Use of Ethephon as a Controlled Abscission Agent on Paprika Pepper

Our objective was to increase the percentage of marketable red fruit at harvest time on paprika pepper (Capsicum annuum L.) plants intended for mechanical harvest by using ethephon [(2-chloroethyl)phosphonic acid] to remove late-developing blooms and green fruit. We conducted three experiments on field-grown plants in southwestern Oklahoma. We tested ethephon solutions of 0, 1000, 2000, 3000, and 4000 μl·liter–1 as a one-time foliar application on various dates. Total dry weight of harvested fruit decreased linearly with ethephon rate in all three studies. Marketable fruit as a percentage of total harvested fruit weight increased linearly with ethephon rate in two studies. There was no consistent effect of ethephon on the intensity of red pigment extracted from dehydrated marketable fruit. With proper timing, as little as 1000 μl ethephon/liter was enough to alter the distribution of total harvested fruit weight toward marketable fruit and away from green fruit. A target spray “window” of the last 10 days in September seemed appropriate for southwestern Oklahoma, and the recommended rate of ethephon was between 2000 and 3000 μl·liter–1.

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Use of Ethephon as a Controlled Abscission Agent on Paprika Pepper

HortScience ◽

10.21273/hortsci.32.2.251 ◽

1997 ◽

Vol 32 (2) ◽

pp. 251-255 ◽

Cited By ~ 3

Author(s):

Brian A. Kahn ◽

James E. Motes ◽

Niels O. Maness

Keyword(s):

Capsicum Annuum ◽

Phosphonic Acid ◽

Foliar Application ◽

Dry Mass ◽

Single Application ◽

Flower Buds ◽

Green Fruit ◽

Precise Timing ◽

Marketable Fruit ◽

Fruit Mass

Mechanical harvest of paprika pepper (Capsicum annuum L.) produces a mixture of marketable and unmarketable fruit. Our objective was to increase the percentage of marketable red fruit in a once-over harvest by using ethephon to remove late-developing flower buds, blooms, and green fruit. Three experiments were conducted on field-grown plants in southwestern Oklahoma. We tested ethephon solutions of 0, 1000, 2000, 3000, and 4000 μL·L-1 as a one-time foliar application on various dates in September and October. Total dry mass of harvested fruit decreased linearly as ethephon rate increased in all experiments. Marketable fruit, as a percentage of total harvested fruit mass, increased linearly with ethephon rate in two of three experiments. Ethephon decreased the percent of total harvested fruit mass due to green fruit in all experiments. We recommend a single application of ethephon at about 2000 to 3000 μL·L-1 as a controlled abscission agent to increase the percentage of harvested red fruit in paprika pepper. The precise timing of the application will vary with the situation, but the last 10 days in September seemed an appropriate interval for southwestern Oklahoma. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).

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Calcium and Ethephon Effects on Paprika Pepper Fruit Retention and Fruit Color Development

HortScience ◽

10.21273/hortsci.29.7.792 ◽

1994 ◽

Vol 29 (7) ◽

pp. 792-794 ◽

Cited By ~ 1

Author(s):

James R. Cooksey ◽

James E. Motes ◽

Brian A. Kahn

Keyword(s):

Fruit Ripening ◽

Foliar Application ◽

Dry Weight ◽

Fruit Weight ◽

Linear Increase ◽

Fruit Abscission ◽

Green Fruit ◽

Color Development ◽

Pepper Fruit ◽

Marketable Fruit

Ethephon has increased yields of red fruit, but its use as a pepper (Capsicum annuum L.) fruit ripening agent has been limited by premature fruit abscission and defoliation. We tested ethephon solutions of 0,1500,3000,4500, and 6000 μl·liter-1 with or without 0.1 m Ca(OH)2 as a onetime foliar application to field-grown paprika pepper in southwestern Oklahoma. There was a linear increase in fruit abscission with increasing ethephon rates in 2 of 3 years, with or without added Ca. Marketable fruit as a percentage of total harvested fruit weight was improved by ethephon at 6000 μl·liter-1 in 2 of 3 years, primarily due to a decrease in weight of harvested green fruit. However, ethephon never significantly increased the dry weight of harvested marketable fruit over that obtained from the control. There also was no effect of ethephon on the intensity of red pigment extracted from dehydrated marketable fruit. The only consistently significant effect of Ca(OH)2 was an undesirable increase in the retention of green fruit on the plants. Ethephon had little value as a fruit-ripening agent for paprika pepper under the conditions of our studies, and Ca(OH)2 was not useful as an additive to ethephon sprays. Chemical name used: (2-chloroethyl) phosphoric acid (ethephon).

