Impact of woody semi-natural habitats on the abundance and diversity of green lacewings in olive orchards

Semi-natural habitat complexity affects abundance and movement of natural enemies in organic olive orchards

Green lacewings are generalist predators whose conservation is important for pest control in olive orchards (Olea europaea L.) Sustainable farming practices, as opposed to conventional management techniques, are believed to foster the presence of natural enemies. This study therefore aims to analyze the effect of 1) herbicidal weed cover removal and insecticide applications, and 2) the general management systems used in the olive orchards of southern Spain on chrysopid assemblages and abundance. Green lacewing adults and larvae were collected from olive orchards under conventional, integrated, and organic management systems. In addition, chemical analyses of residues were carried out to determine the presence of insecticidal and herbicidal residues. Eight adult species and three genera of larvae were identified. No rare species were captured from the most intensively farmed orchard, which therefore recorded the most limited chrysopid diversity with a very marked dominance of Chrysoperla carnea s.l.. No effect of dimethoate treatments on Chrysoperla larvae or C. carnea s.l. adults was observed. However, the presence of insecticide residues was associated with the depletion of Dichochrysa larvae. The absence of herbicide treatments favored C. carnea s.l. adult presence on olive trees while larval abundance decreased. Dichochrysa larvae were more abundant when weed cover received no treatment. In relation to the management systems studied, no difference in Chrysoperla larval abundance was observed between conventional and organic orchards. However, Dichochrysa larvae were more abundant in orchards under organic management.

This research was carried out in pomegranate (Punicae granatum L.) and olive (Olea europaea L.) orchards in the Eastern Mediterranean (Adana, Mersin and Osmaniye provinces) in 2008-2010 in order to determine the spider fauna. In this study, among the 402 individuals (male, female, nimf) collected, 59 species belonging to 51 genera and 17 families were reported at 16 different localities with more spiders in the pomegranate and olive orchards in these regions. Among this species, Theridion hemerobium (Simon, 1914), Aphantaulax cincta (L. Koch, 1866) and Platnickina nigropunctata (Lucas, 1846) are new records for the araneo-fauna of Turkey. This study was the first on spider fauna in pomegranate and olive orchards in Turkey.

Non-destructive measurement of leaf area in olive ( Olea europaea L.) trees using a gap inversion method

A new type of olive (Olea europaea L.) orchard, based on high-density hedgerows harvested by vineyard type straddleharvesters has appeared in recent years. This system greatly simplifies olive harvesting, which has a high labour demand in standard olive orchards. There are, however, no specific low-vigour olive cultivars or dwarfing rootstocks adapted to this system, as exist in other fruit crops. It is therefore crucial to select the optimum density for maximum production without causing serious competition problems. In this study we present initial results of the effect of densities, ranging from 780 to 2,580 olive trees ha-1, on the production of an ‘Arbequina’ olive hedgerow orchard during the first seven years after planting. There were no significant differences in fruit characteristics (oil content and moisture) among density treatments. Density had a linear negative influence on fruit yield tree-1. In contrast, accumulated yield ha-1, for both fruit and oil yield, showed a linear increase with increased density, with coefficients of determination ranging from 0.37 to 0.72. Accumulated oil yield at high density was up to 5,000 kg ha-1 more than at the low density

The effects of landscape attributes on Lepidoptera communities were studied in an agricultural area in Calabria (S-Italy). The association between a set of community descriptors and landscape metrics was determined using a multi-scale approach. Lepi- doptera were sampled using yellow sticky traps in 10 olive groves. The landscape in 5 concentric areas, with radii from 250 to 1250 m, around each sampling site was analyzed. The composition and configuration of the landscape were calculated both at the land- scape and class level based on the main classes of land use. The following life-history traits of Lepidoptera were considered: (i) dis- persal ability of adults, (ii) habitat preferences and (iii) diet breadth of larvae. An index of community vulnerability was calculated by combining life-history traits and species diversity. There were no significant correlations between any of the landscape metrics and species richness or between species richness and abundance of natural or semi-natural habitats. However, life-history traits were significantly correlated with some landscape metrics, depending on the spatial scale. Most notably, landscape diversity is positively correlated with community vulnerability. The presence of sensitive species in olive orchards, but not species richness per se, is asso- ciated with the presence of natural and semi-natural habitats in the surrounding agricultural landscape. In conclusion, responses of communities to landscape changes are more likely to be revealed by an analysis of ecological traits, than species richness. In particu- lar, the vulnerability index, used in this joint analysis of the main ecological traits, seems to be an effective descriptor of the relation- ships between communities and landscape.

