In a two-year experiment, we examined whether increasing plant diversity in the margins of processing tomato fields could attract pollinators and natural enemies of pests compared to weed flora, and questioned the effect on crop yield. Two plant mixtures sown in winter (WM) and spring (SM) were compared with weed vegetation along a tomato crop (CT) and an adjacent irrigation channel (CC). Flower cover was higher in the sown mixtures than the weedy margins, and brought in more visits of pollinating bees (including potential tomato pollinators) than the latter. Flowering species were mainly Eruca vesicaria (WM, SM), Coriandrum sativum and Lathyrus sativus (WM), Fagopyron esculentum and Phacelia tanacetifolia (SM), and Ammi majus, Rapistrum rugosum (CC, CT). Parasitoids (Eulophidae, Braconidae, Scelionidae) were more abundant in the sown and CC margins compared to the CT margin, while the abundance of predators (Aeolothripidae, Orius sp., Thomisidae) was similar among all types of margins. Fruit weight was higher in the field with the sown margins, while pest incidence in the crop was not affected by the margin type. Our findings provide new insights into the contribution of managed and existing field margins in attracting beneficial arthropods, and their implications on yield.

Prickly sida is a troublesome annual weed native to the USA. It was introduced in Greece over two decades ago and has since been infesting cotton crops, where it proved difficult to control. A two-year field study (2021–2022) was conducted in a cotton field (Karditsa, central Greece) heavily infested with prickly sida to evaluate the efficacy of nine treatments against this weed, using pre-emergence (PRE) and early post-emergence (EPOST) herbicides applied at the field rate. At 8 weeks after treatment, prickly sida control was over 90% with pyrithiobac PRE (68.9 g ai ha⁻¹) alone or in mixture with s-metolachlor (960 g ai ha⁻¹) or with isoxaben (150 g ai ha⁻¹) and with the application of pyrithiobac + s-metolachlor PRE (34.5 + 960 g ai ha⁻¹) followed by pyrithiobac EPOST (34.5 g ai ha⁻¹). Flurochloridone + fluometuron PRE (375 + 2000 g ai ha⁻¹), flumioxazin + s-metolachlor PRE (50 + 960 g ai ha⁻¹), or pendimethalin + terbuthylazine PRE (1500 + 750 g ai ha⁻¹) controlled prickly sida by 89–93% in 2021 and 82–90% in 2022. Pyrithiobac EPOST alone or in mixture with trifloxysulfuron did not adequately control prickly sida. Yield was significantly lower in the weedy check and EPOST compared with the PRE treatments. None of the herbicides caused any visual injury to the crop or any reduction in cotton density. Our results can help in the successful management of prickly sida in non-transgenic cotton to maximize cotton yield and quality.

Two field-selected green foxtail (Setaria viridis L.) populations from northern (V1) and western (V2) Greece were investigated for potential nicosulfuron resistance evolution (ALS-inhibiting herbicide), along with two populations from the same regions (SV1, SV2) that had never been exposed to herbicide selection (susceptible). A preliminary screening pot experiment was conducted, in which nicosulfuron was applied at the recommended field label rate (1×, 40 g a. i. ha-1) and twice the rate (2×) to all four populations, while the ACCase inhibitor clethodim was applied at 1× (180 g a. i. ha-1) as an alternative mode of action. An untreated control was also included for each population. Subsequently, a whole-plant dose-response assay was conducted, applying nicosulfuron at 1×, 2×, 4×, 8×, 16× to populations V1 and V2, and 1/16×, 1/8×, 1/4×, 1/2×, and 1× to populations SV1 and SV2, with an untreated control for each population. The preliminary screening assay confirmed the evolution of nicosulfuron resistance in the field-selected populations V1 and V2. Calculated GR50 values [herbicide rate required for 50% reduction of fresh weight] from the whole-plant dose-response assay, were 410 g a. i. ha−1 (V1), 290 g a. i. ha−1 (V2), 8 g a. i. ha−1 (SV1) and 13 g a. i. ha−1 (SV2), resulting in Resistance Factors (RF) of 51 (V1) and 22 (V2). Sequencing of the als gene revealed a point mutation at the Asp-376 position, where Asp was substituted by Glu in both alleles of the field-selected populations. This study reports the first confirmed case of S. viridis resistance to ALS-inhibiting herbicides, and the first detection of the associated mutation in Europe.