University Catalog 2024-2025

Horticultural Science

The Department offers graduate programs leading to the Master of Horticultural Science (non-thesis), Master of Science (thesis) and Doctor of Philosophy (thesis) degrees.  Completion of the respective requirements normally takes 2 to 2 ½ years for the Masters and 3 to 3 ½ years for the Doctor of Philosophy.  Studies may be oriented to floriculture, ornamental and landscape horticulture, pomology (fruit crops) or olericulture (vegetables).  A variety of areas for study and research are available: plant physiology, breeding and genetics, herbicide physiology, nutrition, propagation, plant molecular biology and biotechnology, genomics, growth regulators, postharvest physiology, sustainable and organic agriculture, fruits, vegetables, floriculture, woody ornamentals, and landscape horticulture.

Facilities for graduate studies include 40,500 square feet of greenhouse space; the University Phytotron (available for controlled environmental studies on horticultural crops); 19 well-equipped laboratories; 14 controlled temperature storage rooms, an extensive collection of plant materials, both living and preserved; and a variety of climates and soils from coast to mountains in North Carolina on eighteen outlying research stations.

Financial Assistance

Financial assistance in the form of a Graduate Assistantship may be available for students accepted into the program. However, funding is limited and positions are highly competitive within a major professor’s program area. You should contact the faculty within the department that are working in your area of interest to inquire about assistantship availability. Students must have a confirmed advisor for admission to the program.

More Information

Horticultural Science Program Website

Admission to The Graduate School and the Department is competitive.  Admission is usually limited to students with a grade point average of 3.00 or higher.  Horticultural Science candidates should have completed course work in physics, mathematics (preferably calculus and statistics), chemistry, biochemistry, soils, plant pathology, genetics, plant physiology, entomology, genomics/bioformatics, botany/plant biology, cellular biology, molecular biology and several courses in horticulture.  Landscape Horticulture candidates should have a complete landscape design background.  An applicant deficient in course work may be admitted on a provisional basis until the deficiency is made up.  Applicants must provide the basic Graduate Record Examination (GRE) scores, three letters of reference, an unofficial transcript for each previous degree, a personal statement and resume/CV.  Applicants from other countries must also furnish evidence of proficiency in English (TOEFL, IELTS or Duolingo). TOELF or IELTS test date must be no older than two years (24 months) prior to the beginning of the requested entry term.

Applicant Information

Horticultural Science (MS and PhD)

  • Delivery Method: On-Campus
  • Entrance Exam: None
  • Interview Required: None

Horticultural Science (MR)

  • Delivery Method: On-Campus, Online, Hybrid
  • Entrance Exam: None
  • Interview Required: None

Application Deadlines

  • Fall: January 15 (US and Intl)
  • Spring: August 1 (US and Intl)
  • Summer 1: January 15 (US and Intl)
  • Summer 2: January 15 (US and Intl)

Faculty

  • Lucy K. Bradley
  • Wayne G. Buhler
  • Nancy G. Creamer
  • Angel Elisa Cruz
  • Kedong Da
  • John Martin Dole
  • Gina E. Fernandez
  • Carlos Ariel Iglesias Frascheri
  • William Carl Fonteno III
  • Christopher Gunter
  • Brian Eugene Jackson
  • Julia L. Kornegay
  • Frank John Louws
  • David W. Monks
  • Joseph C. Neal
  • Penelope M Perkins-Veazie
  • Emmanuel Torres Quezada
  • Thomas G. Ranney
  • Michelle Schroeder-Moreno
  • Jonathan R. Schultheis
  • Julieta Trevino Sherk
  • Acer VanWallendael
  • Todd Craig Wehner
  • Brian E Whipker
  • George C. Yencho
  • Jeanine M. Davis
  • Barbara Fair
  • Ricardo Hernandez
  • Massimo Iorizzo
  • Katherine Mary Jennings
  • Helen Tyler Kraus
  • Anthony V. Lebude
  • Dilip Raj Panthee
  • Michael L. Parker
  • Anne McCombe Spafford
  • Hsuan Chen
  • Hamid Ashrafi
  • Mark Hoffmann
  • Timothy Joseph Kelliher
  • Melinda Jean Knuth
  • Thomas Matthew Kon
  • Wusheng Liu
  • Danesha Gita Seth Carley
  • Rebecca Diane Dunning
  • Remington Ariel Ham
  • Marcelo Mollinar
  • Reza Shekasteband
  • Charlotte D. Glen
  • Jing Zhang