The shortening of harvest time attained in hedgerow olive (Olea europaea L.) orchards represents an advantage for the adoption of this cropping system in areas that are prone to suffer frost during the harvest period. To establish an optimal harvesting window, we carried out a study of the fruit ripening process on a hedgerow orchard of ’Arbequina’ olive trees, located in Zaragoza (Spain). From 2007 to 2009, oil accumulation on the fruit (% of dry weight) and oil yield (grams of oil per 100 fruits) were monitored, from early September to late November. Over the three years both variables peaked around November 15th, indicating that Arbequina reached full ripening earlier than has been reported previously for this variety. In two of the three seasons the orchard suffered several frosts during November. Long term climatic data from this area indicated that the risk of early frosts (<–2°C) increases as November progresses with a high risk after November 20th. In conclusion, the optimal harvesting period for Arbequina in this area should not extend beyond November 20th. A rapid harvesting before this date is advisable to avoid the risk of damage caused by early frost in Zaragoza. Hedgerow planting provides an additional advantage in frost-prone areas, because mechanization of operations permits a short harvest period, easier to fit into the optimal harvesting window.

<p>Olive and vine orchards in the island of Crete suffer from extreme soil erosion due to intense rainfall, farm slope and/or the intensification of tilling processes. This research aims to assess the impacts of agricultural practices, land use, and vegetation cover on the quantity of erosion processes in three study areas located in Western Crete. These areas provide the case studies of soil loss (erosion/deposition) monitoring analysis and assessment process. Advanced research treatments of Soil Improving Cropping Systems (SICS) are implemented and tested in three different crop types: (1) Crop cover treatment (i.e. seed with vetch) applied in vineyards (Vitis vinifera) in Alikampos; (2) Tilled treatment applied in Olive orchards (Olea europaea cv. Koroneiki) in Astrikas; and (3) Crop switch treatment from Orange trees to Avocados applied in Koufos. It is notable that an avocado farm, besides providing financial benefits, can also maintain a superior overall soil quality. Soil erosion has not been measured yet for avocados, however, avocado plantations are proposed as a sustainable alternative. Soil loss is estimated for the aforementioned case studies, by comparing the results from treatments applied in SICS areas, with the Control areas, where no treatment has taken place. Three different methodologies are used in order to identify soil loss amount: (a) Sediment traps (all sites); (b) Cross sections measurement (Alikampos and Astrikas) and (c) Soil deposition reference sticks (Alikampos and Koufos). Preliminary results show that soil loss values (tn/ha), are absolute values of erosion/deposition, and range from 2.33 to 16.41 tn/ha for vineyards with no vetch (Control), from 1.64 to 13.46 tn/ha for vineyards with vetch (SICS), from 2.21 to 15.66 tn/ha for no tilled olive orchards (Control), from 0.43 to 5.8 tn/ha for tilled olive orchards (SICS), from 2.63 to 10.05 tn/ha for orange orchards (Control), and from 2.24 to 8.95 tn/ha for avocado orchards (SICS). In addition, the ongoing research has already yielded the following yearly average soil loss rates (tn/ha/yr): vineyards – Control 6.883 tn/ha/yr versus vineyards – SICS 6.587 tn/ha/yr; olive orchards -  Control 7.019 tn/ha/yr versus olive orchards – SICS 3.215 tn/ha/yr; and orange orchards – Control 6.406 tn/ha/yr versus avocados – SICS 5.386 tn/ha/yr. The above field results are also in general agreement with the yearly average soil erosion rates in the island of Crete, modeled by several researchers. All study sites show mitigation of soil loss and improvement of soil quality from the application of SICS treatments. Therefore, it is recommended to raise farmers’ awareness about their effectiveness in order to confront the consequences of soil degradation.</p><p>Keywords: Soil Loss; Sediment Traps; Soil Improving Cropping Systems; Crete</p><p>The research leading to these results is funded by H2020 program under grant agreement n° 633814<strong> (SOILCARE).</strong></p>

Capsule Although subject to human disturbance Turtle Doves do nest successfully in these olive and orange orchards. Aim To investigate the breeding ecology of Turtle Doves in a man‐made agricultural habitat in central Morocco. Methods Turtle Dove nests were monitored in orange and olive orchards over three years (2006, 2007 and 2008). Nest abundance, nest location, egg‐laying chronology, clutch size, nest survival rates and breeding success were determined and compared between orchard types. Results The Moroccan population of Turtle Doves start breeding earlier than European populations. Clutch size, nest survival rates and breeding success were similar in orange and olive orchards. Nest location differed between orange and olive trees. Nest densities were 16 nests/ha in olive orchards and 45 nests/ha in orange orchards. Nest success rate averaged 48%. Daily nest survival rates did not vary according to orchard types, year and date. In the two orchards, no nest position variables were significant predictors of nesting success. Conclusion Although highly frequented by people, fruit orchards seem to be suitable breeding habitats for Turtle Doves in this region.

