Agricultural Science Commons^™

Assessing Freezing Effect On Kiwifruit Cultivars And Mapping Suitable Areas For Growing The Crop In Eastern Texas, Lais De Oliveira Machado

Electronic Theses and Dissertations

Kiwifruit is a perennial vine originating from China where it has been grown for centuries. In the United States, green kiwifruit (Actinidia deliciosa) is primarily produced commercially in California. They are fuzzy, green fleshed and well known in the marketplace. Kiwifruit plants require low to moderate soil pH, adequate winter chilling and adequate precipitation to guarantee plant development and good fructification. Actinidia chinesis or golden kiwifruit are smooth skinned, feature golden flesh and are a more recent introduction into the global market. Kiwifruit crops have attributes that favor production in east Texas, including low pest problems, current long …

Climatic Factors Affecting Maize Grain Yield In Different Growing Areas Of The Philippines, Lakshman Kumara, Tonette Laude, Jose Hernandez, Pearl Sanchez, Moises Dorado, Jose Nestor Garcia, Gerardo Gauna, Pompe C. Sta. Cruz

The Philippine Agricultural Scientist

Seasonal climate variation is one of the problems faced by Filipino maize farmers, due to varying climatic elements such as solar radiation, rainfall, relative humidity, and air temperature. This study determined the seasonal productivity of selected maize varieties in the major growing areas in the Philippines, and identified the yield-limiting climatic factors specific to location and growing season. Grain yield, covering two wet and dry seasons (2016-2018) from seven field trials (representing 3 climatic types) of the National Corn Testing (NCT) were used in the study. Climatic data (2016-2018) were gathered from the PAGASA weather station nearest to the trial …

Flowering Regulation Of Potted Bougainvillea Plants Under Five Water Treatments [Research Note], Kuan-Hung Lin, Jui-Mei Li, Chun-Wei Wu, Yu-Sen Chang

The Philippine Agricultural Scientist

Bougainvillea (Bougainvillea buttiana) is a very popular evergreen landscape plant in the tropical and subtropical areas. The objective of this study was to investigate the growth, flowering, and physiological performance of bougainvillea ‘Taipei Red’ cultivar in response to water-stress conditions that can potentially be used to maximize the economic efficiency and benefits in the development and ACC potential of bougainvillea plants grown in controlled environments. Potted plants were subjected to five different levels of soil VWC: 60% (control), 40%, 20%, 1/3 of leaves visually observed to be drooping (equivalent to 18% VWC), and 2/3 of leaves drooping (15% …

First Detection Of Naturally Introgressed Bt Cry1ab In Asian Corn Borer [Ostrinia Furnacalis (Guenée)] - Resistant Traditional Maize (Silangan) In The Philippines, Merdelyn T. Caasi-Lit, Eureka Teresa C. Ocampo, Artemio Salazar, Jefferson Paril, Bryan Novio, Bernard Panabang, Angelyn Marta Marmeto

The Philippine Agricultural Scientist

Resistance against insect pests is one of the most promising and highly favored characteristics of an economically important crop. In the Philippines, the Asian corn borer (ACB), Ostrinia furnacalis (Guenée), is the most destructive insect pest of maize. The discovery of Bacillus thuringiensis and the Bt toxin, which led to the development of Bt corn, effectively controlled this pest. In this study, four traditional varieties of maize that showed resistance against ACB were tested for the presence of Bt Cry1Ab protein. Out of these four, a traditional variety from San Carlos City, Pangasinan, which was initially thought to have natural …

Epinasty Accompanies Potassium Nitrate-Induced Flower Bud Break In 'Carabao' Mango [Research Note], Ulysses Besas, Calixto Protacio

The Philippine Agricultural Scientist

The hypothesis that potassium nitrate application promotes epinasty in ‘Carabao’ mango through increased ethylene production was investigated. The degree of drooping, apical primordium growth as affected by shoot ethylene and levels after potassium nitrate spraying were monitored. Evidence presented established for the first time in ‘Carabao’ mango that epinasty occurred just before flower emergence, coinciding with visible bud break, and extended up to 18 days, marking floral anthesis. The possible reasons could be the higher levels of ethylene at 0.31% and earlier increase of ethylene in the shoot apex at four hours and apical primordium growth. Increased ethylene levels at …

Establishment Of The In Vitro Culture And Plant Regeneration Of Anubias Barteri Var. Nana 'Mini', Kuan-Hung Lin, Chih-Peng Kuo, Li-Ru Chen

