Agronomy and Crop Sciences Commons^™

Water Quality, Carrier Volume And Droplet Size Effects On Herbicide Efficacy And Drift Potential, Barbara Houston

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

Herbicide performance is directly related to the amount of active ingredient that has been deposited on the plant. Hence, spray solution characteristics and application parameters are crucial in determining the efficacy of an herbicide application. To maximize the effectiveness of chemical control, methods to deliver full chemical dose must be utilized: allowing the active ingredient to be readily absorbed once added to the carrier and mitigating off-target movement and low herbicide doses. Water is the most frequently used carrier in herbicide applications. Chemical parameters, such as water hardness and pH, can have a critical role in herbicide performance. It is …

Recombination Hotspots In Soybean [Glycine Max (L.) Merr.], Samantha J. Mcconaughy

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

Recombination allows for the exchange of genetic material between two parents which plant breeders exploit to make new and improved varieties. This recombination is not distributed evenly across the chromosome. In crops, it mostly occurs in the euchromatic regions of the genome and even then, recombination is focused into recombination hotspots flanked by recombination cold spots. Understanding the distribution of these hotspots along with the sequence motifs associated with them may lead to methods that enable breeders to better exploit recombination in breeding.

In chapter 1 background information on recombination, recombination hotspots detection methods, landscape of recombination (describe recombination patterns …

Pestfacts Wa Issue 06 - June 2022, Cindy L. Webster, Svetlana Micic, Alan Lord, Benjamin S. Congdon, Steve Collins

PestFacts WA

PestFacts WA Issue 06 - June 2022 contents:

• African black beetle
• Aphid and turnip yellows virus update
• Cutworm caterpillars
• European earwigs are damaging canola
• Other recent insect activity
• New PestFacts WA Reporter app available for apple devices

Grain-Filling Rate Improves Physical Grain Quality In Barley Under Heat Stress Conditions During The Grain-Filling Period, Hamid Shirdelmoghanloo, Kefei Chen, Blakely Paynter, Tefera Angessa, Sharon Westcott, Hammad Aziz Khan, Camilla Beate Hill, Chengdao Li

Grain and Other Field Crops Research Articles

Heat stress is a primary constraint to Australia's barley production. In addition to impacting grain yield, it adversely affects physical grain quality (weight and plumpness) and market value. The incidence of heat stress during grain filling is rising with global warming. However, breeding for new superior heat-tolerant genotypes has been challenging due to the narrow window of sensitivity, the unpredictable nature of heat stress, and its frequent co-occurrence with drought stress. Greater scientific knowledge regarding traits and mechanisms associated with heat tolerance would help develop more efficient selection methods. Our objective was to assess 157 barley varieties of contrasting genetic …

Evaluating The Effect Of Coated Urea And Urea-Ammonium-Nitrate Solution On Cane Tonnage, Sugar Yield, And Leaf-Soil Nitrogen Content Under Louisiana Sugarcane Production System, Hector J. Mendoza Lagos

LSU Master's Theses

Nitrogen (N) is a crucial nutrient for proper plant growth and development. N deficiency results in poor tillering and thin, short internode stem production for sugarcane production, thus resulting in low cane tonnage. Therefore, proper N fertilizer management is essential for a sustainable sugarcane production system. This research was conducted at the LSU AgCenter Sugar Research Station in St. Gabriel, LA, from 2019 to 2020 at three Sites (Site 1, 2, and 3). The treatments consisted of different N rates (0, 45, 90, and 135 kg N ha^-1) and sources (urea-ammonium-nitrate solution [UAN]-32%, 30-day [Coated Urea 1], 45-day …

Water Use Efficiency In Western Australian Cropping Systems, Martin Harries, Ken C. Flower, Michael Renton, Geoffrey C. Anderson

Grain and Other Field Crops Research Articles

Rotations and associated management practices in rainfed farming systems of southwest Australia have shifted towards intensified cropping. Survey data from 184 fields spanning 14 Mha of southwest Australia were used to document water use efficiency (WUE) and water-limited yield potential (WLYP) of commercial crops and crop sequences and identify biophysical variables influencing WUE. WUE achieved in commercial wheat crops was 10.7 kg grain/ha.mm. Using a boundary function Ywl = 25 × (WU − 45), farmers achieved 54% of WLYP. Climate variables affected WUE more than management and biotic variates, the highest latitude region having WUE of 9.0 kg grain/ha.mm, compared …

Investigating The Mechanics And Chemistry Of Sickle Polish Development, Justin Jared Dubois

