IntroductionThe agronomic performance of phosphorus (P) recycling fertilizers such as struvite (STR) is commonly assessed in pot or field trials, both of which have inherent limitations in balancing experimental control and field relevance. Mesocosm systems offer an intermediate approach to assess fertilizer performance under semi-realistic yet controlled conditions. This study aimed to (i) assess crop-specific responses to P fertilization, (ii) compare the agronomic performance of granulated STR with that of diammonium phosphate (DAP), soft rock phosphate (sRP), and a control without P fertilization (P0), and (iii) evaluate the effect of magnesium (Mg) supplied with STR.Materials and methodsA two-year crop rotation consisting of ryegrass and forage rye (cover crops) and silage maize and potatoes (main crops) was cultivated in large-scale mesocosms (1000 L), filled with a homogeneous, P-deficient substrate consisting of quartz sand, bentonite, and bark humus. Crop yield, P concentration, and P uptake were assessed across growth stages, alongside changes in CAL-extractable P and CaCl2-extractable Mg concentrations in the substrate.ResultsCrop responses to P fertilization were strongly species-specific. Autumn-sown cover crops showed little or no yield response, whereas the main crops showed pronounced responses to P supply, particularly during early growth. In the main crops, STR outperformed sRP, with relative dry matter yields (gross rDMY, DAP = 100%) of 91% and 83% und STR compared with 78% and 56% under sRP for maize and potato, respectively. However, STR remained inferior to DAP, particularly during early crop development, when P concentrations remained below optimal ranges. Under repeated P application, STR showed a gradual increase in the CAL-extractable P stock over the crop rotation, increasing by 7.84 g P mesocosm-1, compared with 4.35 g P mesocosm-1 under DAP, whereas it decreased under sRP (-0.77 g P mesocosm-1) and P0 (-1.59 g P mesocosm-1). No statistically significant effect of additional Mg supply on DMY was detected under the experimental conditions.DiscussionGranulated STR behaved as a slow-release fertilizer under semi-controlled conditions, showing potential for long-term P supply, while limited early P availability constrained its agronomic performance.
IntroductionVolatile organic compounds (VOCs) play a crucial role in plant communication and defence, with aromatic plants representing an important and promising natural source of these compounds. In this study, we evaluated the role of sage VOCs in enhancing grapevine defence against Plasmopara viticola under both controlled and field conditions.MethodsSage and grapevine were consociated in an airtight box system for 24 or 48 h, after which grapevine leaves were inoculated with P. viticola. In a three-year field trial, sage was intercropped with grapevine along two strips of vine rows spaced 50 m apart to avoid VOC cross-contamination. During each growing season, leaves were repeatedly collected from consociated and non-consociated areas of the vineyard and artificially inoculated with P. viticola in Petri dishes. In selected assays, sage leaves were attached to the lids of the Petri dishes to evaluate a possible incremental effect of sage VOCs.Results and DiscussionOverall, sage VOCs reduced grapevine susceptibility to downy mildew by 35.8 to 52.2% under all experimental conditions, suggesting that they may act as resistance inducers. Moreover, consociation with sage significantly altered the volatilome within the airtight boxes, with the VOC profile of the consociated system closely resembling that of sage alone, resulting in significantly lower disease severity in inoculated grapevine leaves. The further reduction in disease severity (by 26.1 to 59.0%) observed when sage leaves were present during the inoculation assay suggests a possible, direct inhibitory effect of sage VOCs on P. viticola infection. These findings highlight the potential of sage VOCs as a natural tool for enhancing grapevine defence against downy mildew. Further long-term studies are required to confirm our exploratory field observations, elucidate mechanisms for sage VOC efficacy against P. viticola, and assess its agronomic and economic sustainability within an agroecological framework.
Long-lived irrigated plantations require regional screening before site-level land and water appraisal. We developed a non-compensatory remote-sensing and GIS framework to prioritize further investigation for date-palm expansion in Al Ain, United Arab Emirates. Annual 10-m land-cover maps, terrain, persistent surface-water occurrence, regional soil and geology, and salinity categories for 0–50 and 50–100 cm were combined through explicit class precedence. High and Moderate denote mapped limitation under an adequate-irrigation assumption. The executed Base candidate area was approximately 731,449 ha (54.13% of the analytical footprint); treating unresolved salinity coverage as Not assessed reduced it to approximately 730,457 ha (54.06%). Water supply, irrigation-water quality, and allocation remain unquantified. Salinity caused ordinal downgrades across 13.53% of the footprint, but a pixelwise comparison showed no final-class change from adding the generalized deeper layer. Three nested soil–geology interpretations shared 98.01% of their candidate union. Additional tests exposed sensitivity beyond these recodings: raising each valid salinity category by one severity class reduced the coverage-adjusted Base candidate area by 14.17%, while 6.30% of candidates lay within a 90-m raster band around salinity-category or coverage edges. Later mapped establishment comprised 685 ha in 242 persistent Trees/Crops patches, or 0.0541% of baseline-stable land. High and Moderate contained 78.17% of this outcome on 58.93% of risk-set land, giving enrichment of 1.33. Spatial-block resampling ranges depended on block size and included enrichment below one at 10 km. Baseline and outcome share one land-cover product, and the image record raised concerns about some mapped transitions. The results support a regional shortlist for soil-profile, irrigation, drainage, infrastructure, and economic investigation, with no independent demonstration of date-palm identity or agronomic suitability.