The Philippine Agricultural Scientist

Anubias barteri is an ornamental aquatic plant of economic importance worldwide. Effective removal of contaminants has been a major problem for the in vitro propagation of A. barteri. Hydrogen peroxide (H₂O₂) was applied as a pre-disinfectant to treat rhizome bud explants of A. barteri var. nana ‘Mini’ followed by disinfection with mercuric chloride (HgCl₂) to eliminate in vitro contamination. However, application of 0.1% HgCl₂ for 5 min without pre-disinfecting with H₂O₂ significantly reduced the contamination rate to 44.4% compared to other combinations. Moreover, in vitro shoots of A. barteri …

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison K. Ludwig

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …

Livestock Grazing Impacts On Crop And Soil Responses For Two Cropping Systems, Alyssa Kuhn

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Diversified crop, forage, and livestock systems are assumed to be more sustainable and economically competitive than traditional cropping systems. Objectives of this study were to determine effects of integrating grazing livestock into corn (Zea mays)-soybean (Glycine max (L.) Merr.) (C-S) and corn-soybean-wheat (Triticum aestivum L.) (C-S-W) cropping systems on plant population, grain yield, soil nutrients and soil carbon dioxide (CO₂) flux following winter grazing corn residue (both systems) and an oat (Avena sativa) cover crop (C-S-W only) planted after wheat. For the 2019 and 2020 production seasons, neither corn nor soybean plant …

A Method For Visualizing Water Flow Through Modified Root Zones, Dallas M. Williams

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

As the number of impervious surfaces in urban environments increases, the ability of modified root zones to infiltrate water is becoming more important. Current methods of tracing water flow through soil profiles include excavating large pits in situ or analyzing soil cores in the laboratory with computed tomography or magnetic resonance imaging. While useful, these methods may not be suitable for urban settings or practical in every laboratory. We propose a new method that is less invasive, does not require extensive technical equipment and can reliably trace water movement through the soil profile in order to calculate flow rate based …

Sensitivity Of Soybean And Rice To Dicamba, Owen Wesley France

Graduate Theses and Dissertations

Although the integration of dicamba as a postemergence (POST) herbicide has proven useful in controlling many herbicide-resistant weeds, its damage to soybean at low rates, such as supplied by drift and volatility, has been well-documented. Injury to other crops, such as rice, from off-target movement of dicamba and other commonly used herbicides, such as glyphosate, may also occur. Practical options for mitigating injury and yield loss to soybean and other crops from dicamba off-target movement could prove beneficial if dicamba continues to be used during summer months. Experiments were conducted to determine the effects of multiple agricultural practices, including cultivar …

Recapture And Reuse Of Nitrogen And Phosphorus From Rendered Animal Materials To Enhance Nutrient Use Efficiency And Produce Quality In Agricultural Crop, Bhupinder Jatana

All Dissertations

The current fertilizer regime heavily relies on inorganic fertilizers to meet the crop nitrogen (N) and phosphorus (P) demand. However, the United States has a limited N production capacity, with 50% N demand met through imports. On the other hand, the nonrenewable natural reserves of P are being depleted at an unprecedented rate and are expected to be exhausted with in next 100 years. Additionally, high solubility/liability of the field applied inorganic fertilizers often results in lower nutrient use efficiency (NUE;

The MBM led to rapid N mineralization, with 35% of the applied N mineralized within the first five days …

How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross

Electronic Theses and Dissertations

Nutrient levels and aggregation measurements are currently the most accurate means to measure soil health. It has been suggested that bacterial and fungal communities may prove to be a more accurate measure of soil health. In this study soil microbe communities and nutrient levels were compared in rye cover cropped soils to measure for differences between treatments. Effects between the microbial communities and environmental measurements were also measured within those treatments to test for correlations between soil health measures and microbial communities. The plots were put in a biennial corn (Zea mays L.) and soybean (Glycine max …

Economic Potash Fertilizer Rate Recommendations, Kimberly B. Oliver

Graduate Theses and Dissertations

This thesis is comprised of two studies that estimate profit-maximizing potassium (K) fertilizer application rates for various crops across different time periods. Estimation of profit-maximizing fertilizer-K rate (K*) for both studies considered the initial soil test level of K (STK) and yield response information, as traditional recommendations do, and added crop price and the cost of fertilizer. Profit maximum occurs where the marginal revenue from additional yield is equal to the marginal cost of applying an additional unit of fertilizer-K. The first study calculated K* for corn (Zea mays) and cotton (Gossypium hirsutum) and compared results to previous studies on …

