VARIETIES FOR HAND-PICKING (approximately 50-60 days to start of hand harvest in the Willamette Valley).

Processors determine varieties to be grown. Brining quality (firmness, color), length:width ratio, seed development rate, fruit appearance, disease resistance and yield are primary considerations. Varieties suggested for trial for direct market and U-Pick operations are:

Black spine types: Pioneer, Bounty.
White spine: Blitz, Calypso, Cross Country, Duke, FanciPack, Flurry M, Quest, Regal, Triplemech.

Parthenocarpic (need no pollination and seedless when isolated from other cucumbers. Bees must also be excluded). Varieties For Trial Only: Adonis, Alvin, Amanda, Anka, Arena, Christine, Melani, Parmel, Serena.

Note: Most parthenocarpic varieties are also gynoecious, but some may be partially female or monoecious. Most are still being evaluated for fruit quality characteristics and have been used only experimentally by Pacific Northwest processors.

VARIETIES FOR MACHINE HARVEST (60-70 days to harvest for Willamette Valley).

Until about 1989, all pickling cucumbers produced in the Pacific Northwest were harvested by hand. The cost of labor and concerns about its availability have resulted in the adoption of mechanical harvest for much of the acreage. Because machine harvest is a once-over, destructive harvest, as contrasted with multiple hand harvest, new varieties and production practices had to be developed and implemented.

The predominant variety used for machine harvest has been 'Calypso'. It is a non-determinate type. Determinate and parthenocarpic cucumbers are of interest for machine harvest, but these types are not used at present. For an extensive report of OSU trials of pickling cucumber varieties for mechanical harvest in western Oregon, see the reports on Vegetable Research at the NWREC 1989-1990, 1991-1992, and 1993-1994.

Research conducted in the Hermiston area indicates that 'Blitz' and 'Eureka' should be considered for production in the Columbia Basin.

Results from recent trials of 22 varieties conducted by Dr. Wilbur Anderson, Washington State University, in the Skagit Valley of northwestern Washington indicate the following:

The highest ratings, based on yield and quality, were achieved by the varieties Vlaspik B, SRQ 1882 Classic, Vlasspear, Atlantis F1, FMX 5020, PS 14692, HMX 3469, and Calypso M. Because of length:diameter ratio requirements of Pacific Northwest processors, however, only SRQ 1882 Classic and HMX 3469 have the potential to replace Calypso, the dominant variety.

Varieties with significantly higher yield than Calypso included Atlantis F1, PS 14692, Vlasspear, SRQ 1882 Classic, HMX 3469, and FMX 5020. Those with brining ratings that exceeded Calypso included Vlaspik B, Vlasspear, EX 1914, FMX 5020, HMX 3469, SRQ 1888 Classic, and SRQ 2393 Classic.

SOILS

Pickling cucumbers can be grown on a wide range of soils if the soils are well drained and have about 2-3% organic matter, and a high level of fertility. Irrigation is essential to maintain good soil moisture and to obtain high quality fruit. Avoid heavy soils or those easily compacted. Use a soil test to determine the nutrient status and pH.

Avoid fields enclosed by tree rows that limit air movement, since this may provide an environment conducive to foliar and fruit diseases.

TEMPERATURE

Recent research indicates that temperature range for optimum cucumber growth is 86-90 F. Night temperatures above 70 F, especially when combined with moisture stress, result in rapid seed development and softening of internal tissues.

Minimum soil temperature required for germination of this crop is 60 F with the optimum between 70 and 95 F. Pickling cucumbers are sensitive to cool soil conditions. Under such conditions, damping-off can seriously reduce stands, and seedling growth may be very slow.

SEED AND SEED TREATMENT

Cucumber seed numbers approximately 17,600/lb, except Little Leaf types which are smaller, numbering about 32,000/lb. Use treated seed. Pickling cucumbers can be particularly sensitive to damping-off problems. Proper seed treatments can dramatically improve stands.