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CALCIUM AND ETHEPHON EFFECTS ON PAPRIKA PEPPER FRUIT RETENTION AND FRUIT COLOR DEVELOPMENT

HortScience ◽

10.21273/hortsci.28.4.269f ◽

1993 ◽

Vol 28 (4) ◽

pp. 269F-269

Author(s):

James R. Cooksey ◽

Brian A. Kahn ◽

James E. Motes

Keyword(s):

Fruit Ripening ◽

Foliar Application ◽

Dry Weight ◽

Fruit Weight ◽

Linear Increase ◽

Fruit Color ◽

Red Pigment ◽

Fruit Abscission ◽

Color Development ◽

Pepper Fruit

While ethephon [(2-chloroethyl) phosphonic acid] has increased yields of red fruits, its use as a pepper (Capsicum annuum L.) fruit ripening agent has been limited by premature fruit abscission and defoliation. We tested ethephon solutions of 0, 1500, 3000, 4500, and 6000 μl·liter-1 with or without 0.1M Ca(OH)2 as a one-time foliar application to field-grown paprika pepper in southwestern Oklahoma. There was a linear increase in fruit abscission with increasing ethephon rates in two out of three years, with or without added calcium. Ethephon at 6000 μl·liter-1 improved the percent of total fruit weight due lo marketable fruits in two out of three years, primarily by decreasing the weight of harvested green fruits. However, ethephon never significantly increased the dry weight of harvested marketable fruits over that obtained from the control. There also was no effect of ethephon on the intensity of red pigment extracted from dehydrated marketable fruits. The only significant effect of Ca(OH)2 was an undesirable increase in the retention of green fruits on the plants. Ethephon had little value as a fruit ripening agent for paprika under the conditions of our studies, and Ca(OH)2 was not useful as an additive to ethephon sprays.

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Effects of Barnyardgrass (Echinochloa crus-galli) on Growth, Yield, and Nutrient Status of Transplanted Tomato (Lycopersicon esculentum)

Weed Science ◽

10.1017/s0043174500075810 ◽

1988 ◽

Vol 36 (6) ◽

pp. 775-778 ◽

Cited By ~ 14

Author(s):

Prasanta C. Bhowmik ◽

Krishna N. Reddy

Keyword(s):

Unit Area ◽

Tomato Fruit ◽

Growth Yield ◽

Dry Weight ◽

Nutrient Status ◽

Field Studies ◽

Fruit Weight ◽

Fresh Weight ◽

Shoot Dry Weight ◽

Marketable Fruit

Field studies were conducted to determine the effects of various barnyardgrass populations on growth, yield, and nutrient concentration of transplanted “Jetstar’ tomato. Barnyardgrass densities at 16, 32, and 64 plants/m tomato row were tested in 1982 and 1983. Barnyardgrass shoot fresh weights/unit area increased as density increased. Fresh weight of barnyardgrass shoots ranged from 17 100 kg/ha at 16 plants/m of row to 35 500 kg/ha at 64 plants/m of row. At the vegetative stage, tomato shoot dry weight was unaffected by barnyardgrass. As crop growth progressed, tomato shoot dry weight decreased at all barnyardgrass densities. Season-long interference of barnyardgrass reduced marketable tomato fruit number and fruit weight at all densities compared to weed-free plots. Reductions in marketable fruit weight ranged from 26% to 16 plants/m row to 84% at 64 plants/m row. In 1982, concentrations of N, P, K, Ca, and Mg in tomato shoots were unaffected by season-long interference of barnyardgrass at all densities. However, in 1983, concentrations of N and K decreased and concentration of P increased in tomato leaves as the density of barnyardgrass increased. Concentrations of Ca and Mg in tomato leaves were unaltered by barnyardgrass density.

