چكيده لاتين :
Introduction
Today, economic and environmental losses due to excessive use of chemical fertilizers in agriculture are well known. Obviously, a good alternative should be considered for this type of fertilizer. The objectives of sustainable agriculture are, by reducing off-farm inputs such as chemical fertilizers, to increase the nutrient cycle and the use of biological and organic fertilizers to increase agricultural yields. Studies on medicinal plants indicate that the use of sustainable farming systems provide the best conditions for the production of these plants. Biofertilizers are populations of beneficial soil organisms, or one or more of their metabolic products. Mycorrhizal fungi, vermicompost and humic acid are samples of biological and organic fertilizer that can be used, to eliminate or substantially reduce the use of chemical inputs in order to increase the quantity, quality and stability of the products. Mycorrhizal fungi is one of the most important rhizosphere microorganisms which has symbiotic relation with root of most crops. Mycorrhizal symbiosis improves the soil physical quality (through expansion of hyphae of fungus), chemical (through increased absorption of nutrients) and biological (the soil food web). This fungus increased nutrient uptake, such as phosphorus and some micronutrients, water uptake, reduces the negative effects of environmental stress, increases resistance to pathogens and improves the quality of their host plants (Ardakani et al., 2000; Gupta et al., 2002; Kapoor et al., 2004). Vermicompost is the production process of a certain species of earthworms to convert organic materials. Vermicompost contains absorbable nutrients that are available for plants. Humic acid is a completely natural organic matter produced from the final decomposition of soil organic matter by microorganisms. Humic acid stimulates the growth of the aerial parts and plants (Arancon et al., 2004; Atiyeh et al., 2002; Darzi et al., 2008; Ayas & Gulser, 2005; Rezvani Moghaddam et al., 2009).
Fennel (Foeniculum vulgare Mill.) is one of the most important medicinal plants. As the essential oil from the seeds is used in a variety of industries, pharmaceutical, food and cosmetics , Anethole is an important component of the essential oil of fennel seed. The aim of this study was evaluation of the effects of bio (mycorrhiza) and organic fertilizers (vermicompost and humic acid) on growth characteristics and the yield of fennel.
Materials and methods
This experiment was conducted as a factorial-based on a randomized complete block design in order to evaluate the effects of vermicompost application, humic acid and mycorrhizal fungi on quantitative and qualitative aspects of fennel yield at the experimental farm of Shahrood University during the growing season of 2012-2013. This experiment includes 12 treatments and 3 replications. Vermicompost levels include: v1 (no application) v2 (4 t.ha-1) v3 (8 t.ha-1). Mycorrhizal fungi includes: m1 (no inoculation) and m2 (inoculation) and humic acid includes: h1 (no application) and h2 (application). Each plot had 5 rows which were considered with row spacing of 50 cm and row length of 5 m . Mycorrhizal fungi were added to the soil under each seed rows with amounts of 10 grams. Humic acid was sprayed in 3 stages (vegetative, reproductive and seed filling stage) according to the recommended dose (200 mg per liter). Sampling and measuring of traits were done at the end of the season and after removal of border rows. A 50 gram grain sample of each plot was milled and then essence was collected with Clevenger for three hours using water distillation. Percent of fungal colonization was obtained with Gridline Intersect Method. Finally, for analysis of data and drawing shapes, Mstat-C software and Microsoft Excel were used. Comparison of the least significant difference test (LSD) was conducted at the 5% level.
Results and discussion
In this study, plant height, umbels per plant, seed weight per plant, seed and biological yield were significantly affected by the main effects of mycorrhiza, vermicompost and humic acid. The interaction effect of three factors on plant height was significant. The result showed that the highest plant height was obtained with application of 8 t.ha-1 vermicompost with mycorrhizal inoculation and humic acid application. The effects of mycorrhiza, vermicompost and their interaction with the number of seed per umbel were significant. The effects of vermicompost, humic acid and combination effects of mycorrhiza and vermicompost on 1000- seed weight were significant. The interaction effects of vermicompost and mycorrhiza on seed yield were significant. So, mycorrhizal inoculation and 8 t.ha-1 vermicompost application increased about 45% of seed yield over the control plots. The highest value of biological yield was recorded from combination of all factors. So, mycorrhizal inoculation with humic acid and 8 t.ha-1 vermicompost application produced 4823 kg.ha-1 biological yield compared with the control plots (2463 kg.ha-1).
References
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