Search Results

You are looking at 1 - 9 of 9 items for :

  • Author or Editor: Robert L. Geneve x
  • HortTechnology x
Clear All Modify Search

A laboratory exercise is presented that demonstrates the impact of seed coverings and hormones on seed dormancy and release in seeds with endogenous, physiological dormancy. The materials and methods are simple and inexpensive and can be accomplished as an on-campus laboratory or as a distance education exercise. The execution of the laboratory is rapid (≈1 hour), and the results are obtained in 2 weeks. The exercise generates an opportunity for the discussion of a complex subject that involves the interaction of two tissue types within the seed (the embryo vs. the seed coverings) and nicely illustrates their role in seed dormancy maintenance.

Full access

Interactive web-based questions were developed for students to review subject matter learned in an online plant propagation course. Articulate Storyline software was used to build nearly 250 review questions with five different testing styles to ascertain proficiency in subject areas, including the biology of propagation, the propagation environment, seed propagation, vegetative propagation, micropropagation, and cell culture. Questions were arranged to correspond to the supporting textbook chapters in Hartmann and Kester’s Plant propagation: Principles and practices, ninth edition. These are open access and available to instructors and students worldwide. Users received immediate feedback for each question answered correctly or incorrectly. The system remembers where one leaves off, which enables starting and stopping multiple times within a chapter. Means of pre- and posttest responses to nine content knowledge items showed that students perceived a significant content knowledge gain in the course. These online interactive reviews can be adapted easily to other courses in a variety of fields, including horticulture, botany, systematics, and biology. They can also be expanded to overlay multiple objects and trigger events based on user response. Since inception, the website hosting these online reviews averaged 156 unique visitors per month. Students have reported this to be a useful tool to prepare them for course exams.

Free access

A mobile web application called PropG was developed for students to quickly access more than 270 glossary terms defined in a plant propagation textbook. The functionality and usefulness of the app was evaluated by 53 students enrolled in a semester-long online course in plant propagation. Means of pre- and post-test responses to 17 knowledge items showed students perceived a significant knowledge gain in the course for each of the subject categories evaluated. Most students agreed or strongly agreed this learning tool was organized and easy to navigate and would use it in the future. Since 2021, PropG received 153,645 total page views, 90,818 unique visits, and 17,216 returning visits, showing its widespread use in plant propagation.

Open Access

Pawpaw (Asimina triloba) is an under-exploited small tree with commercial potential as a fruit crop, ornamental tree, and source of secondary products with insecticidal and medicinal properties. It is most often propagated from seeds that are recalcitrant and must be stored moist at a chilling temperature. Seeds display combinational (morphophysiological) dormancy. Endogenous, physiological dormancy is broken by about 100 days of chilling stratification followed by a period of warm moist conditions where the small embryo develops prior to seedling emergence about 45 days after the warm period begins. Pawpaw cultivars with superior fruit characteristics are propagated by grafting onto seedling understocks. The most common practice is chip budding. Other methods of clonal propagation have proven problematic. Pawpaw can be propagated from cuttings, but only in very young seedling stock plants. Micropropagation from mature sources is not yet possible, but shoot proliferation has been accomplished from seedling explants and explants rejuvenated by induction of shoots from root cuttings of mature plants. However, rooting of microcuttings and subsequent acclimatization has not been successful.

Full access

The green industry has identified the use of biodegradable containers as an alternative to plastic containers as a way to improve the sustainability of current production systems. Field trials were conducted to evaluate the performance of four types of 1-gal nursery biocontainers [keratin (KR), wood pulp (WP), fabric (FB), and coir fiber (Coir)] in comparison with standard black plastic (Plastic) containers on substrate temperature, water use, and biomass production in aboveground nurseries. Locations in Kentucky, Michigan, Mississippi, and Texas were selected to conduct experiments during May to Oct. 2012 using ‘Green Velvet’ boxwood (Buxus sempervirens × B. microphylla) and ‘Dark Knight’ bluebeard (Caryopteris ×clandonensis) in 2013. In this article, we were focusing on the impact of alternative container materials on hourly substrate temperature variations and plant growth. Substrate temperature was on an average higher (about 6 °C) in Plastic containers (about 36 °C) compared with that in WP, FB, and Coir containers. However, substrate temperature in KR containers was similar to Plastic. Substrate temperature was also influenced by local weather conditions with the highest substrate temperatures recorded in Texas followed by Kentucky, Mississippi, and Michigan. Laboratory and controlled environment trials using test containers were conducted in Kentucky to evaluate sidewall porosity and evaporation loss to confirm field observations. Substrate temperature was similar under laboratory simulation compared with field studies with the highest substrate temperature observed in Plastic and KR, intermediate in WP and lowest in FB and Coir. Side wall temperature was higher in Plastic, KR, and FB compared with WP and Coir, while side wall water loss was greatest in FB, intermediate in WP and Coir, and lowest in plastic and KR. These observations suggest that the contribution of sidewall water loss to overall container evapotranspiration has a major influence on reducing substrate temperature. The porous nature of some of the alternative containers increased water use, but reduced heat stress and enhanced plant survival under hot summer conditions. The greater drying rate of alterative containers especially in hot and dry locations could demand increased irrigation volume, more frequent irrigation, or both, which could adversely affect the economic and environmental sustainability of alternative containers.

