The Designation of Micronutrients Foliar Application Inuence on Rice (Oryza Sativa L. cv. Shiroodi) Yield and Yield Components

Pursuant to micronutrients critical role in the plant nutrition and metabolism, accurate determination of the best term of foliar application as a practical plant nutritional pathway has substantial circumstances in the novel agricultural approaches. In order to properly assess micronutrients liquid fertilizer with commercial name of Rooyesh no and mentioned ingredients (Fe EDTA 0.1%, Zn EDTA 0.05%, B 0.02%, Cu EDTA 0.05%, and Mn EDTA 0.05%) inuence on Shiroodi cultivar yield, this investigation implemented in the Iran Rice Research Institution (Amol, Mazandaran) during two consecutive years (2017-2018). This extensive research conducted in the form of RCBD with eight treatments and three independent replications. The treatments were T0 (control), T1 (one foliar application) to T7 (seven foliar applications). The frequent intervals of foliar applications were seven days and the rst foliar application done nine days after transplantation. The results revealed that the micronutrients application effect was signicant about plant dry weight, grain yield, 1,000 grains yield and harvest index. Also, the interaction of the year and foliar application was signicant about seed Zn content, chlorophyll b and 1,000 grains yield. According to statistical data, it can be concluded that T4 with 4257 kg/ha grain yield compare to control yield 3499.1 kg/ha that indicated 20 percentage approximate enhancement about foliar application treatments, four leaf spraying with 2 liters/ 1000 liters of water dosage of micronutrients could affect grain yield and yield components of rice (shiroodi cv.) signicantly through increasing the number of tillers/plant, improvement of panicle length and increasing the number of grains/ panicle. The micronutrients supply through leaves is more effective procedure in the eld of rice nutrition compare to soil application method due to higher absorption velocity. appropriate amount, composition and timing of application of these elements in relation to the yield and yield components of Shiroodi rice cultivar and other cultivars. The questions raised can be posed in this way, will the agronomic characteristics of rice in the foliar spraying treatments be signicantly different from other treatments and control? And which treatments will be functionally and infrastructurally cost-effective for farmers? 35 days after transplanting to the main land). The area of each plot with a length of 4 meters and a width of 3 meters was equal to 12 square meters. The rst stage of foliar treatment was performed nine days after transplanting the seedlings to the main land. Foliar application of the second treatment was performed 16 days after transplanting. In the same way, foliar spraying of subsequent treatments was performed at a distance of seven days from the previous treatment. At the time of sampling, the middle part of each plot, after removing two plants from the margin, was evaluated for sampling and statistical study of traits. The ten shrubs sampled from each plot for further examinations. The seed Zn content, chlorophyll a, chlorophyll b, carotenoids, plant height, plant dry weight, panicle length, leaf greenness, 1000-grain weight, grain yield and harvest index were the studied traits. The sampling was done randomly and based on the studied trait, in the middle and at the end of each rice growing season and the obtained data were recorded. The total chlorophyll content was measured with a chlorophyll meter (SPAD). To determine the amount of chlorophyll a, b and carotenoids, the pigments were extracted using methanol and the amount of light absorbed was measured using a spectrophotometer (Telavat et al. 2015). To do this, using a puncture, three parts were selected from the middle part of the leaf for extraction, and then the selected parts were placed in 20% methanol solution and kept in the refrigerator for 24 hours. After this time, the pigments were separated by an extraction pump and placed inside a spectrophotometer to determine the percentages of chlorophyll a, chlorophyll b, and carotenoids based on their wavelength. The zinc content in the rice grain was measured by atomic absorption spectrometry and dry ash method (Emam and Pirasteh-Anosheh, 2015). To measure the amount of zinc in the grain, the sample was rst placed in an oven at 550 ° C for 8 hours. The resulting ash was then removed and rst a few drops of distilled water and then 3 ml of hydrochloric acid (2 M)