Some seed companies offer primed seed. Growers may also send seed to specialty companies that will prime seed for them on request. New developments in seed priming (solid matrix priming) offer advantages not available until very recently. Although primed seed may emerge earlier and more uniformly, reducing certain production risks, these advantages may, or may not translate into earlier harvests, higher yields or better quality. Primed seed has limited storage life.

ROTATION

To avoid diseases that survive over winter on debris of cucumbers and other cucurbits it is best not to plant this crop behind cucumbers, muskmelons, squash, pumpkins or watermelons. A good rotation is to follow small grain or corn.

SEEDING

Approximately 60-70 days are required between seeding and first harvest in the Willamette Valley and 55-65 days in the Hermiston area. Sequential plantings are necessary for orderly harvest. Heat-unit systems to schedule plantings are of limited use because days to harvest can be influenced by soil moisture, adequacy and timeliness of pollinators and other factors. Processing company fieldmen will determine schedules appropriate to processing needs.

Cucumbers for pickling are planted in May and June in the Willamette Valley and starting the end of April in the Hermiston area. Fields intended for hand harvest are planted as soon as weather permits with subsequent planting dates left largely up to the grower. Fields for machine harvest are planted on a tight schedule to fit product grade requirements, processing plant capabilities and harvesting machinery availability.

Pickling cucumbers varieties are always direct-seeded. Seed carefully at a depth l/2 to l inch depending on soil moisture. For hand-harvest plantings use about 2 to 2.5 lb seed/acre aiming or populations of about 20,000 plants/acre. Use about 6-9 lb seed per acre and populations of 75,000 to 85,000 plants/acre for machine harvest. Generally 1 lb of seed produces 12,000-15,000 plants under good conditions.

Limited research on the economics of combining hand and machine harvest indicate that plant populations for such fields should be the same as for fields intended for machine harvest only.

Recommended final spacing for hand-harvest is 4-5 feet between rows, 6-8 inches between plants in the row and a plant population of 18,000 to 20,000 per acre (300 to 450 square inches per plant).

For harvesters with 84-90 inch headers, recommended between-row spacing is 18-30 inches, 2-4 inches in the row, 3 or 4 rows per bed and a population of 75,000 to 85,000 per acre for indeterminate types and 85,000 to 120,000 per acre for determinate types.

Note: 74 square inches per plant results in approximately 85,000 plants/acre.

WINDBREAKS

Windbreaks are often overlooked as a crop protection aid. In general, close windbreaks, even between every row, give the best wind protection and may moderate the crop micro-climate enough to promote faster plant growth. Where winter cover crops have been employed, it would be a good practice to leave strips of the cover crop as windbreaks. In this case, the strips for the plant beds can be prepared by rototilling, leaving windbreak strips between the plant rows.

Establishment of a windbreak crop in the previous fall will insure enough growth to become effective as a windbreak by spring planting time. Seed grain thickly, 2-3 seeds per inch. This requires about 10 lb barley, 9 lb wheat, or 8 lb rye to seed grain rows 12 feet apart. Spring grains such as barley may be useful if planted in February in eastern Oregon.

Windbreaks can be removed by mowing, tilling, or an appropriate herbicide once their useful life is over.

FERTILIZER

Good management practices are essential if optimum fertilizer responses are to be realized. These practices include use of recommended varieties, selection of adapted soils, weed control, disease and insect control, good seed bed preparation, proper seeding methods, and timely harvest.

Because of the influence of soil type, climatic conditions, and other cultural practices, crop response from fertilizer may not always be accurately predicted. Soil test results, field experience, and knowledge of specific crop requirements help determine the nutrients needed and the rate of application.

The fertilizer program should insure adequate levels of all nutrients. Optimum fertilization is essential for top quality, yields, and returns.

Recommended soil sampling procedures should be followed in order to estimate fertilizer needs. The OSU Extension Service agent in your county can provide you with soil sampling instructions and soil sample bags and information sheets.

Recommendations are based on a row spacing of 60 inches. With decreased row spacings fertilizer rates should be increased.

