The influence of fertilization rate on nitrogen (N) and phosphorus (P) nutrient partitioning and uptake efficiency of young, container-grown azalea ( Rhododendron L. ‘Karen’) was determined under controlled greenhouse conditions during Spring 2001 and 2002. In 2001, fertilizer treatments included a factorial combination of two N (25 or 250 mg/week) and three P (0, 5, or 25 mg/week) rates; in 2002, an additional N rate (100 mg/week) was included in the experimental design. Five destructive harvests were performed during each study; plant tissues (root, stem, primary and secondary branches and leaves) from each harvest were analyzed to derive total N and P uptake. Leachates from containers were monitored and analyzed weekly to calculate nitrate (NO ₃ -N), ammonium (NH ₄ -N), and orthophosphate (PO ₄ -P) loss. Fertilization rates of 5 mg P per week in 2001 and rates of 100 mg N per week and 5 mg P per week in 2002 maintained optimal growth compared with the highest fertilization rates (250 mg N and 25 mg P per week) in these studies. Increasing N fertilization rate largely promoted shoot growth, whereas decreasing N and P fertilization rates promoted root growth and increased uptake efficiency. In general, increasing N and P fertilization rates increased nutrient N and P leaching from the pine bark substrate. Reducing excess N and P fertilization to match plant growth requirements of young azalea increases nutrient uptake efficiency and reduces nutrient loss to the environment.

Water security in ornamental plant production systems is vital for maintaining profitability. Expensive, complicated, or potentially dangerous treatment systems, together with skilled labor, is often necessary to ensure water quality and plant health. Two contrasting commercial ornamental crop production systems in a mesic region are compared, providing insight into the various strategies employed using irrigation-water containment and treatment systems. The first is a greenhouse/outdoor container operation which grows annual ornamental plants throughout the year using irrigation booms, drip emitters, and/or ebb and flow systems depending on the crop, container size, and/or stage of growth. The operation contains and recycles 50–75% of applied water through a system of underground cisterns, using a recycling reservoir and a newly constructed 0.25 ha slow-sand filtration (SSF) unit. Groundwater provides additional water when needed. Water quantity is not a problem in this operation, but disease and water quality issues, including agrochemicals, are of potential concern. The second is a perennial-plant nursery which propagates cuttings and produces field-grown trees and containerized plants. It has a series of containment/recycling reservoirs that capture rainwater and irrigation return water, together with wells of limited output. Water quantity is a more important issue for this nursery, but poor water quality has had some negative economic effects. Irrigation return water is filtered and sanitized with chlorine gas before being applied to plants via overhead and micro-irrigation systems. The agrochemical paclobutrazol was monitored for one year in the first operation and plant pathogens were qualified and quantified over two seasons for both production systems. The two operations employ very different water treatment systems based on their access to water, growing methods, land topography, and capital investment. Each operation has experienced different water quantity and quality vulnerabilities, and has addressed these threats using a variety of technologies and management techniques to reduce their impacts.

Aronia mitschurinii is a fruiting plant that has the potential of becoming the next-generation superfood. The fruit contains high concentrations of flavonoids, polyphenols, and anthocyanins, which are known to be powerful antioxidants. The fruit is regarded for its potential to treat oxidative stress diseases like cancer. Recent studies have proven that this fruit contains significantly more antioxidants than the acai berry and even 40 times more than tomatoes. Here, we report results for developing and optimizing the horticultural management program for growing aronia on Maryland small farms to produce the crop with the highest possible antioxidant capacity, based on observations since 2009. This was achieved by analyzing how plant age, fertilizers, mineral soil amendments, and other factors like disease and pest pressure affect the antioxidant content. This data can help in improving sustainability of local farm businesses by providing them with new alternative and highly profitable crops to grow and process. Analysis and comparison of the fruit yield, soluble sugar content (degrees Brix), pH, total polyphenols, total anthocyanins, and total flavonoids of aronia based on two treatment levels of nitrogen fertilizer (3 g N plant(-1) year(-1) vs 14 g plant(-1) year(-1)) and conventional and organic-based nitrogen are presented. Plants were fertilized with either 127 g (rows A and C) or 27 g (rows B and D) of Bartlett's Boost Natural at the base of each plant. This equated to 14 and 3 g of N, respectively. Average yields of plants given 14 g of organic N were only significantly higher than those given only 3 g of conventional N but not organic N. The yield in all plants increased year by year from 2009 and until 2019 and slightly decreased in 2020. Even though an increase in the anthocyanin content was noted for a lower N rate, the higher N rate would have produced more fruit and hence more anthocyanin per hectare. A higher nitrogen (N) rate positively affected the yield, but not always the phytochemical content. Organic N did not have a positive effect on the phytochemical content. Additionally, we report the cyanide content of aronia fruit in comparison to other fruits.

Recycling irrigation reservoirs (RIRs) are an emerging aquatic ecosystem of critical importance, for conserving and protecting increasingly scarce water resources. Here, we compare water quality between runoff entrance and middle of four RIRs in nurseries in Virginia (VA) and Maryland (MD). Surface water temperature (T) and oxidation-reduction potential (ORP) were lower in the middle than at the entrance, while the trend was opposite for dissolved oxygen (DO), pH and chlorophyll a (Chla). The magnitude of these differences between the entrance and middle decreased with increasing depth. These differences were magnified by water stratification from April to October. Minimum differences were observed for electrical conductivity (EC), total dissolved solids (TDS) and turbidity (TUR). Cluster analyses were performed on water quality difference data to evaluate whether the differences vary with respect to reservoirs. Two clusters were formed with one consisting primarily of VA reservoirs, and the other consisting mostly of MD reservoirs in both years. Water quality in the middle and at the entrance of RIRs was expected to vary greatly because of runoff inflow. The two-point water quality differences observed here, although statistically significant, are not large enough to cause significant impact on crop health and productivity for most water quality parameters except pH. Additional analysis of outlet data shows that the range and magnitude of water quality difference between the middle and the outlet are comparable to those between the middle and entrance of RIRs. These results indicate that monitoring at a single point is sufficient to obtain reliable water quality estimates for most water quality parameters in RIRs except pH. This is important when considering the cost of labor and equipment necessary for documenting water quality in agricultural production systems. However, additional pH measurements are still necessary to make practical water quality management decisions.