Graduate Theses and Dissertations

This series of experiments is designed to understand the development and chemistry of sickle gloss. Sickles are common in the archaeological record and have long been studied for their eponymous “sickle gloss”. There is debate as to how this gloss is formed. Five experimental sickles containing flint and novaculite blades were used to harvest high and low moisture content rye and common fescue and associated field weeds. The differences in the development of sickle gloss were examined. High moisture content plants create thick, smooth fields of polish with undulating, billowing margins at a higher developmental speed. Low moisture content plants …

Pestfacts Wa Issue 05 - May 2022, Jean Galloway, Cindy L. Webster, Steve Collins

PestFacts WA

PestFacts WA Issue 05 - May 2022 contents:

• Blackleg and the risk of sowing canola on canola
• Meet PestFacts WA team member – Steve Collins

Pestfacts Wa Issue 04 - May 2022, Svetlana Micic, Benjamin S. Congdon, Cindy L. Webster, Andrea Hills, Ravjit Khangura

PestFacts WA

PestFacts WA Issue 04 - May 2022 contents:

• Grasshoppers are hatching
• Aphid activity and turnip yellows virus detections
• Downy mildew and damping off in canola
• Nodorum blotch in wheat
• Plant disease webinar recording can now be viewed online

Economic Viability Of Weed Management Strategies In High-Tunnel Tomato, Gracie Morrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Cost-effective weed suppression is an important consideration for tomato growers. Growers often choose methods which minimize hand labor, as hand weeding can be prohibitively expensive. This project determined economic viability of high tunnel tomatoes treated with several methods of weed control, both organic and chemical. These methods included: 2-week hand weeding, 1-week hand weeding, preemergent, straw, landscape fabric, and untreated weedy control plots. These treatments were applied to randomized blocks in a high-tunnel. Weeding, planting, and harvest were all timed to determine labor and material costs of weed management strategy implementation. After harvest, marketable yield was weighed to determine revenue. …

Dicamba Tank Mixtures And Formulations And Their Effects On Sensitive Crops During Cleanout Procedures, Vinicius Velho

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

The introduction of dicamba-tolerant (DT) soybeans (Glycine max L. Merr) and cotton (Gossypium hirsutum L) in 2017 provided an additional tool for herbicide resistant weeds management. In the subsequent years, off-target movement of dicamba allegedly caused damage to sensitive crops and vegetation.

Possible causes of off-target movement include tank contamination, physical drift, and volatility. Additional products, such as herbicides to control grass, are often added to tank with dicamba, which is used to control broadleaf weeds, to increase the spectrum of control and application efficiency. Dicamba products registered for DT crops require the use of drift reducing …

Evaluation Of Benzobicyclon In Midsouth Rice (Oryza Sativa) Production Systems, Jake Patterson

Graduate Theses and Dissertations

Controlling weedy rice postemergence is challenging for rice producers in the United States because of the lack of herbicide options. Weedy rice is genetically similar to cultivated rice, thus making it difficult to control with mid-season postemergence herbicide applications without also damaging the crop. Hence, there is a need for a new effective postemergence weedy rice control herbicide. Findings from this research indicate that the use of benzobicyclon in current standard quizalofop- and imidazolinone-resistant rice herbicide programs provides tremendous utility for Midsouth rice producers. In both of these production systems, the addition of benzobicyclon to the respective standard herbicide programs …

Evaluation, Characterization, And Utilization Of Weed-Suppressive Sweetpotato Cultivars For Sustainable Weed Management, Isabel Schlegel Werle

Graduate Theses and Dissertations

Sweetpotato (Ipomoea batatas L.) is a low-technology, subsistence crop that enhances food and nutrition security particularly in developing nations. Weed interference with the crop can reduce sweetpotato storage root yields and product quality. Current weed management practices in sweetpotato include PRE or POST herbicides application, cultivation, mowing, or handweeding. Unlike row crops, herbicide options for sweetpotato are few; therefore, alternative weed control practices are needed. The overall objective of this research was to determine the weed suppressive ability of several sweetpotato cultivars. This research also provides information about cover crop use for weed suppression in sweetpotato production in Arkansas. Field …

Using Thermal Units To Predict Biomass Accumulation And Total Nitrogen Uptake For Cover Crops In Arkansas, Mila Victório Pessotto

Graduate Theses and Dissertations

Including cover crops in agricultural production systems is an important management practice. Cover cropping can improve soil health, increase plant-available nitrogen (N), provide surface residue to prevent erosional soil loss, increase water infiltration, and increase weed suppression. Cover crops growth can be predicted using thermal days or growing degree days [GDD] similar to commodity crops such as corn (Zea mays L.) or rice (Oryza sativa). Growing degree day calculations are a well-known tool to predict crop growth stage or development stage and can be adapted for use in any plant species, including cover crops. Identifying and developing the relationship between …

