Effect of iron oxide and iron chelate nanofertilizers and different sizes of micro-tubers on yield and yield components of potato (Solanum tubersum L.)

In terms of harvested land area, potato ranks fourth in the world after wheat, corn and rice. In addition to providing energy and good quality protein, it is also considered as a source of vitamin C and minerals. Despite the fact that iron is the fourth most abundant element in the earth's crust, only a small amount of iron can be used by plants in well-ventilated soils. Therefore, iron deficiency is one of the factors limiting the growth and development of plants.
 

This experiment was carried out in a factorial trial in the base of a completely randomized design in three replications in a greenhouse conditions of Agricultural Research Institute of Hamedan (Jorqan) during the crop years of 2017-2018 and 2018-2029. The experimental factors include the weight levels of microtuber at three levels of 3-1, 3-5 and 5-10 grams and different iron fertilizers at seven levels, control, iron chelate in the form of soil consumption at the rate of 20 micromolar, nano iron oxide in the form of soil consumption to The amount of 20 micromolar was 1 and 2% foliar spraying of iron chelate and 1 and 2% nano iron oxide foliar spraying. The internal temperature of the greenhouse was provided by adjusting the air conditioning system and central heating in the range of 18 to 20 °C  at night and 26 to 28 degrees during the day. The humidity of the greenhouse was also 60-65%. At the end of the experiment, after processing the crop, the plants were harvested and the yield and yield components were determined. Leaf greenness index in this experiment using SPAD device (Minolta 502 model) using three fully developed terminal leaves from ten plants in the budding stage in the middle part of the leaf on one side of the main vein, at 9:30 to 10:00 in the morning. It was measured in order to minimize daily changes. To measure the percentage of dry matter, 200 grams of tubers were randomly selected from each treatment, then the tubers were chopped and placed in an oven at a temperature of 75 degrees Celsius, and after their weight was fixed, they were weighed again. Then, based on the ratio of fresh and dry weight of the tubers, the percentage of dry matter of the tubers was determined (Hagman and Martenssen, 2009). 

The results showed that the height of the plant, the number of stems per plant, the number of tubers per plant, the weight of tubers, the weight of tubers per plant, the percentage of dry matter and the greenness index increased with the increase in the weight of microtubers, and the most improvement in the morphological and qualitative characteristics of potato in microtubers. 5-10 grams were observed. With the application of iron chelate and nano iron oxide fertilizers, potato yield and yield components increased. The maximum tuber weight in the plant was shown in the treatments of 20 micromolar nano iron oxide and 2% nano iron oxide. The highest tuber weight in the plant in the 1-3 gram microtuber is 405.23 grams related to the consumption of 20 micromolar nano iron oxide, in the 3-5 gram microtuber is 444.61 grams related to the application of 2% iron chelate solution and in the microtuber 5-10 grams in the amount of 556.92, 544.52, 482.6 and 465.82 grams corresponding to the treatments of 20 micromolar nano iron oxide, foliar spraying of 2% nano iron oxide, foliar spraying of 1% nano iron oxide and solution The application was 2% iron chelate 

Microtuber 5-10 grams was able to acquire the best size of microtuber due to having suitable nutrients and accelerating the greening of plants and increasing photosynthesis and providing nutrients. The application of nano iron oxide fertilizer was more effective in improving the quantitative and qualitative yield of potatoes compared to iron chelate.