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Introduction: Biofertilizers and intercropping are two main components in sustainable production systems. Materials and methods: A two-year (2020-2021) study was conducted in East Azarbaijan, Iran, to evaluate the effects of arbuscular mycorrhizal fungi (AMF), growth-promoting bacteria (GPB) and chemical fertilizer (CF) on fenugreek (Trigonella foenum-graecum L.) (F) oil yield and compositions in intercropping with Moldavian balm (Dracocephalam mobdavica L.) (MB). The cropping patterns included MB sole cropping, fenugreek sole cropping (F) and replacement intercropping ratios consisted of Moldavian balm: fenugreek (MB:F (1:1)), MB:F (2:2) and MB:F (4:2) and additive intercropping of MB:F (100:50). Results: For both years, among the intercropping patters, the highest seed and oil yields were obtained in MB:F (100:50) intercropping pattern treated with CF and AMF+GPB. In all cropping patterns except MB:F (4:2), the highest anthocyanin, total flavonoid, and mucilage contents were observed in plants received AMF +GPB. At all treatments, the linoleic, oleic, and linolenic acid were the main components of fenugreek oil. In MB:F (1:1), (2:2), (4:2), and (100:50) intercropping patterns, the linoleic acid content in AMF+GPB treatment, increased by 9.45%, 6.63%, 15.20%, and 7.82%, respectively, compared with sole fenugreek. The highest total land equivalent ratio (LERT) values were obtained in 2021 and MB: F (100:50) intercropping pattern treated with CF (1.70) and AMF+GPB (1.63). Conclusions: In general, it could be concluded that MB:F (100:50) intercropping pattern treated with AMF+GPB improved the oil yield and unsaturated fatty acid contents of fenugreek compared with sole cropping and could be recommended in sustainable production systems. [ABSTRACT FROM AUTHOR]

Astrodaucus orientalis is a weed species in cropping systems and rangelands in Iran. The effects of temperature, light, NaCl concentration, water potential, seed burial depth and crop residue cover were assessed on seed germination and seedling emergence of two populations of A. orientalis from Ardabil (Meshginshahr population) and East Azarbayjan (Tabriz population) provinces of Iran. The A. orientalis populations indicated different responses to environmental factors and burial depth. In the Tabriz population the greatest germination (88.5%) was observed in 20/12°C day/night temperature but in the Meshginshahr population (83.2%) it was obtained in 24/16°C day/night temperature. Over a broad range of light period (10–24 hr light) germination was 74–83%, but it decreased (less than 37%) under 24 hr dark in both A. orientalis populations. With respect to water potential, the C50 parameters were −0.62 and − 0.49 MPa for Tabriz and Meshginshahr populations, respectively. The D50 parameters (the burial depth that caused 50% decrease in emergence) for Tabriz and Meshginshahr populations were 2.42 and 3.13 cm, respectively. Generally, the results showed that emergence of both populations of A. orientalis was delayed as depth of burial increased up to 4 cm and in cropping systems a shallow tillage that locates the seeds to >4 cm of depth in soil could be used in order to suppress seedling emergence. Our findings also could be useful in integrated management of A. orientalis in winter annual crops and rangelands. [ABSTRACT FROM AUTHOR]

To study the effects of intercropping different sugar beet cultivars with soybean, Moldavian balm and proso millet in an organic production system on the yield and quality of sugar beet, a factorial experiment was conducted in 2016 and 2017 in West Azarbayjan, Iran. In 2016, the sugar beet-soybean intercropping resulted in the highest Na and α-amino-N concentrations in the sugar beet (2.384 and 2.879 meq. 100 g−1 beet respectively), but in 2017 the concentrations of these compounds were not significantly different between the intercropping patterns. For all intercropping patterns the land equivalent ratio (LER) was greater than one. In 2016, the highest LERT, based on white sugar yield, was obtained in the sugar beet–soybean intercropping system (1.27 for cv. Vaclav), but in 2017 the highest LERT based on white sugar yield, was obtained in sugar beet–Moldavian balm intercropping (1.24 for cv. Vaclav). Among the sugar beet cultivars, Ghazira had the highest sugar concentration and white sugar yield. It was concluded that the sugar beet–Moldavian balm intercropping system could be used in organic production systems to achieve high land productivity. [ABSTRACT FROM AUTHOR]