Effects Of "Lemongrass Factor" On Galleria Mellonella Hemocytes, Jennifer C. Rice

Graduate Theses/Dissertations

The use of conventional chemical insecticides to control agricultural pest has become problematic as they may have a negative impact towards human health and the environment, resulting in a need to research alternative methods to insect pest control. Plant derived substances like essential oils have been used for generations as toxicants, repellants, and anti-feedants to control agricultural pest. More research is needed to understand how insect immune systems react to essential oils and if cellular immune responses of phagocytosis, encapsulation, and nodulation can be inhibited by such. Subjecting Galleria mellonella to various concentrations of “lemongrass factor” lets the researcher/scientist know …

Effects Of Nitrogen Management And Cultivar On Strawberry Production Under Disease Pressure, Kamille A. Garcia-Brucher

Master's Theses

Effects of nitrogen management and cultivar on strawberry production under disease pressure

Kamille Garcia-Brucher

California strawberry growers face increasing regulatory pressures to manage nitrogen (N) applications in their production system. Standard practice in the California strawberry industry is to apply a synthetic pre-plant controlled release fertilizer (CRF) to ensure the crop has sufficient N during winter establishment. Some research from the UC Cooperative Extension suggests this practice is not efficient at delivering N to the crop since most of the N is released from CRF before strawberry crop N uptake is significant. Another concern for California strawberry growers is loss …

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …

Nutrient Uptake And Management Strategies In Recirculating Hydroponic Systems, Lauren Leigh Houston

Graduate Theses and Dissertations

Nutrient management in recirculating hydroponic systems requires the periodic replenishment of water and nutrients to the nutrient solution reservoir. Common nutrient management strategies, such as replenishing the reservoir with fresh solution and maintaining a constant solution electrical conductivity (EC), can lead to ion accumulation and nutrient imbalances since nutrients are taken up by roots and depleted from solution at different rates. To avoid nutritional disorders, commercial growers typically dump and replace the hydroponic solution periodically, which is wasteful and has an economic cost. A potential alternative is to specially formulate the nutrient replenishment solution to balance the supply of nutrients …

Precise Nitrogen Recommendations Improve Economic And Environmental Outcomes In Arkansas Rice Production, Cristin Roberts

Graduate Theses and Dissertations

Soil testing has become an increasingly important tool in making agronomically efficient production management decisions. N-STaR is a N test used in rice production and is unique in its ability to selectively quantify soil organic-N compounds which are readily mineralizable for plant N uptake and contribute to growth and yield. This study uses historical (2002–2018) adoption rates of N-STaR, which is funded through Rice Checkoff funds, to calculate the total cost savings from N-STaR adoption. These cost savings alone would be the “typical” benefits used in a benefit-cost ratio of a public ally funded research program like N-STaR. However, we …

In Situ Nitrogen Mineralization And Nutrient Release By Soil Amended With Black Soldier Fly Frass Fertilizer, Dennis Beesigamukama, Benson Mochoge, Nicholas Korir, Changeh J. Ghemoh, Sevgan Subramanian, Chrysantus M. Tanga

All Peer-Reviewed Publications

Although black soldier fly frass fertilizer (BSFFF) is effective on crop performance, information on nitrogen (N) mineralization and nutrient release capacity of soils amended with BSFFF is lacking. This study utilized field incubation experiments to investigate the ammonification, nitrification, microbial populations, and quantities of nutrients released by soils amended with BSFFF and commercial organic fertilizer (SAFI) for a period equivalent to two maize cropping seasons. For the control treatment, no BSFFF or SAFI was added. Results indicated that most of the N in BSFFF amended soils was available in the ammonium form, while soils treated with SAFI had higher nitrate …

Whole Genome Comparisons Reveal Panmixia Among Fall Armyworm (Spodoptera Frugiperda) From Diverse Locations, Katrina A. Schlum, Kurt Lamour, Caroline Placidi De Bortoli, Rahul Banerjee, Robert Meagher, Eliseu Pereira, Maria Gabriela Murua, Gregory A. Sword, Ashley E. Tessnow, Diego Viteri Dillon, Angela M. Linares Ramirez, Komivi S. Akutse, Rebecca Schmidt-Jeffris, Fangneng Huang, Dominic Reisig, Scott J. Emrich, Juan Luis Jurat-Fuentes

