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  • Author or Editor: C. D. Stanley x
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Abstract

The minimum water requirement to produce the greatest number of marketa- bie cut flowers of Chrysanthemum × morifolium Ramat. ‘Manatee Yellow Iceberg’ was 35 cm with trickle irrigation, a 91% reduction in water uses as compared to overhead irrigation systems. Linear responses for fresh weight, dry weight, leaf area, leaf number, and flower number between 13.6 and 40.7 cm of water supplied during production indicated that an additional 6 cm of water would improve marketable stem's quality.

Open Access

Abstract

Damage by leafminer [Liriomyza trifolii (Burgess)], increased linearly as leaf nitrogen increased from 2.2% to 4.0% in spring and fall plantings of Chrysanthemum x morifolium Ramat. ‘Manatee Yellow Iceberg’. The number of marketable stems was related quadratically to leaf nitrogen with maximum yields estimated to occur at 3.6% at harvest.

Open Access

Abstract

Interactive effects of trickle irrigation rates, cultivars and culture (single or pinched stem), on Chrysanthemum × morifolium Ramat. cut flower yield and quality were evaluated. The minimum amount of water required to produce the greatest number of marketable stems of high quality was estimated to be from 0.96 to 1.07 cm/day. Responses to irrigation rate were similar regardless of culture or cultivar variables. Seasonal water use, however, would vary due to differences in cropping time influenced by the production method and choice of cultivars.

Open Access

Three vegetable irrigation systems, semi-closed subirrigation (seepage), fully enclosed subirrigation (seepage), and drip irrigation, were evaluated for use on sandy soils with naturally high water tables to determine comparative irrigation costs for tomato production. Investment, fixed (ownership), and variable (operating) costs were estimated for each irrigation system. The investment costs of the drip irrigation system were significantly greater than those for the semi-closed and fully enclosed irrigation systems. The variable costs, however, for the semi-closed system were considerably less than those for the fully enclosed and drip irrigation systems. The semi-closed irrigation system, therefore, was determined to be the least-cost tomato irrigation system under present fuel cost and nonlimiting water supply conditions.

Free access

Abstract

A study was conducted to investigate environmental factors which affect leaf water potential (LWP) response of chrysanthemums (Chrysanthemum × morifolium Ramat). Meteorological parameters, including air temperature (TEMP), relative humidity (HUM), total solar radiation (RAD), and photosynthetically active radiation (PAR) were measured simultaneously as LWP determinations were made diurnally for plants grown with 5 different irrigation rates. Stepwise multiple regression analyses using the meteorological parameters as independent variables and LWP as the dependent variable showed that models developed for each irrigation rate included TEMP, HUM, and PAR as statistically significant (P = 5%) independent variables. Coefficients of determination (R2) for the models ranged from 0.83–0.87. A combined model, including irrigation rate (R) as an independent variable along with the meteorological parameters, revealed that TEMP, PAR, HUM, and R were statistically significant at P = 1% and had an R2 = 0.84. Results reveal environmental factors which must be considered in studies involving LWP measurements for chrysanthemums in order to avoid misinterpretation of data.

Open Access

Concerns over the environmental impact and economics of harvesting sphagnum and reed-sedge peat have increased the desire to identify acceptable peat substitutes for use in container substrates. This preliminary study evaluated the use of composted dairy manure solids as a substitute for sphagnum or reed-sedge peat in container substrates for production of woody ornamental shrubs and assessed potential leaching of nutrients. Walter's viburnum (Viburnum obovatum), sandankwa viburnum (Viburnum suspensum), and japanese privet (Ligustrum japonicum) were grown in 3-gal plastic containers with seven substrates containing (by vol.) 60% pine bark, 10% sand, and 30% sphagnum peat (S), reed-sedge peat (R), and/or composted dairy manure solids (C). Substrate composition had no effect on plant quality ratings for any species, growth index (GI) of walter's viburnum, or shoot and root dry weight of walter's viburnum and japanese privet. However, the GI of japanese privet and sandankwa viburnum was the lowest when grown in substrates containing a high percentage of reed-sedge peat (0S:3R:0C). Substrate effects on average nitrate + nitrite nitrogen leachate losses were minimal over the 88-day leachate collection period. However, the substrate containing the highest proportions of composted dairy manure solids (0S:0R:3C) generally had the highest average ammonium nitrogen and dissolved reactive phosphorus losses compared with other substrates. All substrates tested as part of this study appeared to be commercially acceptable for production of container-grown woody ornamental shrub species based on growth and quality. However, average nutrient losses from containers differed depending on the peat or peat substitute used to formulate the substrates.

