Plant Pathology Commons^™

Evaluating Fungicide Programs For Grapevine Disease Management And Fungicide Sensitivity Monitoring, Abraham Ahumada

Master's Theses

Grapevine diseases, such as powdery mildew and Botrytis bunch rot, require repeated fungicide applications to maintain fruit quality and reduce yield losses. However, fungicide performance can vary among products, application programs, disease pressure, and pathogen sensitivity. This thesis evaluated fungicide programs for control of powdery mildew in ‘Chardonnay’ grapes and assessed fungicide sensitivity of Botrytis cinerea isolates collected from California vineyards.

Powdery mildew, caused by the fungal pathogen Erysiphe necator, is a major threat to the production of Vitis vinifera grapes worldwide. Because powdery mildew management relies heavily on fungicide applications, field evaluations are needed to compare the efficacy …

Sustainable Management Of Soilborne Pathogens In Strawberry Production Through Host Resistance And Sanitation Practices, Maria G. Alvarez Arredondo

Master's Theses

Strawberry production in California is significantly impacted by soilborne pathogens that reduce plant productivity and increase management costs. This research addressed management of these pathogens through two independent approaches: evaluation of host resistance in strawberry cultivars and assessment of sanitation practices for reducing pathogen movement between fields.

Macrophomina root rot, caused by Macrophomina phaseolina, was evaluated over two growing seasons (2024–2025 and 2025–2026) using field trials at California Polytechnic State University, San Luis Obispo. In Year 1, disease incidence varied widely among genotypes, with mortality ranging from 1.3% to 88.8% and an average mortality of 26.4%. Area under the …

Can Generative Ai Make Farming Decisions? Current Status And Future Pathways: A Case Study In Row Crop Production With Chatgpt, Nipuna Chamara, Yufeng Ge, Joe Luck, Yu Pan, Saleh Taghvaeian, Cory Walters, Christopher Proctor, Daran Rudnick, Daren Redfearn

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The agricultural decision-making process is experience-based, knowledge-dependent, time-sensitive, complex, and driven by historical data. Planting, fertilization, irrigation, and chemigation are key categories in farm decision-making, and currently there is no one-shot decision-support tool that covers all these activities. Generative Artificial Intelligence (AI) models are more advanced than traditional machine learning and deep learning models. These models have been trained on vast amounts of data from the internet, allowing them to accept unstructured data in various forms and generate human-like text, solutions to problems, and scenario predictions. Given this capability, we became interested in exploring the potential of generative AI in …

Arkansas Soybean Research Studies 2024, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

The 2024 Arkansas Soybean Research Studies includes research reports on topics pertaining to soybean across several disciplines from breeding to post-harvest processing. Research reports contained in this publication may represent preliminary or only data from a single year or limited results; therefore, these results should not be used as a basis for long-term recommendations. Several research reports in this publication will appear in other University of Arkansas Division of Agriculture’s Arkansas Agricultural Experiment Station publications. This duplication is the result of the overlap in research coverage between disciplines and our effort to inform Arkansas soybean producers of the research being …

Variable Temperature And Moisture Requirements For Germination Within Populations Of Kochia (Bassia Scoparia) In Field Margins, Brian Schutte, Rebecca Creamer

Entomology, Plant Pathology, & Weed Science: Datasets

No abstract provided.

Evaluation Of Host Resistance To Rotylenchulus Reniformis In Sweetpotato Germplasm, Timothy S. Miller

LSU Master's Theses

The reniform nematode (Rotylenchulus reniformis) is an emerging plant-parasitic threat to sweetpotato production. Dissimilar from the galling caused by root-knot nematode infections, infections from the reniform nematode occur without visible damage to the root system. In the southern United States, heavily infested sweetpotato fields can lose up to 40% of their total yield. Growers rely heavily on fumigants and nematicides which provide inconsistent control and are not sustainable in the long-term. Past research has been more focused on the efficacy of chemicals than in the identification of host resistance or tolerance in sweetpotato germplasm. This study evaluated past …

Improved Management Strategies For Botrytis Fruit Rot, Macrophomina Root Rot, And Verticillium Wilt In California Strawberry Production, Joseph A. Ramirez

