`Warm Weather's Ambiguous Effect on Olives - Olive Oil Times

Warm Weather's Ambiguous Effect on Olives

By Costas Vasilopoulos
Sep. 4, 2012 07:55 UTC

Undoubtedly, the earth’s cli­mate is get­ting warmer and warmer. It is because of the nat­ural flow of the weather as a whole, or because of the CO2 emis­sions, or a com­bi­na­tion of the two. Southern Europe had con­sec­u­tive peri­ods of very warm weather this sum­mer and in the United States July was the hottest since 1895, accord­ing to the NOAA.

This is both a bless and a curse for olive trees. Very warm weather can destroy the olive fruit fly, but when the olive grove is non-irri­gated it will ren­der the olive fruit very dry result­ing in much lower yields.

The female olive fly lays its eggs into the olive and the new­born cater­pil­lar starts devour­ing the flesh caus­ing heavy dam­age. Olive flies, which are com­mon in the Mediterranean basin and have been spot­ted in California since 1998, are active when the tem­per­a­ture is below 30 degrees Celsius (86 in the Fahrenheit scale). For warmer con­di­tions egg lay­ing is sus­pended, and if the tem­per­a­ture gets over 35 degrees (95 Fahrenheit) the bug becomes totally inac­tive.

On the other hand, dry weather con­di­tions pro­vide no fuel for the olive tree and the dru­pes become too dehy­drated to cre­ate any oil inter­nally. The solu­tion lies in autumn’s rain­falls (if they occur early enough) or irri­ga­tion, which is not fea­si­ble for many of the olive tree cul­ti­va­tions in the Mediterranean due to lack of water or the widely used method of grow­ing xero­phytic” (non-irri­gated) trees for bet­ter olive oil qual­ity.

So, aver­age weather con­di­tions mean good olive oil pro­duc­tion and pes­ti­cide cam­paigns to get rid of the bugs, and warmer weather con­di­tions mean no pes­ti­cides but pre­dictably less olive oil.


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