Search

Ethephon and chlorflurenol were applied to hybrid pickling cucumber Cucumis sativus L. cvs. Pioneer and Pickmore to study the use and effectiveness of the chemicals on promoting fruit yields and quality in a once-over harvest system. Ethephon was applied either at the first or the fourth true-leaf stage of growth. Chlorflurenol was applied at 0, 50 or 100 ppm when 6-8 female flowers reached anthesis. Dollar value per ha was increased by approximately 14% when ethephon or chlorflurenol was used alone. However, when these 2 growth regulators were used in combination, yields were increased by as much as 68% in ‘Pioneer’ and 40% in ‘Pickmore.’ Chlorflurenol significantly increased the number of fruit per plant and reduced the length to diameter ratio. Fruit shape and L:D ratio were significantly improved when ethephon was applied in the fourth true-leaf stage regardless of chlorflurenol usage. Chlorflurenol slightly reduced the fresh quality of ‘Pioneer’ but had no such effect on ‘Pickmore.’ Salt stock quality was improved slightly by chlorflurenol. To obtain best yield, fruit shape, fresh salt stock quality, ethephon should be applied twice, 1 week apart commencing at the fourth true-leaf stage, followed by a 50 to 100 ppm spray application of chlorflurenol when 6-8 female flowers have reached anthesis.

Chlorflurenol (methyl-2-chloro-9-hydroxyfluorene-(9)-carboxylate) was applied to four cultivars of cucumber (Cucumis sativus L.) grown in the greenhouse to determine its effect on sex expression, fruit set, and plant growth habit. The chlorflurenol was applied at three stages of growth, the first, second and fourth true-leaf stages, at concentrations of 0, 0.1, 1.0, 10.0 and 100 ppm. At 0.1 ppm or 1 ppm, chlorflurenol promoted male flower development in predominantly female (PF) Pioneer and monoecious Galaxy. However, at 10 or 100 ppm, chlorflurenol reduced male flower development in monoecious cultivars Galaxy and Wisconsin SMR 58 and in PF Explorer. The effectiveness of chlorflurenol in doing this was dependent on the stage of growth applied. Chlorflurenol did not affect female flower formation. Black-spined Pioneer and Wisconsin SMR 58 produced twice as many fruit per plant as white-spined Explorer and Galaxy when 100 ppm chlorflurenol was applied at the fourth-leaf stage. Plant growth was terminated in all cultivars at the 100-ppm concentration. It was proposed that yields of pickling cucumbers harvested once-over could be improved by increasing plant populations and applying chlorflurenol in the fourth-leaf stage to limit growth and promote fruit set.

Ethephon [(2-chloroethyl) phosphonic acid] increased the yield of red fruit and reduced green fruit and total yields on 5 cultivars of peppers (Capsicum annuum L.) in the greenhouse. The effectiveness of ethephon was dependent on its concentration, the number of sprays, and cultivar. The cultivar Shepherd was the most sensitive to ethephon. A 10-ppm spray applied twice to ‘Shepherd’ was more effective in promoting red fruit coloring than any of the single sprays. Double or single sprays were equally effective in ‘Sweet Hungarian’, ‘Cascabella,’ and, to a lesser degree, ‘Staddon’s Select’, but double sprays were more effective in ‘Vinedale.’ The higher single concentrations of ethephon caused more chlorosis, defoliation, and fruit abscission than repeated application at lower concentration, and total yields were substantially reduced. In the field, 3 applications of 300 ppm ethephon significantly increased yield of red fruit and decreased green fruit in ‘Vinedale’, whereas all multiple applications were equally effective on ‘Shepherd.’ Only a single 750 ppm ethephon treatment significantly promoted fruit ripening in ‘Staddon’s Select.’ Ethephon effectively concentrated fruit maturity in the field for once-over harvest without reducing yield.

