Gene A Giacomelli

PMID: 14552353;Abstract:

The SUBSTOR crop growth model was adapted for controlled-environment hydroponic production of potato (Solanum tuberosum L. cv. Norland) under elevated atmospheric carbon dioxide concentration. Adaptations included adjustment of input files to account for cultural differences between the field and controlled environments, calibration of genetic coefficients, and adjustment of crop parameters including radiation use efficiency. Source code modifications were also performed to account for the absorption of light reflected from the surface below the crop canopy, an increased leaf senescence rate, a carbon (mass) balance to the model, and to modify the response of crop growth rate to elevated atmospheric carbon dioxide concentration. Adaptations were primarily based on growth and phenological data obtained from growth chamber experiments at Rutgers University (New Brunswick, N.J.) and from the modeling literature. Modified-SUBSTOR predictions were compared with data from Kennedy Space Center's Biomass Production Chamber for verification. Results show that, with further development, modified-SUBSTOR will be a useful tool for analysis and optimization of potato growth in controlled environments.

Abstract:

Greenhouse plant production systems include the nutrient delivery system, and the plant culture management technique, that are enclosed within a controlled environment. Fundamental engineering design will be inherent in all successful applications. The nutrient delivery system [NDS] consists of those hardware components that transport nutrient solution [water plus fertilizer] from a central location to each individual plant. The plant culture technique includes the procedures that are completed by the grower in order to produce a healthy crop of desired quality. These procedures or culture tasks are crop specific, but they are directly related to the type of NDS. The controlled environment includes the greenhouse, or other structure, and its environmental control systems that are implemented to obtain the desired climate in order to produce a quality crop within a predictable and repeatable time schedule. The paper will focus on the engineering applications of the nutrient delivery systems. The NDS will be described in terms of its mechanism for plant water delivery. Examples of traditional and unique applications of nutrient delivery systems will be discussed.

Tollefson, S. J., Curlango-Rivera, G., Huskey, D. A., Pew, T., Giacomelli, G., & Hawes. M.C. (2014). Altered Carbon Delivery from Roots: Rapid, Sustained Inhibition of Border Cell Dispersal in Response to Compost Water Extracts. Plant and Soil. doi: 10.1007/s11104-014-2350-z.

Abstract:

Under two combinations of roof and side vent openings of a semiarid greenhouse located in Tucson, Arizona, U.S.A, air and leaf temperatures, relative humidity, ventilation rate and water use (fog injection and plant water uptake) were measured. The natural ventilation rate was continuously measured by using SF6 as the tracer gas. Plant water uptake rate was measured using a sap flow gage. When the roof and side vents open, the inside temperature and ventilation rate were larger than when only the roof vent open. The inside air temperature increased with increasing ventilation rate. Converse responses were found for inside relative humidity and leaf temperature. Therefore, it follows that the vertical distribution of inside air temperature and relative humidity were increased with increasing ventilation rate. Water use in the greenhouse was reduced with decreasing ventilation rate and increasing internal relative humidity. Future work will be to develop the fog and vent control method to make air temperature and relative humidity uniform in the greenhouse and to reduce water use.

Abstract:

Floor heating is a promising technique to heat greenhouses using low quality energy. The large thermal inertia of floor heating systems requires some form of predictive control. To analyze the effectiveness of feedforward logic, first a prediction model has been developed and then an experiment using a controlled-environment chamber has been conducted. Basic control logic has been established and verified for controlling air temperature by energy input only to the floor. The combination of feedforward and feedback control should be the next step.