The Moldavian balm essential oil contains numerous medicinal values in addition to its other wide application. The present study was carried out to evaluate the effect of plant growth-promoting bacteria and mycorrhiza-like fungi inoculation on Moldavian balm (Dracocephalum moldavica L.) essential oil yield and composition under drought stress condition. The experiment was arranged as factorial based on a randomized complete block design with three replications. The first factor was drought stress at four levels including no drought stress, low, medium and high drought stress. The second factor was inoculation treatments comprising of non-inoculated control, inoculation with Enterobacter sp., Pseudomonas sp., Agrobacterium sp. and Piriformospora indica. The results indicated that the interaction effect of drought stress × inoculation was significant on dry weight, essential oil content and yield of D. moldavica. Under all drought stress levels, inoculation with Enterobacter, Agrobacterium and Piriformospora increased the dry weight and essential oil yield of D. moldavica, compared with those in non-inoculated control. While the result of dry weight and essential oil yield from inoculation with Pseudomonas was almost equal to that of the non-inoculated control. The main components of essential oil were geranial followed by geraniol, geranyl acetate, neral, neryl acetate and geranyl formate. The chemical composition of essential oil was affected by drought stress and inoculation levels. Under all drought stress levels, the geranyl acetate content was found to increase in inoculation treatments with Enterobacter sp., Pseudomonas sp., Agrobacterium sp. and Piriformospora indica respectively. In general, inoculations with Piriformospora indica, Agrobacterium and Enterobacter increased the dry weight and essential oil yield under all drought stress levels and could be recommended to growers to reduce the application of chemical fertilizers in D. moldavica production. [ABSTRACT FROM AUTHOR]

Common cocklebur (Xanthium strumarium L.) is a summer annual weed of the corn fields in the north-western parts of Iran. Field experiments were conducted in 2013 and 2014 to examine the seedling emergence and growth of common at different achene (seed) burial depths (3, 6, 9, 12, 15 and 18 cm) and wheat straw mulch amounts (0, 1.5, 3.0 and 4.5 ton ha-1). Results indicated that increasing achene burial depth and mulch amount reduced X. strumarium seedling emergence. In both years, no seedling emergence was observed from 18-cm achene burial depth. X. strumarium biomass and achene number per plant were affected by achene burial depth and mulch amount, and were greater in 2014 than in 2013. The corn leaf area index (LAI) and grain yield were higher in the treatments which deeper achene burial depth and mulch amount were high. Therefore, X. strumarium emergence in the corn can be suppressed by a tillage that buries the achenes to ≥18 cm of soil depth. Maintaining a thick residue cover will provide competitive advantage of corn over X. strumarium due to an inhibitory effect on X. strumarium emergence and growth and may lead to a reduction in the future weed infestation. [ABSTRACT FROM AUTHOR]

This research tries to study the application of chemical and biofertilizers on growth, yield, and fatty acid composition of safflower, intercropped with faba bean. As such, it carries out an experiment, based on a randomized complete block design with three replications at the Research Farm of University of Tabriz during two growing seasons of 2015 and 2016. Sole cropping of safflower, sole cropping of faba bean, and intercropping of safflower and faba bean with ratios of 1:1 and 2:1 make up the first factor, while the second factor entails four levels of fertilizers, viz. no fertilizer, 100%, 30% chemical fertilizer, and 60% chemical fertilizer plus biofertilizer (Azoto barvar-1 and phosphate barvar-2). Results show that the highest Chlorophyll content, plant height, and number of branch per plant belong to safflower/faba bean intercropping (1:1) by means of 60% chemical plus biological fertilizers. Also, integrated use of chemical and biological fertilizers have increased seed yield, oil content (33.81%), linoleic (76.97%), and linolenic (0.32%) fatty acids. The highest land equivalent ratio (1.41) has been achieved in intercropped plants (1:1) with integrated use of 60% chemical and biological fertilizers. For both periods, total actual yield loss for all intercrops has been above zero, indicating the positive advantage of intercropping over the pure one. Overall, intercropping (safflower/faba bean) with integrated use of chemical and biological fertilizers could be recommended as an appropriate method for production of safflower with better quality and quantity. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of reduced doses of trifluralin in integration with non-chemical management treatments on weeds, essential oil yield and composition of dill (Anethum graveolens L.), a 2-year study was conducted in East Azarbaijan, Iran in 2020–2021. The study was conducted as factorial experiment based on randomized complete block design with four replications. The first factor was trifluralin use at four levels (non-use, 480, 720 and 960 g ai ha−1) and the second factor was non-chemical weed management treatments consisted of using the living mulch of fenugreek (Trigonella foenum-graecum L.) (FLM) and bitter vetch (Vicia ervilia (L.) Willd. (VLM), wheat straw mulch (WSM), one time hand weeding (OHW) and without non-chemical management (control). The results indicated that at all trifluralin doses the weed biomasses in OHW and WSM treatments were lower than those in FLM and VLM. The relative ranking of non-chemical weed management treatments for weed biomass reduction and essential oil yield of A. graveolens L.was OHW > WSM > FLM and VLM. The results of GC–MS analysis indicated that the main chemical constituents of essential oil (carvone, limonene and dill apiole) were influenced differently by trifluralin use and non-chemical weed management treatment. We can conclude that recommended dose of trifluralin could be replaced with reduced doses of trifluralin in integration with non-chemical treatments in order to improve the weed control efficacy and essential oil yield of A. graveolens L. in a sustainable production system. • The weed biomasses in living mulches were higher than OHW and WSM treatments. • The trifluralin could be replaced with reduced doses + non-chemical treatments. • The highest dill yield (41.1 kg ha−1) was obtained in OHW + trifluralin (R). • The carvone contents increased in non-chemical treatments compared with control. • The relative ranking of weed management treatments was OHW > WSM > FLM and VLM. [ABSTRACT FROM AUTHOR]

