gherkin crop manual flat cultivation
DESCRIPTION
This Rijk Zwaan step-by-step manual helps you to grow a good gherkin cropTRANSCRIPT
Flat cultivation
Crop rotationThe gherkin is suitable as a good preliminary crop. However, phytosanitary reasons make a three to four year crop rotation recommendable.
Soil requirementsHeat-absorbing, humus-rich soil with good waterholding capacity and good structure is generally suited for cultivating gherkins. These include humic loamy sand and sandy loam as well as black soil. The pH-optimum lies in the range of pH 5.8 to pH 7.
Climate requirementsThe gherkin plant is frost-sensitive. Its thermophily is, among others, demonstrated by the fact that it develops physiological disorders (e.g. stunting) at a night temperature of below 5°C. The gherkin plant germinates and grows at a minimum temperature of approx. 12°C and opens its flowers from 15°C.
Optimal soil temperature is approx. 20°C, air temperature optimum is between 20°C and 35°C. Growth depression and the abortion of fruit have to be expected with temperatures significantly beyond this optimal range. The gherkin plant is relatively wind-sensitive due to a lack of effective evaporation protection.
SowingIn Southern Germany, sowing generally takes place from 10 April. This date, which is by approx. 2 to 3 weeks earlier, becomes possible through the use of poly propylene fleece. This earliness method provides frost protection. Generally, six strips of mulch film placed at a distance of 1.5 m and with a width of 1 m each are covered directly after sowing. The fleece is permeable to air, light and water, slows down wind speed, decreases evaporation and buffers potential slight night frost.
The aforementioned mulch film strips made of 20 – 35µ thick PE film (dyed black) are tightly laid on slightly raised beds with special plastic film layers whereupon a border strip of approx. 20 cm is dug in. The mulch film maintains the winter damp in the seed-bed, increases soil temperature and suppresses weed growth. Drip hoses are placed in the side area at the soil surface below the film each with the drip points turned upwards.Sowing is carried out with up-to-three-row pneumatic sowing stars. These sowing stars penetrate the length of film at a distance of 33 cm and place 3 corn of gherkin seed each at a depth of approx. 2 cm. Thus, 6,000 running meters of film per ha add up to a density of 50,000 plants/ha.
Milestones of yield increase
In Central European flat cultivation, crop yield has increased sixfold in the last 40 years. In the late 70s, the launch of black mulch film as well as of the newly developed ‘gherkin flyer’ contributed decisively to this development. The introduction of the parthenocarpic gherkin varieties Accordia RZ, Harmonie RZ and Melody RZ and the simultaneous use of horticultural fleece have also set new standards in quality and yield. The increase in yield was further brought about by drip irrigation being introduced in about 2000.
Weed controlThe inter-rows can be sealed with soil-applied herbicide film. Please note: In case of torrential rain there is the danger of illuviation. As soon as weeds have emerged hand-high, the fleece is opened. Weeds in the sowing holes have to be pulled out by hand. Between the rows hoeing can be done mechanically or a total herbicide can be applied if a spray screen is used. In the latter case, the fleece must not be closed earlier than half a day or a day later.
FertilisationOne hectare gherkin with a yield potential of approx. 100 t/ha has a nutrient requirement of approx.:• 280 kg N• 100 kg P2O5
• 280 kg K2O
Thereof the following quantities are broadcast as basic fertilizer before laying the film:• 100 kg N,• 80 kg P2O5• 140 kg K2O (chloride-free)
When the fleece is removed for inter-row weed control:• 50 kg stabilised Nare distributed between the rows.
Irrigation and fertilisation by drip generally begins at the first harvest, which is to be expected from mid of June, two weeks after blooming. The fleece should be removed approx. one week before harvest.
During the harvest season, 100% soluble fertiliser is applied corresponding to the volume yield via the drip system: with a harvest loss of 10 to/ha crop:• 15 kg N,• 7 kg P2O5• 24 kg K2O and• 2 kg MgOare withdrawn from the field.
A further 10 kg N/week are needed for plant development within the first three weeks of harvest. This amount is also needed at the time of regeneration (after the main harvest). Then a N : K2O-ratio of 1.3−1.6 : 1 has to be chosen. In times of high yields, fertiliser should be applied with focus on potassium (1 : 1.3). The gherkin does indeed prefer nitrogen in form of ammonium, however, attention should be paid to an alternation between ammonium and nitrate in order to prevent antagonisms with potassium, magnesium and especially calcium. Magnesium is applied in the form of MgSO4, however, never in combination with CaNO3 (precipitation of gypsum). Micronutrients are applied as a chelate cock-tail once a week (Mn, Zn, Mo, B ). The respective amount of fertiliser is applied with approx. 25m3 of water. Afterwards, the drip hoses should be rinsed with water.
IrrigationOn hot summer days, one hectare gherkin plants can evaporate up to 80,000 litres of water. The fruit harvest also corresponds to a disposwal of water (the fruit contains 96% water). A lack of irrigation leads to an abortion of young fruits and hollow spaces in larger fruits. Depending on the type of soil, water has to be applied once or twice per summer day. On heavy soil, up to 8 litres/m2 can be administered with one application. On light soil, this amount has to be split into two applications.
HarvestThe first stem fruits have to be harvested in order to stimulate further fruit setting. A picking rhythm of two to four days is necessary depending on the weather conditions and the fruit size aimed at. For mainly smaller gradings of up to 9 cm, fruits have to be harvested every other day. That adds up to a surface of max. 5 ha (per so-called ‘gherkin flyer’ with 24 people) on which harvest can take place. With a larger grading mix up of to 15 cm, picking can take place at intervals of 3.5 days. In that case, the ‘flyer’ capacity is approx. 8 ha. Regular picking of all target sizes without missing single fruits leads to a very balanced fruiting habit in case of need-adjusted fertilisation and water management.
