Application of ectomycorrhizas – new technology in olive orchards

Olive trees have been grown for thousand years for oil. In Old Testament „oil orchard” is mentioned but according to other sources it is known that 5000 b. c. olives had already been domesticated. It is absolutely certain that before olive orchards were established olives tree had grown in Mediterranean maquis shrubland (maqiua or macchia mediterranea). It means that as other forest tree species olives always live in symbiosis with ectomycorrhizal fungi.

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Nowadays, growing of olive trees worldwide it is an important branch of high input agriculture with high usage of pesticides and mineral fertilizers. Application of industrial means of agricultural production gave a common illusion that high inputs means also obtaining high yield of oil of excellent quality. Application of high amounts of pesticides and fertilizers in long time perspective can lead to devastation of microbiological life and among soil invertebrates pest nematodes dominate what frequently result in reduction of olive yields.

It is obvious that absolute desisting from mineral fertilizers seems to be impossible but they can be replaced and supplemented by biological environmentally friendly method i.e. artificial mycorrhization with ectomycorrhizal fungi because they can help root system in assessing to mineral nutrients and water.

Under conditions of Mediterranean agriculture the most limiting factor of high yield is water deficit. Water shortage results in numerous unfavourable changes in soil environment and the most known is salinization.

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Application of our ectomycorrhizal inocula which are specific for given crops (olives, grapes, almonds etc.) have already brought excellent results. Under semiarid conditions crops gave higher yields of good quality. Very interesting effects on poplar plantation in Andalusia were obtained. After few months draught period mycorrhized plants showed 6 meters growth and soil under plants was wet. Non-mycorrized poplar died out. It was similar to accumulation of water by mycelium known in Tenerife. Mycelium accumulates water like sponge and can extract water from resources not available for roots.

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Left-hand side mycorrhized plants                           Right-hand side control plants

 

Coming to the possibility and effects of mycorrhizal inocula application in olive production can be defined as very good because inoculum is used once in lifespan of plantation and gave good results without additional inputs. By one application of living fungi which cost is distributed to many years of plantation lifespan higher yields of improved quality can be obtained. From our experiments performed in two locations: Croatia (Omajola) and Catalonia (Oleic Bovera) the following effects were observed:

  • – higher growth rate and higher number of buds;
  • – higher number of flowers and fruit;
  • – increase of fruit size;
  • – higher oil content in fruit;
  • – lower infestation by flies larvae;
  • – in total investment in artificial mycorrhization can be returned very quickly it can be assumed that annual cost of mycorrhization is 50 Euros per 30 year of plantation lifespan what is compensated by yield increase.

 

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Values of some physical and chemical parameters of olives (mycorrhization May 2014; harvesting December 2014; Bovera – Catalonia; mean values from three replicates)

Fatty acids %

Oil content %

Tocopherols

mg/1000 g oil

16:0

16:1

18:0

18:1

18:2

α18:3

Control

15.4

1.5

1.8

74.1

5.4

0.72

30.21

144.9

Mycorrhiza

15.9

1.6

1.9

74.5

5.4

0.76

32.90

156.8

 

Vertical diameter (mm)*

Horizontal diameter (mm)*

Weight of 10 fruit (g)**

Stone weight (%)**

Control

11.5 ± 1.0

12.8 ± 1.1

14.6 ± 1.1

37.3 ± 3.7

Mycorrhiza

12.0 ± 0.9

13.7 ± 0.8

16.1 ± 1.1

33.1 ± 2.7

*mean value from 150 measurements ± standard error

** mean value from 15 measurements ± standard error

We would like to emphasize high quality of ectomycorrhizal inocula produced by MYKOFLOR which contain only living spawn of mycorrhizal fungi what in practice means that symbiosis with root system happens fast and reliable way. The additional feature of our inocula is their high specify what indicates that inocula are effective. This effectiveness comes from method of production of our inocula the first step is isolation of mycorrhiza from trees which grow in forest of good status. From this year we have introduced new component to our inocula. We successfully obtained fungi which are able to live in symbiosis with root systems of higher plants and simultaneously can actively fighting against parasite nematodes and pest insects. It can have direct and positive impact on yield. It is worth to mention that majority of mycorrhizal inocula on the market are based on spores of arbuscular mycorrhizas (Glomus sp.) which are specific for green plants (grasses, vegetables etc.). Their application for trees is a pure misunderstanding and cannot give any positive effects.

Summing up, it can be concluded that application of MYKOFLOR inoculum dedicated for olives is similar to buying of winning lottery ticket because they give a good chance for obtaining high and profitable olive yields even in harsh conditions of many countries struggling with problems of water shortage. In this term artificial mycorrhization is a very effective and economical as well as environmentally friendly method of increasing of olive production.