Four cultivars each of lettuce (Lactuca sativa L.), radish (Raphanus sativa L.) and spinach (Spinacia oleracea L.) were grown at three NH4NO3 levels (0, 14.7 and 29.4 g N/m2) in a muck soil as a commercial greenhouse crop under winter conditions (low light intensity and short photoperiod). Analysis of the tissues for NO3-N showed that all three vegetable crops contained high concentrations of NO3-N when grown under these conditions: radish highest, followed by lettuce, then spinach. Total N and NO3-N were increased by N fertilizer only in radish roots, and yield was promoted by the additional N only in lettuce. Lettuce cultivars Domineer and Korrekt contained significantly less NO3 than Grand Rapids or Noran and were higher yielding than the standard cultivar Grand Rapids. The NO3 content of radishes was extremely high, especially in the root of the white cultivar Icicle (1.68% NO3-N). Yield of roots from Icicle was not significantly different from Champion, Early Scarlet Globe and Red Boy, cultivars which did not contain as much NO3-N. Smooth-leaf spinach cultivar Northland was higher yielding with significantly less NO3 than savoyed cultivars America, Winter Bloomsdale or Savoy. High NO3 tissue concentrations can be reduced in these crops by growing cultivars that accumulate less NO3.

Leaves of nonglaucous cotton and tomato absorbed Mn whether or not a surfactant was added to a MnSO4 spray solution, whereas the leaves of glaucous cabbage and onion absorbed Mn only when a surfactant was added. Manganese was absorbed by cabbage leaves only when a surfactant was added or when leaf surface wax formation was inhibited by ethyl N,N-dipropylthiolcarbamate (EPTC). Non-glaucous and glaucous pea mutants did not significantly absorb Mn unless surfactant was added to a MnSO4 spray, after which both mutants equally absorbed Mn. Surfactants increased the concn of 59fe penetrating into a wax paraffin model to a 0.5 mm depth by 8- to 30-fold over a no-surfactant treatment. Both the rate and depth of penetration were increased by surfactant. No Fe was absorbed by cabbage leaves unless surfactant was present in the spray solution or the leaf wax was disturbed by brushing. Thus, surfactant efficiently overcame an external leaf wax layer as a barrier to the absorption of foliar applied ions and thereby increased ion movement into the leaf.

No NO3 accumulated at any photoperiod in leaves or roots of table beets when N was not added to the soil. When N was applied at rates from 100 to 400 lb./acre less NO3 accumulated in both plant parts as photoperiod was extended from 8 to 20 hr. Addition of N to the soil increased the total N content of leaves and roots. Larger total N concn were observed in plants grown under an 8-hr photoperiod than in plants grown under longer photoperiods. Various radish, spinach, and snap bean cultivars were grown at different soil N rates and harvested 0, 6, and 12 hr after the initiation of the light period. Radish leaves and snap bean pods contained less NO3-N as the plants were harvested further into the light period. Nitrate concn of radish roots and spinach leaves were not changed by harvesting at 6 AM, 12 noon or 6 PM. The addition of N fertilizer increased the NO3-N concn of radish and spinach but decreased the NO3-N concn of snap bean pods. Cultivars differed in their capacity to accumulate NO3 in all 3 species. Nitrite accumulation was proportional to the quantity of NO3 in the tissue.

Nine growth-regulating chemicals were sprayed at concentrations of 50 and 100 ppm on pickling cucumbers (Cucumis sativus L., cult Pioneer) in an effort to induce parthenocarpic fruit development. A morphactin formulation, IT 3456 (methyl-2-chloro-9-hydroxyfluorene-(9)-carboxylate), and TIBA (2,3,5-triiodobenzoic acid) were the most effective in stimulating parthenocarpic fruit-set and development at both concentrations used. Between six and seven fruits per plant were induced parthenocarpically when 100 ppm IT 3456 morphactin was used. Two other morphactins tested, IT 3233 (n-butyl-9-hydroxyfluorene-(9)-carboxylate) and Bay 102614 (2,7-dichloro-9-hydroxyfluorene-carboxylate-(9)-methyl ester), produced no more fruits than the control. A new growth regulator, CCDP (3-carboxy-1-(p-chlorophenyl)-4,6-dimethyl-2-pridone), significantly increased the number of fruits per plant at the 100-ppm concentration, and also increased the number of female flowers per plant produced within 50 days of planting, at both concentrations. The other four compounds tested, designated EL 531 (α-cycloprophyl-α-(4-methoxyphenyl)-5-pyrimidine methanol), BAS 0660-W (N-dimethyl-morpholiniumchloride), TD 692 (mono-("coco" dimethylamine) succinate), and Chemagro 8728 (5-chloro-2-thenyl-tributylphosphonium), were not effective inducers of parthenocarpy in the cucumber.