Master's Theses

Strawberry production in California is limited by plant diseases such as Macrophomina root rot (MRR) caused by Macrophomina phaseolina, Verticillium wilt (VW) caused by Verticillium dahliae, and Botrytis fruit rot (BFR) caused by Botrytis cinerea. Current disease management strategies are compromised due to fumigant regulations or ineffective disease management practices. This thesis investigated methods to potentially improve the management of these three diseases. Two host plant resistance evaluations for MRR and VW were conducted for the 2022-2023 and 2023-2024 growing seasons. Sixty-three strawberry genotypes were screened in both years. All plants were exposed to the pathogen via artificial …

Maximizing Crop Production And Profitability Through Double Cropping Corn And Soybean Systems In South Carolina, Bennett Harrelson

All Dissertations

Profitability is critical for farm sustainability, efficiency, and longevity. Over the last decade, corn and soybean commodity prices have fluctuated considerably, and more recently, extreme increases in input prices have narrowed profit margins. Non-traditional cropping systems that can boost profit are becoming of interest to farmers in South Carolina, specifically double cropping soybean behind corn. In this scenario, corn is harvested at high moisture contents and followed by ultra-late planted soybean. However, prior research related to the agronomic production practices of double cropping corn and soybean is minimal. To develop best management practices for growers interested in double cropping corn …

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 …

Arkansas Soybean Performance Tests 2024, J. F. Carlin, R. D. Bond, T. C. Swanson, J. C. Mccoy

Arkansas Agricultural Experiment Station Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/ or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.

Arkansas Soybean Research Studies 2023, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

The 2023 Arkansas Soybean Research Studies includes research reports on topics pertaining to soybean across several disciplines from breeding to post-harvest processing. Research reports contained in this publication may represent preliminary or only data from a single year or limited results; therefore, these results should not be used as a basis for long-term recommendations.

Several research reports in this publication will appear in other University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station publications. This duplication is the result of the overlap in research coverage between disciplines and our effort to inform Arkansas soybean producers of the research …

Clonal Variation In Effector Gene Expression As A Mechanism For Pathogenic Adaptation In Magnaporthe Oryzae, Rebekah J. Ellsworth

Theses and Dissertations--Plant Pathology

Magnaporthe oryzae is a filamentous fungal pathogen that causes destructive diseases in cereals, including rice blast, wheat blast, and gray leaf spot. It is responsible for 10–30% annual yield losses in rice (Nalley et al., 2016) and up to 100% loss in wheat under favorable conditions (Kohli et al., 2011). Disease management typically relies on the use of resistant cultivars, but M. oryzae rapidly overcomes host resistance by mutating or deleting avirulence (AVR) genes recognized by host immune receptors. This rapid adaptation, often occurring within one to two growing seasons, presents a major challenge to breeding for durable resistance.

The …

Induced Systemic Resistance Against Nematodes By Plant Growth-Promoting Microbes In Potatoes, Cole Grannan

Master's Theses

Biofertilizers consist of plant growth-promoting microorganisms that establish symbiotic relationships with plant roots and stems. These beneficial microbes play a crucial role in enhancing plant defenses against various threats including insects, nematodes, and microbial pathogens. The purpose of this study was to investigate the effectiveness of two fungal biofertilizers (an endophytic strain of Beauveria bassiana (BA) and a mixture of arbuscular mycorrhizal (AM) fungi), specifically their ability to induce systemic resistance against plant- parasitic nematodes (PPNs) in potatoes (Solanum tuberosum cv. Masquerade) under controlled greenhouse conditions. The study utilized soil collected from Colorado State University’s San Luis Valley (SLV) Research …

Evaluating The Duckweeds Lemna Minor And Spirodela Polyrhiza As Alternative Aquatic Hosts For The Spread Of The Bacterial Wilt Pathogen, Ralstonia Solanacearum, Irelynn Smith