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278 A Ratoon Cropping System for Fall Bell Pepper Production

HortScience ◽

10.21273/hortsci.35.3.439b ◽

2000 ◽

Vol 35 (3) ◽

pp. 439B-439

Author(s):

Brian A. Kahn ◽

Daniel I. Leskovar

Keyword(s):

Capsicum Annuum ◽

Cropping System ◽

Late Summer ◽

Fruit Weight ◽

Fruit Yield ◽

Bell Pepper ◽

Average Height ◽

Bell Peppers ◽

Marketable Fruit

Studies were conducted to examine the effects of pruning treatments applied to spring-transplanted bell peppers (Capsicum annuum L.) on marketable fruit yield in late summer and fall. Control plants were set in the field in early May 1997 (Oklahoma) and Apr. 1998 (Oklahoma and Texas) and were harvested weekly into October (Oklahoma) or periodically into December (Texas). In 1997, there were no differences in total marketable fruit weight among four treatments involving height and method of pruning, but all reduced total marketable fruit weight relative to the control. In Oklahoma in 1998, the control was compared to plants mowed on 27 July at an average height of ≈24 cm. Mowed plants produced less total marketable fruit weight but more U.S. Fancy fruit than control plants. Also, control and mowed plants did not differ in weight of U.S. no. 1 fruit. In Texas in 1998, the control was compared to plants mowed on 4 Sept. at a height of ≈20 cm. Mowed plants produced more than double the weight of U.S. no. 1 fruit and fewer cull fruit than control plants. Nonpruned transplants set in the field in Summer 1998 (Oklahoma and Texas) gave low marketable yields. Maintaining spring-transplanted bell peppers is a viable technique for fall pepper production, and the highest total marketable yields may occur if these plants are not mowed. However, mowing offers an opportunity for increased fall production of premium fruit, and mowed plants would be easier to manage than unpruned plants.

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623 PB 445 ALTERNATIVES TO METHYL BROMIDE FUMIGATION IN TOMATO PRODUCTION

HortScience ◽

10.21273/hortsci.29.5.521e ◽

1994 ◽

Vol 29 (5) ◽

pp. 521e-521

Author(s):

Sandra L. Barbour ◽

Kathy H. Brock ◽

B.A. Fortnum ◽

Dennis R. Decoreau

Keyword(s):

Methyl Bromide ◽

Agricultural Practices ◽

Dry Weight ◽

Fruit Weight ◽

Tomato Production ◽

Plastic Surface ◽

Black Plastic ◽

Total Dry Weight ◽

Environmentally Sound ◽

Polyethylene Mulch

Pest control-related problems jeopardize the advancement of our nation's vegetable industry. Because of the adverse effects of many fumigants. the grower is increasingly pressured to utilize sustainable. environmentally sound agricultural practices yet still maintain a marketable, blemish-free product. The effects of wavelength selective mulches and three different fumigants on overall plant development and nematode control were studied in field grown, staked tomatoes. Plots were fumigated with methyl bromide. Telone II, or Telone C17. Within rows, mulch color was established by application of either white or red exterior enamel paint to the black plastic surface of polyethylene mulch. Reflective light from each mulch color was measured using a LiCor 1800 Spectroradiometer. Temperature below the mulch surface was monitored with a datalogger. Prior to the first marketable harvest, plants grown on white mulch produced greater fruit weight and total dry weight than plants grown on black or red mulch. Total marketable yields, however. were not significantly different between the three mulches. Early and marketable yields from fumigated plots did not differ from control treatments. The lack of response due to fumigation may have been due to low initial nematode populations in the field.

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Effect of Harvesting Time and Iron Application on Moldavian balm

Notulae Scientia Biologicae ◽

10.15835/nsb649357 ◽

2014 ◽

Vol 6 (4) ◽

pp. 505-508

Author(s):

Prshang KHALILI ◽

Reza AMIRNIA

Keyword(s):

Essential Oil ◽

Iron Content ◽

Oil Content ◽

Foliar Application ◽

Block Design ◽

Dry Weight ◽

Herbaceous Plant ◽

Harvest Time ◽

Branch Number ◽

Study Results

Dracocephalum moldavica L. of the Labiatae family is an annual herbaceous plant. In Iran it is known as Badrashbi and Badrashboo. Recent publications have reported antibacterial and antimicrobial properties of its essential oil, which have a wide usage in industry. In this research, the effects of iron foliar application and different yields’ harvest times on the essential oil content and some morphological treats (plant height, branch number, fresh and dry weights, essential oil content and leaf Iron content) were investigated under experimental study in faculty of Agriculture of Urmia University during 2012. A factorial experiment in a randomized complete block design with three replications was used in the present study. Results showed that foliar application of iron had a significant effect on branch number, fresh and dry weight, biomass and oil percentage. Similarly, harvest time had a significant influence on fresh and dry weight, essential oil content, essential oil yield and leaf iron content, but its effect was not significant on stem diameter and branch number. The best harvest time for Dracocephalum moldavica L. was at 100% of flowering and 6 ml/l of iron application showed the best results in all characters measured.

