The effect of foliar feeding of iron, zinc and manganese nanochelates on chlorophyll fluorescence, iron, zinc and manganese concentration in seeds and soybean yield

Dehydration stress disrupts the balance of absorption and transfer of micronutrients from roots to aerial organs and is a serious threat to agricultural products. This experiment was conducted to investigate the effect of iron, zinc and manganese nano chelate spraying on chlorophyll index, chlorophyll fluorescence, concentration of iron, zinc and manganese elements in seeds and their relationship with soybean yield.
The experiment was carried out in the form of a split plot, in the form of a completely randomized block design with three repetitions in two consecutive years. The main factor of the irrigation regime in the main plot includes stopping irrigation at the stage of flowering, podding, seed filling and full irrigation and the secondary factor of spraying with distilled water (control), iron, zinc, manganese, iron + zinc, iron + manganese, zinc + manganese. And iron + zinc + manganese were in sub-plots.
Drought stress significantly reduced grain yield, which was the largest reduction in podding stage (31.4% reduction compared to the control). The lowest and highest amount of chlorophyll fluorescence was obtained due to stress in the stage of podding and full irrigation. Iron and iron + zinc treatments had the highest chlorophyll fluorescence and chlorophyll index, respectively. The control treatment had the highest and the stress treatment had the lowest concentration of iron, zinc and manganese in the seed during the podding stage.
Fertilization of iron, zinc and manganese nanochelates in water deficit conditions is a practical method to reduce chlorophyll fluorescence, increase the content of micronutrients in seeds and seed yield. The combined treatment of iron + zinc was the best treatment.