Honors Theses

Ralstonia solanacearum is a plant pathogen that causes bacterial wilt disease in major crops such as tomatoes and potatoes. Recently, this bacterium was discovered in floating pennywort (Hydrocotyle ranunculoides) and Pennsylvania smartweed (Polygonum pennysylvanicum), two previously unsuspected aquatic plants. Duckweed is an aquatic plant with a high level of resilience and short doubling time. Common duckweed (Lemna minor) has previously demonstrated its capability as a versatile high-yield infection model for other types of pathogenic bacteria. Given this newfound branch of aquatic hosts and the fact that duckweed is a common pond weed previously identified in several ponds located nearby infected …

Lupin Root Diseases - Diagnosis And Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Root, hypocotyl and stem base diseases can be significant problems in lupin crops, reducing stand density, plant vigour and yield. Root disease is present in nearly all narrow leafed lupin (Lupinus angustifolius) paddocks but in the majority of paddocks has only a small impact on crop development. However, in paddocks where high levels of root rot occurs, plant establishment, seedling vigour and crop yield can be significantly affected.

When a root disease is present in a crop very little can be done to manage it in that cropping season. It is therefore vital that the cause is correctly identified to …

Spot Form Net Blotch And Its Management In Barley, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Spot form net blotch (SFNB) has become increasingly more common in Western Australia (WA) due to the widespread cultivation of susceptible varieties, such as Spartacus CL and RGT Planet.

These crops generate large amounts of inoculum, which is carried between seasons on infected stubble. Crops grown onto or located close to infected stubble are at greatest risk of infection. The disease can be effectively managed using a combination of varietal selection, crop rotation, and fungicides.

Insect Pests And Their Management In Oats, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Field pests

Damage from invertebrate pests is generally not a major factor for oat crops, however there is a zero tolerance to live pests in export hay.

Significant damage can occur if pest populations build up. Planning rotations to minimise pest carryover, timely sowing, adequate crop nutrition, and good control of weed and root diseases will assist in reducing the likelihood of crop damage by insect pests. Check crops regularly throughout their growth for field insects.

• Control redlegged earth mite and lucerne flea during the seedling stage if necessary.

• Aphids should be checked for and controlled from flag …

Bean Yellow Mosaic Virus And Its Management In Lupins, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Bean yellow mosaic virus (BYMV) is an aphid-transmitted virus that commonly causes necrotic symptoms that kills lupin plants when infected early before pod set. When plants are infected after pod set, black pods develop (known as black pod syndrome).

BYMV is found predominantly in high rainfall areas of the Western Australian (WA) grainbelt. This page outlines the symptoms, diagnosis, factors favouring disease risk and spread, yield and quality impacts, and management for BYMV in lupin crops in WA

Cucumber Mosaic Virus And Its Management In Narrow Leafed Lupins, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Cucumber mosaic virus (CMV) is a seed- and aphid-borne virus that infects narrow-leafed lupins. Western Australian (WA) grainbelt regions most at risk are the high rainfall zones of the northern and central agricultural region and the south coastal region.

The principal infection source for lupin crops is sowing infected lupin seed.

Ascochyta Blight Disease And Its Management In Faba Beans, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

This factsheet summarises the symptoms, disease risk, infection cycle and control measures for Ascochyta blight (Ascochyta fabae) in faba bean compared to the diseases, Alternaria and Cercospora.

Blackleg And Its Management In Canola, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Blackleg, caused by the fungus Leptosphaeria maculans, is the most common and serious disease of canola in Western Australia (WA). Blackleg can cause significant damage by infecting the cotyledons or first leaves early in the season, leading ultimately to crown lesions or cankers later in the season.

Changes in variety choice, crop rotation, earlier sowing times, and stubble retention have extended the risk of blackleg disease. Because of early emergence, later stages of crop growth are more likely to be exposed and infection can occur on all parts of the plant above ground, including canola flowers, stems, and branches (this …

Root Lesion And Burrowing Nematodes And Their Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Nematodes are common soil pests that feed on the roots of a wide range of crops in all agricultural areas of Western Australia, resulting in significant crop yield loss. Root lesion nematode can be managed but not eradicated.

This factsheet summarises the biology of the root lesion nematode (RLN, Pratylenchus spp.) and burrowing nematode (Radopholus spp.) species that damage Western Australian (WA) crops, and their diagnosis and management.

