Strawberry (Fragaria x ananassa Duch.) is one of the mosteconomically valuable vegetable crops in Egypt for local consumption andexportation.
The top strawberry producers in Egypt are Qalyubia, Ismailia,Sharqia and Beheira governorates with a total strawberry area of about (5774.6)hectare and yield of 40 – 47( ton/hectare) (FAO, 2014). Because of theimportance of strawberry for local consumption and export, there is a high needfor yield prediction system month/s before harvest.
This system enables optimalmanagement for strawberry production and exportation. Studies comparing conventionaland organic production technique andfruits quality are often difficult to proceed, involving a large number offactors, leading with non-decisive results (Vallverdú-Queralt;Lamuela-Raventós, 2015). Organic farming system, which primary ,excludes the useof synthetic pesticides and fertilizers,is becoming more and more popularworldwide (Brandt and Molgaard, 2001). In the organic production systemPlant vegetative growth, measured as leaf number, leaf area and vegetativebiomass, was less than in the conventional system (Palomaki et al., 2002).Strawberry plants whichgrown with synthetic fertilizer had more total dry weight than strawberryplants that grown with composted poultry litter or untreated control.
Organicgrowers employ cultural practices that support soil health for certification,to increase crop quality and yields, and to improve environmentalsustainability. Organic manure plays a direct role in plant growth as a sourceof all necessary macro and micronutrients in available forms duringmineralization and improves physical and chemical properties of soils(Chaterjee et al., 2005).
Abo Sedera et al. (2010) noticedthat supplying the plants with mineral fertilizers at 125% of the recommendeddose and spraying the plants with amino acids or humic acid at the high levelof them resulted in the highest TSS, vitamin C, reducing and total sugars aswell as anthocyanin concentration except total acidity which was the highest infruits produced from the control treatment. Shehata et al.
(2011)studied the effect of soil addition of compost and foliar fertilizer with Humicand/or amino acids on growth and yield of strawberry cv. Festival. Despite the difficulty of obtaining conclusive results instudies associating production systems, most research compares only singleproperties (Organic vs. Conventional). The aim of this study was to comparestrawberries quality of commercial farm pairs, having organic system farm andconventional systems farm composing each pair, previously selected in one ofthe most important producing regions of Egypt.
Different colored mulcheshave multiple effects on the crops being grown. The optical properties ofvarious colored mulches can influence soil and air temperatures around the cropas well as impact weed growth under the mulch. The use of plastic mulch inagriculture has increased dramatically in the last decades throughout theworld. This increase is due to benefits of mulchingsuch as an increase in soil temperature, reduced weed pressure, moistureconservation, reduction of certain insect pests, higher crop yields, and moreefficient use of soil nutrients (Kyrikou and Briassoulis, 2007; Kasirajan andNgouajio, 2012).Polyethylene mulch color is important in plant response, butalso important are the time of year and the climate in which the mulch is used,as mulch effect on plants will be positive or negative depending onenvironmental conditions. The light color that is perceived by the plantcan possibly influence the development of the plants including itsphysiological characteristics. Fatemi et al.
, (2013) reported that thechlorophyll content of Cucurbita pepo was increased when grown with coloredpolyethylene mulch. Plastic mulch and fertilization are two vital factors forthe growth and productivity of strawberry (Abo Sedera et al., 2010a and b).Positive significant effects of organic and synthetic mulches on vegetativegrowth, flowering traits and yield and its components of strawberry plants havebeen reported by several investigators (Hasanein et al 2011; Abou Elyazied andMady, 2012; Muhammad Haroon et al 2014).
Remote sensing (RS) for cropmonitoring is a vital requirement for agricultural development locally andglobally. It has been used frequently for the assessment of the parameterscharacterizing the physiological state of the plants (Sims and Gamon, 2002).Data parameters include yield, chlorophyll content and dry biomass. RStechniques include different tools that are based on the spectralcharacteristics of plants (Zhang et al., 2010; Carter and Knapp, 2001). Changesin the reflection spectra of the crops during the growing season are based onplant pigments and chlorophyll content (Jorgensen et al.
, 2006; Maire et al.,2004). Vegetation indices (Vis) were used to determine spectral reflectancecharacteristics in different spectral regions specifically, red, near infraredand green (Gitelson et al., 2005). They are used to estimate the chlorophyllcontent (Chapelle et al., 1992; Gitelson and Merzlyak, 1997; Gitelson, 2004).Among different (Vis) normalized difference vegetation index (NDVI) is the mostcommon ones (Cabrera-Bosquetet al.
, 2011; Gajjar et al., 2005). The objectiveof this study was to determine the effect of organic and conventionalstrawberry growing systems under different treatments of fertilization, somecolors of plastic mulch such as clear, black, and silver and their interactionson the vegetative growth, chemical content, fruit yield and chemical quality ofstrawberry cv. Sweet Charlie and their effect of these treatments on spectralreflectance characteristics.
Identification of the spectral reflectance patternunder different treatments (different colors of plastic mulches and differentfertilization treatments) was carried out and different (VIs – yield) modelswere generated. It is essential for the proposed method to be applicable underlocal agricultural conditions that might be different from a country to anotherand sometimes are different even within the same country.