Background and objectives: Medicinal plants play major roles in human health services worldwide. Many people in both developing and developed countries are turning to herbal medicine. There is a growing demand for plant based medicines, health products, essential oils, fragrances, cosmetics and natural aroma chemicals in the national and international markets. The quality of the economic products of medicinal plants is an absolute necessity. Nutrient enrichment of soils by nitrogen fixing symbiotic bacteria present in bean has been known.Materials and methods: In order to study the impact of replacement and Additive intercropping series on yield and yield components of bean and ajowan as a medicinal plant, an experiment was conducted based on a randomized complete block design with three replications at the Agricultural Research Station, Shirvan College of Agriculture and Natural Resources during 2012-2013 growing season. Seven replacement and Additive intercropping series such as 75% ajowan+ 25% bean, 50% ajowan+ 50% bean, 25% ajowan+ 75% bean, 50% ajowan+ 100% bean, 100% ajowan+ 25% bean, 100% ajowan+ 50% bean, 25% ajowan+ 100% bean and their monocultures were considered as treatment. Criteria such as yield components, biological yield, seed yield, essential oil content, essential oil yield and harvest index of ajowan and yield components, biological yield, seed yield and harvest index of bean were measured and calculated accordingly.Results: The results showed that the effect of replacement and Additive intercropping series was significant (p≤0.01) on yield components, biological yield, seed yield, harvest index and essential oil yield of ajowan and yield components, biological yield, seed yield and harvest index of bean. The maximum biological and seed yield of ajowan were observed in its monoculture with 192.82 and 113.19 g m-2 and these minimum were in 50% bean+100% ajowan with 43.50 and 12.79 g m-2, respectively. The highest and the lowest essential oil yield of ajowan were obtained in its monoculture and 100% bean+25% ajowan with 3.51 and 0.54 g m-2, respectively. The maximum number of branches per plant, number of pods per plant and number of seeds per pod were achieved in 75% ajowan+25% bean with 18 branches per plant, 35 pods per plant and 10 seeds per pod, respectively. The highest and the lowest biological yield and seed yield of bean were observed in its monoculture (1984.87 and 893.81 g.m-2) and 25% ajowan+100% bean (552.42 and 252.50 g.m-2), respectively. Range of partial land equivalent ratio (LER) for ajowan was calculated with 0.12-0.55 and it was 0.28-0.83 for bean and the highest total LER was computed in 50% bean+100% ajowan with 1.14.Conclusion: Based on the result intercropping of ajowan and bean increase biodiversity, sustainability and stability of agroecosystem. It could be effective for ecologic production of medicinal plant. It could decrease chemical input because of nitrogen fixation.