Courses

HS 502/PP 502/CS 502  Plant Disease: Methods & Diagnosis  (2 credit hours)  

Introduction to the basic principles of disease etiology in plants and the methods used to research and diagnose plant diseases caused by bacteria (and other prokaryotes), fungi (and oomycetes), nematodes and viruses. Lab-based course intended to give graduate students a practical, hands-on research experience for diagnosing and characterizing each plant pathogen group. Introduction to pathogen-specific as well as more general experimental techniques utilized in plant pathology. No course prerequisites, but prior experience in microbiology and/or completion of PP 315, PP 501 or equivalent will benefit the PP 502 learning experience.

Prerequisite: Graduate standing or department consent

Typically offered in Fall only

HS 503/HS 403  Plant Micropropagation and Tissue Culture  (3 credit hours)  

The course will introduce advanced plant propagation methods that cover micropropagation, tissue culture, sterile seed sowing, embryo rescue, fern spore culture, anther/pollen culture, and plant acclimation. Biotechnology based on tissue culture, including polyploid manipulation and gene transformation, will be also introduced. Emphasis will be placed on the technical aspects of plant propagation, as well as the biological basis for the responses demonstrated by plant species to different micropropagation protocols.

Prerequisites: C- or better in HS 301, or C- or better in CS 211, or C- or better in HS 215, or C- or better in GN 311, or C- or better in PB 250.

Typically offered in Fall only

HS 510  Applied Statistics in Horticultural Research  (1 credit hours)  

This course will introduce statistical methods frequently used in Horticulture research and will provide Horticulture graduate students with statistical guidance for their graduate research. The class will address (1) basic statistical methods for horticulture research, (2) options when working with skewed data, (3) horticulture relevant research design, and (4) evaluating inappropriate statistical analysis, interpretation, and experimental design.

R: Graduate students in Horticultural Science only

Typically offered in Fall only

HS 516/HS 416  Planting Design  (4 credit hours)  

Developing and cultivating a design process for creating meaningful and compelling ornamental planting designs through the study and practice of spatial articulation (form, enclosure, permeability), physical properties of plants (line, form, texture, color), client/site analysis and program development, visual journaling, garden narrative, presentation skills, utilizing principles of visual composition, design communication, and understanding and resolving technical and horticultural issues in contemporary planting design.

Prerequisite: Landscape Horticulture (11HORTTHL) concentration, HS 400

Typically offered in Fall only

HS 520/HS 420  Green Infrastructure  (3 credit hours)  

Green infrastructure is defined as the interconnected networks of natural and constructed ecological systems within and in-between urban areas. When implemented in a holistic way, green infrastructure can provide benefits at the residential, neighborhood, community levels providing for greater health and well-being, an improved functional environment, and a thriving dynamic economy. Well-designed urban landscapes offer significant economic and social benefits that directly improve the urban environment for people, plants and animals- from increasing real estate value and reducing energy costs, to enhancing health and food security, and providing habitat for a diverse population of animals and plants. Since addressing environmental issues requires a multidisciplinary approach, this course is designed for any student with interests in horticulture, biological engineering, landscape architecture, environmental sciences, urban forestry, and any others who care about the sustainability of their communities.

Typically offered in Fall only

This course is offered alternate even years

HS 521/HS 421  Temperate-Zone Tree Fruits: Physiology and Culture  (3 credit hours)  

Physiology and culture of the major temperate-zone tree fruit and nut crops of the United States. Fundamental principles underlying woody plant growth as applied to the culture of specific tree-fruit crops with emphasis on crops of commercial importance to North Carolina.

