gherkin crop manual for vertical indoor cultivation
DESCRIPTION
This Rijk Zwaan step-by-step manual helps you to grow a good gherkin cropTRANSCRIPT
Vertical indoor cultivation
2
Young plant propagationFor gherkin young plant propagation it is very impor-tant to use light substrate (peat or cocopeat), or a mixture of both of them. Gherkin young plant propaga-tion can be done in two ways: • direct sowing into pots or trays;• via re-transplanting from trays into pots.
For uniform seed germination the temperature of the substrate should be around 24 to 25 degrees Celsius. For better seed germination and better seed coat opening it is good to use thin cloth or perforated plastic foil to cover the pots or trays with it. After about 20-30 percent of seeds produce hypocotyls hooks the thin cloth or foil coverage should be removed. The temperature should be than reduced to 20 degrees Celsius with a relative humidity (RH) of 80 to 90 percent and artificial lighting should be turned on. During the seed germination process we recommend to measure the temperature of the soil/substrate and not the temperature of the surrounding air.
The segment of ‘protected cultivation’ mainly supplies the East European market with gherkins.Especially early and late sets are cultivated to ensure the supply with fresh gherkins for as long as possible.This implies high demands on the varieties as they have to be cultivated under low-light conditions and non-optimal temperatures.The summer sets also supply the processing industry with gherkins.
Seeds will be sown around 1 to 2 cm below
the soil/substrate surface.
Growing stage Day temperature ºC
Night temperature ºC
Artificial light, in hours
Sowing 24-26 24-26 –
Germination 22-23 21-22 24
Transplanting 20-21 19-20 18
Young plants 20-21 18-19 16-18
Before planting in greenhouse 19-20 17-18 12-14
Planting in greenhouse 20-21 19-20 –
3 days after planting in greenhouse 19-24* 17-18 –
* During cloudy days, day temperature should be 19-20º C, however during sunny days about 24º C.
3
During winter sowings of gherkins with low light conditions it is recommend to use artificial light in form of sodium lamps which are hung up 2m above the plants to achieve a better young plant quality.Minimal artificial light intensity for gherkin young plants must be around 100 Watt/m2. Bulbs with the power of 400 or 600 Watts are normally used. The below mentioned temperature ranges are recommended if the described artificial light levels are used.
Optimal irrigation water EC for cucumbers
0,4-0,7 mS.
During winter gherkin young plant growing it is better to use pots with a minimal volume of 0,5 L. This makes it possible to get young plants with 3-4 real leaves and well developed root systems. Such young plants can survive stress situations better during plantation into the greenhouse. In general, the later we sow in winter, the younger young plants can be used, with fewer amounts of real leaves and it is also possible to grow them in pots/trays with smaller substrate volumes.During young plant growing it is not only important to control the climate, but it is also important to provide proper fertilization. The EC (Electrical Conductivity) level of clean water is important because so lower it is, so more nutrients are available for uptake via the root systems of the plants.
Optimal irrigation water EC for cucumbers
0,4-0,7 mS.
After emergence of the first real leaf plants start to use nutrients available in the root zone. Therefore we recommend to provide with each watering fertilizers for the balanced plant development. In the table below the recommended amounts of fertilizer salts are given for 10 L of irrigation solution. To avoid a precipitation of calcium and phosphor it is recommended to dissolve the calcium nitrate in one tank / bucket with 5 L of water and the rest of the nutrients in another tank / bucket with 5 L of water. Afterwards both solutions can be mixed together.
Use of fertilizers
Fertilizers* Irrigations
1st 2nd 3rd 4th 5th
Monopotassium phosphate 2 2 2 2 2
Calcium nitrate 3 3 3 4 5
Potassium nitrate – – 2 2 3
Magnesium nitrate – 2 2 3 4
Total, grams 5 7 9 11 14
* In general it is possible to use other water soluble fertilizers too as soon as the irrigation solution is balanced regarding main nutrient elements and microelements.
It is very important to have a proper irrigation during young plants growing. The watering is done when needed, so that the roots are forced to search for the water. With a proper watering strategy the whole pot/tray volume is filled with the root system.
4
Planting in the greenhouse and irrigation
Before main soil preparation it is recommended to introduce organic fertilizers. Introduction of dairy cattle manure positively affects the gherkin crop. The manure improves the soil structure in the greenhouse. During plantation of young plants into the greenhouse the temperature of the soil is important. Firstly if the soil temperature is lower than 14 degrees Celsius, the root system cannot develop and secondly so lower the soil temperature is it facilitates the development of root fungal diseases (root rots, Fusarium) which leads in the most worse case to a dying of the young plants.