Background and Objectives: Intercropping is a valuable cultivation system in the world due to the better use of resources and increase the quantitative and qualitative yield of plants. It also can be considered as one of the approaches to improve yield and stability in production. Recently, medicinal plants intercropped by legumes have been noticed. In order to evaluate faba bean and fennel intercropping advantage under row-replacement and Additive series, an experiment was conducted in 2019. Materials and Methods: This experiment was carried out at the research farm of the Azarbaijan Shahid Madani University, Tabriz, Iran, in a randomized complete blocks design with three replications. Treatments including 6: 0, 4: 2, 3: 3, 2: 4, and 0: 6 of faba bean: fennel rows under replacement series and 6: 3, 6: 2, 2: 6, and 3: 6 of faba bean: fennel rows under Additive series. After reaching a constant weight of fennel fruits, yield and its components (number of umbels and umbellets and fruits per umbellet, 1000-seed weight, biological yield, seed yield, and harvest index) were measured in fennel plants. The essential oil content in fennel fruits was also measured using a Clevenger apparatus. Faba bean biomass was measured after harvesting plants in the flowering growth stage. Finally, the relative crowding coefficient, land equivalent ratio, actual yield loss or gain and intercropping advantage of faba bean: fennel mixed cultivation were calculated in the row-replacement and Additive series. Results: The results showed that intercropping of faba bean and fennel had a significant effect on all studied traits. The highest number of umbels per plant was obtained from sole cropping (12. 10). Also, the highest number of umbellets/umbel was related to intercropping of two rows of faba bean: four rows of fennel and three rows of faba bean: three rows of fennel by 22. 05 and 19. 62, respectively. The highest 1000-seed weight was obtained from sole cropping of fennel (5. 62 g) and replacement intercropping, especially from two rows of faba bean: four rows of fennel (5. 56 g). The highest biological yield (1503. 47 kg/ha) and seed yield (617. 73 kg/ha) were obtained from the sole cropping of fennel. The maximum harvest index was related to the intercropping of three rows of faba bean: three rows of fennel, which shows that such a mixture ratio leads to the highest seed yield rather than biological yield produced. The highest fennel essential oil content was obtained from Additive series. The highest faba bean biomass was found in the sole cropping (1933. 02 kg/ha) and the lowest in treatments in which two rows of faba bean has been planted. Two rows of faba bean + six rows of fennel had the highest (3. 96) relative crowding coefficient. The land equivalent ratio in all row-replacement and Additive series was more than one or close to one, which indicates the usefulness of faba bean and fennel intercropping. The highest actual yield (0. 07) and intercropping advantage indexes (0. 17) were related to three rows of faba bean + three rows of fennel. Also, the lowest actual yield was related to Additive series, especially treatments in which fennel had a higher mixture ratio than faba bean. Conclusion: Based on the results obtained in this study, environmental resources including light, water, and nutrients have been used optimally in the three faba bean rows + three fennel rows and there was no effective competition to achieve them in this row-replacement series. In other words, ecological niche separation in this intercropping system has been done favorably, and subsequently the actual yield index increased. Therefore, the mixture ratio by 50: 50 in the row-replacement series is recommended to achieve the highest benefit in semi-arid conditions where this experiment was conducted.

In order to evaluate the effect of intercropping with replacement and Additive series for hemp (Cannabis sativa L.) and sesame (Sesamum indicum L.), a field experiment was conducted during growing season 2006-07 at the Agricultural Research Station of Ferdowsi University of Mashhad, Iran. A randomized complete block design with three replications was used. Treatments included different combinations of intercropping with replacement (75% sesame+25% hemp, 25% sesame+75% hemp, 50% sesame+50% hemp) and Additive (50% sesame+100% hemp and 100% sesame+50% hemp) series and their monoculture. Results indicated that the highest and the lowest leaf area index (LAI) and dry matter (DM) accumulation of hemp were observed in 50% sesame+50% hemp (2.99 and 1921.7 gm-2) and 50% sesame+100% hemp (1.06 and 929 gm-2), respectively. The highest and the lowest LAI and DM accumulation of sesame were observed in monoculture (1.34 and 551.27 gm-2) and 50%sesame+100% hemp (0.23 and 51.73 g.m-2), respectively. The maximum crop growth rate (CGR) of hemp and sesame were observed in 50% sesame+50% hemp (76.58 gm-2day-1) and monoculture (22.78 gm-2day-1), respectively. It seems that the intercropped sesame with hemp reduced the growth indices of sesame due to increasing shading on it and decreasing the absorption of radiation.