Organic management of olive orchards increases the predation rate of overwintering pupae of Bactrocera oleae (Diptera: Tephritidae)

Chapter 9 - Precision Irrigation in Olive (Olea europaea L.) Tree Orchards

Numerous species of the family Chrysopidae, commonly found in agroecosystems, whose larvae predate on several pests of economic importance, are regarded as biological control agents. Their abundance and diversity are influenced by vegetation cover, although little is known about the effects of semi-natural habitats on their populations. The objective of this study is to gain a better understanding of the relationship between the trees in semi-natural habitats adjacent to olive groves, juvenile stages of the family Chrysopidae and factors influencing their population decline, which is crucial for an effective habitat management program aimed at conserving these important predators. Using cardboard band traps (eight per tree), the juvenile stages were collected from 25 almond, oak, olive and pine trees over a one-year sampling period. The population decline was caused by parasitoids (26.5%), predators (5.1%) and unknown factors (13.2%). In addition, chrysopids established in olive trees showed the lowest rate of parasitism. We identified ten chrysopid species that emerged from the juveniles collected from almond, oak, olive and pine trees, with a predominance of Pseudomallada prasinus. The chrysopid–parasitoid complex was composed of five species; Baryscapus impeditus (Eulophidae), which was the most abundant, was preferentially associated with Chrysopa pallens, Chrysoperla lucasina and Chrysoperla mediterranea.

Olive is one of the dominant crops in the Mediterranean basin, although is also an expanding crop in other areas of the World with similar climate type (Camposeo and Gómez, 2023). Olive trees are cultivated in arid and semi-arid areas, and this has resulted in a management strategy oriented towards limited vegetative ground cover to improve water availability for the crop. This fact, combined with cultivation in sloping areas and periodic high-intensity rainfall events, has led to high erosion rates in many olive-growing areas (Milgroom et al., 2007; Camposeo and Gómez, 2023).  Implementation of appropriate soil management and strategies for erosion control relies on an adequate appraisal of the erosion intensity, processes and the relationship between soil management and environmental (soil, climate…) conditions by stakeholders. Evaluation of water erosion risk at the farm level is usually a complex process based on modelling approaches and it is not appealing to end-users who need simpler and easier-to-understand tools. There are successful examples of tools for appraisal erosion risk at farm level in olives trees, like the one of Milgroom et al. (2006, 2007). However, the implementation of these tools is limited to some management practices and region in which they were developed (e.g. organic olive orchards in southern Spain, Milgroom et al., 2006). Within the context of the TUdi project, there is on-going research to develop generalized versions for appraising erosion risk in woody crops in contrasting environments and management strategies (Gómez et al., 2023). This communication will show the complete version of a field tool for appraising water erosion risk in olive groves, valid for all olive-growing areas, developed in cooperation with projects SCALE, TUdi, ECOMED and BIOLIVAR. It is based on a dual approach combining erosion risk estimation from basic farm and management features, based on simplified RUSLE factors (Renard et al., 1997) combined with erosion symptoms. In this communication, the theoretical basis of the tool and its calibration, and the interpretation of the results based on several examples across the contrasting areas will be presented. With this approach, this tool aims to achieve these objectives:1- To provide a standardized tool valid across multiple environments and cropping conditions to evaluate water erosion risk in olive cultivation.2- To develop an educational tool to provide training on prevention water erosion in olive orchards.Acknowledgements: This work is supported by the projects SCALE (EJP Soil Horizon 2020 GA 862695), ECOMED (PR.AVA23.INV202301.035), GOPO-SE-20-0002 (EIP-Agri), TUdi (Horizon 2020, GA 101000224) and PID2019-105793RB-I00 (Spanish Ministry of Science and Innovation). 

Effect of N dose on soil GHG emissions from a drip-fertigated olive (Olea europaea L.) orchard

The effect of irrigation schedules on the water relations and growth of a young olive ( Olea europaea L.) orchard