Western Oregon

For fields intended for hand-harvest, rates of 80 to 150 lb N/A are suggested with the lower rates of N being applied when legumes were grown the preceding year or a green manure crop is incorporated into the soil before planting. Apply one-half the N at or just before planting and the rest when vines begin to "run".

Exercise care in N fertilization and irrigation. Excess applications of water or N may result in viney plant growth that may also interfere with bee pollination and machine harvest. This may also promote foliar and fruit diseases, resulting in reduced fruit set, loss of small pickles in machine harvest, and an increase in fruit disorders.

For machine-harvested fields, N rates of 60 to 100 lb/A should be adequate. All the N may be applied at or just before planting. Determinate vine cultivars may produce highest yields at the higher N rates per acre without danger of excessive vine growth.

Although plant populations are much higher for machine harvested fields than hand-picked fields, the machine-harvested fields have a much shorter production period, generally being harvested once destructively. Fields intended to be hand-picked several times before a machine harvest would have to have N managed differently.

Pickling cucumbers are sensitive to fertilizer burn. If the application of N plus potash (K2O) exceeds 50 lb/A, there is danger of seedling injury from the fertilizer if it is all banded at planting time. There is less danger if the band application is split into two bands. The danger is aggravated as the band comes closer to the seed, and is greater with sandy than with finer textured soil. Immediate irrigation at the first sign of burn should reduce further injury. There is more possibility of damage to seedlings on acid soils where the pH is below 5.5.

Phosphorus (P)

Phosphorus fertilizer should be banded at planting for vigorous early seedling growth. Bands should be located 2" to the side and 2" below the seed. Phosphorus management would be the same for hand and machine-harvested fields.

           If the soil test*              Apply this amount of
           for P reads (ppm):             phosphate (P2O5) (lb/A):
                 0 to 15                          120-150
                l5 to 60                           90-120
                 over 60                           60- 90 

*Assumes extraction procedures similar to those used by the OSU Central Analytical Laboratory. Specific information on soil test procedures is available from the Crop and Soil Science Department.

In some areas, a diluted phosphoric acid solution sprayed in a 1-2 inch wide band directly over the seed row has been shown to reduce crusting, improve P nutrition of the crop and increase yield. The benefit of this treatment would be most likely to occur with early plantings on cool soils.

Potassium (K)

Potassium for both hand and machine-harvested fields should be applied before planting or banded at planting time. Amounts above 40 lb K2O/A should be broadcast and worked into the seedbed. See statements on fertilizer banding under "Nitrogen."

            If the soil test*      Apply this amount of
            for K reads (ppm):       potash K2O (lb/A):
                0 to  75                 100-150
               75 to 150                  60-100
              150 to 200                  40- 60
                over 200                   None                           

Sulfur (S)

Include 20-30 lb S/A in the annual fertilizer program for vine crops. Sulfur is sometimes contained in fertilizers used to supply other nutrients such as N, P, and K but may not be present in sufficient quantity.

Plants absorb S in the form of sulfate. Fertilizer materials supply sulfur in the form of sulfate and elemental S. Elemental S must convert to sulfate in the soil before the S becomes available to plants. The conversion of elemental S to sulfate is usually rapid for fine ground (less than 40 mesh) material in warm moist soil.

Sulfur in the sulfate form can be applied at planting time. Some S fertilizer materials such as elemental S and ammonium sulfate have an acidifying effect on soil.

Magnesium (Mg)

When the soil test value is below 1.5 meq Mg/100g of soil or when calcium (Ca) is ten times more than the Mg, apply 10-15 lb Mg/A banded at planting. If Mg deficiency symptoms appear, spray with 10 lb Epsom salts in 100 gal water/A.

Magnesium can also be supplied in dolomite, which is a liming material and will reduce soil acidity. Dolomite should be incorporated into the seedbed at the rate of 1-1.5 T/A.

Boron (B)

In general, boron deficiencies are uncommon. If the soil test value for B is less than 1 ppm, an application of 3 lb B/A is suggested. Boron should be applied uniformly to the field as a spray or broadcast. Never band B fertilizer. Cucumbers are sensitive to excess B.