Lepidium vesicarium is a weed species with a wide distribution in the rangelands and dry-land farming in East Azarbaijan, Iran. The experiments were undertaken to assay the effects of light, temperature, pH, osmotic potential, NaCl concentration and burial depth on seed germination and emergence of L. vesicarium. Germination was maintained at high levels (> 80%) over a wide day/night temperature range (10/5 to 30/20°C), but a severe reduction in the germination rate of L. vesicarium was found below 20/10°C. Germination of L. vesicarium was influenced by different light/dark regimes, as the germination rate was highest at 16 h light for the all treatments (0, 8, 12, 16 and 24 h light). Germination was 92-95% over a wide range of pH (2-10). Germination was >50% at a water potential of −0.7 MPa and salinity of 21 dS/m, indicating that drought and salt conditions have a minimal impact on seed germination. With increasing burial depth from 0 to 2 cm, the number of days required for 50% emergence increased and no germination was observed at burial depths deeper than 3 cm. This suggests that L. vesicarium would become troublesome in the rangelands and for growers in reduced-tillage cropping systems. The ability to emerge from shallow depths, coupled with tolerance of a wide pH range, drought and salinity at germination, should be taken into account when managing this weed species. [ABSTRACT FROM AUTHOR]

Multispecies competition effects of Xanthium strumarium L. and Datura stramonium L. have not been characterized in maize (Zea mays L.). Such information would be useful in developing an integrated approach to managing these two problematic weeds. Field experiments were conducted during 2 yr to evaluate multiple weed species interference of X. strumarium and D. stramonium at the total densities of 0, 4, 8, 12, and 16 plants m-2 (alone, and all possible combinations of the two weeds) with maize. Crop yield was associated with the density of D. stramonium and X. strumarium and decreased severely with increasing weed density. The maximum maize yield loss (63%) occurred when 12 X. strumarium and 4 D. Stramonium plants m-2 were allowed to compete with the crop. The total weed density (expressed in X. strumarium equivalent density) required to cause a 5% maize yield loss was about 0.50 and 0.56 plants m-2 in 2006 and 2007, respectively. Total canopy leaf area index and crop yield were reduced more strongly by competition with X. strumarium than with D. stramonium. Averaged over multispecies populations, X. strumarium contributed 84 and 67% of the total weed biomass in the first and second years, respectively. Owing to the high competitive ability and biomass production of X. strumarium in mixed crop and weed communities, it should be given a greater priority for control than D. stramonium in maize. [ABSTRACT FROM AUTHOR]

Field experiments were conducted in 2006 and 2007 to evaluate the competitive ability of bush type red kidneybean (RKB) ( Phaseolus vulgaris L.) cultivars against redroot pigweed ( Amaranthus retroflexus L.). Three cultivars of RKB (Akhtar, Sayyad and D81083) and five A. retroflexus densities (0, 4, 8, 16 and 32 plants m −2 ) were established in a factorial arrangement. A. retroflexus had a greater plant height and growth rate (GR) but a lower leaf area index (LAI) than RKB cultivars in almost all treatments. Higher densities of A. retroflexus increased LAI and GR but decreased yield of RKB cultivars. The cv. Sayyad and D81083 had the greatest and lowest LAI and GR, respectively, in competition with A. retroflexus . The maximum intercepted photosynthetically active radiation (PAR) at noon by A. retroflexus was 90.4 and 66.0% in competition with cv. D81083 and Sayyad, respectively. The seed yield and pod number per plant of RKB cultivars decreased severely with increasing A. retroflexus density. A. retroflexus seed number m −2 was the highest and lowest in competition with cv. D81083 and Sayyad, respectively. The competitive ability of RKB cultivars was compared using parameters estimated through two-parameter yield loss-relative leaf area model. The relative ranking of the RKB cultivars examined for their competitiveness, supported by modeling results, was Sayyad > Akhtar > D81083. [ABSTRACT FROM AUTHOR]