All Peer-Reviewed Publications

Background: The fall armyworm (Spodoptera frugiperda (J.E. Smith)) is a highly polyphagous agricultural pest with long-distance migratory behavior threatening food security worldwide. This pest has a host range of > 80 plant species, but two host strains are recognized based on their association with corn (C-strain) or rice and smaller grasses (R-strain). The population genomics of the United States (USA) fall armyworm remains poorly characterized to date despite its agricultural threat. Results: In this study, the population structure and genetic diversity in 55 S. frugiperda samples from Argentina, Brazil, Kenya, Puerto Rico and USA were surveyed to further our understanding of …

Field Evaluation Of A New Third Generation Push-Pull Technology For Control Of Striga Weed, Stemborers, And Fall Armyworm In Western Kenya, Duncan Cheruiyot, Frank Chidawanyika, Charles A.O. Midega, Jimmy O. Pittchar, John A. Pickett, Zeyaur R. Khan

All Peer-Reviewed Publications

Production of cereal crops in sub-Saharan Africa is threatened by parasitic striga weeds and attack by stemborers and the invasive fall armyworm (FAW), compounded by increasing hot and dry conditions. A climate-smart push-pull technology (PPT) significantly reduces effects of these biotic challenges. To improve further resilience of the system to climate change, more adapted and suitable companion plants were identified and integrated in a new version of PPT, termed 'third generation PPT'. Our study evaluates field performance and farmer opinions of this new version in comparison with the earlier version, climate-smart PPT, and farmers' own practices of growing maize in …

Temperature-Dependent Modelling And Spatial Prediction Reveal Suitable Geographical Areas For Deployment Of Two Metarhizium Anisopliae Isolates For Tuta Absoluta Management, Ayaovi Agbessenou, Komivi S. Akutse, Abdullahi A. Yusuf, Sospeter W. Wekesa, Fathiya M. Khamis

All Peer-Reviewed Publications

Tuta absoluta is one of the most devastating pests of Solanaceae crops in Africa. We previously demonstrated the efficacy of Metarhizium anisopliae isolates ICIPE 18, ICIPE 20 and ICIPE 665 against adult T. absoluta. However, adequate strain selection and accurate spatial prediction are fundamental to optimize their efficacy and formulations before field deployment. This study therefore assessed the thermotolerance, conidial yield and virulence (between 15 and 35 °C) of these potent isolates. Over 90% of conidia germinated at 20, 25 and 30 °C while no germination occurred at 15 °C. Growth of the three isolates occurred at all temperatures, but …

Mating Behaviour, Mate Choice And Female Resistance In The Bean Flower Thrips (Megalurothrips Sjostedti), Adeyemi O. Akinyemi, Sevgan Subramanian, David K. Mfuti, Tom W. Pope, Amanuel Tamiru, William D.J. Kirk

All Peer-Reviewed Publications

Many species of thrips (Thysanoptera) in the family Thripidae form mating aggregations, but the adaptive significance of these aggregations and the extent of male and female mate choice is poorly understood. We studied the mating behaviour of the bean flower thrips Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), which forms male aggregations and occurs across sub-Saharan Africa. We tested whether males choose mates by female age or mating status. No-choice mating bioassays with one male and one female were used to simulate the way males usually encounter only one female at a time in aggregations in the field. Virgin females violently resisted …

Immediate Impacts Of Covid-19 Measures On Bean Production, Distribution, And Food Security In Eastern Africa, Eileen Nchanji, Cosmas Kweyu Lutomia, David Karanja

All Peer-Reviewed Publications

The outbreak of coronavirus was expected to adversely affect African countries more than any other region in the world. This assertion was based on the existing conditions in sub-Saharan Africa that exposed the region to the dire consequences of the pandemic. Previously existing underlying conditions that affected the food system include a high dependence on trade for inputs supply, the adverse effects of climate change, crop pests and diseases, poverty, low input use, weak institutions and ineffective policies, and insecurity and conflicts. We collected data from farmers, aggregators, bean research coordinators, and urban and peri-urban consumers in five Eastern African …

Forage Production From Perennial Vs. Annual Crop R~ On In Sandy Soils In Egypt, Z. Abdelhalim, O. Niemeläinen, I. A. Hanna, A. M. Rammah

IGC Proceedings (1977-2023)