Full access

Abstract

Trees of apple cv. Gala (Malus domestica Borkh.), which had previously been dormant pruned, were pruned in mid-December (early summer pruned—73 days after full bloom), mid-January (late summer pruned—108 days after full bloom), or were only dormant pruned (control). On 2 harvest dates (late February and early March) fruit from 4 different regions of the tree canopy were assessed for red blush, background color, soluble solids concentration, and fresh weight. Penetration of photosynthetic photon flux density (PPFD) to each region was measured at the summer pruning times and at the First harvest. Summer pruning increased the percentage of red blush—but not background color—for both pruning dates, decreased fresh weight of fruit from the early pruned trees, and decreased the soluble solids concentration of fruit from the late-pruned trees. The percentage of red blush and fruit fresh weight both showed a highly positive correlation with PPFD penetration, but for fruit fresh weight, the correlation also was dependent on the pruning treatment. The concentration of soluble solids also was related to PPFD penetration although, in comparison with fresh weight, the differences were reduced. Background color was relatively independent of tree position or pruning treatment.

Open Access

Abstract

In Florida, most producers of cut chrysanthemums (Dendranthema grandiflora Tzvelev.) use overhead irrigation systems and fertilize with soluble fertilizer injected through the system. Trickle irrigation can be used to produce cut chrysanthemums with substantial savings in water (2). Controlled-release fertilizers can be successfully used to produce cut chrysanthemums (1) and may be advantageous in certain production situations (3). Direct yield comparisons influenced by the four possible combinations of irrigation and fertilization practices have not been researched in previous studies. We, therefore, evaluated main and interactive effects of overhead or trickle irrigation in conjunction with soluble or controlled-release fertilization on the yield and postharvest quality of cut chrysanthemums.

Open Access

Strawberry (Fragaria ×ananassa Duch.) was grown for two seasons with microirrigation. Preplant fertilizer treatments of zero, one, two, three, and four times the basic N and K rate of 17 and 15 kg·ha–1, respectively, were applied each season. Additional N and K were applied twice weekly through the microirrigation system at 1.12 and 0.92 kg·ha–1·day–1, respectively. Total marketable fruit yield and marketable fruit per plant were not affected by preplant fertilizer rate. The percentage of marketable fruit increased with increased preplant fertilizer to the 51N–45K (three times basic rate) kg·ha–1 rate the first season. Average fruit weight increased the first season but decreased the second season with increased preplant fertilizer. Plants were larger the first season in treatments receiving preplant fertilizer.

Free access

Sixteen field-located drainage lysimeters (each 60 cm wide, 2.44 m long, 60 cm deep) designed specifically for determination of water requirements for fruiting strawberry production (season - Oct to April) were installed in 1986. Each lysimeter was equipped with individual micro-irrigation and drainage collection systems automated for minimal management input. Initially, computer control (using a low-cost microcomputer) was used to continuously check switching-tensiometers located in each lysimeter and apply irrigation water as needed, A drainage suction (-10 MPa) was applied continuously to simulate field drainage conditions. Manually-installed lysimeter covers were used to protect the plots from interference from rainfall when needed, Initial irrigation application treatments were set at four levels of soil moisture tension controlled by tensiometers and were measured using flow meters for each lysimeter. This paper will discuss problems that were experienced with the initial setup (difficulty in measuring actual application amounts, tensiometer and computer control, elimination of rainfall interference, uniformity of irrigation application, and salinity in the rooting zone) and the modifications (pressurized reservoir tanks, construction of motorized rain-out shelter, micro-irrigation emitters used, and fertilization program) which have been made to overcome them,

Free access