Breeding Soybean [Glycine Max (L) Merr.] Under Reduced Irrigation, Francia Seconde Ravelombola

Graduate Theses and Dissertations

Soybean [Glycine max (L) Merr.], a legume species native to East Asia in the Fabaceae family, ranks among the most important food crops in the world. It is widely grown and known for its high protein and oil concentration. Soybean is valuable because its seeds have multiple applications in food, feed, pharmaceutical, and industrial enterprises. Even though seed yield is the most important trait, breeders have recently given a significant attention to quality traits, such as high protein or modified oil concentration. Soybean seed protein inheritance has been extensively studied; however, genetics of high-protein ‘BARC-7’ soybean are still unknown.On the …

Winter Cover Crop Impacts On Weed Dynamics In Eastern And Central Nebraska, Elizabeth Ann Oys

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

Reducing tillage in cropping systems causes weed management to be dependent on chemical and cultural methods for weed control. Over time, herbicide-resistant weeds have developed due to the continuous selection pressures from herbicides, particularly in the Midwest Corn Belt. Integrated weed management strategies, such as cover crops, can be used to mitigate some of these issues. Cover crops are primarily known for their soil health benefits, but there is evidence that cover crops can suppress weeds. However, less research has been done at the field-scale level to address cover crop impacts on the weed seedbank and aboveground weeds during the …

Regional Plant Community Differences In The Nebraska Sandhills, Travis Millikan

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

The Nebraska Sandhills is very valuable to the state of Nebraska, representing one of the most in-tact and largest grassland ecosystems in temperate regions in the world. Rangeland managers must understand plant community dynamics across the Sandhills to better inform management decisions. The first objective of this study was to evaluate plant community variability on upland Sands ecological sites across different precipitation zones in the Nebraska Sandhills. The second objective of our study was to utilize the Rangeland Analysis Platform (RAP) to examine spatial and temporal variability in biomass production and cover on pastures of ranches analyzed in the first …

Exploration Of Genes Controlling Grain Yield Heterosis In Hybrid Wheat (Triticum Aestivum L.) Utilizing 3ʹ Rna Sequencing, Nichole Lynn Miller

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

The implementation and future success of hybrid wheat (Triticum aestivum L.) is impacted by breeders’ inability to create consistent high yielding, high heterosis hybrids. This research addresses this problem by conducting an exploration of transcriptomes from hybrids and parent lines to determine what genes are active in heterotic or non-heterotic hybrids and how their level of expression can explain the phenotype of grain yield heterosis. Using hybrids that showed positive mid-parent heterosis (MPH), classified as heterotic in our study, and negative or no difference MPH hybrids, classified as non-heterotic, differentially expressed genes (DEGs) potentially related to heterosis and hybrid …

Pestfacts Wa Issue 03 - May 2022, Svetlana Micic, Dustin Severtson, Jean Galloway, Cindy L. Webster

PestFacts WA

PestFacts WA Issue 03 - May 2022 contents:

• Seeing chewing damage in sprayed canola crops but can’t find the culprit?
• Mites and lucerne flea are active
• Slaters
• Meet PestFacts WA team member – Svetlana Micic
• Field pea blackspot forecasts for WA are available online
• PestFacts WA podcast

Wayne E. Sabbe Arkansas Soil Fertility Studies 2021, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Oestrogenic Subterranean Clover Guide. Identification And Remediation, Kevin J. Foster, Megan H. Ryan, Daniel R. Kidd

Bulletins 4000 -

Subterranean clover (subclover, Trifolium subterraneum L.) is an annual pasture legume that provides high quality feed for livestock. It is estimated to be sown over 30 million hectares across southern Australia, with cultivars developed for the low, medium and high rainfall zones. Unfortunately, some older cultivars contain high levels of phytoestrogen which can affect the reproductive system of sheep and cause other health issues. This became a significant issue for sheep producers from the 1940s as new land was cleared and sheep grazed subclover-dominant pastures. There was a collection of livestock issues observed and these were grouped together under the …

Chromosome-Level Thlaspi Arvense Genome Provides New Tools For Translational Research And For A Newly Domesticated Cash Cover Crop Of The Cooler Climates, Adam Nunn, Isaac Rodríguez-Arévalo, Zenith Tandukar, Katherine Anna Frels, Adrián Contreras-Garrido, Pablo Carbonell-Bejerano, Panpan Zhang, Daniela Ramos Cruz, Katharina Jandrasits, Christa Lanz, Anthony Brusa, Marie Mirouze, Kevin Dorn, David W. Galbraith, Brice A. Jarvis, John C. Sedbrook, Donald L. Wyse, Christian Otto, David Langenberger, Peter F. Stadler, Detlef Weigel, M. David Marks, James A. Anderson, Claude Becker, Ratan Chopra

