As continuously efforts to maximize utilization from nan-science in agriculture sector, one–year old fig (Sultani cv.) seedlings (grown in shade house of Pomology Dept, National Research Centre, Giza, Egypt) were been subjected during two growth seasons (2016-2017) to current study that test hypothesis concern with full replacement conventional mineral fertilizer with Nano-fertilizer. Nano fertilizer applied at different rates (100, 200, 300 and 400 ppm) comparing with conventional fertilizer at (500 ppm). Fig seedling were sprayed (twice times per week) with Nano-fertilizers and conventional fertilizer as foliar application. At the end f each growth season, leaves were collected to record some vegetative parameters (Leaf fresh and dry weight and leaf area) then these samples of leaves were dried and digested to determine nutrient statues under tested treatments. Moreover, activity of two enzymes (Peroxidase (POX) and polyphenol oxidase (PPO) was evaluated. Obtained results reveals that leaf fresh weight, leaf dry weight and leaf area has increased when applying Nano-fertilizes at high levels comparing with conventional fertilizer. In respect of nutrient status, although chlorophyll content didn’t increase when Nano-fertilizer applied, there was no significant difference between Nano-fertilizer at (400 ppm) and control (500 ppm conventional fertilizer). Besides, there were no markedly differences in nitrogen and phosphorus content among control and other treatments. In regard to potassium, calcium and magnesium, low doses of Nano-fertilizer produced the lowest values of the nutrients content. However, high doses of Nano-fertilizer (400 and 300 ppm) didn’t differ significantly than control. Also, higher activities of POX and PPO enzymes at resulted of applying Nano-fertilizer at all comparing with conventional fertilizers which recorded the lowest activities of these enzymes with (two bands). Current results were indicated that with applying Nano-fertilizer there is an ability to reduce doses of mineral fertilizer without negative impact on growth or chlorophyll and nutrient content . Despite of this, an increment in enzyme activities was recorded.
The common fig (Ficus carica) is a species of flowering plant in the genus Ficus, from the family Moraceae, known as the common fig. The Common fig tree has been cultivated since ancient times and grows wild in dry and sunny areas, with deep and fresh soil; also in rocky areas, from sea level to 1,700 meters. It prefers light and medium soils, requires well-drained soil, and can grow in nutritionally poor soil. The plant can tolerate seasonal drought, and the Middle Eastern and Mediterranean climate is especially suitable for the plant (http://en.wikipedia.org/wiki/Common_fig).
Lianju et al., (2003) mentioned that fig fruits as well as leaves contain a plenty of amino acids and inorganic elements, showing their high nutritional value. Fig also contains several medical components such as flavone, rutin and quercetin, which can be used in cardiovascular disease medicine production. Additionally, the extracts from fig had significant inhibition in growth of several cancer cells in mouse bodies, the inhibition to spleen cancer high up to 64.06%, EAC 53.85%, Lewis lung cancer 48.85%, HAC liver cancer 44.44% and S180 cancer 41.82%. The nontoxic extracts of fig could increase the immunity of the bodies and postponed the life span after the mice were irradiated by 60Co. These results implied that fig might have an important role in human body health.
Egypt occupies the second rank after Turkey in fig production with (165483 MT) in the world (FAO State 2011: http://faostat.fao.org/site/339/default.aspx). Although this advanced rank among the world countries, Egypt imports a huge amount of dried fig each year especially in Ramadan month. Besides it is known that, Egyptian environmental conditions (climate, soil and water quality) are suitable to cultivate different genotypes of fig on large scale which can lead to narrow gap between fig production and consumption and reduce exhausting foreign currency.
Under new reclaimed land conditions, soil fertility is considered the most critical factor in addition to irrigation to thrive cultivation and deficiency in one of them has impact on growth, productivity and quality.
Nowadays, the Nanotechnology has many applications in all stages of production, processing, storing, packaging and transport of agricultural products (Mousavi and Rezai 2011, Ditta 2012). Utilizing the Nanotechnology in agriculture and forestry will likely have environmental benefits (Froggett, 2009). Utilizing Nano-materials in agricultural sector are being developed in order to offer the opportunity for more efficiently and safely administer pesticides, herbicides, and fertilizers by controlling precisely when and where they are released (Kuzma and VerHage, 2006). The Nanotechnology as a new powerful technology has the ability to create massive changes in food and agricultural systems. Fertilizer derived from the Nano-technology has started to attract attention in agriculture. Nanotechnology can have a profound impact on energy, the economy and environment, by improving fertilizer products (DeRosa et al. 2010).
Nano-fertilizer can be encapsulated inside Nano-materials, coated with a thin protective polymer film, or delivered as particles or emulsions of nanoscale dimensions DeRosa et al. 2010. Naderi and Danesh-Shahraki, (2013)showed that, the use of Nano-fertilizers causes an increase in nutrient efficiency , reduce leaching pollutants into soil and ground water, minimizes the potential negative effects associated with over dosage and reduce the frequency of the application. Hence, Nano-fertilizer has a high potential for achieving sustainable agriculture especially in developing countries. In description to a strategy for sustained release of fertilizer (i.e. nitrogen) into the soil, Kottegoda et al. (2011) reported, nano-fertilizer showed an initial burst and a subsequent slow-release even on day 60 compared to the commercial fertilizer, which released heavily early followed by the release of low and non-uniform quantities until around day 30.
The main benefits of applying the Nano- technology are:
1- Improving efficiency of fertilizing program
2- Reducing fertilizer amount (reducing cost).