Free access

The performance of biocontainers as sustainable alternatives to the traditional petroleum-based plastic containers has been researched in recent years due to increasing environmental concern generated by widespread plastic disposal from green industry. However, research has been mainly focused on using biocontainers in short-term greenhouse production of bedding plants, with limited research investigating the use of biocontainers in long-term nursery production of woody crops. This project investigated the feasibility of using biocontainers in a pot-in-pot (PIP) nursery production system. Two paper (also referred as wood pulp) biocontainers were evaluated in comparison with a plastic container in a PIP system for 2 years at four locations (Holt, MI; Lexington, KY; Crystal Springs, MS; El Paso, TX). One-year-old river birch (Betula nigra) liners were used in this study. Results showed that biocontainers stayed intact at the end of the first growing season, but were penetrated to different degrees after the second growing season depending on the vigor of root growth at a given location and pot type. Plants showed different growth rates at different locations. However, at a given location, there were no differences in plant growth index (PGI) or plant biomass among plants grown in different container types. Daily water use (DWU) was not influenced by container type. Results suggest that both biocontainers tested have the potential to be alternatives to plastic containers for short-term (1 year) birch production in the PIP system. However, they may not be suitable for long-term (more than 1 year) PIP production due to root penetration at the end of the second growing season.

Free access

Containers made from natural fiber and recycled plastic are marketed as sustainable substitutes for traditional plastic containers in the nursery industry. However, growers’ acceptance of alternative containers is limited by the lack of information on how alternative containers impact plant growth and water use (WU). We conducted experiments in Michigan, Kentucky, Tennessee, Mississippi, and Texas to test plant growth and WU in five different alternative containers under nursery condition. In 2011, ‘Roemertwo’ wintercreeper (Euonymus fortunei) were planted in three types of #1 (≈1 gal) containers 1) black plastic (plastic), 2) wood pulp (WP), and 3) recycled paper (KF). In 2012, ‘Green Velvet’ boxwood (Buxus sempervirens × B. microphylla siebold var. koreana) was evaluated in 1) plastic, 2) WP, 3) fabric (FB), and 4) keratin (KT). In 2013, ‘Dark Knight’ bluebeard (Caryopteris ×clandonensis) was evaluated in 1) plastic, 2) WP, and 3) coir fiber (Coir). Plants grown in alternative containers generally had similar plant growth as plastic containers. ‘Roemertwo’ wintercreeper had high mortality while overwintering in alternative containers with no irrigation. Results from different states generally show plants grown in fiber containers such as WP, FB, and Coir used more water than those in plastic containers. Water use efficiency of plants grown in alternative containers vs. plastic containers depended on plant variety, container type, and climate.

Free access

As high-input systems, plant production facilities for liner and container plants use large quantities of water, fertilizers, chemical pesticides, plastics, and labor. The use of renewable and biodegradable inputs for growing aesthetically pleasing and healthy plants could potentially improve the economic, environmental, and social sustainability of current production systems. However, costs for production components to integrate sustainable practices into established systems have not been fully explored to date. Our objectives were to determine the economic costs of commercial production systems using alternative containers in aboveground nursery systems. We determined the cost of production (COP) budgets for two woody plant species grown in several locations across the United States. Plants were grown in plastic pots and various alternative pots made from wood pulp (WP), fabric (FB), keratin (KT), and coconut fiber (coir). Cost of production inputs for aboveground nursery systems included the plant itself (liner), liner shipping costs, pot, pot shipping costs, substrate, substrate shipping costs, municipal water, and labor. Our results show that the main difference in the COP is the price of the pot. Although alternative containers could potentially increase water demands, water is currently an insignificant cost in relation to the entire production process. Use of alternative containers could reduce the carbon, water, and chemical footprints of nurseries and greenhouses; however, the cost of alternative containers must become more competitive with plastic to make them an acceptable routine choice for commercial growers.

Free access