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Different planting dates, plant densities and pinching practices were used to determine the production practices that produced the best quality cut stems from field grown godetia under Kentucky conditions. Godetia `Grace Salmon' transplants were planted at a plant density of 40 plants m-2 on Mar 23, Apr 8 and Apr 23, 1991 in ground beds with black plastic mulch. All plants flowered in early to mid June, but plants from the Mar 23 planting date had the highest yields of commercial quality stems (387 stems m-2) and over 80% of the stems were longer than 55 cm. In a separate experiment, transplants of `Grace Red' and `Grace Rose Pink' were planted on April 5 at plant densities of 4.5 m-2 (unpinched), 10 m-2 (soft pinch on May 1) and 23 m-2 (hard pinch on May 1). Pinching treatments were used to increase the number of secondary and tertiary branches on each plant. Although the pinching treatments produced more branches, a low percentage of the branches were commercial quality cut stems.

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Drought stress was imposed in two `Delicious' apple (Malu×domestica Borkh.) orchards on a sandy loam soil of different soil depths (0.8 and 1.2 m) in the semi-arid environment of central Washington by withholding irrigation all season or from 3, 5, 7, 9, 11, 13, 15, or 17 weeks before harvest. Total pan evaporation was 1005 mm and precipitation was negligible from May through Sept. Soil of the control trees was near field capacity all season, and stem water potential (Ψstem) averaged -1.29 MPa. Total available soil water (TAW) declined after irrigation was terminated for each treatment. As TAW declined to 35%, the TAW that commercial growers are recommended to allow soil to dry to before irrigating, Ψstem was 93% of the controls, fruit growth rate was 97% of the controls, and leaf senescence did not exceed the control trees. As TAW decreased below 30%, leaves senesced acropetally starting with transition leaves near the bud-scale scar. Soil moisture of nonirrigated trees was depleted in July in the orchard on shallow soil and in late August in the orchard on deep soil. Normal June drop was reduced in the driest treatments, but crop load was not affected in the other treatments. There was no difference in drought response between the two rootstocks studied (M.7 and MM.111), but nonspur-type trees exhibited slightly greater symptoms of drought stress than the smaller spur-type trees. A Crop Water Deficit Index (CWDI) based on Ψstem measurements was linearly related to fruit weight at harvest (r 2 = 0.87). All trees were well-watered the following year and yield was reduced only for trees that were severely stressed the previous year.

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A standard fruit growth curve, used commercially as an aid to hand thinning, was compared to periodic volume measurements of apple fruit (Malus domestica Borkh. `Delicious') subjected to early season regulated deficit irrigation (RDI) to determine when to end RDI, which is used to control vegetative growth and save water. RDI suppressed stem water potential, stomatal conductance, and fruit growth rate compared to the trickle- and furrow-irrigated controls, which wetted about one-half and the entire soil volume, respectively. Full irrigation was restored to RDI trees by trickle and microsprinklers, which wetted about one-half and the entire soil volume, respectively, after terminal buds set. Stem water potential, stomatal conductance, and fruit growth rate of RDI trees increased to that of the controls, except for RDI/trickle trees, which had 80% the stomatal conductance of the other treatments. Fruit weight at harvest was affected by an interaction of irrigation treatment and cropload. RDI trees had similar or less vegetative growth and similar or higher yield efficiency than the controls. We recommend ending RDI before fruit growth declines below the standard curve.

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Warm season annual flowers were trialed as field grown cutflowers in the summer of 1989. Plants were transplanted to the field in early or late May and grown at densities of 40 plants m-2 in beds with black plastic mulch, trickle irrigation and support wires. Tall ageratum, `Horizon Blue'., plants were harvested throughout the summer with total yields of 290 stems m-2with stem lengths over 36 cm long. Stem lengths increased significantly over the summer; 40% of the stems harvested in September were over 56 cm long. Spray asters, `Matsumoto Blue', Matsumoto Red' and `Serene Red', were harvested eight weeks after transplanting with yields of 20 to 30 stems m-2; 60% of the stems were 36-45 cm long and 40% were 46-55 cm long. Tall, crested celosia, `Red Chief', `Gold Chief' and `Fire Chief', plants were harvested 8 weeks after transplanting with yields of 45 stems m-2 over 60% of the stems were 45 cm long or longer. Godetia, `Grace Red' and `Grace Salmon', plants sown March 3 and planted in the field April 10, performed well; later plantings were much less successful. Plants were planted at a density of 5 m-2 and produced 25 to 50 flower stems per plant; stem lengths were 30 to 38 cm long.