Forage production was studied on newly reclaimed sandy soil in Egypt trom perennial lucerne (Medicago sativa L.) and two annual crop rotations. The cropping systems were: A) lucerne, B) berseem clover (Trifolium alexandrinum L.) in the winter followed by pearl millet (Pennisetum glaucum R. Br. Emend. Stantz.) in the summer and C) triticale (XX Triticosecale Wittm.) (forage cut + grain harvest) in the winter followed by maize (Zea mays L.) (grain + stover) in the summer. Mean annual dry matter yields (t ha^-1 ) were 20.65, 26.59 and 27.48 from A, B and C, respectively. However, …

Carry-Over Effect In Forage Rotations On Newly Reclaimed Sandy Soil In Egypt, Z. Abdelhalim, O. Niemeläinen, I. A. Hanna, A. M. Rammah

IGC Proceedings (1977-2023)

This study was carried out to investigate the carry-over effect of a preceding crop on the productivity of the following crop in various rotations in newly reclaimed lands in Egypt. The productivity of peanut (Arachis hypogaea L.), soyabean (Glycine max (L.) Merr.), maize (Zea mays L.) and pearl millet (Pennisetum glaucum (L.) R. Br.) in summer season were much higher following berseem (Trifolium alexandrinum L.) or lentil (Lens culinaris Medic) than after wheat (Triticum aestivum L.) or barley (Hordeum vulgare L.) in both years of the study. Soyabean was the best summer …

Direct Drilling Of Soybean In A Pensacola Bahiagrass Pasture In The Northwest Region Of Rio Grande Do Sul, Brazil, R. B. Medeiros, J. Riboldi, J. C. De Saibro, J. E. G. Zambra

IGC Proceedings (1977-2023)

The response of methods of soil preparation (M₁=conventional tillage, and with notillage using the following herbicides M₂=50% Paraquat plus 50% Orizalin; M₃=50% Paraquat plus 50% Diquat and M₄=Paracol (20% Paraquat plus 20 Diuron)) and row spacing (E₁=17 cm, E₂=24 cm, E₃=51 cm and E₄=68 cm) on soybean grain yield direct drilled in an eight-year-old grazed sward of Bahiagrass cv. Pensacola (Paspalum notatum var. saurae Parodi) were studied in southern of Brazil. The results showed that direct drilling of soybean on Pensacola accompanied by …

Forage Quality Evaluation Of Chopped Elephantgrass Hay Through Intake And Digestibility Trial, E. M. De Aguiar, G. F. Da C. Lima, L. G. Da Paz

IGC Proceedings (1977-2023)

The research was carried out to evaluate forage quality of chopped elephantgrass (Pennisetum purpureum Schum.) hay and to define a proper stage for cutting and haymaking of this grass. Chemical composition, voluntary intake, and apparent digestibility of the hays were studied at five different growth stages (30, 48, 63, 76, and 91 days). Twenty-five common wethers were utilized in a completely randomized experimental design. Dry matter (DM) voluntary intake was not different (P> 0.05) from 30 to 63 days of regrowth and from 63 to 91 days and comprised 3.9; 3.5; 3.2; 2.1; and 2.4% of animal liveweight, respectively …

Seeding Rate Effects On Forage Mass And Vegetation Dynamics Of Cool-Season Grass Sod Interseeded With Sorghum-Sudangrass, John A. Guretzky, D. D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Interseeding annual warm-season grasses into perennial cool-season grasses has the potential to increase summer forage mass and nutritive value. Knowledge of how seeding rate affects annual warm-season grass establishment, forage mass, and vegetation dynamics remains limited. From 2016–2017, we conducted a field experiment evaluating the effects of seeding rates on sorghum-sudangrass (Sorghum bicolor x S. bicolor var. sudanense) density and forage mass and on the frequency of occurrence of plant species in cool-season grass sod in Lincoln, NE. The experiment had a completely randomized design consisting of six replicates of four seeding rates [0, 14, 28, and 35 …

Berseem Clover In Binary Mixtures With Oats, Triticale Or Barley For Silage And Late Season Grazing, S. M. Ross, J. R. King

IGC Proceedings (1977-2023)

An experiment was conducted at northerly latitudes with berseem clover (Trifolium alexandrinum L) in binary mixtures with oats (Avena sativa L.), barley (Hordeum vulgare L.) and triticale (X Triticosecale Wittmack). The effects of cereal species, variety and density were assessed for a two cut harvest. Total dry matter yields were 11.7 to 14.5 t ha^-1, with 7.8 to 10.2 t ha^-1 as silage, and 2.0 to 6.0 t ha^-1 as berseem regrowth. Berseem regrowth added an average of 4.0 t ha^-1 in forage yield. Total yields did not differ with cereal …