Three herbicides, cycloate, alachlor and lenacil, gave acceptable weed control in spinach (Spinacia oleracea L.), while 7 other herbicide combinations did not Cycloate, alachlor, lenacil, prometryne and chlorpropham + PPG 124 significantly increased the NO3-N concentration of both spinach blades and petioles by as much as 3-4 times over weeded and non-weeded checks. DCPA significantly increased NO3 in the petioles. Cycloate, alachlor and lenacil significantly increased total Ν concentration in the petioles, while none of the herbicide treatments affected total Ν in the blades. Lenacil significantly increased fresh weight of blades and petioles compared to a weeded check, while plant fresh and dry weights from cycloate and alachlor treatments were not less than the checks.

Cucumbers (Cucumis sativus L.), ‘Bounty’ and ‘Premier’, were grown at 8 population densities ranging from 50,000 plants per ha (46 × 46 cm spacing) to 850,000 plants per ha (10 × 10 cm spacing). Sections of the field were harvested once-over on 2 sampling dates. Yields as dollars per ha and as tons per ha increased with increasing plant population at densities of 50,000 to 100,000 and 250,000 to 500,000 plants per ha. Over the common commerical populations, 100,000, 150,000, 200,000 and 250,000 plants per ha, yields did not increase as population increased. Delay in harvest for 4 days did not affect dollars per ha yield but doubled the tons per ha produced. Fruit sizing was slower in higher plant populations (250,000 to 850,000 plants per ha) than in the lower plant densities (50,000 to 200,000 plants per ha). The number of fruit per plant decreased with increasing plant population. Length to diameter ratios of ‘Premier’ were lower at the lowest plant population, 50,000 plants per ha. L:D ratios of ‘Bounty’ were unaffected by plant population. Varying plant populations did not affect the percent off-shape fruit, or fruit color (green quality and uniformity) of either cultivar.

Reciprocal cleft and pistillate floral bud grafts were made between parthenocarpic ;Fertilla' and nonparthenocarpic ;MSU 713-5' cucumber (Cucumis sativus L.) lines to localize the site for stimulation of parthenocarpic fruit set. No fruit set on ;MSU 713-5' controls, scion grafted to ;Fertilla,' or rootstock with ;Fertilla' as the scion. ;Fertilla' controls, rootstock, and scions all produced parthenocarpic fruit when grafted to ;MSU 713-5.' When pistillate floral buds of ;MSU 713-5' were grafted to ;Fertilla,' no fruit were produced. However, individual immature pistillate buds of ;Fertilla' developed into mature fruits when grafted onto ;MSU 713-5.' Hence, the immature ovary is the site of stimulation for parthenocarpic fruit set in cucumber.

MnSO4 and Rayplex-Mn were found to be effective sources of Mn for tomato seedlings grown on a Mn deficient high organic sandy soil. Tomato seedlings absorbed Mn from MnSO4 or Rayplex-Mn applied in the starter band on or under the seed with equal effectiveness. The amount absorbed was directly related to the Mn concentration in the band. MnSO4 at 100 mg Mn/ft of row increased the Mn content of the tissue from 17 ppm to more than 100 ppm. MnEDTA at a rate to supply 10 to 25 mg Mn/ft of row in bands on or under the seed did not affect seedling growth and Mn uptake was less than from the same rate of MnSO4. Rates of 50 and 100 mg Mn/ft of row from MnEDTA in the starter band on or under the seed caused death or severe stunting of tomato seedlings because of toxicity. Band applications of Mn sources increased Mn composition of the tomato tissue relatively much more than did the broadcast application.

