Investigation of nano-iron and nano-zinc application on some qualitative and quantitative traits of Lallemantia royleana Benth

One of the important needs in agricultural planning in order to achieve high yield and optimal quality, especially in the case of medicinal plants, is the evaluation of different methods of plant nutrition. Also, the use of nanofertilizers in agriculture is one of the most beneficial methods of feeding plants. The use of nanofertilizers leads to increasing the efficiency of nutrient consumption, reducing soil toxicity, minimizing the negative effects of excessive fertilizer consumption, and reducing the frequency of fertilizer application. Therefore, considering the medicinal importance of Lallemantia, a research was conducted to investigate the effect of iron nano-fertilizer and zinc nano-fertilizer on some traits of this medicinal plant. Factorial experiment was conducted in a randomized complete block design with three replications at Shahid University of Tehran. The treatments consisted of nano-iron at four levels (0, 1.5, 3 and 4.5 g.l-1) and nano-zinc at four levels (0, 1.5, 3 and 4.5 g.l-1). The source of iron fertilizer used was 9% iron chelate nanofertilizer and the source of zinc fertilizer used was 12% zinc nanofertilizer, which was used as foliar spraying in the above concentrations. In this study, traits such as plant height, number of nuts per plant, leaf dry weight, chlorophyll a, b and carotenoid, total phenol, total flavonoid and antioxidant activity were evaluated. The results showed that the highest plant height (41.3 cm) was obtained using 4.5 g.l-1 of nano-iron fertilizer. Application of 1.5 g.l-1 nano-iron and 3 g.l-1 nano-zinc increased the number of nuts in plant (593.3) and carotenoids in this plant. The highest leaf dry weight (3.6 g per plant) and chlorophyll b (3.7 mg.g-1 fresh weight) concentration were obtained by using 4.5 g.l-1 nano-iron and 4.5 g.l-1 nano-zinc. The concentration of chlorophyll a was also increased by application of 3 g.l-1 nano-iron and 1.5 g.l-1 nano-zinc. The use of nano-iron improved total phenol production and the antioxidant activity. While the lowest amount of antioxidant activity (94.47%) was observed in the control treatment. Finally, the use of 4.5 g.l-1 nano-iron and 3 g.l-1 nano-zinc increased total flavonoid (81.6 mg.g-1) in this plant. In general, the use of higher levels of iron (4.5 g.l-1) and zinc (3 g.l-1 and 4.5 g.l-1) resulted in the best results in the growth and phytochemical characteristics of Lallemantia compared to not using these fertilizers. Therefore, by using appropriate amounts of iron and zinc nano-fertilizers, in addition to reducing fertilizer consumption and reducing environmental pollution, it is possible to improve the quantitative and qualitative characteristics of Lallemantia medicinal plant.