Introduction
Due to growing trend of population ampli cation and increasing requirement of the strategic foots supply like rice, lack of appropriate product yield and decreasing the rice cultivation area due to environmental restrictions and humans activities, obtaining the novel agricultural approaches is the determinative factor to access food security. Approximately 50% of the daily calories of the human body are provided by consuming cereals such as rice, wheat and corn.
Although rice is in the second place in terms of importance, but in the Asian countries it is crucial both from a nutritional and economic point of view (Zibaee 2013). Since rice provides 21% of the required energy as well as 15% of human protein needs, the level of production and the quality of produced rice is very important (Gnanamanickam ss 2009). The producing higher quality crops requires the adoption of new plant nutrition methods such as foliar spraying, proper pest and disease management, and the use of high-yield cultivars adapted to climatic and farm characteristics that produce marketable products for consumers and pro table for farmers. Increasing the level of e ciency will not be possible without accurate knowledge of the morphological and physiological characteristics of the rice and the plant nutritional needs in the different vegetative and reproductive periods. The research has shown that the simultaneous use of macro and micronutrients in different growth stages, according to farm conditions such as climate, soil characteristics and cultivar features, through affecting the plant metabolism and increasing the intracellular reactions in various dimensions such as Increasing vegetative growth, increment of the number and length of panicles, as well as increasing plant resistance to pests and diseases and, environmental stresses have been effective in eld of the rice production enhancement. In this relation Hosseinzade and his colleagues (2012) reported that by evaluating the effect of the concentration and consumption time of micronutrients on yield and yield components of rice grain elements of Deylamani and Shiroodi cultivars, the results revealed that grain yield per hectare, harvest index, number of tillers and 1000-grain weight has shown signi cant different and also the best foliar spraying time And it was clustering. Furthermore, Liew and his colleagues (2012) proved that foliar application of copper and boron elements had a signi cant effect on reducing the contamination of rice plant diseases and consequently on increasing its yield. According to research, micronutrients are slightly needed by the plant, but their de ciency reduces the growth and yield of rice crops. On the other hand, Zayed and his colleagues (2011) expressed that the application of individual and combined micronutrients had a signi cant effect on the growth rate of rice in both years of the experiment. Also, Furoharnia and colleagues (2010) reported that the foliar application of different levels of micro-mineral fertilizer has been signi cant on rice yield and the most economical stage of foliar application is the initial pedicle phase. The Shiroodi cultivar was introduced in 2008, which is obtained from the intersection of Caspian and Tarom Deylamani cultivars. This cultivar, with its high yield and good cooking quality, also has a very good marketability in terms of grain shape (IRRI 2015). The crops often absorb and use less than half of the fertilizer used, and the rest may be added to groundwater and rivers, causing biological pollution. Also, by binding to soil particles, it will cause salinity and pollution of agricultural soils and air pollution (Nolan and Stoner 2000). Therefore, the foliar application method, while providing the nutrients needed by the plant in a timely manner, also plays a signi cant role in reducing biological pollution. Micronutrients include boron, chlorine, copper, iron, manganese, molybdenum, nickel and zinc. In this study, simultaneous and foliar application of boron, copper, iron, manganese and zinc considered to investigate their in uence on morphological, physiological and yield characteristics of rice. The concentration of trace elements is less than 0.025% or 250 ppm in the dry matter of the plant. The plant nutrients are not able to be absorbed by the plant without ionic charge, except boron, which is absorbed by plants without ionic charge (boric acid). The rest of them have ionic charge so that they can be absorbed by the plant and participate in the plant metabolism (Jones and Olson-Rutz 2016).With considering the results of other investigations that conducted in the eld of present research and perceiving the unfavorable and unexpected yield of rice elds, especially in the northern provinces of the country like Mazandaran, proper nutrition of rice farms seems to be a determining factor in improving yield on a large scale. Also, the vital role of micronutrients in plant nutrition, such as increasing the productivity of macronutrients and activating critical enzymes that directly affect crop performance, the importance of this research and other complementary researches is more clear in order to determine the appropriate amount, composition and timing of application of these elements in relation to the yield and yield components of Shiroodi rice cultivar and other cultivars. The questions raised can be posed in this way, will the agronomic characteristics of rice in the foliar spraying treatments be signi cantly different from other treatments and control? And which treatments will be functionally and infrastructurally cost-effective for farmers? depth range of zero to thirty centimeters of the eld and after determining the type of soil texture, the physical and chemical properties of the soil sample were measured ( Table 1). The fertilizer recommendation was based on the results of soil tests about the studied cultivar. In order to determine the effect of foliar application of micronutrients on yield and yield components of rice in Shiroodi cultivar, the experiment was conducted in two consecutive cropping years (2017 and 18). This investigation was implemented in the form of a randomized complete block design (RCBD) with eight treatments and three replications.
