In addition to applications in medicine, electronic materials, construction, energy, nanotechnology in agriculture is currently a new direction for the agricultural industry with great potential to replace pesticides and chemical fertilizers; at the same time, it is one of the superior options for safe and clean agricultural production.

Nanotechnology helps balance nutrients for plants to grow and develop

According to assessments from specialized sectors, currently, agricultural production is increasingly using chemical fertilizers and pesticides; along with that, the thinking and farming practices of many farmers are still limited, and the arbitrary use of pesticides, chemical fertilizers... poses a potential risk of harm and negative impact on public health and the environment due to the overdose, lack of technical knowledge, using pesticides without complying with the quarantine period. As a result, post-harvest agricultural products do not meet the necessary safety criteria due to remaining impurities that can cause poisoning such as NO3- residue, heavy metals, microorganisms... which causé direct effects to consumer health. Poor quality food, pesticide residues, and excess food preservatives are long-term problems. Inappropriate use of fertilizers and pesticides also indirectly harms the economy, when agricultural products with pesticide residues do not meet the standards for export. Chemical agents in agriculture, when used improperly, will pose a threat to the environment; residual amounts can pollute the soil and water environment, causing an imbalance in the ecosystem.

Faced with the above situation, the agricultural industry has given a lot of solutions to produce and supply agricultural products that are not only safe for consumers' health but also environmentally friendly. Along with strengthening inspection and testing of fertilizer and pesticide quality; promoting propaganda and advising farmers to use fertilizers and pesticides properly; expanding production area according to VietGAP, GlobalGAP standards... In recent years, the agricultural industry has promoted the application of new technology in production, including the application of nanotechnology in production.

In order to help farmers access and expand production areas to apply new technology in preventing pests and diseases, reducing the rate of fruit loss and cracking, while reducing the amount of pesticides of chemical origin, creating high-quality agricultural products, ensuring food safety and hygiene, protecting the health of producers and consumers, protecting the environment... are especially suitable for concentrated fruit production areas produced according to VietGAP standards, from 2021 until now, the Department of Agriculture and Rural Development continues to coordinate with relevant units to organize the construction of a pilot model "Application of nano silver and nano copper products in fungus prevention, limiting early fruit loss and fruit cracking on longan trees. The model is implemented on an area of 30 hectares, at Da Loc longan production cooperative, Dong Vang cooperative (An Thi), Tien Chau longan cooperative (Hung Yen city) with 70 participating households. Along with the amount of supported nano and fertilizer, households are guided on the process of using nano silver and nano copper products.

Through evaluation by the Department of Agriculture and Rural Development, periodic spraying of nano products has been highly effective in preventing some major fungal diseases on longan trees such as downy mildew, fruit rot, virus disease, and black spot disease... The effectiveness of preventing some major pests and diseases on longan trees shows that nano silver and nano copper preparations have the same effect as some chemical drugs used locally for the same number of times of preventative spraying. However, monitoring shows that the effectiveness of nano silver and nano copper is slower in eliminating disease when disease pressure is high. Regarding the rate of fruit setting and preventing premature fruit drop, nano silver products, in addition to preventing and eliminating diseases, also add a number of other trace elements such as (Ca, Boron) that play a role in supplementing and balancing nutrition for plants to grow and develop, especially during the flowering and fruiting stages; helping inflorescences grow strong and healthy, balancing the ratio of male and female flowers, enhancing pollen function and vitality, promoting pollination, developing flower buds, increasing fruit set rate, and preventing early fruit from dropping, limiting the harmful effects of acid rain that damages young flowers and fruits. Therefore, the fruit loss rate (10%) is lower than the farmer's conventional farming model (15 - 20%). Because nano silver and nano copper products have the effect of killing bacteria and fungus on fruit, the fruit skin is bright and thick, reducing the rate of cracking and fruit loss. Besides, the ripening time of the fruit is extended from 3 to 5 days compared to the conventional intensive farming method, thereby reducing the pressure on harvest time. Nano products are safe for producers, do not cause residues, drug resistance, do not affect the environment and beneficial organisms, and suitable for longan production areas according to VietGAP standards.