Optimal
soil temperature 18-20ºC. In spring plantings the plants density is about
2,5-3,0 pl/m2 whereas the plant density in autumn plantings should be only 2-2,5 pl/m2.Plants in the greenhouse are planted in a single row or a double row. In single row plantings the plants are ‘V’ wired, onto two wires whereas in the double row plantings the plants are planted in a staggered order. All the measures are intended to provide maximal light penetration into the plant canopy. Below the two described planting types are depicted.
The greenhouse climate after plantation is important. Factors as air temperature, light levels, air humidity etc. are all used to describe the climate. The main goal is to create optimal conditions for growth
and development of gherkin the plants.
0.4m
0.8m
0.8m
0.8m
0.4m
0.45-0.5m
0.45-0.5m
3.2m
0.5m
0.6m
1.0m
0.6m
0.5m
0.45-0.5m
0.45-0.5m
3.2m
The single row plantingDistances between the rows can be as well 1m. In this case the distance between plants is 0.3-0.35 m. Both schemes are possible.
The double row planting.The distance between rows can be changed according to the growing conditions. The planting density however should be maintained.
5
In early winter plantings in the greenhouse it is difficult to hold the right climate such as temperature and the relative humidity due to many dull days.Taking into consideration the above conditions, we have to apply a proper irrigation strategy and fertilization. With 95 percent and more relative humidity in the greenhouse it is not recommended to irrigate, since in these circumstances almost no transpiration takes place. Optimal relative humidity in the greenhouse for growing ranges between 80-85 percent. The watering of plants after planting should be done on demand and especially on sunny days.
Optimal temperatureof irrigation water is 18-20ºC.
The plants do not need frequent irrigations and big water volumes before fruits start to grow. In this period it is important to get a good root system established by forcing the roots to search for water.
In the early spring the start of irrigation should not be earlier than 2-3 hours after sunrise and in addition the irrigation should not be done unless it has been warm enough in the greenhouse (+20ºC) for at least two hours so that the plants are heated. If the above mentioned conditions are not met the plants are not ready to get water and therefore can lose roots which can lead to fruit abortion.
First transpiration,then irrigation.
Irrigation should stop at about 2-3 hours before sunset after a sunny day and before 4-5 hours after a dull day. The daily water demand of a cucumber plant can range from 0,2 till 2,5 L. The amounts are dependent on soil type, plant growing stage, the temperature and humidity in the greenhouse. The irrigation should be divided into 3-4 cycles in a single day. However 70 percent of the daily water should be given from 11 am till 3 pm i.e. in the period of high water uptake due to evapotranspiration.
6
Fertilization
Gherkin plants are regarded as a fast growing crop which quickly uses its nutrients in the root zone. Therefore it is important to provide nutrients throughout the whole growing period.During the calculation of the fertilizer recipe it is important to have clean water analysis results. The rule of thumb is that:
1mS = 1 gram fertilizers dissolved in
1 liter of distilled water.
E.g. the clean irrigation water has an EC of 0.5 mS. In order to water
plants with an EC of 1.8 mS, we can dissolve 1.3 gr. of fertilizers in 1 L
of that water.
For fertilizer calculations it is better to use amounts of fertilizers per water volume (ex. 1,000 L or 1m3) rather than amounts per m2 greenhouse area. By applying fertilizers via drip irrigation we reach the root zone immediately where fertilizers are readily available to the plants. On the other hand by controlling irrigation we also can control applied fertilizer amounts which is important in the early phases of growing.
However, by calculating fertilizer amounts per m2 we apply them in solid form and thus cannot spread them even. This can lead to the increased salinity of the soil. In the table below the optimal concentrations of elements in the irrigation solution are given for different growing periods together with irrigation solution properties (mg/L).
Elements Young plantspropagation
Intensive growing period
Harvesting period
N 160 - 170 190 - 220 200 - 240
K 180 - 220 250 - 290 280 - 330
P 40 - 60 40 - 45 40
Ca 160 - 190 170 - 180 160 - 170
Mg 30 30 - 40 35 - 45
pH drip 5,0 - 5,5 5,0 - 5,5 5,2 - 5,7
EC drip 1,6 - 1,8 2,1 2,1
* In general it is possible to use other water soluble fertilizers too as soon as the irrigation solution is balanced regarding main nutrient elements and microelements.