The number of foliar application of micronutrients (Fe EDTA 0.1%, Zn EDTA 0.05%, B 0.02%, Cu EDTA 0.05%, and Mn EDTA 0.05%) considered as experimental treatment with recommended dosage 2liters/ 1,000 liters of water ( Table 2). The control was determined without spraying until T7 treatment with seven sprays. The Shiroodi cultivar was studied in this research and the operation of farm preparation and seeding in the seedling site began in the second half of April 2017. The required basic fertilizers were applied to the soil in the amount of 250, 150 and 200 kg of NPK, respectively, according to the results of the local soil test and the recommendation of the soil and water research department of the Rice Research Institute. Transplanting the seedlings to the main ground when they reached a height of 20 cm was done manually. In the second year of the experiment, ie the second half of April 2018, a similar operation was performed. The recommended amount of fertilizers for Shiroodi cultivar in the farm soil, was calculated based on the studied plots and given to the land, was as follows: Urea (250 kg / ha, which is 40% of the fertilizer applied before transplanting, 30% three weeks after transplanting, and 30% remaining 35 days after transplanting of seedlings to the main land), triple superphosphate (150 kg / ha, that all of this amount was given to the main land before transplanting) and potassium sulfate (200 kg / ha, half of which was given to the main land before transplanting and the remaining fertilizer was given 35 days after transplanting to the main land). The area of each plot with a length of 4 meters and a width of 3 meters was equal to 12 square meters. The rst stage of foliar treatment was performed nine days after transplanting the seedlings to the main land. Foliar application of the second treatment was performed 16 days after transplanting. In the same way, foliar spraying of subsequent treatments was performed at a distance of seven days from the previous treatment. At the time of sampling, the middle part of each plot, after removing two plants from the margin, was evaluated for sampling and statistical study of traits. The ten shrubs sampled from each plot for further examinations. The seed Zn content, chlorophyll a, chlorophyll b, carotenoids, plant height, plant dry weight, panicle length, leaf greenness, 1000-grain weight, grain yield and harvest index were the studied traits. The sampling was done randomly and based on the studied trait, in the middle and at the end of each rice growing season and the obtained data were recorded. The total chlorophyll content was measured with a chlorophyll meter (SPAD). To determine the amount of chlorophyll a, b and carotenoids, the pigments were extracted using methanol and the amount of light absorbed was measured using a spectrophotometer (Telavat et al. 2015). To do this, using a puncture, three parts were selected from the middle part of the leaf for extraction, and then the selected parts were placed in 20% methanol solution and kept in the refrigerator for 24 hours. After this time, the pigments were separated by an extraction pump and placed inside a spectrophotometer to determine the percentages of chlorophyll a, chlorophyll b, and carotenoids based on their wavelength. The zinc content in the rice grain was measured by atomic absorption spectrometry and dry ash method (Emam and Pirasteh-Anosheh, 2015). To measure the amount of zinc in the grain, the sample was rst placed in an oven at 550 ° C for 8 hours. The resulting ash was then removed and rst a few drops of distilled water and then 3 ml of hydrochloric acid (2 M) were added to it and placed at 70 ° C for 60 minutes. Then, the sample was taken to a volume of 50 cc in a balloon with distilled water and read at a wavelength of 9.213 with an atomic absorption apparatus for the zinc element. The leaf color diagram (LCC) was used to determine the leaf greenness. Based on the instructions for using the leaf color diagram, leaf color was measured 13 days after transplanting and was done in two stages until the beginning of clustering. The leaf color diagram was read from 2 to 4 pm. To read leaf color, at least 10 disease-free and pest-free leaves in the same plant population were randomly selected from the central part of the plots. To read the leaf color, the longest leaf of each tiller was selected and the middle part of the leaf was placed on the LCC and the leaf color was compared with the color of the strips on the diagram. If the leaf color was between the two parts of the diagram, the average of the two values would be considered. During the harvest period, plant height, cluster length, 1000-seed weight, economic yield, biological yield and harvest index were evaluated. To harvest for evaluation of economic yield, 80 plants were harvested from the central part of the plots and after threshing and weighing, the moisture content of the seeds was measured using a hygrometer. The weight of 1000 seeds was obtained by counting ten hundred samples and their weight was obtained based on moisture content of 12%.To calculate the harvest index, ve plants were harvested from each plot and the plants were kept on the farm for one day (24 hours) until their moisture content reached about 13%. After threshing, grain weight and straw were measured and harvest index was calculated as a percentage of economic yield divided by biological yield. At the end of the year, the analysis of the evaluated traits was performed according to the implemented statistical plan and at the end of the second year, composite analysis was performed. Data were analyzed using SAS statistical software and mean data were compared using LSD test. Curves and tables were drawn using Excel and Word software.