Zinc (Zn)

Zinc deficiencies are uncommon in Willamette Valley soils. When the soil test is below 1 ppm Zn, a response to Zn is expected and 4 lb Zn/A should be included in the fertilizer band.

Lime

Experiments have shown that vine crops will produce good yields over a fairly wide range of soil acidity. Lime applications are suggested when the soil pH is 5.6 or below, or when calcium (Ca) levels are below 5 meq Ca/100g of soil. Optimum pH is between 5.8 and 7.0.

The rate of lime application can be estimated from the following SMP buffer table.

           If the SMP buffer*     Apply this amount of
          test for lime reads:        lime (T/A):
               Below 5.2                   4-5
               5.2 - 5.6                   3-4
               5.6 - 5.9                   2-3
               5.9 - 6.2                   1-2 

Lime should be mixed into the soil at least several weeks before planting. A lime application is effective over several years.

Some soils may have a fairly high SMP buffer value (over 6.5) and a low pH (below 5.5). This condition can be caused by the application of acidifying fertilizer. In this case the low pH value is temporary and the pH of the soil will increase as the fertilizer completes its reaction with the soil. This temporary "active" acidity from fertilizer is encountered following recent applications of most N fertilizer materials. Acidifying fertilizers also have a "long term" acidifying effect on soil that is cumulative and leads to lower SMP buffer readings.

Sandy soils to which fertilizers have not been recently applied sometimes record low pH and high SMP buffer values. In such cases, a light application of 1-2 T/A of lime should suffice to neutralize soil acidity.

For acid soils low in Mg (less than 0.8 meq Mg/100g of soil), 1 T/A of dolomite lime can be used as a Mg source. Dolomite and ground lime stone have about the same ability to neutralize soil acidity.

The possibility of seedling injury from the band application of fertilizer is less when the soil pH is 5.6 or above. Some Willamette Valley experiments have shown decreased uptake of phosphorus from band applications of phosphorus when the pH approaches 5.5.

Lime applications should be broadcast, preferably in the fall, and incorporated into the seedbed. Do not plow lime down leaving the surface soil unlimed.

Fertilizer Guide #2, "Liming Materials for Oregon", which is available from your local OSU Extension Office, provides additional information lime.

Eastern Oregon:

Nitrogen: 40-60 (N) lb/acre
Phosphate: 100-150 (P205) lb/acre
Potash: 50-70 (K20) lb/acre

Just before the vines begin to spread, sidedress with 50-75 lb N/acre.

These fertilizer recommendations are based on research conducted by OSU Horticulture and Crop and Soil Sciences Department faculty, and are quoted from OSU Fertilizer Guide FG 68.

FLOWERING AND POLLINATION

Depending on cultivar, pickling cucumbers plants may bear separate male and female flowers on the same plant (monoecious), only female flowers (gynoecious), or perfect flowers (male and female organs in the same flower) mixed with either male or female flowers, i.e. andromonoecious or gynomonoecious (the varieties Lemon and Crystal Apple are the only examples of the latter type).

Some modern cultivars have plants that bear only female flowers (gynoecious), or bear predominantly female flowers (PF), so seeds of plants that are monoecious are mixed into the seed lot (usually 10 to 15%) to allow for a pollen source. These seeds are usually dyed a different color from the seeds of the cultivar being planted.

Bees are needed to transfer pollen from the male flowers to the female flowers, thus making fruit set possible. For hand-picked fields, we recommend that 1-2 honey bee colonies of 30,000 to 50,000 bees each be introduced for every acre during the blooming period. High population plantings intended for machine harvest require 2-3 colonies per acre for the 1-2 week period coinciding with peak bloom. For more information on beehive quality and pollination, see the OSU Publication PNW-245 Evaluating Honey Bee Colonies for Pollination, A Guide for Growers and Beekeepers.

