Researchers at the the Institute of Olive Tree, Subtropical Crops and Viticulture in Chania have given advice on the best practices in olive harvesting to ensure top quality olive oil. With the main harvesting period getting under way, the scientists emphasise that there are all the conditions for an excellent result, so long as farmers follow certain basic steps. Giorgos Koubouris, head of the olive cultivation laboratory at the Institute of Olive Tree, gave Haniotika Nea some basic advice for producers.

When to start
“From the middle to the end of October is fine for starting with trees which have a medium crop. Since we had a good amount of rain in the spring, the trees were not short of water in the summer. That’s the general rule. The conditions are ideal, the fruit is in good shape,” Mr Koubouris said, drawing attention however to the fact that if a harvest is delayed, and coincides with heat and humidity, there may be an upsurge of the olive fly (dakos).

“We would advise people not to delay. That is to say they can harvest from the end of October to the end of November,” he said, adding that “the general rule is to harvest the heavily-laden trees after the medium- and lightly-laden ones.” The lack of manpower is one reason why many producers are unable to harvest in a very organised way.

Should the olives be left to turn black?
“That is something which we can forget. There is no ‘the later the better’, but nor is there ‘the sooner the better’, with some people going to the other extreme. The producers know that we don’t gather in the rain, as this can cause a lot of damage to both the trees and the fruit”

Crates versus sacks
“It’s important for quality that we move to crates for the provisional storage and transport of the fruit. Plastic sacks are out of the question, we don’t recommend them at all. Even the hessian ones are not ideal. Crates are more trouble, they are more difficult than sacks to transport, and people don’t want to pay for them, but they are the best method,” Mr Koubouris said.

Tsunates
“Most producers of this variety lay nets on the ground and wait for the olives to fall. Those will have already begun the first gathering, and the best advice we can give them is to go and lift the nets more often to avoid the olives decaying.

“Those who prefer to beat the trees [with canes or electric harvesters] should collect the olives which have fallen, then beat them in November-December so as to have good quality, and then there may be some fruit left which will fall later and which can bring them some income.

“Tsunates are still in favour because the cost of harvesting is lower. There is less labour involved, but you end up with an inferior olive oil.”

Labour
The lack of manpower can be made up for if the producers join forces to engage workers for specific periods: firstly for harvesting, then for pruning and then for spraying against the olive fly in summer.

Basic principles
There are some basic principles which producers ought to follow, which unfortunately they neglect out of habit.

1. NO to pruning at the same time as the harvest. Especially, the use of chainsaws should be avoided. Sheets and nets must be clean.

2. It has been found that exhaust gases or fuel from the machinery can penetrate the fruit, so producers need to be extra careful about this.

3. Electric harvesters should not work at full speed, as this does a lot of damage, and the operator should not move a lot around the tree.

4. They should avoid stepping on the fruit as there is a risk of deterioration and particles of dirt and rubber finding their way into the oil. “The oil can come out at 4 to 5 grams*, but be off-specification because it has an odour of earth or rubber,” Mr Koubouris explains.

5. If sacks are used they should not be stacked one on top of the other, as this compresses the fruit.

6. As regards transport, the emphasis is on a quick transfer to the oil mill so that the fruit can be pressed as soon as possible, avoiding contact with motor oils and other contaminants.

7. The oil mill should ensure correct production methods, with clean water, the appropriate temperature, etc.

Joint processing
This type of production is being used a great deal recently by cooperatives in Eastern Crete, but in the Chania area only by Terra Creta and one other olive mill. “It has many advantages, in terms of quality and for the mill’s operating costs,” Mr Koubouris observed, “but the problem is with attitudes, our own reluctance to work with others. We always think that when the fruit is mixed with someone else’s, as we have the best, it will be spoiled. We tend to say: ‘I have got the best oil and it will be spoiled if it is mixed with someone else’s.’ It is a question of prejudices, rather than something being lost. Joint processing needs cooperation.”

After the harvest
“The first priority is to spray with a copper insecticide to protect the wounds in the trees. Fertilisers should come afterwards: phosphorus and potassium should generally be applied earlier, preferably in December. Nitrogen can be applied later. All that can be derived from the soil analysis which the grower should have done.”

Although the price of olive oil has made it difficult for producers to make a living from their crop, Mr Koubouris reckons that with the implementation of the PGI Crete mark [Protected Geographical Indication], in cooperation with the growers and with the application of a different marketing model with more branding and certification, better prospects can be created for olive oil in Crete.
(Haniotika Nea, 14/10/26)

* Equivalent to 0.4% to 0.5% acidity, i.e. within the range for extra virgin olive oil. While 1 gram is usually calculated as equivalent to 1% of 100 grams of oil, in that case 4 to 5 grams would imply an acidity of 4% to 5% – an improbably high figure when most olive oil produced in Crete is extra virgin, i.e. no more than 0.8% acidity. It therefore seems likely that the speaker is calculating on the basis of a percentage of 1 kg of oil.