**2.2 Nanoinsicticidal potential**

Copper oxide nanoparticles (CuONPs) are synthesized through different methods [22] such as precipitation [23] and chemical reduction [24]. Many plant aqueous extracts have been reported such as *Citrus limon* juice [25] and carob leaves [26]. Applications led many researchers to develop different ways to synthesis ZnONPs such as chemical route [27], precipitation method [28], hydrolyzed in polar organic solvents [29] and microwave synthesis [30]. Different plant extracts have been reported in the open literature for green synthesis of ZnONPs such as *Olea europaea*, *Solanum nigrum* leaves [31] and *Azadirachta indica* [20]. Different methods for synthesis MgOHNPs and MgONPs have been reported such as hydrothermal route, water-in-oil microemulsion and microwave reaction [32]. MgOH was synthesized by green methods using nontoxic and eco-friendly such as *Neem* leaves extract, *Citrus limon* leaves extract, *acacia* gum, *Brassica oleracea* and *Punica granatum* peels [3, 22]. In agriculture sector, there are several uses available like nanotech based pesticides and fertilizers with effective impact on plant growth and molecular farming with the help of nanovectors which is hoping to take the place of viral vectors [33].

#### **2.3 Antimicrobial activity**

Several nanomaterials are used as antimicrobial agents in food packing in which silver nanoparticles are in great interest. This is because of its extended use. Some

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*Applications of Nanotechnology in Agriculture DOI: http://dx.doi.org/10.5772/intechopen.88390*

packaging material [39].

other nanoparticles currently used are titanium dioxide (TiO2), zinc oxide (ZnO), silicon oxide (SiO2), magnesium oxide (MgO), gold and silver. All of them have specific characteristics and functions, for example, zinc nanocrystal shows antimicrobial and antifungal activity [34]. Silver was a disinfectant and sterilizing agent used by NASA and Russian Space station for water [35], silver zeolite and silver. Gold has high temperature stability and low volatility and good antifungal and antimicrobial effects against 150 different bacteria [36]. FDA in 2009 approves the direct use of silver as disinfectant in commercial water, since with effective result against microorganisms. The antimicrobial effect of these are *E. coli, L. monocytogenes* and *Staphylococcus aureus* [37], and nanosilver particles coated with cellulose acetate phthalate also provided similar results [37]. Some nanoparticles have shown their antifungal activity. These fungi include *Candida albicans*, *Aspergillus niger* [38] and yeast [39]. AgNPs are also found to be effective against methicillin resistant *Staphylococcus aureus* [39]. Other nanoparticles besides silver are also found to have antimicrobial characteristics like titanium oxide (TiO2). Its antimicrobial activity in UV light was obvious. Zinc oxide is reported to have antimicrobial activity in

Zinc oxide nanoparticles synthesized using *Punica granatum* peel aqueous extract has shown effectiveness as antibacterial agents against standard strains of Gram-positive *Staphylococcus aureus* and Gram-negative *Escherichia coli* [1, 40].

The use of nanosilver has been studied recently against phytopathogen *Colletotrichum gloeosporioides* [41]. Other nanoparticles (Fe, Cu, Si, Al, Zn, ZnO, TiO2, CeO2, Al2O3 and carbon nanotubes) have been reported to have some adverse effects on plant growth apart from the antimicrobial properties [42]. Sometimes, nanoparticles also have an effect on the growth of useful soil bacteria, such as *Pseudomonas putida KT2440* [43]. Various research groups focused their interest on the usage of eco-friendly pesticides. Similar to chemical pesticides, nanoparticlebased pesticides and herbicides are being explored for the application of the antimicrobial agents to protect crops from various diseases. Extensive studies on nanoparticle-based systems may eliminate the intensive use of pesticides in the agricultural sector [44]. The antifungal properties of nanoparticles can help to formulate nanoparticle-based pesticides [41]. Among the different inorganic nanoparticle-based antimicrobial agents, silver has been extensively studied by many researchers because of its several advantages over other nanoparticles such as

Both the concentrations of nickel nanoparticles (50 and 100 ppm) inhibited the fungal mycelial growth on solid media, and the inhibitions were significant (p ≤ 0.05) over control (**Figure 1**). Nickel nanoparticles at 100 ppm concentration inhibited the mycelial growth of *F*. *oxysporum* f. sp. *lactucae* and *F*. *oxysporum* f. sp.

The inhibitory effects of nickel nanoparticles were also assessed in liquid medium, and the results were similar with solid media. In the liquid media, the fresh mycelial weight of the tested fungal pathogens decreased significantly and more than 50% reduction was recorded with the use of nickel nanoparticles at the concentration of 100 ppm. The results revealed that mycelial growth of tested pathogens was inhibited in a concentration dependent manner. These results

**2.4 Nanotechnology application as nanofungicides**

copper, zinc, gold, ZnO, Al2O3 and TiO2.

