Abstract
During the last decade, several nanoparticles have been synthesized such as nano-silver, nano-silica, nano-aluminum, nano-zinc oxide, nano-copper, carbon nanotubes, and nano-titanium dioxide. The use of these nanoparticles is rapidly increasing in various areas such as textiles, pharmaceutics, cosmetics, and environmental remediation. In sustainable agriculture and crops improvement, these NPs are being used mainly as nanopesticides, nanofertilizers, and nanosensors, and their application raised a big question about their risk of toxicity to the plants and the environment. Many authors described the use of NPs, their types and the conditions of their use; they further reported their positive and negative effects on growth, germination, and photosynthesis on plants. However, because of the plethora of information available; one gets confused on choosing the most adequate conditions and the most adequate NPs to use to improve crops productivity and avoid toxicity. We thus aimed in this review to report the major current applications of NPs that only had a positive impact on plants growth and productivity. We further review concisely the optimum method of delivery of NPs, their properties, and their concentration limit. Hence, we want this review to serve as a handbook guide for nano-users in plants field.