Added value in all segmentsVariety name Character Segments Added value
Smooth Spined L/D Flat out-door
Mecha-nical harvest
Hand-pick
Open plant easy pick
Very early
Strong against downy mildew
High regene-ration
Concen-trated fruit-setting
Majestosa RZ F1 3,2
Fuga RZ F1 3,1
Schubert RZ F1 3,2
Componist RZ 3,2
Karaoke RZ F1 3,0
Wagner RZ F1 3,1
Sonate RZ F1 3,0
Puccini RZ F1 3,1
Chopin RZ F1 3,2
Lehar RZ F1 3,1
Strauss RZ F1 3,2
Liszt RZ F1 3,2
12-303 RZ F1 3,1
12-305 RZ F1 3,1
Diseases
Crops are generally less susceptible with good crop management.
Breeding focusOur varieties offer high cultivation reliability due to the high resistance level against Powdery Mildew (Px), Cucumber Scab (Ccu) as well as Cucumber Mosaic Virus (CMV). Important diseases such as Downy Mildew (Pcu) and Zucchini Yellow Mosaic Virus (ZYMV) are focal points of our breeding.
Downy Mildew (Pseudoperonospora cubensis)Downy Mildew (Pseudoperonospora cubensis) has to be regularly treated from the very beginning of infection. Warm and humid weather with night temperatures above 13°C and fluid water on leaves for several hours are favourable conditions for infections. In South Germany, first symptoms appear already in early June. In case of disease pressure, allowed chemicals have to be regularly applied at intervals of approx. 7 days. At least two different active ingredients (systemic and contact) should be mixed. An alternation of active ingredients is important in order to prevent resistances.In our parthenocarpic assortment you may find already less susceptible varieties such as Majestosa RZ, Fuga RZ, Schubert RZ and Chopin RZ in the smooth segment and Karaoke RZ in the spined segment.
Angular leaf spot (Pseudomonas syringae)This bacterial leaf disease can also infect fruits. The disease spreads only in wet crops. Copper is said to have a certain bactericidal effect. Various varieties show lower symptom expression: Schubert RZ, Chopin RZ und Strauss RZ. Rijk Zwaan is increasingly working on resistant varieties.
Gummy stem blight (Didymella bryoniae)This fungal disease also infects wet crops. Only few fungicides are effective if applied preventively. Stems, leaves and fruits can be infected. Fruit infection takes place via the flower. Resistance against especially the fruit symptoms are a breeding aim of first priority.
Lygus bug (Lygus pratensis)Stinging into young leaves and shoot tips causes holes in leaves as well as stunted shoots. More damage is done to the fruits due to stunted growth. Chemical treatment with e.g. pyrethroids is possible.
Spider mite (Tetranychus urticae)Hot and dry conditions are favourable. The pest always starts with spots in the hottest and driest parts of the field. The mites are sucking at the downside of leafs, protected by a delicate spider web. Spraying with allowed acari-cides has to be done immediately. Border treatment can prevent immigration. Plant-bitter varieties such as Puccini RZ and Gershwin RZ are avoided by spider mites.
Virus diseases of gherkin Virus diseases of gherkin such as CMV (cucumber mosaic virus) and ZYMV (zucchini yellow mosaic virus) are especially dangerous in combination. The plant grows sickly, the fruits show black distortions when infested by ZYMV. Vector control as well as physical distance to other cucurbitaceae are precautionary measures. Beyond that, only resistances can help. All Rijk Zwaan cucumber varieties are resistant to CMV. There already are varieties such as Kybria RZ, Shakthi RZ and 12-302 RZ which are resistant to or, at least, strong against ZYMV.
Our gherkin specialists
Rijk Zwaan’s descriptions, illustrations, growing advices and any other information in whatever form for example on expiry, sowing, planting and harvesting dates are based as precisely as possible on experiences in trials and in practice. However, Rijk Zwaan does not accept in any case liability for damages resulting from the use of such descriptions, illustrations, growing advices and information. The buyer/user itself is responsible for proper storage of the seeds and will be deemed to determine whether the products and growing advices are suitable to be used for the intended cultivations and under the local conditions. Inclusion of a variety in this edition does not automatically imply that such a variety is available for purposes of exploitation; it might be available for testing only. For more information, please contact Rijk Zwaan (www.rijkzwaan.com). The pictures in this edition show the types to which the varieties as mentioned belong and not all varieties as such. These pictures do not constitute any warrranty, expressly or implied, of crop performance.
Crop coordinator international Gerald [email protected]
Specialists according to culture method
Flat manual
Germany, Austria, Czech Republik Gerald [email protected]
Vertical outdoor temperate Hungary Laszlo Ragyak [email protected]
Vertical outdoor subtropicalIndiaPrasanna D.G. [email protected]
Vertical indoorUkraineAndriy Galagurja [email protected]
Flat mechanical USA, CanadaGeorg Pape [email protected]
Further gherkin specialists according to country
Bosnia, Montenegro, Serbia Djurdje Spasojevic [email protected]
Brazil Marcelo Sartori [email protected]
Central AsiaNasredin [email protected]
Poland , the Baltic StatesMarcin Pawlak [email protected]
Romania George [email protected]
RussiaGennady [email protected]
TurkeyIsmail [email protected]
UkraineStanislav [email protected] VietnamGerard [email protected]
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
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