2011 Annual Report
1a.Objectives (from AD-416)
The objective of this unified research effort is to improve the efficiency of plant production through a multi-disciplinary team approach that focuses on scheduling, the environment, energy, nutrient, water, and chemical growth regulator resources.
1b.Approach (from AD-416)
Develop protocols to flower plants at a specified plant size for the retail environment, and extending the marketing season by producing early- or late-flowering plants for different locations in the U.S. A single product or tank mix growth retardant applications for new crops that reduce elongation most without delaying flowering and whether innovative practices such as rewetting of foliage increases efficiency of growth regulators. Identify the crops and stages of development in which lighting is most effective. In addition, photoperiodic lighting is increasingly being used to induce earlier flowering during the winter and spring. Determine how photoperiodic lighting can be maximized by investigating how light quantity, quality, and duration (including cyclic lighting) impact flowering of a range of popular garden plants. Potential energy savings will be quantified by optimizing light and temperature to produce crops in the most efficient and cost-effective manner for different locations in the U.S. Develop tools and techniques that allow growers to more precisely control and manipulate flowering of greenhouse crops. Techniques will be developed for producing 'programmed' liners that have the branching, height potential, and flower bud development necessary so that the liner can be simply transplanted and quickly finished. "Bud meters" will be developed for important floriculture crops so that growers can manage greenhouse environments in order to properly time flowering on finished crops or to possibly reduce greenhouse temperatures to save fuel costs while still hitting the targeted market dates. Determine optimal fertilziation rates and tissue nutrient levels to maximize growth of flowering plants and characterize the symptoms of nutritional disorders. Measure nutrient uptake through leaves, stems, and roots at different stages of rooting under greenhouse and controlled hydroponic conditions to match fertilizer supply with demand. Quantify the interaction of applied water and fertilizer rates on leaching of different forms of nutrients from propagation media. Identify the fertigation strategies that reduce nutrient leaching while maintaining crop health.
We continued to research the effect of temperature on crop timing and plant quality for a range of popular bedding plant species. Nineteen different crops were grown at temperatures ranging from 57 to 79 °F, and flowering data were recorded including flowering date, flower number at first flowering, and plant height at flowering. From this data, we are estimating the base temperature, which is the temperature at which plant development begins. We are repeating this experiment so that models can be developed for each crop with more robust data sets.
We continued to develop genetic and genomic resources to improve the efficiency of breeding for complex traits in petunia, including crop timing traits. We screened the currently available gene sequences for petunia to identify sequences that would be useful as molecular genetic ‘markers’. Additionally, we continued to develop hybrid populations that will be useful for identifying novel traits for improvement of petunia and for elucidating the genetic control of these traits.
In the past year, we have published much of our research in various grower magazines, and have presented the information to growers at meetings throughout the U.S. These articles appeared in print and are also available online at the Michigan State University Floriculture website.
This information helps growers improve crop scheduling and understand the impacts of temperature and light on floriculture crop production. In addition, some of the crop-specific information generated in this project has been incorporated in Virtual Grower, allowing growers to identify the effects of temperature on cropping time and energy consumption for heating.
We identified approximately 200 molecular genetic markers that will be useful for genetic mapping of traits in petunia. We developed a genetic linkage map for an interspecific hybrid petunia population comprising 110 of these markers. We also collected phenotypic data on the population, including traits related to crop timing, such as leaf unfolding rate, days to flower and the number of leaves that form prior to flowering, and crop quality traits such as flower size, branching habit, internode length and plant height. Combining these data sets allowed us to identify regions of the petunia genome that control these traits. The molecular markers located nearest to these genomic regions will be useful ‘landmarks’ for breeders looking to improve these traits.
This research relates to ARS parent project sub-objective 2a: evaluate the use of non-destructive sensor technology to measure and predict the impact of biotic and abiotic stresses in ornamental crops. The project was monitored through periodic reports and conference meetings.