• Integration of herbicides with straw mulch increased the weed control efficacy and EO yield in Moldavian balm. • Generally the weed control efficacy of trifluralin was higher than that of pendimethalin. • The highest weed biomass reduction (83.8 %) and EO yield (22.51 kg ha−1) were observed in trifluralin R + mulch. • Straw mulch application increased the geraniol content and decreased the geranyl acetate content in EO of Moldavian balm. • Trifluralin 50 %R + mulch could be recommended as a more sustainable weed management method in Moldavian balm production. In sustainable production of medicinal and aromatic plants, reduction in herbicide application rate and using straw mulch could be used as strategies for integrated weed management. The field study was carried out to evaluate the effects of herbicides reduced rate integrated with straw mulch on sustainable weed management, essential oil (EO) content and composition of Moldavian balm (Dracocephalum moldavica L.). The experiment was done in Agricultural Research Station of University of Tabriz, Iran, from April 2016 to July 2017. The treatments were consisted of two herbicide rates including recommended rate (R) and reduced rate (50 % R) of trifluralin and pendimethalin, integration of all herbicide treatments with mulch application (5 t ha−1) and mulch application alone. The effect of weed management treatment was significant on weed density and biomass and Moldavian balm dry weight and EO yield. Among the weed management treatments, the lowest weed biomass (17.1 g m-2) and the highest EO yield (22.51 kg ha−1) were observed in trifluralin R + mulch (TR + M) treatment. Integration of all herbicide treatments with straw mulch reduced the weed density and biomass and increased the Moldavian balm dry weight and EO yield, significantly. Generally the weed control efficacy of trifluralin was higher than that of pendimethalin. Gas chromatography - mass spectrometry analysis showed that the main constitutes of EO were geraniol, geranial, geranyl acetate, neral, nerol and neryl acetate. The contents of main components were influenced by weed management treatments, differently. The highest content of geraniol (41.4 %) and geranial (24.7 %) were obtained in TR + M and pendimethalin R + mulch (PR + M) treatments, respectively. Integration of all herbicide treatments with straw mulch increased the geraniol content and reduced the geranyl acetate content in EO. The weed density and biomass and Moldavian balm EO yield in trifluralin 50 % R + mulch (T50R + M) treatment were not significantly different with those in trifluralin R (TR). Therefore TR treatment could be replaced with T50R + M and recommended to medicinal plants growers as a more sustainable weed management method in Moldavian balm production. [ABSTRACT FROM AUTHOR]

Cropping systems of safflower (Carthamus tinctorius L.) with faba bean (Vicia faba L.) under different fertility were compared with sole cropping of each crop during 2015 and 2016 at the Research Farm of Tabriz University in Iran. The treatments were cropping systems (safflower and faba bean sole croppings, intercropping systems of safflower and faba bean with ratios of 1:1 and 2:1), and nutrient levels (100% chemical fertilizers, 60%, 30% chemical + biofertilizers and no fertilizer). A factorial set of treatments based on a randomized complete block design replicated three times was used. Cropping system and fertility effects were significant for yield and yield components of each crop. Yield and yield components were increased with the integrated use of 60% chemical plus biofertilizers for both years, while seed yield was reduced by intercropping. Maximum land equivalent ratio (LER), relative value total (RVT), system productivity index (SPI) and monetary advantage index (MAI) were achieved in nutritive level of 60% chemical plus biofertilizers as intercropped plants in ratio of 1:1 for both years. The total actual yield loss (AYL) values were positive and greater than zero in all mixtures, indicating an advantage from intercropping over sole crops. Intercropped safflower had a higher relative crowding coefficient (RCC) than intercropped faba bean, indicating that safflower was more competitive than faba bean in intercropping systems. From this study, it is inferred that intercropping (safflower and faba bean) with integrated use of the reduced chemical and biofertilizers may give better overall yield and income than sole cropping of each crop species. [ABSTRACT FROM AUTHOR]