13°
Austria
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FERTILIZER

CONTAINING

NUTRIENT

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CROP

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  • Soil texture
    loamy sand or sandy clay soils
  • Min. temperature
    soil temperature > 10°C
  • pH
    5.5 – 7.0
  • Water demand
    > 300mm
  • Vernalisation
  • Plant density
    1.5 to 2 Seeds/ha, row spacing 70cm, distance in row 90cm
  • Seeding Depth
    2-3cm
Oil Pumpkin
Pumpkins came to Europe from Latin Amerika in the 19th century. Today, pumpkins are found worldwide but need high solar radiation and a relatively warm climate. High rainfall for a prolonged period of time impairs germination and causes rotting. Oil pumpkin tolerates short periods of drought, but an appropriate water supply is required for high yields.
According to their geographical origin, pumpkins prefer sandy and well-aerated soils that can warm up quickly.

Soils with higher silt and clay content offer higher water and nutrient retention. All soils with a good structure and that are free from waterlogging are suitable. 

Pumpkins are mainly used as vegetables but also the seeds are utilised for pumpkin oil production. The Styrian oil pumpkin (Cucurbita pepo var. styriaca, or oleifera) produces seeds without hulls, which facilitates a more efficient extraction of the oil. This oil was not widely known outside its traditional production areas in Austria (southern Styria and Burgenland), Hungary and Slovenia until the 1970s. Since then the popularity and growing area has increased significantly. 
Key facts
  • Needs warm, well aerated soil that is not waterlogged.

  • It is best to sow early, but pumpkin plants are not frost tolerant.

  • Fertilizers with a low chloride content are recommended.

  • Weed control required before emergence. 

  • The yield is strongly influenced by weather conditions.

General Information
General Information
Nutrient demand
Nutrient demand
Fertilization
Fertilization

It is important to plant pumpkins in weed-free fields, as weed control is difficult during the growth period. This should also be considered when selecting the preceding crop in rotation. Oil pumpkins cannot be cultivated for two or more consecutive years in the same field. It is recommended to keep a break of two or ideally three years between growing pumpkins. All cereals and grain maize are good preceding corps but crops sensitive to the Sclerotinia sclerotiorum fungus (sunflowers, soybean, and rapeseed) should be avoided. 

The soil preparation should provide an optimum seedbed without compaction, which can led to waterlogging. Planting should be done as early as possible in the season when soil temperature reaches a minimum of 10°C. Early planting facilitates the establishment of an early and dense coverage of soil with vegetation  and good use of the soil moisture after winter. The closed soil cover reduces weeds, soil erosion and drying of the soil.

Weed control is important and should be carried out within one day of planting. A seed dressing can prevent the most prevalent diseases during germination.  

The yield depends strongly on the weather conditions during the vegetation period. The plants have male and female flowers and depend on bees and in particular on bumblebees for pollination. 

Pumpkins have a relatively high demand for potassium. An appropriate supply of calcium, phosphorus and potassium is important. Fertilization is mostly carried out using a compound NPK fertilizer which can either be broadcast or placed.  

Yield figures:
  • Seeds / ha: 300 – 1,600kg
  • Pumpkins: 10 – 20tons FM/ha
  • Oil: 200 – 650litre/ha
  • 2.2 – 2.5kg seeds / litre Oil (~ 35 pumpkins)

The press cake, which is a by-product left over after oil pressing, is rich in protein is mainly used as high-quality raw material in the animal feed industry.
Extraction rates of oil pumpkins

Element

Uptake

(Unit/t of production)

Removal

(Unit/t of production)

Sensitivity to deficiency

N

110

80

Moderately Sensitive

P₂O₅

80

50

Moderately Sensitive

K₂O

270

20

Sensitive

TE

This table shows uptake and extraction per tonne of oil pumpkin seeds. A yield of one of tone seeds requires 110kg nitrogen. Depending on the soil properties and preceding crop, the soil provides between 50 and 60kg nitrogen. A fertilization of 50 to 60kg nitrogen is sufficient in most cases (= 400kg COMPLEX 15/15/15 + 7SO3+Zn).

First application in spring

Second application

First application in spring

Nitrogen fertilization of 60kg/ ha is sufficient, provided that the soil properties are appropriate. Nutrient requirements can be covered by using a compound NPK fertilizer (COMPLEX 15/15/15 + 7SO3+Zn, or chloride reduced COMPLEX 12/12/17 +MgO+12SO3+B+Zn) at the time of seedbed preparation. Fertilizers containing chloride should be applied at least two weeks before planting.

Second application

A second nitrogen fertilization can be beneficial on soils with low N replenishment and high yield expectations. An additional dose of 30 kg N/ha (110 kg/ha NAC 27N) at the two to four leaf growth stage maximizes yields.