2-Chloro-9-hydroxyfluorene-9-carboxylic acid (chlorflurenol)3 at 50 or 100 ppm increased fruit production of a gynoecious cucumber (Cucumis sativus L. cv. MSU 713-5) under field conditions of both normal and reduced pollination. A monoecious cultivar, ‘Wisconsin SMR 18’, treated with (2-chloroethyl) phosphonic acid (ethephon) and then chlorflurenol produced over twice as many fruit as the control when pollen was plentiful, and more than 4 ⨯ as many when pollen supply was limited. Ethephon sprays alone increased pistillate flower formation on the monoecious cultivar but did not increase fruit set. Chlorflurenol treatments increased the proportion of fruit in the smaller, more valuable size grades and appear advantageous for mechanically harvested pickling cucumbers.

Nitrate accumulated in spinach plants that did not receive additional fertilizer N when temp was increased above 15°C. When 50 mg N/kg soil was added the NO3 concn increased above 10°C and with 200 mg N/kg soil NO3 increased with temp increments above 5°C. When N fertilizer was added the NO3 concn decreased with a subsequent increment in temp from 25°C to 30°C. The effect of N fertilizer on NO3 accumulation became more apparent with each 5°C rise in temp to 25°C. Either N fertilizer or a temp rise from 5°C to 25°C led to a significant increase in the total N concn of the plants. Changes in total N were correlated with changes in NO3-N when N fertilizer was added to the soil or when the temp was changed. Nitrite did not accumulate appreciably at any of 6 temp or 3 N fertilizer levels used.

Fat-sugar derived surfactants were examined as to their effectiveness in the promotion of absorption of nutrient ions through leaf surfaces and subsequent translocation of these ions through the plant. The fat-sugar derived surfactants and several other commercial surfactants were added to solutions of P to test the effectiveness of the surfactants in promoting ion absorption and translocation. The surfactants in the nutrient sprays at a 0.5% concentration were generally more effective than at 0.1% or 1.0% concentration with the exception of Polyoxyethylenated Tallow Sucroglyceride (PTS) which had its greatest effect at a 1.0% concentration. Sucro sperses and Sucro sols with 3 fatty acid molecules per sucrose molecule were more effective in increasing P uptake and transport than formulations with 1.5 or 4.5 fatty acid molecules per sucrose molecule. A 40:1 ratio of ethylene oxide to sucrose was most effective for increase of P absorption. Combining PTS and Sucroglyceride T-110 (T-110) increased P absorption more than if either surfactants were used alone. Ratios of 1:3 or 3:1 respectively, were most effective. T-110 and Sucrose Monotallowate (SMT) did not significantly increase absorption of P at any concentration tested. PTS was effective in increasing nutrient ion uptake at a 1% concentration, but it was found to be somewhat phytotoxic at this level. The fat-sugar complexes used as surfactants increased ion uptake in some instances more than 20 times compared to using no surfactant. When these same surfactants were compared to commercially used surfactants, they generally proved to be superior for use with the foliar applied nutrients.

‘Winter Bloomsdale’ spinach plants were grown in a growth chamber with a light intensity of 2400 ft-c until 2 weeks before harvest when light intensity treatments of 600, 1600, 2400, and 3500 ft-c were imposed. The total N and NO3 concn of the leaves were increased by the addition of N to the soil and by reduction of light intensity. At 600 ft-c the plants accumulated NO3-N and total N at all soil N levels, but response to soil increments of N was greater at higher light intensities. The concn of K in the tissue increased with a reduction in the light intensity from 2400 to 600 ft-c or application of N fertilizer to 200 mg/kg of soil. Less P was found in spinach leaves as N fertilizer was added to 100 mg/kg of soil. The P content was variable with light intensity.

not available

Varying the level of added P to a deficient soil from 0, 25, 50, 75, 100, 200 and 400 ppm made it possible to study the influence of deficiency, sub-adequate, adequate and excess amounts of P on its distribution into P fractions within tomato leaves. Plant growth response was obtained at P rates up to 100 ppm. The P fractionation data indicated that inorganic phosphate constituted about one quarter of the total plant P even when the plant is deficient in P. The plant did not accumulate phosphate until it was supplied at rates that exceeded requirements of growth and then it was accumulated mainly as inorganic phosphate while the levels of soluble organic P, RNA-P, DNA-P, phospholipid-P and phosphorprotein-P remained unchanged over the entire range of P rates.