*2.4.1 Effect of nickel nanoparticles on fungal mycelial growth*

*lycopersici* by 60.23 and 59.77%, respectively, over control.

#### *Applications of Nanotechnology in Agriculture DOI: http://dx.doi.org/10.5772/intechopen.88390*

*Applications of Nanobiotechnology*

and pyrethroids [20].

**2.2 Nanoinsicticidal potential**

take the place of viral vectors [33].

**2.3 Antimicrobial activity**

stable formation of nanoparticles has been reported.

sweet pepper. The results showed that there was no any metal accumulation in any of the plant fruits. Foliar spray by synthesized of MgOH nanoparticles for green pepper leaves revealed that the foliar spraying leaves with 100–800 ppm metal nanoparticles are very beneficial to plant growth and produced healthy plants with greener leaves and high fruit quality compared to the control. Researchers made significant efforts toward the synthesis of nanoparticles by various means, including physical, chemical and biological methods [1]. Green methods for synthesizing nanoparticles with plant extracts are advantageous as it is simple, convenient, environment friendly and require less reaction time. Nanomaterials prepared by eco-friendly and green methods may increase agriculture potential for improving the fertilization process, plant growth and pesticides. In addition, this technology minimizes the amount of harmful chemicals that pollutes the environment [4]. The green peach aphid is considered as a key pest on peach and globally important pest of a broad range of arable and horticultural crops, including Jordan. The pest is categorized as of the most important agricultural pest in the world. This devastated pest combats organophosphorus and carbamate insecticides by overproducing insecticide-degrading carboxyl esterases. Moreover, control of such a pest is becoming increasingly difficult, because the overproduction of resistance for aphid individuals when using chemical insecticides such as carbamates, organophosphates

Nanomaterials such as copper oxide (CuONPs), zinc oxide (ZnONPs), magnesium hydroxide (MgOHNPs) and magnesium oxide (MgONPs) were synthesized by different physical and chemical methods [21]. With the growing needs to minimize the use of environmental-risk substances, such as insecticides, the biosynthesis of nanoparticles as an emerging highlight of the intersection of nanotechnology and biotechnology has received increasing attention. The rate of reduction of metal ions using plants has been found to be much faster as compared to microorganisms and

Copper oxide nanoparticles (CuONPs) are synthesized through different methods [22] such as precipitation [23] and chemical reduction [24]. Many plant aqueous extracts have been reported such as *Citrus limon* juice [25] and carob leaves [26]. Applications led many researchers to develop different ways to synthesis ZnONPs such as chemical route [27], precipitation method [28], hydrolyzed in polar organic solvents [29] and microwave synthesis [30]. Different plant extracts have been reported in the open literature for green synthesis of ZnONPs such as *Olea europaea*, *Solanum nigrum* leaves [31] and *Azadirachta indica* [20]. Different methods for synthesis MgOHNPs and MgONPs have been reported such as hydrothermal route, water-in-oil microemulsion and microwave reaction [32]. MgOH was synthesized by green methods using nontoxic and eco-friendly such as *Neem* leaves extract, *Citrus limon* leaves extract, *acacia* gum, *Brassica oleracea* and *Punica granatum* peels [3, 22]. In agriculture sector, there are several uses available like nanotech based pesticides and fertilizers with effective impact on plant growth and molecular farming with the help of nanovectors which is hoping to

Several nanomaterials are used as antimicrobial agents in food packing in which silver nanoparticles are in great interest. This is because of its extended use. Some

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other nanoparticles currently used are titanium dioxide (TiO2), zinc oxide (ZnO), silicon oxide (SiO2), magnesium oxide (MgO), gold and silver. All of them have specific characteristics and functions, for example, zinc nanocrystal shows antimicrobial and antifungal activity [34]. Silver was a disinfectant and sterilizing agent used by NASA and Russian Space station for water [35], silver zeolite and silver. Gold has high temperature stability and low volatility and good antifungal and antimicrobial effects against 150 different bacteria [36]. FDA in 2009 approves the direct use of silver as disinfectant in commercial water, since with effective result against microorganisms. The antimicrobial effect of these are *E. coli, L. monocytogenes* and *Staphylococcus aureus* [37], and nanosilver particles coated with cellulose acetate phthalate also provided similar results [37]. Some nanoparticles have shown their antifungal activity. These fungi include *Candida albicans*, *Aspergillus niger* [38] and yeast [39]. AgNPs are also found to be effective against methicillin resistant *Staphylococcus aureus* [39]. Other nanoparticles besides silver are also found to have antimicrobial characteristics like titanium oxide (TiO2). Its antimicrobial activity in UV light was obvious. Zinc oxide is reported to have antimicrobial activity in packaging material [39].

Zinc oxide nanoparticles synthesized using *Punica granatum* peel aqueous extract has shown effectiveness as antibacterial agents against standard strains of Gram-positive *Staphylococcus aureus* and Gram-negative *Escherichia coli* [1, 40].