Naturally occurring bee populations are not considered to be adequate since their presence may not coincide with the full blooming period, or their numbers may be too low. Furthermore, the new gynoecious pickling varieties are less attractive to bees. Information from the Midwest indicates that pickling cucumbers require at least 15 bee visits to each flower for normal pollination and fruit set, and maximum yields, although some of the new all-female varieties may set as much as one-third of their yield without being pollinated.

Another reason for a high bee population at first bloom is that pollination of flowers in the crown area over a short period (1-2 days) will result in the desired multiple fruit per plant and a range of usable fruit sizes. If pollination of flowers occurs over an extended period of time (several days) the later pollinated flowers will not develop until the first pollinated fruit is removed. This results in the often observed single fruit per plant in the crown area with all other fruit development stopped.

Hives should be placed at the edge of the field after the first blooms are visible so that no point in the field is more than 200-300 yards away from a colony. Placing bees prior to flowering may result in the bees establishing themselves on nearby crops thus reducing their effectiveness in cucumber pollination. Research indicates that total yield increases resulting from good bee management can range from 25 to 50 percent. Pickling cucumber growers in the Midwest are reported to have experienced an average increase of 30 percent from effective use of bees.

A new group of pickling cucumber varieties that are being used experimentally is parthenocarpic (needing no pollination). Bees must be excluded from fields of parthenocarpic varieties and such fields must be isolated from conventional fields or serious fruit quality problems will occur.

Early research (Michigan, 1970) suggested that IF a machine-harvest field can be isolated from ANY natural bee activity, yield and dollar value per acre might be increased by DELAYING the introduction of bee colonies for about 10 days AFTER the initiation of bloom. This is based on three studies that found that increases in yield and value resulted from an increase of well-shaped cucumbers and more fruit per plant when pollination was delayed for 11 days after the initiation of bloom. It was suggested that stronger root and vine growth were basically responsible for this increase, but perhaps this was also due to larger (and more numerous) female flowers (opening simultaneously), which occurred on the more mature plants. Caution: These findings have not been substantiated by research in the Pacific Northwest with current varieties.

GROWTH REGULATORS

Gibberellic acid (GA) is labelled for stimulation of fruit set in cucumber during periods of cool temperatures. The rate is 2 g ai/acre in sufficient water to obtain thorough foliage coverage. The label calls for one application before bloom followed by up to four more applications at intervals of 10-14 days. Caution: The efficacy of GA applications for fruit set in cucumber has not been confirmed by research in the Pacific Northwest.

IRRIGATION

Irrigation requirements depend on the length of harvest. Some fields may be hand harvested 10-12 times and need to be kept growing adequately.

Ten to 15 inches of water may be required depending on seasonal variation and variety. Irrigations need to be coordinated with picking schedules. When possible, irrigate very early in the morning in order to avoid interfering with bee activity, and terminate irrigation to allow vines to dry before nightfall.

Adequate, uniform water applications are necessary to produce high quality fruit. Water stress contributes to higher incidence of nubs and reduced fruit length. Water stress coupled with high night temperatures also results in rapid seed development and softening of cucumber internal tissues.

Field observations in fields intended for machine harvest indicate that as harvest approaches (when fruit reaches a mean grade of 2.0), irrigation and soil moisture can have a dramatic effect on fruit sizing. When irrigation is applied at this time, especially during warm temperatures, fruit grade size can increase by 0.2 of a grade per day, necessitating harvest in 2 to 2.5 days. Conversely, if fruit sizing needs to be slowed or delayed, irrigation should be delayed, as long as it does not result in fruit wilting or crop damage.

Soil type does not affect the amount of total water needed, but does dictate frequency of water application. Lighter soils need more frequent water applications, but less water applied per application.

See also the OSU Irrigation Guide for this crop.

HARVESTING, HANDLING, AND STORAGE

In western Oregon, pickling cucumbers are hand harvested from about mid-July to mid October machine harvested from mid-July to late August to meet processor scheduling needs. The prime harvest season for hand harvest is from the end of July to the end of September.