Oxalis pes-caprae L. (soursob), an invasive perennial herb native to South Africa, has become a dominant and problematic weed across Mediterranean agroecosystems. This study evaluated the effectiveness of weed treatments and agroecological alternatives on its vegetative regeneration capacity and investigated the interference dynamics between soursob and a forage legume rotation, Sulla coronaria (L.) Medik (sulla) in a cereal farming system of Sardinia (Italy). Sulla (cv. Bellante) was sown in autumn (October 2024) following triticale (x Triticosecale Wittmack) in a randomized complete block design with three replications. Plots had previously undergone eight weed treatments: cover-cropping, mowing, sulfonylurea and phenoxy herbicides at two rates, timely destructive soil tillage, and an untreated control. Over two growing seasons, sulla and soursob plant densities, aboveground dry matter and nitrogen yields, and derived competitive indices were measured. Achieving the highest weed suppression, sulfonylurea herbicide and soil tillage significantly reduced soursob density (11- and 6-fold), biomass (8.5- and 4-fold, respectively), and nitrogen accumulation (about 3-fold) compared to untreated control. Conversely, sulla plant density and growth were enhanced. The same trend (p < 0.001) but with low absolute values was recorded in the second growing season, likely resulting from the combination of the residual effect of treatments and stand age of sulla. A significant multivariate separation among treatments confirms that the competitive mechanism from sulla shifted from density (first year crop cycle) to plant vigour dependence (second year crop cycle) with 5-fold individual weight reached. Although soursob was not completely removed and even increased in some treatments, its competitive role was strongly reduced in the best-performing treatments due to the suppressive effect of the sulla canopy. The initial weed management strategy applied before crop rotation and subsequent sulla biomass were significant determinants of the final soursob density. Overall, results pointed out that sulla does not only coexist with soursob but actively contributes to limiting its spreading. Throughout its biennial cycle, successfully established sulla provides distinct interference mechanisms, serving in meantime as valuable forage crop and effective biological barrier against soursob.
IntroductionCucumber Fusarium wilt is an important soil-borne disease that can substantially limit cucumber production. Despite its importance, the Fusarium populations associated with cucumber wilt in Jordan have not been comprehensively characterized at the species, pathogenic-group, host-range, and management levels. This study aimed to determine the occurrence and identity of Fusarium species associated with symptomatic cucumber plants, characterize pathogenic groups of Fusarium oxysporum associated with cucumber, evaluate their pathogenicity and host specificity, and compare selected disease-management strategies under Jordanian production conditions.MethodsA total of 165 symptomatic cucumber plants were collected from major cucumber-producing regions of Jordan during 2024. Fusarium isolates were characterized morphologically, and representative retained isolates were subjected to RPB2-based molecular identification and phylogenetic analysis. F. oxysporum isolates were screened using pathogenic-group-specific PCR markers. Pathogenicity and host specificity were evaluated in three controlled-environment experiments using cucumber and selected cucurbit hosts. Representative symptomatic/dead plants were used for pathogen re-isolation to support the pathogenicity assessment. In addition, an on-farm greenhouse trial compared conventional tillage, deep tillage, grafting, soil fumigation, a grower-style fungicide program, and an untreated control in a randomized complete block design.ResultsNinety-six Fusarium cultures were retained from symptomatic cucumber plants, and 50 isolates yielded usable RPB2 sequences. Among the sequenced isolates, F. oxysporum was predominant (46/50), whereas F. falciforme (2/50), F. incarnatum (1/50), and F. solani (1/50) occurred at low frequencies. Pathogenic-group PCR screening identified Groups 1, 3, and 4 among the tested F. oxysporum isolates, with Group 1 being the most frequent and consistently causing the greatest cucumber mortality in the pathogenicity experiments. The tested cucumber-associated isolates showed a restricted host response under the experimental conditions, with disease occurring primarily in cucumber and little or no mortality in the tested non-cucumber cucurbits. In the on-farm trial, treatment significantly affected all end-of-season variables. Soil fumigation with metam potassium and grafting onto Shintoza Prime rootstock produced the lowest cumulative mortality, whereas the untreated control and conventional tillage had the highest cumulative mortality.ConclusionFusarium oxysporum was the predominant Fusarium species recovered among the sequenced isolates from symptomatic greenhouse cucumber plants in Jordan. The study identified pathogenic Groups 1, 3, and 4 among the tested F. oxysporum isolates and demonstrated differences in aggressiveness, with Group 1 producing the greatest cucumber mortality. The host-response experiments supported a strong association of the tested isolates with cucumber, while pathogen re-isolation from representative symptomatic/dead cucumber plants provided additional support for pathogenicity. Under the conditions of the on-farm trial, soil fumigation and grafting provided the strongest suppression of disease-associated mortality. These findings provide a basis for continued surveillance of cucumber-associated F. oxysporum populations and for developing integrated management programs under Jordanian greenhouse production conditions.