Prerequisite: BIO 181 or B0 200

Typically offered in Spring only

This course is offered alternate odd years

HS 532/HS 432  Introduction to Permaculture  (3 credit hours)  

Permaculture means "permanent culture," and ..."is the conscious design and maintenance of cultivated ecosystems that have the diversity, stability, and resilience of a natural ecosystem." [Bill Mollison] This course will explore a design/thinking methodology that seeks to provide our essential physical needs, food, water, shelter, energy, etc., while doing so in an environmentally friendly, sustainable manner. This course is restricted to upper level undergraduate, graduate, or matriculated continuing education students. STUDENTS MAY NOT RECEIVE CREDIT FOR BOTH HS 432 AND HS 532.

Typically offered in Fall and Summer

HS 533/HS 433  Public Garden Administration  (3 credit hours)  

This course addresses the practices, programs, and professional skills that are critical to the successful management of public gardens. The aim of the course is to better prepare graduate students and upper-level undergraduates for potential careers in public garden administration. Topics will include a brief history, impact, and current trends of public gardens in the United States; plant collections; managing staff, volunteers, and boards, and the visiting public; finances and fund raising; educational programming; visitor services; and careers in public gardens. Two Saturday off-campus field trips are required.

Typically offered in Fall only

This course is offered alternate even years

HS 541/CS 541  Plant Breeding Methods  (3 credit hours)  

Overview of plant breeding methods for advanced undergraduate and beginning graduate students. Covers principles and concepts of inheritance, germplasm resources, pollen control, measurement of genetic variances, and heterosis. Special topics include heritability, genotype-environment interaction, disease resistance, and polyploidy. In-depth coverage on methods for breeding cross-pollinated and self-pollinated crops. Prepares students for advanced plant breeding courses.

Prerequisite: ST 511, Corequisite: ST 512

Typically offered in Fall only

HS 550  Environmental Nursery Production  (3 credit hours)  

The course focuses on the impacts of the nursery industry on the environment and environmentally sound nursery practices. Exploration of the major challenges facing the nursery industry that drive decision making during production. Evaluation of past and current research addressing these challenges and sampling procedures and interpretation will be learned. Graduate status and an undergraduate nursery production or management course or working knowledge of nursery production required.

Prerequisite: HS 411, Nursery Management, or an equivalent course.

Typically offered in Fall only

This course is offered alternate odd years

HS 551/HS 451  Plant Nutrition  (3 credit hours)  

An understanding of the basic mineral nutrient requirements, nutritional monitoring procedures, and fertilizer application methods in horticultural production systems including those for fruits, field vegetables, fruits and vegetables under plasticulture, nursery crops, landscapes, greenhouse flowers and vegetables, interior plantscapes, hydroponics, and organic farming.

Prerequisite: SSC 200

Typically offered in Spring only

HS 562/FS 562/FS 462/HS 462  Postharvest Physiology  (3 credit hours)  

Preharvest and postharvest factors that affect market quality of horticultural commodities with an emphasis on technologies to preserve postharvest quality and extend storage life of fruits, vegetables and ornamentals.

Typically offered in Spring only

HS 576/HS 476  Crop Physiology and Production in Controlled Environments  (3 credit hours)  

This course focuses on plant eco-physiological responses to different environmental factors such as: light intensity, quality, duration and penetration; CO2 diffusion; thermodynamic properties of moist air; root environment; air dynamics; water relations; and canopy energy balance. In addition, the course emphasizes the application of controlled environment technologies to manipulate crop responses. The laboratory is designed to optimize the production of edible crops in greenhouses and vertical farms by applying the foundational knowledge of plant eco-physiology in combination with advance controlled environment technologies.

Prerequisite: PB 321 or PB 421 and either MA 114 or MA 121 or MA 131 or MA 141

Typically offered in Spring only

HS 590  Special Problems in Horticultural Science  (1-6 credit hours)  

Selection of a subject by each student on which to do research and write a technical report on the results. The individual may choose a subject pertaining to his or her particular interest in any area of study in horticultural science.

