Current recommendations for sufficiency of nutrients in soil-less media for container grown nursery crops have been based on weak acid extraction and pour through sampling of media. Since the concentration of nutrients found in pour through samples are similar to those available in the media solution, sufficiency levels as determined by hydroponics studies have also been considered to be applicable to plants grown in a solid medium such as pine bark. Many variables, however, may affect nutrient availability in a solid medium which are not the same as those in a well-stirred hydroponics system. Objectives of this experiment were to compare growth and nutrient uptake patterns of Euonymous kiautschovica `Manhattan' and Prunus persica `Jefferson' grown in a pine bark/sand medium or a hydroponics system. Quantitative growth characteristics, depletion rates of nutrients in solution, concentration of ions in pour through samples, and tissue levels of N, P, K, Ca, and Mg will be reported.
Hydroponics is the method of growing plants under soilless conditions with nutrients, water, and an inert medium ( Savvas, 2003 ). Systems can be circulating, in which the nutrient solution is recirculated and nutrient levels are manipulated, or
), seedlings with similar growth and development were transferred to a hydroponics system. Seedlings were selected based on similar leaf counts and shoot heights, and deference was given to intact root systems to help ensure survival. The roots were dipped in
, 2008 ). Therefore, we have conducted a hydroponics study to test the efficacy of SYTOX blue dye in differentiating the viable and dead leaf and root cells of ‘Mariner’ and ‘Penncross’ under salt stress using confocal microscopy. Leaves and roots ≈2.0 cm
Abstract
Shoot or leaf cuttings can be rooted in flats of perlite under intermittent mist for use in a static solution culture system (Hershey and Merritt, 1986). However, removing perlite from the roots before transfer to hydroponics is tedious and damages the roots; also, all the perlite cannot be removed, which causes errors in dry mass and nutrient concentration determinations. A hydroponic propagation system was constructed of inexpensive, readily available materials that allowed rooting of large numbers of cuttings under intermittent mist.
The financial effectiveness of a soilless vertical bag system of hydroponics culture was evaluated for off-season strawberry (Fragaria ×ananassa Duch) production in heated greenhouses in northern Greece. Financial analysis revealed that the implementation of this soilless culture system instead of the traditional production system under plastic tunnels would not be profitable for Greek farmers due to its high initial investment and high fuel consumption. Sensitivity analysis indicated the importance of product price in affecting the magnitude of benefits, confirming the interest of farmers to produce off-season strawberries to market them when prices are likely to be higher. In addition, yield increase will have a positive effect upon farmers' income.
Nutrient uptake and allocation patterns of Forsythia ovata × europaea `Meadowlark' grown in a recirculating hydroponic system in the greenhouse were observed for 5 months. Dormant rooted cuttings were placed in the system on 8 May 1995. The nutrient solution supplied (in mg·L–1) 100 N, 48 P, 210 K, 30 Mg, 60 Ca, 117 SO4, 3 Fe, 0.5 Mn, 0.15 Zn, 0.15 Cu, 0.5 B, 0.1 Mo. Solutions were completely replaced every 2 weeks. Leaves, stems, and roots were harvested for dry weight and nutrient analysis at monthly intervals. Nitrogen uptake and dry-weight accumulation in the roots increased throughout the experiment, reaching a maximum in the fifth month (September). Nitrogen uptake and dry-weight accumulation of leaves and stems increased rapidly throughout the first 3 months, then leveled off. Whole-plant N recovery (N taken up/N in hydroponics system) reached a maximum (58%) between 6 July and 3 August. N recovery in the hydroponics system was about 10 times greater than what we observed in related experiments with woody plants in typical production environments, suggesting that there is potential for manipulating fertilization and cultural practices to increase fertilization efficiency in woody ornamentals. Nutrient recovery and accumulation patterns of P and K also will be presented.
Seedling of “Cortland” and “Idared” apples (Malus domestica) were grown in hydroponics and the shoots and roots were evaluated for percent concentration of calcium. “Cortland” is reported to be efficient in calcium uptake in comparison to “Idared”, reputed to be less efficient in calcium uptake and utilization. The seedlings were grown in hydroponic solutions containing calcium ranging from 0.5 ppm to 3.0 ppm concentrations. The shoots and the roots of the seedlings were analyzed for calcium content after 45 days. “Idared” seedling roots and shoots had higher calcium content at 0.5 ppm. However, at 1.5 ppm and at 3.0 ppm “Cortland” seedlings appear to be more efficient at calcium uptake. Early screening may be a useful tool in helping apple breeders select future cultivars that are more efficient at calcium uptake
Relative salinity tolerance of 33 creeping bentgrass (Agrostis palustris Huds), one colonial bentgrass (A. capillaris L.), and one velvet bentgrass (A. canina L.) cultivars were determined via hydroponics in a controlled-environment greenhouse. After gradual acclimation, grasses were exposed to moderate salinity stress (8 dS·m-1) for 10 weeks to determine tolerance to chronic salinity stress. Relative dry weight of leaf clippings (RLW), percentage of green leaf area (GL), root dry weight (RW), and root length (RL) were all effective parameters for predicting salinity tolerance. Following 10 weeks of salinity stress, RLW was correlated with GL (r = 0.72), with RW (r = 0.71), and with RL (r = 0.66). The range of salinity tolerance among cultivars was substantial. `Mariner', `Grand Prix', `Seaside', and `Seaside II' were salt-tolerant, `L-93', `Penn G-2', `18th Green', and `Syn 96-1' were moderately salt tolerant, and `Avalon', `Ambrosia', `SR1119', `Regent', `Putter', `Penncross', and `Penn G-6' were salt sensitive.
The effect of specific ion toxicity during salt stress was tested in the present study. The experiment was repeated twice, in 1996 and 1998, with `Nemaguard' peach seedlings and rooted cuttings grown in hydroponics under two NaCl concentrations (50 and 30 mm). Foliage was separated in symptomatic and symptomless leaves and the amount of sodium (Na+) and chloride (C1–) was determined. Significantly higher Na+ content was found in symptomatic than in symptomless leaves in both experiments, whereas in only two of the six cases was Cl– content higher in symptomatic than in symptomless leaves. The Na+ threshold for leaf scorch was somewhere between 4 and 6 mg·g–1 dry weight. Results indicated that Na+ accumulation, rather than Cl– accumulation, was associated with the familiar marginal and interveinal scorch symptoms seen in salt-stressed peach leaves.