INFLUENCE OF YEAST AND INTERCROPPING SYSTEM ON GROWTH AND YIELD TRAITS OF PEA Mohammed Mahmood Mohammed* and Ridha Mustafa Al-Ubaidy Dept. of Horticulture and Landscape Gardening Design, College of Agril. Engg. Sciences, University of Baghdad, Iraq. E-mail: plantbreeding666@yahoo.com Abstract: A factorial experiment according to Randomized completed block design (RCBD) with three replications was carried out during the autumn growing season of 2019 at Department of Horticulture and Landscape Gardening Design, College of Agricultural Engineering Sciences, University of Baghdad to investigate the effects of intercropping agriculture and foliar spraying with yeast on growth and yield traits of pea plants. The experiment included two factors, the first was cultivation type (intercropping with spinach and monoculture) for two cultivars of pea (Joff and Anward) which symbolized (J,A) respectively and treatments of intercropping were symbolized (JS, AS). The second factor was foliar spraying with three levels of yeast extract (0,5,10 g/l) symbolized (Y0, Y5, Y10). The results showed the superiority of the treatment Y5 (5 mg.l -1 ) which gave the highest values for all studied characters except branch number. Also the results showed that the highest values were noticed for the treatment JY5 for leaves number 26.87 leaf.plant -1 , pod number 24.03 pod.plant -1 and plant yield 177.00 g.plant -1 and the treatment AY5 referred to decrease days number until 50% of flowering to 110.10, pod weight 7.57 g.pod -1 , seed number per pod 7.13 seed.pod -1 and percentage of protein 24.80% while treatments of intercropping showed that the growth and yield parameters of pea cultivars when planted alone were higher as compared with their intercropping with spinach. Key words: Pisum sativum, Intercropping system, Yeast, Sustainable agriculture, Legumes. Cite this article Mohammed Mahmood Mohammed and Ridha Mustafa Al-Ubaidy (2020). Influence of Yeast and Intercropping System on Growth and Yield Traits of Pea. International Journal of Agricultural and Statistical Sciences. DocID: https:// connectjournals.com/03899.2020.16.1577 1. Introduction The sowing of more than one crop in the same field is called intercropping where mainly it is practiced for helping countries to decrease the inputs in the agricultural systems and to increase the outputs with different products under the same environment and conditions [Lithourgidis et al. (2011)]. Legumes had the ability to fix the atmospheric nitrogen and transform it from an inorganic to available for plants to uptake through symbiotic bacteria, that help to improve the fertility of soil, therefore, legume plants such as pea will be a good choice to select as main or sub crop in the intercropping system where that will improve the soil and increase the production in the same field [Fustec et al. (2010), Adeniyi (2011), Muhammad (2016), AL- Ubaidy and Mohammed (2018)]. There are many differences recorded among the main and combined crops through using an intercropping systems due to its competition on available resources of nutrients, light and water and nutrients [Tsubo et al. (2001)]. The grow up of world population made the researchers and farmers intended to decrease the inputs of agricultural process through using the organic fertilizers and one of the most important organic fertilizers is yeast extract where both of Al-Amery and Mohammed (2017) referred to that yeast extract (saccharomyces cerviciae) with adding and spraying on snap bean plants under abiotic stress showed an important role to plant alleviation due to its contents of proteins, vitamins and its ability to produce hormones such as (Cytokinins, Int. J. Agricult. Stat. Sci. Vol. 16, Supplement 1, pp. 1577-1580, 2020 www.connectjournals.com/ijass DocID: https://connectjournals.com/03899.2020.16.1577 ISSN : 0973-1903, e-ISSN : 0976-3392 ORIGINAL ARTICLE *Author for correspondence Received September 02, 2020 Revised November 28, 2020 Accepted December 12, 2020