Typically offered in Fall, Spring, and Summer

HS 601  Professional Presentation Skills in Horticultural Science  (2 credit hours)  

The purpose of this course is to familiarize the students with the professional presentation skills they need to be successful. These skills include speaking, writing, poster and website development, based on the student's proposed research/project and literature review.

Typically offered in Fall only

HS 610  Special Topics in Horticultural Science  (1-6 credit hours)  

Investigation of special theoretical problems at 600 level in horticultural science not related to a thesis problem; new 600-level courses during developmental phase.

Typically offered in Fall, Spring, and Summer

HS 615  Advanced Special Topics  (1-6 credit hours)  

Investigation of theoretical problems at the 600 level in horticultural science not related to a thesis problem; new 600-level courses during the development phase.

Typically offered in Fall, Spring, and Summer

HS 685  Master's Supervised Teaching  (1-3 credit hours)  

Teaching experience under the mentorship of faculty who assist the student in planning for the teaching assignment, observe and provide feedback to the student during the teaching assignment, and evaluate the student upon completion of the assignment.

Prerequisite: Master's in Horticultural Science

Typically offered in Fall, Spring, and Summer

HS 688  Non-Thesis Masters Continuous Registration - Half Time Registration  (1 credit hours)  

For students in non-thesis master's programs who have completed all credit hour requirements for their degree but need to maintain half-time continuous registration to complete incomplete grades, projects, final master's exam, etc.

Prerequisite: Master's in Horticultural Science

Typically offered in Fall and Spring

HS 689  Non-Thesis Master Continuous Registration - Full Time Registration  (3 credit hours)  

For students in non-thesis master's programs who have completed all credit hour requirements for their degree but need to maintain full-time continuous registration to complete incomplete grades, projects, final master's exam, etc. Students may register for this course a maximum of one semester.

Prerequisite: Master's in Horticultural Science

Typically offered in Fall and Spring

HS 690  Master's Examination  (1-9 credit hours)  

For students in non thesis master's programs who have completed all other requirements of the degree except preparing for and taking the final master's exam.

Prerequisite: Master's in Horticultural Science

Typically offered in Fall, Spring, and Summer

HS 693  Master's Supervised Research  (1-9 credit hours)  

Instruction in research and research under the mentorship of a member of the Graduate Faculty.

Prerequisite: Master's in Horticultural Science

Typically offered in Fall, Spring, and Summer

HS 695  Master's Thesis Research  (1-9 credit hours)  

Thesis research.

Prerequisite: Master's in Horticultural Science

Typically offered in Fall, Spring, and Summer

HS 696  Summer Thesis Research  (1 credit hours)  

For graduate students whose programs of work specify no formal course work during a summer session and who will be devoting full time to thesis research.

Prerequisite: Master's in Horticultural Science

Typically offered in Summer only

HS 699  Master's Thesis Preparation  (1-9 credit hours)  

Original research on specific problems in fruit, vegetable and ornamental crops.

Prerequisite: Master's in Horticultural Science

Typically offered in Fall, Spring, and Summer

HS 703  Breeding Asexually Propagated Crops  (1 credit hours)  

Principles and problems associated with breeding clonally propagated crops and techniques used in overcoming these problems. Taught third five weeks of semester. Drop date is by last day of 3rd week of minicourse.

Prerequisite: CS 413

Typically offered in Fall only

HS 704  Plant Nomenclature  (1 credit hours)  

A practical foundation in plant nomenclature and nomenclatural references. Emphasis on the evolution of international rules for naming plant taxa and their application in both wild and cultivated plants. Nomenclature applications used in patents, cultivar releases and journal articles. Taught mid-semester. Taught five weeks of semester.

Prerequisite: PB 421

Typically offered in Spring only

HS 705  Physiology Of Flowering  (1 credit hours)  

Examination of physiological basis of flowering in plants such as: floral initiation, transition to reproductive growth; floral development; plant response to light, temperature, nutrition, water supply; plant age; chemical growth regulation and in vitro flowering. Taught first five weeks of fall semester. Drop date is by last day of 3rd week of minicourse.

