economical value, and plays a most important role in …

Continuous Machine Line For Grassland Management On Slopes In Czechoslovakia, L Gonda, S Likavsky

IGC Proceedings (1977-2023)

Permanent grass covers in Czechoslovakia are to a great extent spread in sloping and rolling countryside. From the total area presenting 1,672 thousand hectares, 240 thousand ha are stretched on slopes with a gradient of 16 to 22 degrees. Research has shown that from 35 to 48 per cent of these pieces of land arc of size less than 10 ha and there are 75 per cent of intensive pastures with size smaller than 6 ha in typical moun­tainous regions of Czechoslovakia. Mechanization of grass picking on slopes is effected by speci­fic features predetermined by geographical conditions and requirements of …

Studies On Irrigated Tropical Forage Legumes In Sudan, M.A M. Khair

IGC Proceedings (1977-2023)

The drought which had struck Sudan in the last few years had necessitated the introduction of the livestock within the farming systems of the irrigated schemes. This implies growing of enough forages in these irrigated schemes. Lablab, Lablab purpureus, clitoria, Clitoria ternatea and phi­lipesara, Phaseolus trilobus are the most commonly grown for­age legume in the Sudan. Information pertaining to the agronomy of these forages are limited in the Sudan. In this report, two ongoing experiments concerning the agronomy of these legumes are discussed. The main objective of exper­iment I was to study the interactive effects of seed rates and cutting …

Monitoring Annual Medicago Ley Pastures For Management Decisions, P G. Tow

IGC Proceedings (1977-2023)

The Ley Farming System of southern Australia uses a rotation of cereal and pasture comprising annual Medicago (medic) or Trifolium (clover) species. Pastures regenerate in autumn from the permeable fraclion of seed reserves. For M. truncatula cv. Jemalong barrel medic, this is about 10 % annu­ally (Crawford, 1970). In a survey of medic persistence in South Australia, Carter (1982) found that medic seed in the top 5 cm soil was highly correlated with plant density and production potential in the following year. Seed reserves associated with 400-500 plants/m2 were classed as 'good' in commercial practice, but such cases were uncommon, …

Factors Affecting The Productivity Of Elephant Grass, G.E D. Tiley

IGC Proceedings (1977-2023)

Elephant grass (Pennisetum purpureum Schumach) is a highly productive and palatable fodder which is widely grown in the tropics (Bogdan, 1977). Optimum utilisation of its production potential is, however, limited by management factors which are associated with plant form and growth habit (Horrell and Tiley, 1970). These factors were studied in a series of trials at Kawanda Research Station, Kampala, Uganda (0°27'N, 32°30'E). A summary of the princi­ pal results is given.

Effect Of Fall/Winter Harvest On Alfalfa (Medicago Sativa L.) Productivity And Persistence In A Mediterranean Climate, V L. Marble, C A. Schoner Jr, G Peterson

IGC Proceedings (1977-2023)

In California alfalfa fields are grazed or harvested one or more times after the last normal season harvest (LNSH). Schoner (1981) reported that one LNSH 30 days after the last (6th) harvest reduced yield for semidonnant (SD) WL 318 and very nondormant (VND) CUF 101 9 % over three years. With two harvests, losses were similar (12 % ) for WL 318, but doubled (27 %) for CUF 101. Worker and Marble (1987) found ( 10 annual harvests) no reduction in yield, vigor or stand with either one or two fall/winter (F /W) harvests if a 45 day rest was …

Time Effect Of Top-Dressing On Yield And Quality Of Pangola Grass At Different Growth Seasons In Taiwan, Yeong-Chyn Wang

IGC Proceedings (1977-2023)

Pangola grass (Digitaria decumbens) is one of two major for­age grasses in Taiwan. Usually, top-dressing of fertilizer after clipping will not be performed under no irrigation until rain comes. Thus, the dressing practice in the regeneration period is occasionally delayed several weeks just for waiting rainfall. Whether the delay of top-dressing will affect forage yield and quality of pangola grass becomes an interesting question. In order to understand the effects of time and amount of top­dressing on forage yield and quality of pangola grass, a 2-year field experiment was conducted.

Autumn Management Of Lucerne, S J. Herbert, M Dempsey, D Cooley, G V. Litchfield

IGC Proceedings (1977-2023)

Past recommendations for lucernc autumn cutting manage­ment in the Northern USA have suggested a 'critical period' of 4-6 weeks growth prior to the first killing frost as necessary for long-term lucerne survival. Research had indicated that this period of growth prior to frost enabled plants to build up carbohydrate reserves to carry them through winter and pro­vide energy for regrowth in spring (Smith, 1972). If an autumn cut was desired, it was recommended it should be taken after the killing frost so that stand vigor and longevity is maintained. Inappropriate management may reduce plant vigor, and increase susceptibility to Fusarium …

Increasing The White Clover Content In Pasture By Overseeding And Management, I Rais, J Kralovec, J Radej

IGC Proceedings (1977-2023)

The aim of our research was to increase the content of white clover in pasture sward by a direct drilling and by different management under two levels of nitrogen fertilization.

Effects Of Cutting Height On Forage Yield And Quality Of Napier Grasses, F H. Hsu, K Y. Hong, M C. Lee

IGC Proceedings (1977-2023)

Napier grass (Pennisetum purpureum) is a tall and C4 grass. 11 produces the highest dry matter yield among grasses. Tt is one of the two major species grown as forage crops in Taiwan. Sev­eral new lines of napier grasses have been selected to grow in Taiwan recently. In order to understand how to manage the new lines of napier grasses, we conducted a three-year exper­iment to determine effects of cutting height on forage quality and dry matter production of napier grasses.

Response To Cutting Frequency And Persistency Of Alfalfa Varieties Bred In Japan, F Fujimoto, K Yamashita, M Kanbe, S Inami

IGC Proceedings (1977-2023)

In wanner region of Japan, alfalfa growing is going to spread for the need of high quality forage. Suitable cutting frequency with an adapted variety is the important key to success of alfalfa growing in these districts. Breeding of alfalfa varieties adapted to warmer Japan started in 1964 and two varieties, Natsuwakaba and Tachiwakaba, were released from Aichi-ken Agricultural Research Center up to this time. Other promising strains are also on the breeding program. Response to cutting frequencies and persistency of these varieties were studied, and comparing with two American varieties, their adaptability to wanner region of Japan was clarified.

Response Of A Pennisteum Interspecific Hybrid And Local Cultivar Millo Blanco, Sorhum Biocolor L. Moench, To Cutting Intervals And Locations, A Sotomayor-Rios, S Torres-Cardona, W Hanna, A Quiles-Belen

IGC Proceedings (1977-2023)

Napiergrass, Pennisetum purpureum (2n = 28), a robust per­ennial tropical cullivar, has a potential dry matter yield (DMY) of over 35,000 kg ha·1 yr·1 under intensive cutting management. Its digestibility, however, is lower than other tropical species and does not breed true from seed. Despite these drawbacks, it is a useful male parent for the development of interspecific hyb­rids with Pearl Millet, Pennisetum glaucum (2n = 14). Cytoplasmic male-sterile lines of Pearl Millet, crossed with Napiergrass result in an excellent interspecific triploid hybrid (3x = 21) which is seed propagated (Hanna and Monson, 1980). These triploid interspecific hybrids arc highly …