Net Form Net Blotch And Its Management In Barley, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Net form net blotch is a fungal disease that can reduce yield and grain quality of barley crops. It can vary in appearance depending on the pathogen, variety of barley, and stage of infection. This factsheet describes the symptoms, and how this disease is managed.

Yellow Spot And Septoria Nodorum Blotch And Their Management In Wheat, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Leaf spot diseases affecting wheat in Western Australia (WA) are yellow spot (Pyrenophora tritici-repentis), septoria nodorum blotch (Parastagonospora nodorum), and septoria tritici blotch (Zymoseptoria tritici). They are caused by 3 different fungal pathogens but the disease symptoms and biologies are similar.

Impact from leaf spot diseases vary greatly from season to season and between locations. They are a problem in continuous wheat crops in stubble retention (no-till) farming systems. For the most effective control, an integrated disease management (IDM) approach is required.

This page outlines the symptoms, diseases spread and risk factors, yield and quality losses, and management options for …

Wheat Streak Mosaic Virus And Wheat Curl Mite And Their Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Wheat streak mosaic virus (WSMV) is a seed and mite-borne virus that infects wheat, causing severe leaf symptoms and reduced yields. The symptoms and damage are more severe in wheat than other hosts, in which infection is symptomless.

Wheat streak mosaic virus can cause crop failure when widespread infection occurs in seedling wheat, particularly when a heavily WSMV-infected green bridge is not controlled before sowing an early crop, and warm temperatures favour mites.

Wheat curl mite (Aceria tosichella) is the only known vector of WSMV. It can transmit the virus in its nymph and adult stages.

Armyworms And Their Management In Cereal Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Armyworms are pests of cereals crops. They are frequently found along the south coast of Western Australia and occasionally in other grainbelt locations.

When barley crops are maturing in spring, large armyworm caterpillars climb plants and can chew through the stems, causing the heads to fall to the ground. Damage to wheat and oat crops occurs less frequently and is usually minor compared to damage in barley. Armyworms are seldom a serious problem in pastures.

Sclerotinia Stem Rot And Its Management In Canola, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Sclerotinia stem rot, caused by the fungus Sclerotinia sclerotiorum, is a disease of canola that can cause significant yield losses exceeding 20% under conducive conditions. This disease occurs in all areas of the WA grainbelt.

Sclerotinia stem rot is one of the most variable and unpredictable diseases of canola, with incidence of infection varying greatly between paddocks and between years. Yield losses can be severe in years of higher moisture, cool conditions, and high humidity, which favour disease development.

This factsheet details the symptoms, disease risk and spread, yield and quality losses, and integrated disease management tactics for sclerotinia stem …

Barley And Cereal Yellow Dwarf Viruses And Their Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Barley yellow dwarf viruses (BYDV) and cereal yellow dwarf viruses (CYDV) damage cereal crops worldwide. These yellow dwarf viruses infect wheat, barley, oats and grasses and are transmitted by aphids.

This page describes these collective yellow dwarf viruses (barley and cereal yellow dwarf viruses), which damage cereals crops and advises on their diagnosis, monitoring, and management the viruses in the Western Australian (WA) grainbelt.

Growers are encouraged to check cereal crops for aphids on a regular basis, especially early in the season during autumn when winged aphids migrate into cereal crops during the crops’ most vulnerable growth phase. Early detection …

Septoria Avenae Blotch And Its Management In Oats, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Septoria avenae blotch (Phaeosphaeria avenaria f.sp. avenaria) is a stubble borne fungal disease of oats and is the most common oat disease in Western Australia and occurs throughout the cereal growing areas.It is host specific, meaning it only affects oats.

This page summarises the symptoms, factors favouring disease risk and spread, yield and quality losses, and management strategies for the disease

Rust Disease And Its Management In Faba Beans, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Faba bean rust (Uromyces viciae-fabae) is host specific, meaning it does not infect cereals or other break crops. The rust is not widespread in Western Australia but low to moderate levels occur in the Esperance and Katanning regions. Individual crops suffer yield losses in some years.

Rust has also been recorded in the high rainfall region in the northern agricultural area, around Dongara.

This page summarises the symptoms, infection cycle, disease risk and spread, and management recommendations for faba bean rust disease.