Prerequisite: PB 421

Typically offered in Fall only

HS 707  Environmental Stress Physiology  (1 credit hours)  

Physiology of plant responses to environmental stresses, with emphasis on current research in selected physiological, molecular, and biochemical mechanisms for tolerance to environmental stresses such as temperature extremes, drought, salt, pathogens and other plants.

Prerequisite: PB 421

Typically offered in Fall only

This course is offered alternate odd years

HS 708  Application of Genomics to Plant Breeding  (1 credit hours)  

The latest advancements in plant breeding with genomics and sequencing technologies will be evaluated, and Linux, cloud computing, and Perl programming will be used to analyze genomics and transcriptomics data. Students will work with software packages commonly used for plant breeding and will give students practice with analyzing large data sets and manipulating text files beyond the capabilities of Microsoft Excel or similar spreadsheet programs.

R: Graduate Standing

Typically offered in Fall only

HS 709  Applied Plant-Light Interactions: Light Effects on Crop Yield, Morphology, and Development  (1 credit hours)  

This course focuses on the impact of light spectra on plant growth, morphology, and development. Plant responses to light intensity, ultraviolet, blue, green, red, and far-red light are presented and reinforced with examples from current research. Applications of these impacts are valuable throughout the agricultural sector.

Typically offered in Spring only

This course is offered alternate even years

HS 716/CS 716  Weed Biology  (3 credit hours)  

This course analyzes the interactions between human disturbance and dynamics of weed populations and communities. Emphasis is given to factors that drive weed control actions and the ecological and evolutionary processes by which weeds survive and adapt to these actions. Similarities and differences between weeds and invasive plant species are discussed as well as benefits and limitations of using traditional ecological theory from natural systems to explain weed behavior in highly disturbed environments.

Prerequisite: CS 414

Typically offered in Spring only

HS 717/CS 717  Weed Management Systems  (1 credit hours)  

Weed management systems including integration of cultural, biological, mechanical and chemical methods for vegetables, fruits, ornamentals, turf, small grains, corn, tobacco, cotton, peanuts, aquatic and non-cropland settings. Taught second 5 weeksof semester. Drop date is by last day of 3rd week of minicourse.

Prerequisite: CS 414

Typically offered in Fall only

HS 720/CS 720/GN 720  Molecular Biology In Plant Breeding  (3 credit hours)  

Theory and principles of molecular biology applied to plant breeding. Understanding of the relationship between genes and crop traits. Principles and molecular mechanisms of crop traits, and their applications to solve breeding problems and improve crop traits, which include heterosis, male/female sterility, self-incompatibility, polyploidy, double haploid, protoplast fusion, random mutagenesis, plant regeneration, transgenic breeding, advanced genome editing for breeding, gene silencing, gene activation, gene drive, plant synthetic biology, metabolic engineering, epigenetics for trait improvement, gene stacking, decoy and R genes, and bioconfinement.

P: CS 211 or GN 311 or equivalent, and PB 421 or equivalent.

Typically offered in Spring only

HS 725/SSC 725/TOX 725/CS 725  Pesticide Chemistry  (1 credit hours)  

Chemical properties of pesticides including hydration and solvation, ionization, volatilization, lipophilicity, molecular structure and size, and reactivity and classification according to chemical description, mode of action or ionizability. Taughtduring the first 5 weeks of semester. Drop date is last day of 3rd week of the minicourse.

Prerequisite: (CH 201 or CH 203) and (CH 221 or CH 225)

Typically offered in Fall only

HS 727/SSC 727/TOX 727/CS 727  Pesticide Behavior and Fate In the Environment  (2 credit hours)  

Sorption/desorption, soil reactivity, movement, volatilization, bioavailability, degradation and stability of pesticides in the environment. Taught during the last 10 weeks of semester. Drop date is last day of 3rd week of the minicourse.

Prerequisite: CS(HS,SSC,TOX) 725,SSC 200

Typically offered in Fall only

HS 729/CS 729  Herbicide Behavior In Plants  (2 credit hours)  

Chemical, physiological and biochemical actions of herbicides in plants including uptake, translocation, metabolism and mechanism of action.

