A study of applying growth retardants under overhead and subsurface irrigation systems was conducted on bermudagrass (Cynodon dactylon L. cv. Tifway) grown from rhizomes in 15-cm pots containing sand medium. Paclobutrazol (50%) at 2 mg/pot was used as foliar spray or charged-hydrophilic polymers (Super Sorb C) and either incorporated or put below medium surface. Mefluidide (28%) at 0.01% ml/pot was used only as foliar spray. Before spray treatments, grasses were cut at 2 cm from medium surface, and the second cut was made at the 6th week from treatment. All growth retardant treatments reduced grass height compared to non-treated plants. The lowest grass height was produced by paclobutrazol as foliar spray under overhead irrigation in the 6th and 9th week. By the 9th week, all hormonal treatments under the two irrigation systems had no effect on grass quality, color, and establishment rate. Both paclobutrazol foliar spray and below medium surface charged-polymer treatments under subsurface irrigation had the lowest water loss and dry weight by the 6th and 9th week. The paclobutrazol charged-polymer treatment under subsurface irrigation had also the the lowest root dry weight among all treatments. Although mefluidide foliar spray was less effective on grass height than paclobutrazol, they had similar effect on water loss and shoot dry weight.
Production of five commercial cut flowers in different culture media, namelyI nutrient film technique (NFT), soilless media (perlite and an equal mix of perlite and peatmoss), and soil mix (2 sand: 1 loam by volume), was investigated in controlled fiberglass-house. Two rose varieties (Rosa hybrida var. Baccara and Madina); carnation (Dianthus caryophyllus var. William Sim); Chrysanthemum morifolium var. Delta, and Dahlia hybrida var. variabilis were used. Plants were watered as they needed by the same nutrient solution used for NFT.
Generally, growth and yield of Baccara and Madina roses, Chrysanthemum and Dhalia plants were superior in NFT than in the other media. On the contrary, the growth and yield of carnation plants were significantly greater in conventional soil or perlite and peatmoss mix than in NFT or perlite.
Flower crops grown in NFT generally reached harvest stage 5-10 days earlier than those grown in the other media except carnation plants. There were variations in the accumulation of N, P, K mg, ca, and Fe in plant leaves among the various culture media.
Effects of mefluidide, paclobutrazol, and their mixture on shoot and root growth of perennial ryegrass (Lolium perenne L. `Wendy') and creeping red fescue (Festuca rubra L. `Dawson') were studied under container culture. Mefluidide applied alone or in combination with paclobutrazol caused significant reduction in shoot and root growth of perennial ryegrass and red fescue. These treatments also enhanced turf green color of both species and increased their root–shoot percentage, with no major effect on turf quality. Paclobutrazol applied alone reduced shoot height of perennial ryegrass and red fescue by 10% and 32%, respectively, and caused little reduction in their shoot weights, with no effect on turf quality and color. Although paclobutrazol applied alone reduced the root length and percentage of root–shoot dry weight of perennial ryegrass, it did not affect red fescue.
Foliar spray of either BA or GA3 alone or in combinations of the two growth regulators were tested for their effects on Bryophyllum plants. Neither BA nor GA3 alone succeeded in stimulating lateral branching or flowering. GA3 totally inhibited bulbils formation. In a panel evaluating the ornamental quality, plants treated with GA3 at 100 ppm ranked top. The combination of BA and GA3 enhanced growth, branching, flowering and bulbils formation. The combinations of BA and GA3 at 50 ppm each, significantly improved the propagative qualities of the bulbils. Chemical names used: N-(phenylmethyl) -H purin-6-amine (BA), Giberllic acid (GA3).
Freshwater resources are being rapidly depleted because of the increased demand resulting from exponential world population growth and the effects of climate change, especially in arid and semiarid regions (e.g., Saudi Arabia). The present study aimed to examine the changes in growth and inflorescence production of snapdragon (Antirrhinum majus L.) plants in response to irrigation with saline or magnetized water, in addition to application of inorganic and/or organic soil amendments. Three different water types—tap water, magnetized saline water, and nonmagnetized saline water—were used to irrigate A. majus plants with or without soil amendments consisting of ferrous sulfate (Fe2SO4) and/or peatmoss. Irrigation with magnetized saline water adversely affected vegetative growth, inflorescence production, mineral contents, and survival rates of A. majus plants as compared with irrigation with tap water or magnetized saline water. Nevertheless, compared with unmagnetized saline water treatment, magnetizing nonmagnetized saline water before irrigation significantly improved water characteristics and plant growth and survival. Moreover, the addition of inorganic or organic soil amendments enhanced the growth of A. majus plants regardless of irrigation water type. Interestingly, the combination of irrigating with magnetized saline water and soil amendments (Fe2SO4 and peatmoss) significantly enhanced the growth of A. majus plants to a level that was comparable to that of control plants irrigated with tap water without soil amendments. Magnetization improved water quality and increased plants’ ability to absorb water and nutrients from soil solution. The utilization of magnetized saline water for irrigating food and forage crops either alone or in combination with soil amendments has potential benefits that warrant further research.