Effect of Row Intercropping Patterns on Yield, Yield Components, and Weed Control of Fenugreek (Trigonellafoenumgreacum L.) and Anise (Pimpinellaanisum L.)

Due to population growth and food shortage agricultural production is on increasing demand. In this order increasing cultivation area and yield per unit area are two ways of obtaining higheragricultural production (20). There is another important way that without incurring additional costs and use of water and fertilizer could result in higher production. This approach is increasing agricultural production per unit area by growing more than one crop in a year. Intercropping will be successful when competition for sources issless than competition within a species. Plants in the mixture can be chosen in a way that a species benefits from environmental changes caused by other species in mixed cultures directly (7, 15). Intercropping inhibits the growth and development of weeds and leads to increased production. Since the system will reduce the pesticide use, environmental pollution will be also less proportionally (37). In order to evaluate the yield, yield components and potential weeds control under intercropping fenugreek and anise, an experiment was carried out based on a randomized complete block design with three replicationsat the Agricultural Research Field of Yasouj University during growing season of 2012-2013. Treatments included pure cultures of fenugreek and anise, single-row, double-row and three-tier intercropping of fenugreek and anise at no weed control and weed control conditions. The results showed that different intercropping treatments had significant effects on pod number per plant, grain weight and grain and biological yield of fenugreek and also, on number of lateral branches, number of grains per plant and grain and biological yield of anise. There were nosignificant effects on plant height, number of lateral branches, number of grain per pod, harvest index of fenugreek, as well as plant height, number of umbel let per plant, seed weight and harvest index of anise. The lowest weed dry weight was observed in two rows intercropping and the maximum dry weight of weeds in fenugreek monoculture, respectively. Evaluation of land equivalent ratio showed that intercropping of fenugreek and anise is superior to pure culture and single-row intercropping had highest land equivalent ratio (1.39). Index values of the actual yield loss were also positive, which indicates the usefulness of mixed culture compared to monoculture of each plant. Among the different treatments tested AYL's highest were allocated by single-row intercropping treatments in the absence of weed. AYL minimum belonged to two rows intercropping treatments and without weed. All positive values of AYL indicated the utility of intercropping. Therefore it can be concluded that intercropping in all proportions, combined with the principle of protection, is benefiial. The effect of weed control on grain yield in the absence of fenugreek was observed in single-row, double and triple rows cultivation without weed control, respectively. This resulted in a decrease of 3%, 21% and 18% yield, and indicates a greater impact of single row cultivation on the weed control. It speculated that the higher nitrogen fixation under the triple rows may help higher weed growth. Results showed that higher yield in treatments of intercropping compared to pure culture. Other indicators also showed the utility of intercropping, mixed farming profitability. In this study for all treatments, intercropping, and land equivalent ratio was greater than single cultivation. Thus achieving higher LER than one indicates that mixed cultures compared with pure cultures of environmental resources, such as light and nutrients more effectively used as components of mixed cultures were complementary. This advantage is due to physiological and morphological differences between the components that are in mixed cultures. It seems to increase the diversity of crop species and increases the competition between crops and weed species, more efficient allocation of resources and their distribution among crop species occurs, resulting in reduced weed infestation. Absorption of light by a dense canopy of intercropping, reduces the amount of light loss by the canopy and thus reduces weed growth and seed germination. Fenugreek and anise single-row intercropping is better than pure cropping.