Department of Agronomy and Horticulture: Faculty Publications

Thlaspi arvense (field pennycress) is being domesticated as a winter annual oilseed crop capable of improving ecosystems and intensifying agricultural productivity without increasing land use. It is a selfing diploid with a short life cycle and is amenable to genetic manipulations, making it an accessible field-based model species for genetics and epigenetics. The availability of a high-quality reference genome is vital for understanding pennycress physiology and for clarifying its evolutionary history within the Brassicaceae. Here, we present a chromosome-level genome assembly of var. MN106-Ref with improved gene annotation and use it to investigate gene structure differences between two accessions (MN108 …

Agricultural Intensification Can Help Protect The Amazon Forest And Reduce Global Warming / Protecting The Amazon Forest And Reducing Global Warming Via Agricultural Intensification, Fabio R. Marin, Alencar J. Zanon, Juan P. Monzon, José F. Andrade, Evandro H.F.M. Silva, Gean L. Richter, Luis A.S. Antolin, Bruna S.M.R. Ribeiro, Giovanna G. Ribas, Rafael Battisti, Alexandre B. Heinemann, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

The Amazon basin includes 550 M ha covered with rainforests, with 60% of this area being in Brazil. Conversion of rainforest for soybean production raises concerns about the degree to which Brazil can reconcile production and environmental goals. Here we investigated the degree to which intensification could help Brazil produce more soybean without further encroachment of the Amazon Forest. Our analysis shows that continuation of current trends in soybean yield and area would lead to conversion of additional 5.7 M ha of forests and savannas during the next 15 years, with an associated 2550 Mt of CO2eq released into the …

Climate Change And Management Impacts On Soybean N Fixation, Soil N Mineralization, N2O Emissions, And Seed Yield, Elvis F. Elli, Ignacio A. Ciampitti, Michael J. Castellano, Larry C. Purcell, Seth Naeve, Patricio Grassini, Nicolas C. La Menza, Luiz Moro Rosso, André F. De Borja Reis, Péter Kovács, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Limited knowledge about how nitrogen (N) dynamics are affected by climate change, weather variability, and crop management is a major barrier to improving the productivity and environmental performance of soybean-based cropping systems. To fill this knowledge gap, we created a systems understanding of agroecosystem N dynamics and quantified the impact of controllable (management) and uncontrollable (weather, climate) factors on N fluxes and soybean yields. We performed a simulation experiment across 10 soybean production environments in the United States using the Agricultural Production Systems sIMulator (APSIM) model and future climate projections from five global circulation models. Climate change (2020–2080) increased N …

Pertumbuhan Dan Hasil Kangkung Akuaponik Dengan Perlakuan Berbagai Jenis Pupuk Foliar Dan Padat Tebar Lele Pada Sistem Budikdamber Lele-Kangkung, Nyayu Siti Khodijah, Reza Arisandi, Herry Marta Saputra, Ratna Santi

Jurnal Kultivasi

Kangkung (Ipomoea reptans Poir) adalah sayuran potensial untuk dikembangkan pada sistem akuaponik. Kelemahan akuaponik adalah nutrisi yang hanya bertumpu pada sisa pakan dan kotoran ikan, sehingga tanaman memerlukan pasokan hara dari sumber lain. Pemberian pupuk foliar merupakan salah satu upaya yang dilakukan untuk meningkatkan hasil kangkung pada sistem akuaponik. Penelitian ini bertujuan untuk mengetahui pengaruh jenis pupuk foliar dan padat tebar lele terhadap hasil kangkung pada sistem akuaponik menggunakan budidaya ikan dalam ember (budikdamber). Penelitian ini dilakukan mulai Oktober sampai Desember 2021 di unit Penelitian Universitas Bangka Belitung. Percobaan menggunakan Rancangan Split Plot dengan dua faktor perlakuan. Faktor pertama (petak …

Peningkatan Hasil Tiga Varietas Bawang Merah Asal Biji Dengan Pemanfaatan Pupuk Organik Ikan Di Dataran Tinggi Basah, Bina Karo, Agustina Erlinda Marpaung, Susilawati Barus, Rina Christina Hutabarat, Rasiska Tarigan