3- Eliminate environment pollution (especially soil and ground water sources) through reducing amount of added fertilizers
The main goal of current study is determining efficiency of Nano-fertilizer to provide fig seedlings with its nutrient requirements as well as impact of Nano-fertilizer on in vivo enzymes activity.
Results and discussion
Data in tables (1 & 2) show that, applying Nano-fertilizers has a positive impact on most of measured vegetative and chemical parameters of fig seedlings (Sultani).
In regard to the vegetative growth, whereas the highest value of leaf area was recorded with Nano-fertilizer at (300ppm), meanwhile control treatment (500 ppm of conventional fertilizer) recorded the lowest value of this parameter. Also, the same trend was noticed for leaf dry weight, the highest value of dry weight was recorded with both (300 and 400 ppm of Nano-fertilizer) and the lowest value for leaf dry weight was recorded with conventional fertilizers at (500 ppm). Besides, the other treatments (100 and 200 ppm of Nano-fertilizer) came in the second rank. For leaf fresh weight, Nano-fertilizer at (400ppm) resulted in the highest value of leaf fresh weight without significantly differences with the other levels of Nano-fertilizer (100, 200 and 300 ppm). However, conventional fertilizer produced the lowest value of leaf fresh weight.
In respect to leaf nutrients content, data indicated that most nutrients status improved with applying Nano-fertilizers and other nutrients (nitrogen and phosphorus content) recoded no markedly differences with control.
In respect for chlorophyll, it could be noticed that, Nano-fertilizer at (400ppm) didn’t differ significantly than control treatment (conventional fertilizer at 500ppm), meanwhile the other doses of Nano-fertilizer produced lower values of chlorophyll content in leaves comparison with control treatment. The same trend was repeated with potassium whereas Nano-fertilizer at (400 ppm) didn’t differ than convenient fertilizer (500ppm) and other Nano-fertilizer doses (100, 200 and 300ppm) produced lower values of potassium content in comparison with conventional fertilizer (500ppm) without markedly differences among these doses. For calcium and magnesium, the trend was differed whereas the differences among Nano-fertilizer doses were not significant, However, both of Nano-fertilizer at (200, 300 and 400ppm) recorded weak differences comparing with conventional fertilize (500ppm). Also, the same trend was noticed for magnesium, whereas Nano-fertilizer at (300 and 400ppm) recoded the poor differences comparing with conventional fertilizer (500ppm).
Peroxidase (POX) and polyphenol oxidase (PPO) profiles enzymes:
POX analysis scored three isoenzymes with Rf value ranging of (0.475 to 0.765). However, PPO profiles displayed four isoforms with Rf value ranging of 0.421 to 0.828 (Table 3). The highest POX and PPO activities were found in cultivar Sultani (treated with Nano-fertilizer at 300ppm) (four isoforms). However, the lowest enzyme activity was recorded in control cultivar S (500) (two isoenzymes).
Finally, applying Nano-fertilizers resulted in either an improvement in most measured characters or at least the same values of these characters in comparison to the case of control treatment. However, despite the fact that there were no significant differences between Nano-fertilizers treatments and the control one in some measuredparameters, a 20% reduction of the applied fertilizers doses has been achieved in the case of Nano-fertilizers which will have many positive impacts on the environment protection, human health and economy.
In general, aforementioned data were not a surprise, especially, several studies were carried out on Nano-fertilizers and its impact on the plant’s growth parameters (Mahajan et al. 2011; Taha et al., 2016; Taran et al., 2014; Pradhan et al. 2013; Ghafariyan et al. 2013, Liala et al., 2018a and b). Their results indicated a promising future of the Nano-technology for seed germination, growth rate and nutrients content in treated plants in comparison with conventional forms.
Results of many studies also indicated promoting effects of spraying Nano-fertilizers as reported by several authors who worked on Nano-fertilizers (Millan et al., 2008; Kottegoda et al,. 2011), they worked on Urea-coated zeolite chips and urea-modified hydroxyapatite nanoparticles as a source of Nitrogen. They referred these stimulation aspects to the use of Nano-fertilizers. This can be contributed to the increased ratio of surface to volume of the Nano-fertilizes which reinforces the efficiency and their role in metabolic processes (Chhipa, 2017). Also, several researchers compared between fertilizers in both form (conventional form and Nano-form) and stated that Nano-fertilizers have positive effects on promoting growth of plants. Liu et al., (2004) mentioned that Ca in Nano-form as an alternative to the conventional Ca causes 15% enhancement in biomass of Arachishypogeae. Moreover, they worked in 2014 on Ca and P hydroxyapatite in Nanoparticles’ form, their results showed 20 and 33% enhancement in Glycine max seed’s yield in comparison with conventional phosphorus (Liu and Lal, 2014). Finally, Delfaniet al. (2014) developed Mg as Nanoparticles and used it as an alternative of normal Mg. He recorded 7% increase in Vignaunguiculata seed weight.
Nano-fertilizer has a promising and fruitful future. Utilizing Nano-fertilizer can be good effective tool as remediating eco-balance, reducing soil degradation, and environmental pollution. Besides, reducing amount of mineral fertilizer will have a positive impact on soil-microorganisms activity Also, using Nano-fertilizers has another demission related to economic impact through reduces the amount and consequences cost of fertilizer and pesticide expense. Finally, Nano-fertilizer need more efforts to investigate its impact on yielding, fruit quality, food safety and environmental protection.