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Satin flower (Clarkia amoena ssp. whineyi: syn. Godetia whitneyi) is a cool temperature, high light plant grown as a cutflower in Japan, Europe and California. In preliminary greenhouse cutflower and pot plant trials, satin flower plants flowered in 10-11 weeks when grown under 24hr supplemental HID lighting compared to 20-22 weeks under ambient winter conditions. In Sept. and Nov. 1989, satin flower plants were treated with the following supplemental and photoperiodic lighting treatments ambient light; SD (ambient day, black cloth 1600 to 800 HR); LD (ambient day, incandescent light 1600 to 400 HR, 5 μmol s-1 m-2); SD-SPL (ambient day supplemented with 100 μmol s-1m-2 HPS, black cloth 1600 to 800 HR); LD-SPL (ambient day supplemented with 100 μmol s-1m-2 800 to 400 HR), Node number and days to flowering were significantly different between the treatments. Plants grown under LD-SPL flowered in 10 weeks and had 32 nodes, LD -13 weeks and 37 nodes (weak, spindly, few flowers), SD-SPL - 17 weeks and 70 nodes, SD - 21 weeks and 75 nodes. Strategies for supplemental lighting for greenhouse cutflower production will be discussed.

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Abstract

Enzyme expression of desert willow [Chilopsis linearis (Cav.) Sweet] was studied for malate dehydrogenase, 6-phosphogluconate dehydrogenase, esterase, diaphorase, alcohol dehydrogenase, and phosphoglucose isomerase using leaf tissue. Each enzyme was polymorphic and well-resolved by starch gel electrophoresis. One polymorphic region of activity was exhibited by each enzyme, except phosphoglucose isomerase, which produced two polymorphic regions. Malate dehydrogenase or diaphorase and phosphoglucose isomerase can be used to uniquely identify each of the six desert willow cultivars from leaf tissue.

Open Access

Abstract

With thousands of species and named cultivars to choose, it is a challenge to select appropriate plants for landscape applications (3). Selections of annual and perennial plants with specific pictorial characteristics (color, height, longevity, and blooming period), water requirements, and propagation methods can be time-consuming.

Open Access

Eucodonia ‘Adele’ initiates seasonal shoot growth from a scaly rhizome. Larger rhizome segments (>2.5 cm) produced shoots at a greater percentage compared with smaller rhizome segments. Shoots produced on larger segments were initiated sooner and had a longer length. However, when shoot formation efficiency was calculated as the number of potential shoots per original stock rhizome, smaller rhizome segments were more efficient, producing three to four times as many shoots. Rhizome segments (2.5 cm) soaked overnight in benzyladenine (BA) produced three to four times more shoots per rhizome (four shoots) compared with untreated or water-soaked rhizomes (0.3 and 0.7 shoot, respectively). The scaly rhizome consists of a central stem-like core surrounded by numerous leaf-like scales. Scales appear to be storage leaf tissue based on anatomy and presence of numerous amyloplasts. New shoots initiate as axillary shoots formed from the central core at the scale attachment. Isolated individual scales also have the capacity for adventitious shoot formation, but only form in about 25% of isolated scales. Leaf cuttings were capable of producing adventitious shoots, roots, and rhizomes. Untreated petiole and lamina cut leaf cuttings formed approximately three rhizomes per leaf cutting compared with less than one adventitious shoot per leaf cutting. Benzyladenine-treated leaf cuttings did not show an increase in rhizome initiation, but soaking lamina cut leaf cuttings in water or BA increased shoot formation to ∼1.5 shoots per cutting. This work with isolated rhizome segments and leaf cuttings presents efficient systems for regenerating rhizomes that can be used to produce stock plants for a stem cutting system for Eucodonia ‘Adele’ as a seasonal pot plant.

Open Access

For most grocery stores, external quality standards require that premium mandarins be orange, unblemished, and large. Thus, for consumers to differentiate among the premium mandarins on any dimension other than price, additional positioning attributes must be evaluated. This study considered consumer preferences for price ($2.18/kg, $4.39/kg, or $15.41/kg), packaging (1.36 kg of loose fruit, 1.36-kg bag, 2.27-kg box, or 0.23-kg clamshell with peeled fruit sections), type of mandarin (clementine, satsuma, tangerine), shelf life from the day of purchase (3, 14, or 31 days), and vitamin C content (with or without a label stating high in vitamin C). A conjoint survey was conducted in four grocery stores located in Birmingham and Montgomery, Ala. In total, 289 respondents used a 7-point intention-to-buy scale to rate photographs of 16 product profiles. Six market segments were identified, based on maximal similarity of preferences within each segment and maximal differences between segments. A simulation was conducted of the effect that an introduction of peeled-and-sectioned satsumas would have on the market share and gross revenue of other mandarins. This product showed great potential, but should be offered in a product mix that includes the loose form as well. Labeling for vitamin C was preferred by all segments, but did not contribute much to the intention-to-buy rating. Awareness and recognition of satsumas needs to be addressed in promotional campaigns. The longest shelf life was the first choice of almost half the respondents.

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