Jurnal Kultivasi

Salah satu cara untuk meningkatkan produktivitas tanaman bawang merah pada musim hujan yaitu dengan penggunaan bahan tanaman yang sehat melalui penggunaan benih true shallot seeds (TSS), karena secara umum penggunaan umbi bawang merah sebagai bahan perbanyakan tidak efektif di musim hujan. Penelitian ini bertujuan untuk mengetahui dosis dan jenis pupuk organik ikan yang dapat meningkatkan produksi tiga varietas bawang merah asal TSS di dataran tinggi basah. Penelitian ini dilaksanakan mulai bulan Mei – September 2018 di Instalasi Penelitian dan Pengkajian Teknologi Pertanian (IP2TP) Berastagi, Kabupaten Karo, pada ketinggian tempat 1340 meter dengan jenis tanah Andisol. Rancangan yang digunakan adalah Rancangan …

Two Fingerprinting Sets For Humulus Lupulus Based On Kasp And Microsatellite Markers, Mandie Driskill, Katie Pardee, Kim E. Hummer, Jason D. Zurni, Keenan L. Amundsen, Annette Wiles, Claudia Wiedowi, Josef Patza, John A. Henningi, Nahla V. Bassili

Department of Agronomy and Horticulture: Faculty Publications

Verification of clonal identity of hop (Humulus lupulus L.) cultivars within breeding programs and germplasm collections is vital to conserving genetic resources. Accurate and economic DNA-based tools are needed in dioecious hop to confirm identity and parentage, neither of which can be reliably determined from morphological observations. In this study, we developed two fingerprinting sets for hop: a 9-SSR fingerprinting set containing high-core repeats that can be run in a single PCR reaction and a kompetitive allele specific PCR (KASP) assay of 25 single nucleotide polymorphisms (SNPs). The SSR set contains a sex-linked primer pair, HI-AGA7, that was used …

Marker-Trait Association Mapping Of Sorghum Mosaic Virus Resistance In Sugarcane, Chenie Zamora

LSU Master's Theses

Mosaic is a potentially devastating disease of sugarcane that had severe economic impact on Louisiana’s sugarcane industry in the 1920’s and has caused periodic problems ever since. The disease is vectored by migrating aphids that transmit Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV) in a non-persistent manner. Mosaic in Louisiana is currently caused by strains of SrMV. Mosaic has been controlled primarily by developing resistant cultivars. Recently, mosaic was detected in some near-commercial clones in the cultivar selection program. This prompted extensive screening of breeding program parent populations that detected infiltration of susceptibility and revealed the need for …

Re-Evaluation Of Late Season Action Thresholds And The Effect Of Seed Treatments On Early Season Colonization Of Threecornered Alfalfa Hopper, Spissistilus Festinus (Say), In Louisiana Soybean, Glycine Max (L) Merr, Tyler Ray Tagle Musgrove

LSU Master's Theses

Soybean, Glycine max (L.) Merr, is considered the most economically important oil and feed crop in the US and is grown on nearly 35,000,000 ha on an annual basis. Factors that limit yield include weed pressure, disease infection, and of particular interest to entomologists, insect herbivory. Soybean is targeted by a range of above and below ground pests which are primarily controlled by insecticides. Neonicotinoids are a recently popularized insecticide class that when applied as a seed treatment, can provide protection from early season pests. The most economically significant early season pest is threecornered alfalfa hopper, Spissistilus festinus (Say), whose …

Pemilihan Teknik Aplikasi Dan Dosis Pupuk Hayati Pelarut Kalium Untuk Meningkatkan Serapan Kalium Dan Pertumbuhan Tanaman Jagung Pada Tanah Inceptisols, Diyan Herdiyantoro, Tualar Simarmata, Mieke Rochimi Setiawati, Nenny Nurlaeny, Benny Joy, Mahfud Arifin, Jajang Sauman Hamdani, Iin Handayani

Jurnal Kultivasi

Salah satu strategi yang diterapkan pada pupuk hayati untuk menunjukkan efek positif pada tanaman yang diinokulasi adalah pemilihan teknik aplikasi dan dosis yang tepat, baik pada tanah, benih, atau kombinasi keduanya. Tujuan dari percobaan ini adalah mendapatkan teknik aplikasi dan dosis pupuk hayati pelarut K yang memberikan hasil terbaik terhadap penyerapan K dan pertumbuhan tanaman jagung (Zea mays L.) pada Inceptisols Jatinangor. Percobaan dilaksanakan pada November 2018-Januari 2019 di rumah kaca Fakultas Pertanian Universitas Padjadjaran. Percobaan menggunakan rancangan acak kelompok dengan 9 perlakuan dan 3 kali ulangan. Perlakuan terdiri dari tanpa perlakuan (kontrol), aplikasi pada benih 400 g.ha-1 dan 800 …