Olive fruit dry matter and oil accumulation in warm environmental conditions

The present study was carried out during 2007, 2008 and 2009 on 6 olive cultivars to investigate the process of oil and dry matter accumulation in response to warm and dry conditions in Dallaho Olive Research Station of SarpoleZehab, Kermanshah province, Iran. Results showed that oil begins to accumulate in the fruit from July, increases gradually through August and reaches its maximum as the fruit becomes completely black in November. Patterns of oil accumulation over the period of the study varied between cultivars. Dry matter acquisition was continuous and increased with a slow slope in all cultivars during fruit growth. Oil content correlated with the percentage of fruit dry matter, so that Roghani with the highest dry matter had the highest oil content in fresh fruit and dry matter. There was a linear relationship between dry matter and oil content in all cultivars. This relationship varied for different cultivars and was not strong however it can be an indicator of oil content. According to the results, olive cultivars showed different responses to warm conditions and oil accumulation was related to temperature. In conclusion, oil accumulation is a trait that can be influenced by environmental conditions and it depends on olive cultivars.