The xylem-limited bacterium Xylella fastidiosa Wells is the causal agent of severe diseases of several cultivated and wild plants. It is transmitted by xylem-sap feeder insects, such as spittlebugs (Hemiptera: Cercopoidea) and sharpshooters (Hemiptera: Cicadellinae). A dramatic epidemic of X. fastidiosa subspecies pauca sequence type 53 is currently affecting a large area of the Apulia Region of Italy, where it is spread by Philaenus spumarius L. adults within olives. In 2015 and 2016, field surveys were carried out in Apulian olive groves to investigate host plant selection of spittlebug nymphs, to identify the main plant species that can act as reservoirs of the vectors. Two different sampling methods were used: randomized plant sampling and quadrats sampling. Host plant selection by P. spumarius and Neophilaenus campestris (Fallén) nymphs was estimated using Manly's selection index. The botanic families presenting the highest number of plants infested by P. spumarius nymphs were Asteraceae, Fabaceae, and Apiaceae. Nymphs of P. spumarius were sampled on 72 plant genera, and among the most common 25 genera, Sonchus, Knautia, Glebionis, Urospermum (Asteraceae), Medicago, Vicia, Melilotus (Fabaceae), and Daucus (Apiaceae) were the ones selected preferentially, according to Manly's index results. Populations of P. spumarius nymphs peak in early April, with densities ranging between 10 and 40 nymph/m 2 , were about 10-fold those of N. campestris. Plant infestation rate by spittlebug nymphs in 2016 was significantly higher in olive groves located in Lecce province (infected area) than those situated in Bari province (noninfected area).

This paper reports a survey on the weed flora and seed bank in an almond orchard sited in Apulia region (Southern Italy), where the following soil management practices have been compared for over 30 yrs: no-tillage, keeping the soil totally weed-free throughout the year by using pre-emergence herbicides to prevent plant emergence or post-emergence herbicides in case of weeds already emerged; no-tillage, with post-emergence herbicides; no-tillage, with mowing of natural weed flora in spring; cover cropping, with faba bean sown in November and green manured in springtime; conventional soil tillage. The different management techniques influenced significantly the weed flora in experimental plots, both in terms of quantity and quality. The seed bank was clearly impoverished after the long-term applications of pre-emergence herbicides, both in terms of richness and of diversity. During the fall period, the plots of conventional tillage or pre-emergence herbicides had less natural ground-flora than the others. During springtime, prior to the sward control practices, the plots treated by foliar herbicides or mowing had the highest total weed cover. We conclude that post-emergence weed control by mowing or using chemical herbicides or the green manure of the cover crop may be proposed to reduce impact to the soil and to promote the growth of abundant and sufficiently diversified and balanced flora. If appropriately managed, this flora can provide potential ecological services, without competing with the orchard, as suggested by the literature. During the autumn, natural flora can uptake soil nitrogen thus preventing leaching in the rainy season. In springtime, after the sward has been destroyed, natural flora can supply a substantial amount of biomass to the soil. Indicator species analysis was also used to find the species characterizing each treatment and some of their combinations. Weeds belonging to the Poaceae botanical family were significantly associated with post-emergence herbicides and mowing treatments. These species produce a substantial amount of biomass and have bunched roots; consequently, they supply beneficial effects by improving porosity and structure of the soil and reducing erosion hazard

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Living mulch gives many benefits to agro-ecosystems such as erosion control, nitrogen fixation and nutrient recycling, increasing of organic matter, weed and pest control, and increasing of soil organism. The experiment, carried out in Puglia, Southern Italy on transplanted broccoli raab (cv. Grossa fasanese), evaluated four soil management systems (SMSs): Trifolium subterraneum and T. repens used as living mulch, undisturbed weedy, and conventional tillage. For each SMS, four rates of nitrogen and phosphorous (NP0, NP1, NP2, and NP3) were supplied, using an organic fertilizer. The following data were collected: weed infestation, leaf chlorophyll in the plants (as SPAD units), weight, diameter, and colour of the inflorescences, anion and Mg, Fe, Na, K, Ca content. Fertilization showed prominent effects on most of parameters evaluated. The Sufficient Index of broccoli raab plants was higher in fertilized plots. With the increasing of fertilization rates, weight of primary inflorescences and the marketable yield linearly increased, confirming the great influence of nitrogen fertilization on the yield of Brassicaceae vegetables and highlighting the importance of combining living mulch and fertilization. By increasing fertilization rates, some elements, such as Mg and Fe, increased, whereas a decrease of Na, K, and Ca was observed. The nitrate content in the inflorescences was different only between the fertilized and unfertilized plots, although it was very low. In NP2 and NP3 a greener colour was found. Living mulch did not clearly affect quality and yield of broccoli raab but was effective in weed control. Results show the positive effects of living mulch and organic fertilization in the sustainable production of broccoli raab.

Weeds are a major problem in cropping systems and in urban areas. The aim of this study was to assess the effectiveness of organic mulching with olive leaves and almond hulls to control weeds in fennel (Foeniculum vulgare Mill.) and in flower beds (urban areas). A 3-cm thick layer of olive leaves or almond hulls was applied as mulching material in fennel. Control consisted of both an unmulched treatment and a weed free control. Moreover, in a flower bed of a railway station, plots mulched with 3 cm layer of olive leaves and almond hulls were compared with an unmulched treatment. Weed infestation was evaluated and the weights of the whole plant and of the marketable part of fennel (grumolo) measured. Mulching with olive leaves and almond hulls reduced weed infestation in both vegetable crop and flower beds. However, olive leaves reduced the weights of the whole plant and of the grumolo. The adoption of almond hulls and olive leaves as organic mulches could be an effective strategy for weed control. Further investigations should be carried out to assess whether the effectiveness of these mulching materials is mainly due to a mechanical activity or allelopathic compounds also play a significant role in weed suppression