not available

The squash bug, Anasa tristis (DeGeer) (Heteroptera: Coreidae), is considered an important pest of cucurbits in open fields in the U.S. (Bonjour and Fargo, 1989; Cook and Neal, 1999). In the greenhouse, the squash bug can infest Beit alpha cucumber causing considerable damage (Rondon et al., 2003) (Fig. 2). This document is HS992, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: October 2004. https://edis.ifas.ufl.edu/hs233

In Florida, high market prices, consumer demand, and a suitable environment for growing colored peppers under protected agriculture have encouraged greenhouse growers to consider the economic viability of this crop. This document is HS979, one of a series of the Department of Horticultural Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: July 2004. https://edis.ifas.ufl.edu/hs228

The strawberry (Fragaria x ananassa Duchesne) hosts a wide variety of aphid species. Most of these species have an ample variety of alternate hosts that include strawberries. The true strawberry aphid, Chaetosiphon fragaefolli (Cockerell) (Fig. 1), is considered an important pest of wild and cultivated strawberries worldwide. This aphid species is a vector of strawberry viruses such as cytorhabdovirus, one of the most dangerous viruses affecting strawberry (Krczal, 1979) (Fig. 2). Our ability to recognize this pest and the damage it causes is important in determining successful control methods. This document is HS1009, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: March 2005. HS1009/HS253: Biology and Control of the Strawberry Aphid, Chaetosiphon fragaefolli (Cockerell) (Homoptera: Aphididae) in Florida (ufl.edu)

Angular Leaf Spot (ALS) is a bacterial disease caused by Xanthomonas fragariae Kennedy & King, a pathogen highly specific to wild and cultivated strawberry, Fragaria x ananassa Duchesne (Legard et al. 2003). ALS is an important disease on winter strawberry production worldwide. In the U.S., it ranks 6th in economic importance after gray mold (Botrytis cinerea L.), verticillium wilt (Verticillium alboatrum Reinke & Berth), powdery mildew (Sphaerotheca macularis L.), anthracnose (Colletotrichum spp.), and pythium root rot (Pythium spp.) (Sorensen et al. 1997). The rapid spread of ALS is influenced by the increasing rate of interchange of plant material. This is document PP-199, a publication of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: June 2004. PP-199/PP120: Angular Leaf Spot of Strawberries (ufl.edu)

Neoseiulus californicus McGregor (Acari: Phytoseiidae) is an oblong, tiny, mobile, predatory mite that feeds on a variety of prey (Fig. 1). It belongs to the suborder Acariforme in the Acari order. The division includes more than 30,000 described species included in the ancient group of Arachnida (Krantz, 1978). This document is HS1001, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: November 2004.

Parthenocarpy was induced in cucumber Cucumis sativus L. by foliar application of morphactin. Morphactin (chlorfluorenol) was most effective in inducing parthenocarpy when applied in the flowering stage, and the response was enhanced by prior treatment with Ethrel (2-chloroethylphosphonic acid). Morphactin stimulated pistillate flower development in a monoecious cultivar but did not modify sex expression of a gynoecious line.

Galia muskmelon (Cucumis melo Reticulatus group L.) is a specialty melon with green flesh and a golden-yellow netted rind, prized for its bold aroma and high sugar content. This document is HS919, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food andAgricultural Sciences, University of Florida. Publication date: May 2003.

The strawberry, Fragaria ananassa Duch., is an intensively cultivated high value crop that requires inputs of chemicals, including insecticides and miticides. Through early identification of arthropod problems, and targeted releases of reared beneficial insects and mites, it may be feasible to minimize the requirements for pesticides on strawberry. This document is HS923, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: June 2003.