Typically offered in Fall only

HS 745/CS 745/GN 745  Quantitative Genetics In Plant Breeding  (1 credit hours)  

Theory and principles of plant quantitative genetics. Experimental approaches of relationships between type and source of genetic variability, concepts of inbreeding, estimations of genetic variance and selection theory.

Prerequisite: CS(GN, HS) 541, ST 712, course in quantitative genetics recommended

Typically offered in Spring only

This course is offered alternate years

HS 746/CS 746/GN 746  Cytogenetics in Plant Breeding  (2 credit hours)  

Theory and principles of plant breeding methodology including population improvement, selection procedures, genotypic evaluation, cultivar development and breeding strategies.

Typically offered in Spring only

This course is offered alternate years

HS 757/GN 757/ST 757  Quantitative Genetics Theory and Methods  (3 credit hours)  

The essence of quantitative genetics is to study multiple genes and their relationship to phenotypes. How to study and interpret the relationship between phenotypes and whole genome genotypes in a cohesive framework is the focus of this course. We discuss how to use genomic tools to map quantitative trait loci, how to study epistasis, how to study genetic correlations and genotype-by-environment interactions. We put special emphasis in using genomic data to study and interpret general biological problems, such as adaptation and heterosis. The course is targeted for advanced graduate students interested in using genomic information to study a variety of problems in quantitative genetics.

Prerequisite: ST 511

Typically offered in Fall only

This course is offered alternate even years

HS 790  Special Problems in Horticultural Science  (1-6 credit hours)  

Selection of a subject by each student on which to do research and write a technical report on the results. The individual may choose a subject pertaining to his or her particular interest in any area of study in horticultural science.

Typically offered in Fall, Spring, and Summer

HS 815  Advanced Special Topics  (1-6 credit hours)  

Investigation of theoretical problems at 600 level in horticultural science not related to a thesis problem; new 600-level courses during development phase.

Typically offered in Fall, Spring, and Summer

HS 860/CS 860/GN 860  Plant Breeding Laboratory  (1 credit hours)  

Visitation of plant breeding projects in the Depts. of CS and HS at NC State, along with commercial seed companies. Discussion and viewing of breeding objectives, methods and equipment and teaching and practice of hybridization methods.

Prerequisite: HS 541 or CS 541

Typically offered in Spring only

This course is offered alternate even years

HS 861/CS 861/GN 861  Plant Breeding Laboratory  (1 credit hours)  

Visitation of plant breeding projects in the Depts. of CS and HS at NC State, along with commercial seed companies. Discussion and viewing of breeding objectives, methods and equipment and teaching and practice of hybridization methods.

P: CS 741 or GN 741 or HS 741

Typically offered in Fall only

This course is offered alternate even years

HS 885  Doctoral Supervised Teaching  (1-3 credit hours)  

Teaching experience under the mentorship of faculty who assist the student in planning for the teaching assignment, observe and provide feedback to the student during the teaching assignment, and evaluate the student upon completion of the assignment.

Typically offered in Fall, Spring, and Summer

HS 890  Doctoral Preliminary Examination  (1-9 credit hours)  

For students who are preparing for and taking written and/or oral preliminary exams.

Prerequisite: Doctoral student

Typically offered in Fall, Spring, and Summer

HS 895  Doctoral Dissertation Research  (1-9 credit hours)  

Dissertation Research

Prerequisite: Doctoral student

Typically offered in Fall, Spring, and Summer

HS 896  Summer Dissertation Research  (1 credit hours)  

For graduate students whose programs of work specify no formal course work during a summer session and who will be devoting full time to thesis research.

Prerequisite: Doctoral student

Typically offered in Summer only

HS 899  Doctoral Dissertation Preparation  (1-9 credit hours)  

For students who have completed all credit hour requirements, full-time enrollment, preliminary examination, and residency requirements for the doctoral degree, and are writing and defending their dissertations.

Prerequisite: Doctoral student

Typically offered in Fall, Spring, and Summer