Management of olive lace bug

Management of olive lace bug

Every year I receive several emails like the one above concerning Olive Lace Bug (OLB). It is a serious olive tree pest which can cause heavy defoliation and total crop failure if not managed effectively. Effective control depends just as much on ensuring your olive trees are in optimal healthy as it does on controlling the numbers of OLB by a well-timed spraying regime. The three most important areas to focus on are: Tree Health Spotting OLB early in the Spring Early, Effective use of insecticide sprays Read Full...
The Role of Epidemiology Data in Developing Integrated Management of Anthracnose in Olives – a Review

The Role of Epidemiology Data in Developing Integrated Management of Anthracnose in Olives – a Review

Read Online Colletotrichum species have the capacity to produce asymptomatic latent (quiescent) infections on various olive tree tissues: during this symptomless biotrophic phase, the pathogen invades the host without killing them and feeds on living cells. Re-infection of the tree by the repeating conidial stage is then responsible for increased anthracnose symptoms during summer, leading to new growths. Normally developed fruit and fruit damaged by abiotic factors, leaves and stems may have asymptomatic infections of Colletotrichum acutatum and C. gloeosporioides in susceptible cultivars ‘Barnea’, ‘Manzanillo’ and ‘Kalamata’. Anthracnose under favourable conditions can also infect less susceptible cultivars. The infection can persist from season to season, depending on olive cultivar, environment, crop management, and pathogen virulence. Brown lesions with anthracnose fungal spores were observed in young green stems and leaves and dieback of young shoot tips of olive susceptible cultivars in orchards in early spring and summer. Flowering, fruit set and immature fruits can be observed during fruit development on a single peduncle; both flowers and fruit set late in the season, in summer rather than spring, and carry fungal infection. Immature rotten fruits are mummified. Colletotrichum fungi overwinter in mummified fruits on the tree, woody tissue and leaves; the fungus has long saprophytic survival ability on dead peduncle and pedicels. Fungal inoculum present year-round throughout the canopy. Hemibiotrophic anthracnose fungal pathogens grow first on living tissue and then cause host death in later, necrotrophic growth. The ability to survive and multiply in the absence of symptoms may explain why anthracnose fungi often cause unexpected crop losses in olives. Successful management of anthracnose relies on understanding the conditions that promote...
Occurrence of Pseudomonas syringae pv. syringae

Occurrence of Pseudomonas syringae pv. syringae

Maesomeh Ashorpoura, Mostafa Niknejad Kazempoura, Mohamad Ramezanie | View Article Several nurseries of olives in Fayoum and Giza were surveyed for root rot incidence during early summer of 2003. In Fayoum, root rot incidence reached 53% while in Giza, disease incidence was 44%. Disease symptoms consist of partial wilting, leaves browning and twig dieback, which was associated with severe root rot and basal stem cankers and followed, in most cases, by plant decline and...
Survey of Olive Leave Spot in New Zealand

Survey of Olive Leave Spot in New Zealand

A.J. Macdonald, M. Walter, M. Trought, C.M. Frampton and G. Burnip | View Article Olive leaf spot (OLS) or peacock spot, caused by the fungal pathogen Spilocaea oleagina, can cause reduced growth and yield in olive trees (Olea eurapaea). Investigations were carried out during December 1999 and January 2000 to measure the prevalence and severity of olive leaf spot in the Auckland, Waiheke Island, Wairarapa, Marlborough and Canterbury growing regions of New Zealand. The susceptibility of six cultivars (Barnea, Manzanillo, Frantoio, Leccino, Nabali and Souri) to OLS was assessed. OLS was found in all study areas with Auckland and Marlborough the worst affected. OLS appeared to be particularly severe on trees that were growing in sheltered parts of an olive grove. Severity increased with age and a correlation between prevalence and severity was found. Souri and Nabali were the worst affected cultivars while Frantoio and Leccino were least...