Foliar application of arginine, jasmone, and kaolin ameliorate photosynthesis of olive trees

In Northeast Portugal, olive orchards cover over 75000 ha and involve approximately 36000 producers, being olive oil the only saleable product for many families. Despite the physiological defense strategies that olive trees dispose against summer stress, the projected climate change characterized by severe summer conditions, with low rainfall, excessive heat load and high irradiance leveis might affect this crop. Cropping practices for adaptation of olive orchards to climate change must be pursued. In this work we aimed to investigate the introduction of foliar applications of compounds that have shown a central role in stress tolerance in different plant species. The study was conducted in an organic orchard at Quinta do Prado, Lodões, Vila Flor (41°20'13. 3"N, 7°05'54. 2"W) and shows the impact of the application of arginine (l mM), jasmonate (100 |-iM) and kaolin (5%; w/v) on leaf gás exchange parameters at 6 different times between July and October 2016. Ali compounds, specially kaolin, contributed to the improvement of the photosynthetic activity of olive trees during measurements made during August and September, mainly due to lower stomatal limitations, although a drop of non-stomatal limitations were also recorded at midday period, namely by the end of August. The present study gives new insights about the effect ofthis new cropping practice for olive orchards that can help to mitigate the harsh climatic conditions projected forthe Mediterranean summers.

Foliar application of arginine, jasmone, and kaolin ameliorate photosynthesis of olive trees Artigo de Conferência