2017 ASHS Annual Conference

As an ornamental landscape plant, olives (Olea europaea) offer an unusual silver-green foliage color on an easily-pruned medium-sized tree. More traditionally, olives are known as a useful orchard crop for producing culinary olive oil, table/eating olives, and olive oil-derived products for skin and hair care. The United States (US) is the world’s largest consumer of olive oil, but only about five percent is produced domestically. While California has long been the largest domestic olive producer in the US, the last decade has witnessed the growth of olive orchards in southern states such as Texas, Georgia and Florida. Interest in olives is increasing in Louisiana, but the crop has never been evaluated by a university here. A 2015 survey of Louisiana Master Gardeners indicated high levels of interest but little specific knowledge about required growing practices. To help provide insight into this unfamiliar species in Louisiana, the LSU AgCenter’s Hammond Research Station (USDA Hardiness Zone 8B) planted a varietal evaluation of olive trees in May 2015 with the goal of observing establishment success and growth characteristics over a two-year period. The orchard was completely randomized with four replications of 15 olive varietals. A traditional orchard spacing layout was used with 25 feet (7.62 meters) between rows and 18 feet (5.49 meters) between trees. Orchard rows were raised an average of 12 inches (30.48 centimeters), drip irrigation was installed, and trees were minimally staked after planting. A clean orchard floor protocol is followed, but excessive weed pressure has required the regular use of herbicides. The orchard has experienced above-average annual rainfall totals, two major flood events, and one Arctic cold front that dropped temperatures to 22F (-5.56C) on two consecutive nights. First year results will be presented based on ratings of establishment success, disease pressure, insect pressure and ornamental value. Despite the challenging growing conditions, ‘Anglandau’, ‘Arbequina’, ‘Bouteillan’, ‘Grossane’, ‘Manzanilla’ and ‘Picual’ were the best-established varietals after the first year of the evaluation. ‘Arbosana’. ‘Frantoio’, ‘Koroneiki’ and ‘Mission’ established well but suffered greater cold damage compared to other varietals. ‘Bouteillan’, ‘Grossane’ and ‘Picual’ varietals were rated highest for ornamental value during the evaluation’s first year.