title: Phosphorous Nutritional Level, Carbohydrate Reserves and Flower Quality in Olives.
abstract: The olive tree is generally characterized by relatively low final fruit set consequential to a significant rate of undeveloped pistils, pistil abortion, and flower and fruitlet abscission. These processes are acknowledged to be governed by competition for resources between the developing vegetative and reproductive organs. To study the role of phosphorus (P) nutritional level on reproductive development, trees were grown under four levels of P for three years in large containers. Phosphorus nutritional level was positively related to rate of reproductive bud break, inflorescence weight, rate of hermaphrodite flowers, pistil weight, fruitlet persistence, fruit set and the consequential total number of fruits. The positive impact of P nutrition on the productivity parameters was not related to carbohydrate reserves or to carbohydrate transport to the developing inflorescence. Phosphorous deficient trees showed significant impairment of assimilation rate, and yet, carbohydrates were accumulated in inflorescences at levels comparable to or higher than trees receiving high P. In contrast to female reproductive organs, pollen viability was consistently higher in P deficient trees, possibly due to the enhanced carbohydrate availability. Overall, the positive effect of P on female reproductive development was found to be independent of the total carbohydrate availability. Hence, P is speculated to have a direct influence on reproductive processes.
authors.affiliation: Gilat Research Center, Agricultural Research Organization of Israel, Israel.
authors.forename: Ran
authors.initials: R
authors.lastname: Erel
authors.affiliation: Gilat Research Center, Agricultural Research Organization of Israel, Israel.
authors.forename: Uri
authors.initials: U
authors.lastname: Yermiyahu
authors.affiliation: Gilat Research Center, Agricultural Research Organization of Israel, Israel.
authors.forename: Hagai
authors.initials: H
authors.lastname: Yasuor
authors.affiliation: Gilat Research Center, Agricultural Research Organization of Israel, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Cohen Chamus
authors.affiliation: Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
authors.forename: Amnon
authors.initials: A
authors.lastname: Schwartz
authors.affiliation: Gilat Research Center, Agricultural Research Organization of Israel, Israel.
authors.forename: Alon
authors.initials: A
authors.lastname: Ben-Gal
authors.affiliation: Gilat Research Center, Agricultural Research Organization of Israel, Israel.
authors.forename: Arnon
authors.initials: A
authors.lastname: Dag
mesh_terms: D050260:Carbohydrate Metabolism; D035264:Flowers / Q000254:growth & development / Q000378:metabolism*; D005638:Fruit / Q000254:growth & development / Q000378:metabolism; D031658:Olea / Q000254:growth & development / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D063245:Plant Development; D012098:Reproduction
chemical_list: D010758:Phosphorus