Olive yield

The yield of the olive will depend on numerous factors that we are going to analyze ( variety of olive tree , annual climatic conditions , load of the olive tree , cultivation area , type of plantation , date of harvest , olive tree care , etc …).

Harvest time

The harvest date of the olives has an important influence on the final yield obtained.

Although the oil in the olive grove, stops increasing as soon as the olive tree enters a vegetative stop. As we saw in our publication  Why do olives wrinkle? , the olives lose moisture over time.

Depending on the percentage of dry matter that the olive has, the yield of the olives in the oil mill will increase more or less with the passage of time.

For this reason, in olive analysis, a reference to take into account is the fat yield on dry matter, that is, when the moisture present in the olives is completely eliminated. With this information, it is easier to observe the process of fat accumulation in olives.

Although the loss of moisture from the olives reduces the kilos delivered and represents a certain saving in transport and grinding. This saving can be counterproductive, since the quality of the olive oil produced decreases and the overrun of the olive tree is encouraged .

On the other hand, with the passage of time, the olive falls to the ground and its collection is not always profitable.

Olive variety

High-yield olive varieties can exceed 20% oil on olives without wrinkling.

Among others, they produce high-yield olives, usually above 20%, the following varieties: Picual , Cornicabra , Verdial de Badajoz , Morisca , Arbequina , Farga , Picudo , Pajarero …

With an average yield between 15% and 20% we can include: Empeltre , Hojiblanca ,  Blanqueta …

Varieties with low yields, less than 15%: Manzanilla Cacereña , Gordal Sevillana …

One thing is the gross yield and another is the net yield that is obtained when grinding in the oil mill. Depending on the extractability of the variety and the machinery used, 3-4 yield points are lost in alpeorujo. These losses are deducted from the olive’s gross yield to make the settlement. Some analyzes include an estimate of industrial performance (estimate of the oil that the mill will be able to extract from our olives).

Weather conditions

The warm Mediterranean climate of southern Spain is ideal for the accumulation of olive oil in olives. Warm and sunny areas outperform cold or shady areas in production and performance.

In addition to the climate of the location, the annual variations can favor or worsen the accumulation of olive oil.

For example, the 2018-2019 olive campaign , where the olive has not accumulated the usual amount of oil. This has been due to several situations:

  • Delay in the flowering of the olive tree, due to the large amount of rainfall in spring.
  • Lower biological activity of the olive tree, consequence of a colder summer than usual.
  • Harvest above average.

As a consequence, the olive has had a significant delay in ripening and the fat yields have fallen 3-4 points compared to the 2017-2018 campaign.

Olive tree load

During the years of high load, the resources of the olive tree must be distributed among a large number of fruits. This situation causes delays in the ripening of the olives, which reach a yield of less than one year with a medium-low load.

Type of plantation

The type of plantation influences the lighting of the olive tree and the kg of olives produced per hectare . In this way, yields decrease as planting density increases .

This is one of the reasons why the fat yield of a variety planted in a super- intensive olive grove is lower than that of the same variety grown in a traditional olive grove.

How does olive tree care influence the olive yield?

Olive tree care has an important influence on the olive yield.

Olive tree pruning : To increase yield, good lighting of the branches should be favored.

Olive fertilizer : trees with nutritional deficiencies have difficulties in producing photoassimilates. This has a negative influence on the yield and the size of the fruits is smaller than it should be.

Water stress: Being subjected to water stress, the olive tree reduces its biological activity to reduce water consumption. On the other hand, plantations with a sufficient water supply will be able to produce larger olives, with a higher yield on dry matter.

Olive tree pests and diseases: Pests and diseases weaken the olive tree, reducing its potential harvest of olives and olive oil.

Sampling

When taking samples for analysis, this should be as representative as possible of the consignment. To do this, it is recommended to use random and automatic sampling systems (cups). The sample size will depend on the batch, the automatic systems collect olives during the entire weighing phase. 1 kg is representative enough to analyze a batch between 2,000 and 3,000 kg.

Olive yield analysis

Performing analysis to calculate the yield of the olive is a common practice in most Spanish mills and cooperatives.

The result of the analysis is taken as a starting point to calculate the net yield of the olives.

In the case of cooperatives, on the one hand the real yield is calculated ( total oil produced / kilos of olives milled ) and on the other hand a weighted average of the yields obtained in the analyzes is made.

Cooperatives : In cooperatives, to obtain the correction points, the performance of the gross analysis is subtracted from the actual performance obtained. For example, if the average gross yield is 19.8% and the actual yield is 17%, we lose an average of 2.8 oil points in olive oil. When making the settlement, 2.8 points are subtracted from the partner’s gross yield and thus the net yield for each partner is obtained.

Oil mills: Oil mills do not spin so fine and will apply the correction coefficient they deem appropriate, according to their machinery and the type of olive received. Usually between 3 and 4 points.

Although the yield measurement equipment is expensive, it is essential to carry out periodic analyzes of the olive oil at the oil mill. In this way, it can be verified that the oil extraction is being carried out well and that there are no unnecessary yield losses.

In addition, many oil mills and cooperatives have their own laboratory, equipment, and personnel to analyze the performance of received batches.

However, in many cases it is preferable to send the samples to a specialized laboratory . In this way, the analyzes are carried out with equipment of greater precision and in a more impartial way .

 

How much does it cost to conduct a performance analysis?

As we see in the following table, the price of the performance analysis varies depending on the number of samples analyzed and the type of analysis performed.

We made a query to the LABISER laboratory , which very kindly responded with their rates for the 2018-2019 campaign .

NUMBER OF SAMPLES

FAT + MOISTURE

FAT + MOISTURE + ACIDITY

1 a 25

5.00 €

7.00 €

26 a 100

4.00 €

6.00 €

101 a 500

3.00 €

5.00 €

501 a 1000

2.50 €

4.00 €

1001 a 2000

2.25 €

3.75 €

2001 onwards

2.00 €

3.50 €

The price does not include  21% VAT and the costs that we assume for the delivery or shipment of the samples. The sample size currently recommended by the laboratory is 1 kg .

The results are delivered within 24-48 hours after receiving the samples.

Recommended reading

If you liked our publication on olive yield, surely some of the following topics may be to your liking:

What is the most profitable olive variety?

How do you keep a young and productive olive grove?

Electric or gasoline olive harvesters?

What is it and how is the degree of acidity of olive oil calculated?

Ellie Lauderdale

My name is Ellie Lauderdale, MD and I am USA based professional Nutritionist .

I am a Registered Dietitian Nutritionist and board certified specialist in sports dietetics who is trained in integrative medicine. I have worked with hundreds of clients, from those suffering with chronic disease to professional and olympian athletes. My goal is to help optimize you from the inside so that you can feel, perform, and look your best on the outside.

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