Under certain conditions, vegetable greenhouse crops can develop physiological disorders that predispose plants to diseases that decrease plant growth, fruit yield, and fruit quality. One plant disorder in bell pepper (Capsicum annuum L.) is the “Elephant's Foot,” which is characterized by the presence of epidermal injuries on a swollen stem region developed at the base of the plant stem. The epidermal injuries increase the plant susceptibility to fungal infections that can lead to plant death. This publication describes the symptoms and possible causes of this basal stem physiological disorder in greenhouse-grown bell pepper, and presents pepper production methods to avoid the disorder. This document is HS959, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: January 2004. https://edis.ifas.ufl.edu/hs206

The organic vegetable industry is flourishing due to consumers preference for organically grown produce over traditionally produced vegetables. As a result, an increase in the variety and selection of many vegetables in retail supermarkets and restaurants throughout the United States has occurred recently. With the new regulation (October 2000) requiring organic seed sources for organically labeled vegetables, many organic growers are searching for certified organic seed. Smaller seed companies have produced the majority of organically produced seed to date. The commercial seed sector is starting to provide a more diverse selection of cultivars, yet there are still many hybrids that are not yet available. For growers in Florida, there is opportunity to produce organic, though it is not widely practiced. This report serves as a guide to organic seed production in Florida. This document is HS981, one of a series of the Department of Horticultural Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: July 2004. https://edis.ifas.ufl.edu/hs227

Sap beetles (Coleoptera: Nitidulidae) are conspicuous arthropods that feed on flowers, fruits, sap, fungi, stored products, decaying and fermenting plant tissues from diverse trees and crops, including strawberries. Sap beetles work in association with yeasts and other fungi causing the fermentation of infested plant parts (Fig. 1). They also are known to transport a variety of microorganisms that cause plant diseases; a few species can behave as predators of various ornamental pests (Dowd, 1991; Dowd and Weber, 1991). Sap beetles are often considered minor pests; however, their main impact is due to the contamination of products caused by adults and larvae. This document is HS993, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: October 2004. HS993/HS234: Sap Beetle (Coleoptera: Nitidulidae) Management in Strawberries (ufl.edu)

Predatory mites such as Neoseiulus californicus McGregor (Fig. 1) and Phytoseiulus persimilis Athias-Henriot (Fig. 2) feed on important fruits and ornamental pests such as the twospotted spider mite (Tetranychus urticae Koch), broad mite (Polyphagotarsonemus (Stenotarsonemus) latus Banks), cyclamen mite (Tarsonemus pallidus L.), and other mite species. These predatory mites are associated with several agricultural cropping systems including strawberries, raspberries, roses, grapes, citrus, ornamentals, and vegetables. Predatory mites have been used as an alternative to miticides on a variety of crops. Their commercial availability is crucial. This document is HS1000, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: November 2004.

Fruit development from pollinated flowers of cucumber (Cucumis sativus L.) on early nodes inhibited fruit set on later nodes. Application of chlorflurenol (methyl-2-chloro-9-hydroxyfluorene-(9)-caroxylate) overcame this inhibition and increased the number of fruit which developed from both pollinated and nonpollinated ovaries. In nonpollinated flowers, chlorflurenol promoted fruit set through parthenocarpy. In chlorflurenol treated plants, approximately 80% of the fruit from pollinated flowers produced seed, while the remaining 20% were parthenocarpic. However, chlorflurenol reduced the quantity of seed in the nonparthenocarpic fruit by 30%. This included fruit set from flowers that had been pollinated up to 5 days before chlorflurenol application. Pollination tended to improve the effectiveness of chlorflurenol to increase fruit set.

In field experiments with cucumber (Cucumis sativus L.) on both sandy and clay loam soils (2-chloroethyl)phosphonic acid (ethephon) at 125 or 250 ppm applied twice to the foliage was more effective in promoting pistillate flowers and yield on ‘Wisconsin SMR 58’, a monoecious cultivar, than granular ethephon applied at various rates as a sidedress at planting, placed directly on the seed at planting, or applied as a sidedress in the first true-leaf stage. Foliar sprays on ‘Pioneer’ were effective in reducing the number of staminate and increasing the number of pistillate flowers. However, ethephon applied by any method did not increase yields in ‘Pioneer’, a predominantly pistillate cultivar.