Objective: This research was carried out in order to evaluate the effect of intercropping of replacement and addition series on the yield and yield components of Camelina and Lentil under rainfed and irrigated conditions. Materials and Methods: The experiment was carried out in the form of split plots in the form of a basic design of randomized complete blocks with three replications in the research farm of the Faculty of Agriculture of Ilam University in growing season in 2020-2021 and 2021-2022. The main plots include irrigation on two levels (rainfed and irrigated) and the subplots include alternative and incremental mixed cropping patterns in nine levels including (75% Camelina+ 25% lentils, 50% Camelina+ 50% lentils, 25% Camelina+ 75% lentils), 100% Camelina+ 25% lentils, 100% Camelina+ 50% lentils, 100% Camelina+ 75% lentils, 100% Camelina+ 100% lentils, monoculture of Camelina and lentils). Results: The results showed the highest grain yield (1827 kg ha-1) and biological yield of camelina (7012 kg ha-1) in the series of 100% camelina+ 25% lentil and the highest grain and biological yield of lentil was 750 and 1950, respectively, related to monoculture lentil cultivation. The evaluation of the ratio of land equality showed the superiority of all ratios of camellia and lentil intercropping over their monoculture, and the incremental rows of 100% camellina+ 75% lentils and 100% camellina+ 100% lentils had the highest LER. Conclusion: The results showed that the intercropping of camelina and lentils under irrigation and rainfed conditions was beneficial and superior compared to their monoculture.

In order to study the effect of intercropping (Additive and replacement series) on yield and radiation use efficiency of safflower and chickpea, a field experiment was conducted based on a randomized complete block design with three replications and nine treatments at the research farm, Faculty of Agriculture, Ilam University during the growing season in 2020. Experimental treatments were include: sole crops: safflower (S) (25 plants. m-2) and chickpea (Ch) (25 plants. m-2), intercropping of replacement series: (70% S, 30% Ch), (50% S, 50% Ch), (30% S, 70% Ch) and intercropping of Additive series: (100% S+ 30% Ch), (100%S + 50% Ch), (100% Ch + 30% S) and (100% Ch + 50% S). The results showed that the highest grain yield (190 kg. ha-1) and biological yield (1070 kg. ha-1) of safflower were obtained in Additive series 100% S+ 30% Ch. The highest (1. 47) and the lowest (0. 86) land equivalent ratio was obtained from Additive series 30% S+ 100% Ch and replacement series of 30%S+ 70% Ch, respectively. The highest radiation use efficiency (RUE) of safflower and chickpea was obtained in the treatments of 100% S + 30% Ch and 50% S + 50%Ch, respectively. The highest radiation absorbed (603 MJ. m-2) was obtained in the treatments of 100% S+ 50% Ch. Intercropping patterns of chickpea and safflower improved the radiation absorption and radiation use efficiency and increased the total yield per unit area and LER.

A field experiment was conducted in a field located in Shirvan in 2011 to determine the effect of various com and mungbean intercropping series on yield, yield components and weed biomass. The experimental Treatments were included: sole com (C), sole mungbean (M), 75% com+ 25% mungbean (C75M25), 50% com+ 50% mungbean (C50M50), 25% corn+ 75% mungbean (C75M75), 100% com+ 25% mungbean (C100M25), 25% com+ 100% mungbean (C25M100), 100% com+ 50% mungbean (C100M50), and 50% com+ 100% mungbean (C50M100). The results indicated that intercropping treatments had significant effect on weed biomass. Additive intercropping leads to reduction of weed biomass when compared with replacement intercropping. The lowest weed dry weight was resulted from C50M100 treatment. This treatment leads to reduction of lambsquarters, pigweed and johnsongrass biomass compared with other treatments. The highest yield of com (11254.33 kg.ha-1) and mungbean (1905.07 & 1840.17 kg.ha-1) was resulted from C100M25 and M and C25M100 treatments, respectively. The highest land equivalent ratio (LER=1.75) was obtained from C100M50 treatment.