Fertilizer recipe During the intensive growing and harvesting periods it is possible to use the following fertilizer recipe: For 1,000 L irrigation solution for gherkins: • Potassium nitrate 550 gr.• Magnesium nitrate 400 gr.• Calcium nitrate 400 gr.• Monopotassium phosphate 150 gr.• Ammonium nitrate 100 gr.• Total fertilizers 1,600 gr.
The properly prepared irrigation solution should be opaque and with no precipitates. To reach that in praxis usually two irrigation tanks are utilized; one tank to dissolve calcium, potassium, nitrates, magnesium, iron and microelements and another tank to dissolve sulfates, nitrates, phosphates and micronutrients. Both solutions will be than mixed during the irrigation process.All nitrates can be mixed with each other. Only the monopotassium phosphate (MKP) should be dissolved separately in warm water and then added to the irrigation tank which should be filled already two third with water.
We first build a ‘factory’ then get production.
7
Crop management
The main goal is to get a strong cucumber plant, which can support the later fruit load.
After wiring newly planted plants it is necessary to prune. i.e. removal of flowers together with the ovary below. Depending on circumstances and light condi-tions the pruning is done until the 3rd to 8th leaf axil of the stem. This is done in order to let the root system develop itself. Later on all stem fruits are left. However all side shoots are removed until the wire. As soon as the single stem reaches the wire the stem is wired 2-3 times over the wire and the head is removed. At the same time it is recommended to decrease night temperature until 16ºC for 5-7 days in order to stimulate side shoots. 2-3 side shoots are than left on the stem part which is under the wire. Later it is better to remove those side shoots after they have produced fruits.
For better fruit quality and better growth of side shoots it is important to let light enter inside the plant canopy. Therefore it is sometimes needed to remove leaves on the top.Harvesting should be done daily to ‘unload’ the plants. This is important in the early stage when the stems have not reached the wire. For getting stable early and stable harvest in general it is necessary to keep the crop balanced between vegetative and generative growth.
In the tables below the main features are described which can be used to understand the crop and help us to make proper decisions for the crop management.
Main features for visual crop understandingVegetative growth Generative growth
Stem Robust Thin
Leaf Big, fragile Short
Flowers Big Small
First flower Much below point of growth Close to point of growth
Fruit growth Slow Quick
Side shoots Fast growth Slow growth
Plant Light green Dark green
Depending on the crop condition in the greenhouse by imple menting the actions in the table below we can steer the crop either to vegetative or generative direction.
Actions Causal of vegetative growth
Causal of generative growth
Start of irrigation Early Later
Stop of irrigation Later Early
Irrigation frequency/duration Frequent/short Less frequent/long
Salt concentration in irrig. solution Low High
Humidity in the soil High Low
Temp difference day/night Small Big
24 hour average temperature Low High
Leaf amount on the plant Many Less
For achieving high yields the multisided approach as well as a good management of all mentioned factors is needed.
Variety OverviewVariety Spined Smooth Earli-
nessRecommended size Vigour Added value
< 9 cm
9-12cm
> 12cm
Multi-fruit
High regene-ration
Lenara • – • • • • • • • • • • • • –
Chaikovskiy • – • • • • • • • • • • –
Kybria • – • • • • • • • • • • • • • • •Gravina • – • • • • • • • • • • –
Trilogy – • • • • • • • • • • • • • • • • •12-306 • – • • • • • • • • • • • • •Karaoke • – • • • • • • • • • • • • •
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
Vertical outdoor temperateHungary Laszlo Ragyak [email protected]
Vertical outdoor subtropicalIndiaPrasanna D.G. [email protected]
Vertical indoorUkraineAndriy Galagurja [email protected]
Flat manualGermany, Austria, Czech Republic Gerald Krischke [email protected]
Flat mechanicalUSA, 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 and the Baltic StatesMarcin Pawlak [email protected]
Romania George Puican [email protected]
RussiaGennady Sudenko [email protected]
TurkeyErkut Baç [email protected]
UkraineStanislav Ovcharyk [email protected]
VietnamGerard Hulisz [email protected]
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
P.O.Box 40 | 2678 ZG De Lier | The Netherlands | T +31 174 532 300 | [email protected] | www.rijkzwaan.com