Oregon plantings are mostly machine harvested at this time. Different prices are paid for machine-harvested and hand-harvested fruit. Processing requirements are set according to variety and desired product. Pickling cucumbers are graded by diameter. One processor grades: Grade #1: cucumbers less than 1"; grade #2: 1"-1.5"; grade #3: 1.5"-2". Fruit over 2" diameter is rejected by some or accepted up to 2.5" at minimal value for a maximum percentage per load by others. Nubs and crooks are also graded separately and paid for at a minimal price.

Approximate average hand-harvest yields of pickling cucumbers are about 12 tons per acre for fields that are picked about 10-12 times. Good yields are approximately 15-18 tons/acre. Where contracts are on a tonnage basis, and because of labor constraints, growers may over-plant acres so as to fulfill their contracts with fewer (7-10) pickings.

For highest returns, thoroughly harvest marketable fruit at regular intervals. Remove oversize fruit so later fruit can develop properly. During warm weather conditions, pickling cucumbers may grow very rapidly and it is important to shorten harvest intervals. Pickling cucumbers can have a 40 % weight increase in 24 hours, especially when fields are well irrigated (see IRRIGATION section above), and may depreciate in value by 5 to 15 % over the same period.

Machine-harvested yields may average 6 tons/A. with good yields about 10 tons/A. Return is greatly dependent on the grade of the harvested product, so tonnage figures are a poor indicator of dollar return per acre. New harvesters (FMC) have demonstrated the capability of picking a higher percentage of small fruit and a better dollar return per acre.

For once-over, destructive, machine harvest, proper timing is a major decision. Maximum dollar return per acre, and maximum value per ton, do not occur at the same time. Harvest time must be based on accurate field sampling. The processing company may dictate time of harvest based on their requirements for cucumber sizes and harvester availability. The grower must establish an agreement with the processor on time of harvest and grade values based on interactions of the type of machine harvester, variety, plant population and time of harvest. Machine harvesting and bulk handling capability may be limiting, and would have to be considered.

Pickling cucumbers are picked into large bins for delivery to processors. Care should be exercised in minimizing mechanical damage and protecting loads from heat build-up to minimize spoilage and maintain brining quality.

Harvesters

Machine-harvest with a Wilde or Byron harvester is usually begun when the average graded weight of harvested pickles is about 2.5. This generally occurs just when grade 4 (oversize) pickles reach between 5 and 10 percent.

Other harvesters such as the tractor-mounted Cuc. Inc. machine and the Pik Rite harvester (Lewisburg, PA) are available. The Cuc. Inc. machine has been used to a limited extent in the Pacific Northwest. The Raven Pickle Harvester, built by Jerry's Welding of Ravenna, Michigan, has an oversize eliminator that sorts oversize cucumbers and puts them back on the field. To our knowledge, it has not been used in the Pacific Northwest.

It is important to note that processors will differ in their grade requirements, and varieties differ in their size-grade distribution, and the rate of change of grade distribution with each day's delay of harvest. Varieties also differ in the quality of their large and oversize cucumbers. These factors affect the value of any given load. In the Willamette Valley, this can result in a change of $100 per day per acre in gross returns with the variety Calypso and similar lines.

Machine-harvested cucumbers should be washed and cooled immediately after harvest to reduce losses due to mechanical damage from the machine and soil abrasion. Portable washing equipment is commercially available in 3000 and 5000-gallon capacity tanks by some of the manufacturers of harvesting machines.

STORAGE (Quoted or modified from USDA Ag. Handbook 66 and other sources)

Pickling cucumbers have been successfully hydrocooled under experimental conditions and then held 4 days at 40 F. They should be utilized immediately after removal from cold storage.

PESTS

A number of diseases and insect pests may seriously affect pickling cucumber production. Because cucumbers intended for machine harvest are not subject to extensive handling before harvest, foliar diseases have been less of a problem than in hand-harvested fields. High plant populations allow for rapid ground covering and shading of weeds, but because herbicide tools are limited care should be exercised in field selection and timely weed control.