Backgrounds and objectives: Nowadays, intercropping is highlighted as a solution to optimize usage of inputs, to decline pesticides and to produce safe food in agriculture. The previous studies represent relative advantages of multiple cropping versus sole cropping. Since, garlic and pea are well-adapted plants to northern climatic conditions of Iran and there were no comprehensive studies about their intercropping, the present study was aimed to evaluate and determine the best intercropping treatment between garlic and pea in terms of yield. Materials and methods: The research was conducted at research farm of Gonbad Kavoos University and Sari region during 2013-2014. The experiment was arranged based on randomized complete block design with three replications. Treatments were nine levels including sole cropping of garlic and pea and replacement series of 25: 75, 50: 50 and 75%: 25% pea: garlic and Additive series of 25, 50, 75 and 100% pea +100% garlic. Results: The biological yield of garlic in Gonbad Kavoos region (2357. 21 g/m2) was 10 percent lower than Sari region. Means sulfur percentage in garlic bulb was recorded 0. 81 and 0. 94 for Gonbad Kavoos and Sari region, respectively. The maximum bulb yield (1193. 42 g/m2) was belonged to sole cropping of garlic in Sari conditions. Seed yield of pea was 399. 3 and 736. 17 kg/ha in Gonbad Kavoos and Sari, respectively. Results indicated that the maximum seed yield of pea was recorded in sole cropping and followed by Additive series of 100% garlic + 100% pea by 53. 3 g/m2. In Sari region, the seed nitrogen and phosphorous content in was 4. 85 and 0. 29 %, respectively, which these rates were about 3 and 11. 5 % more than Gonbad Kavoos region. Also, the maximum seed potassium (1. 53%) was related to Additive series of 25% pea + 100% garlic in Sari conditions. The highest land equivalent ratio (1. 76), relative crowding coefficient (7. 4), aggressivity (0. 79) and relative value total (1. 53) was recorded when Additive series of 75, 25, 100 and 75 % of pea + 100% garlic intercropped in Sari climatic conditions, respectively. Conclusion: Overall, results of different Additive and replacement series of intercropping showed that the Additive series intercropping of 75 and 100 % pea + 100% garlic resulted the maximum quantitative and qualitative yield in both studied regions.

In order to investigate the effect of Additive series intercropping of legume and cereal (the line of 2561 of broad leaf vetch and Abidar cultivar of barley) on species diversity ecological indices and weeds dominance, a field experiment was conducted in 4 × 5 factorial with three replications in the dry land conditions in the research farm of the Faculty of Agriculture, University of Lorestan in the cropping years of 2015-17. The intercropping treatments reduced numbers and total dry weight of weeds ratio in sole cropping. The best treatments in first and second year for weeds control were once-weeding and seed ratios 70: 100 and 100: 100 (vetch: barley) and double-weeding×70: 100. The three factor interactions (year, weed and intercropping) represent the contribution of 40: 100 and 70: 100 with once-weeding in weed dry weight losses (17. 98 and 17. 16 in the first and second years, respectively). In the second year, this interaction also resulted to the lowest weed dry weights (20. 82 and 20 g/m-2). The lowest species richness was belonged to once and double weeding and non-weeding treatments with 100: 100 seed ratio, respectively. Also, mentioned treatments indicated the weeds were more dominance in the first year compared to the second year.

Adding parameters to a known distribution is a valuable way of constructing flexible families of distributions. In this paper, we introduce a new model, the modified Additive hazard rate model, by replacing the Additive hazard rate distribution in the general proportional add ratio model. Next, when two sets of random variables follow the modified Additive hazard model, we establish stochastic comparisons between the series and parallel systems comprising these components.

In order to evaluate the quantitative and qualitative traits of safflower and chickpea in Additive and replacement intercropping series, an experiment was conducted as randomized complete blocks design with 11 treatments and 3 replications at research field of Kurdistan University during 2015-2016 growing season. Experimental treatments included sole cropping of safflower, sole cropping of chickpea, replacement series consisted of 4: 4, 2: 2, 1: 1, 3: 1, 1: 3 and Additive series consisted of 20% and 40% chickpea (in two situations: I, between and II, around of safflower rows). Results showed that the highest and lowest seed, biological and oil yields of safflower obtained from 40% I and 4: 4 intercropping patterns, respectively. The highest seed and biological yields of chickpea obtained from its sole cropping, but the minimum number and weight of chickpea root nodules were achieved from this treatment. The highest value of LER obtained from 40% I Additive series. It seems that the mentioned treatment improved yield and quality of safflower; therefore choosing the suitable cropping pattern has positive effect on quantitative and qualitative yield of plants.