513 Effect of Production Systems on Phenolic Compositions of Strawberry Fruits S. Khanizadeh 1,2 , Li Fan 1,3 , Chengquan Fang 3 , M.T. Charles 1 and Tao Shutian 4 1 Horticulture Research and Development Centre, Agriculture and Agri-Food Canada, 430 Blvd. Gouin, St-Jean-sur-Richelieu, Quebec, J3B 3E6, Canada 2 Eastern Cereals and Oilseeds Research Centre, Agriculture and Agri-Food Canada, K.W. Neatby bldg., 960 Carling Ave., Ottawa, Ontario, K1A 0C6, Canada 3 Institute of Pomology, Chinese Academy of Agricultural Sciences, Xinghai Road, Xingcheng, Liaoning, 125100, China 4 College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China Keywords: genetic, production system, phytochemicals, ORAC Abstract Fruit consumption is associated with a healthy diet and consumers are interested in ingesting natural health compounds displaying antioxidant properties. It is, therefore important to pay particular attention to improve the chemical composition of fruits through different technological approaches. Genetic is the major factor controlling the chemical composition but the phytochemicals concentration in fruits is affected by many pre- and postharvest factors including production system, environmental factors such as microclimate and location. We examined two production systems, plastic mulch (PM) and plastic mulch with row covers (PMRC) versus the commonly used matted-row system (MRS) and evaluated the phenolic compositions and oxygen radical absorbance capacity (ORAC) of ‘Orléans’ strawberry at three different harvest times during growing season. Production systems significantly affect the antioxidant capacity and phenolic content of strawberry. PMRC generally enhanced the phenolic content and total antioxidant capacity compared to MRS and PM, but the effects varied during the harvest season. Therefore, PMRC could be a recommended production system to improve the nutraceutical value of strawberry fruits especially in cooler climates. It seems that the production and growing system has to be taken into account in a breeding program. INTRODUCTION Many factors affect strawberry quality, planting date, temperature, mulch type, fertilizer and production systems (Kivijärvi et al., 2002; Anttonen et al., 2006; Khanizadeh, 1994) Matted row system (MRS) has been used in Eastern Canada due to its lower establishment costs and feasibility (Hancock et al., 1997). In recent decades, plasticulture has been used by growers and researchers to extended the season and especially for day neutral cultivars (Scheel et al., 1982; Himelrick et al., 1993; Moor et al., 2004; Fan et al., 2011). Use of floating row covers and low tunnel plastic have also been used in establishment of strawberry plantation. It has been shown the production systems such as hill plasticulture increases the phytochemicals composition of strawberries (Wang et al., 2002) In spite of extensive use of plastic mulch (PM) and plastic mulch with row covers (PMRC) as replacement for MRS, little information and research has been done on pre and post harvest fruit quality. The aim of this study is to evaluate the effects of PM and PMRC versus the conventional MRS on the yield, fruit weight, SSC, TA, firmness and antioxidant capacity of strawberry fruits at different harvest times during growing season. MATERIALS AND METHODS Field Experiment Design A complete randomized design with 26 plants of ‘Orléans’ was planted under Proc. 7th Intl. Strawberry Symp. Eds.: Yuntao Zhang and J. Maas Acta Hort. 1049, ISHS 2014