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A Ratoon Cropping System for Fall Bell Pepper Production

HortScience ◽

10.21273/hortsci.36.5.897 ◽

2001 ◽

Vol 36 (5) ◽

pp. 897-899

Author(s):

Brian A. Kahn ◽

Daniel I. Leskovar

Keyword(s):

Capsicum Annuum ◽

Cropping System ◽

Late Summer ◽

Fruit Weight ◽

Fruit Yield ◽

Bell Pepper ◽

Average Height ◽

Bell Peppers ◽

Marketable Fruit

Studies were conducted to examine the effects of pruning treatments applied to spring-transplanted bell peppers (Capsicum annuum L.) on marketable fruit yield in late summer and fall. Control plants were set in the field in early May 1997 (Oklahoma) and Apr. 1998 (Oklahoma and Texas) and harvested weekly into October (Oklahoma) or periodically into December (Texas). In 1997, all four treatments (involving height and method of pruning) reduced total marketable fruit weight, but differences among treatments were nonsignificant. In Oklahoma in 1998, plants were mowed on 27 July at an average height of ≈24 cm. Mowed plants produced less total marketable fruit weight but more U.S. Fancy fruit than did control plants, while weight of U.S. No. 1 fruit was not affected. In Texas in 1998, plants mowed on 4 Sept. at a height of ≈20 cm produced more than twice the weight of U.S. No. 1 fruit and fewer cull fruit than did control plants. Nonpruned transplants set in the field in Summer 1998 (both Oklahoma and Texas) produced low marketable yields. Maintaining spring-transplanted bell peppers is a viable technique for fall pepper production, and the highest total marketable yields may be obtained if these plants are not mowed. However, mowing offers an opportunity for increased fall production of premium fruit, and mowed plants would be easier to manage than nonpruned plants.

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Yield Losses from Delayed Harvest of Paprika Pepper

HortScience ◽

10.21273/hortsci.27.9.979 ◽

1992 ◽

Vol 27 (9) ◽

pp. 979-981

Author(s):

Brian A. Kahn

Keyword(s):

United States ◽

Capsicum Annuum ◽

Red Pigment ◽

Yield Losses ◽

Southwestern United States ◽

Harvest Dates ◽

Second Year ◽

Marketable Fruit

Paprika pepper (Capsicum annuum L.) plants were subjected to a single, destructive harvest in either October, November, or December to determine an optimal month for once-over harvest. Studies were conducted at two locations in Oklahoma each year for 2 years. Total and marketable fruit yields were highest with October harvest dates in three of the four experiments. Marketable fruit red pigment intensity decreased between the November and December harvest dates at both locations in the second year. When the crop is established by transplanting, paprika harvest should be completed during October in the southwestern United States.

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Interaction between leaf pruning and fruiting of pot-grown Valencia orange cuttings

Australian Journal of Agricultural Research ◽

10.1071/ar9691087 ◽

1969 ◽

Vol 20 (6) ◽

pp. 1087 ◽

Cited By ~ 4

Author(s):

DH Maggs ◽

A McEAlexander

Keyword(s):

Dry Weight ◽

Fruit Weight ◽

Net Assimilation Rate ◽

Assimilation Rate ◽

Leaf Production ◽

Full Size ◽

Valencia Orange ◽

Number Of Leaves ◽

Net Assimilation ◽

Total Dry Weight

The effects of leaf pruning on plants with and without fruit were studied in a 4-month pot trial. Pruning levels were (a) leaves intact, (b) leaves halved, and (c) leaves quartered. Leaves were pruned when they attained full size. Fruiting had no effect on total dry weight increment whereas leaf pruning reduced it. For fruiting trees, however, leaf pruning affected mainly fruit weight, the vegetative increments differing by only 10.7% of their mean. Fruiting had no significant effect on the proportions of leaf, stem, or root but leaf pruning increased the proportion of leaf at the expense of root. The proportion of fruit in the total increment decreased with increasing severity of leaf pruning. The intact defruited plant continued to produce flowers throughout the experiment. The total number of leaves produced was approximately halved by fruiting. The net assimilation rate of intact defruited plants was at least 30% less than that of all other treatments. It is concluded that fruit does not compete successfully for metabolites against a stimulated leaf production.

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