Results And Discussion
The results of combined analysis of variance of biennial data showed that the effect of micronutrient foliar application treatment was signi cant at 1% probability level for traits such as seed Zn content, plant dry weight, chlorophyll a and b, carotenoids, leaf greenness, grain yield, 1000-grain weight and harvest index were (Table 4). In this regard, the interaction of foliar application and year for seed Zn content, chlorophyll b, carotenoids and 1000-grain weight was signi cant at 1% probability level. Also, the simple effects of micronutrients foliar application on chlorophyll a, carotenoid content, plant dry weight, seed Zn content, grain yield and 1000-grain weight were signi cant ( Table 4). The statistical results showed that the highest number of tillers per plant T4 (24), the highest plant height T4 (156.8 cm), the highest dry weight of plant T7 (44.4 gr / m2), the highest number of seeds per cluster T3, T4 (149) and the highest cluster lengths T3 (30.8 cm) were obtained when the plants received micronutrients through the leaves. On the other hand, the lowest index of grain yield and plant dry weight during two years of experiment was related to the control (Table 3).

Seed Zn content
The results of combined analysis of variance showed that foliar application of micronutrient fertilizer on the concentration of zinc in rice grain was signi cant at the level of 1% and also the interaction of year and foliar application was signi cant in this regard (Table 4). In this regard, the comparison of the biennial mean showed that the highest concentration (about three times the normal limit) was related to T6 (67.02 mg.kg − 1 ) and the lowest was related to the control (Fig. 1a). It seems that foliar application of zinc-containing micronutrient fertilizer at different vegetative and reproductive stages of rice has signi cantly increased the content of zinc in the grain in foliar application treatments compared to the control. In this regard, Jiang and his colleagues (Jiang et al., 2008) reported that this could be related to the connections between the xylem and phloem vessels in the wheat panicle and the exchange of elements between them. Also Ishimaru and his colleagues (Ishimaru et al., 2005) expressed that in the study of zinc transport within the rice plant tissue, it was reported that this element is stored in the plant after being absorbed through the stomata and transferred to the leaves. This causes the transfer of zinc from decaying leaves at the end of the growth period through the phloem to the seed and thus plays a role in increasing the amount of this element in the seed.

Leaf chlorophyll content
The content of chlorophyll a was signi cantly affected by the use of micronutrients at a probability level of 1% in foliar treatment compared to the control treatment based on statistical results ( Table 4). The highest number of chlorophyll a was related to T4 with 0.56 and four times foliar application and the lowest was related to T2 with 0.29 with mg.g-1fwt unit (Fig. 1b). Considering the signi cance of the results of the mentioned trait, it is possible that the foliar spray of micronutrients that play a crucial role in the synthesis of chlorophylls such as zinc, iron and copper could have a signi cant effect on increasing the chlorophyll content of cell. In a similar study by Server and his colleagues (Sarwar et al., 2013), they reported phenological response of rice to different levels of micronutrients under calcareous soil conditions in all treatments was signi cant, especially in tillering stage except full ooding treatment increased in both years of research. The use of zinc alone or in combination with boron increased the chlorophyll content of rice.
As can be seen in Table 4, the chlorophyll b content was affected by the foliar application of micronutrients, so that the difference between the content of chlorophyll b and the control was signi cant at the level of 1% probability. The interaction effect of year and foliar application was also signi cant for this trait at 1% probability level. The comparison of mean data in two consecutive years showed that the highest number of chlorophyll b was related to T4 with 1.42 and the lowest was related to T6 with 0.88 with mg.g-1fwt unit (Fig. 1c). The simultaneous supply of essential micronutrients affecting the formation of chlorophyll pigments seems to increase the chlorophyll content of rice through foliar application during the tillering and stem formation stages, which increases light absorption and accelerates photosynthetic processes. In a similar study by Zayed and his colleagues (Zayed et al., 2011) expressed chlorophyll content (SPAD index) was signi cantly improved as a result of receiving micronutrients compared to the control when the rice plant received micronutrients and also the treatment of iron, zinc and manganese was found to have the highest value among the studied traits.

Carotenoids
According to Table 4, the amount of carotenoids increased signi cantly (at a probability level of 1%) compared to the control when micronutrients were used, and the interaction of foliar application and year was also signi cant at the same level. The highest number of carotenoids was related to T4 with 0.429 and the lowest number was related to T2 with 0.253 with mg.g-1fwt unit based on the comparison of the mean of statistical data during two years of experiment (Fig. 1d). Due to the role of micronutrients used, the activation of enzymes responsible for the synthesis of proteins such as zinc along with copper, which is an essential element for the formation of pigments, may have played a role in the structure and activation of vital enzymes and facilitating intracellular reactions. According to the Gomez-Garcia and Choa-Alejo (2013) opinion, it seems that in line with the theories proposed in this eld, increasing the amount of carotenoids in the studied foliar spraying treatments compared to the control is due to the determinative role of these elements. Pursuant to most accepted theories, carotenoids are synthesized by the three genes cl, c2, y, as well as several enzymes involved in the synthesis of carotenoids in chili peppers, although little is known about the molecular mechanism of this process.

Plant height, panicle length and plant dry weight
The statistical results indicate the in uence of foliar application of micronutrient fertilizer on plant height was not signi cant (Table 4). In this relation, the interaction effect of foliar application and year was not signi cant, too. The results of comparing the mean data over two years show that the highest plant height was related to T4 (156.8 cm) with four sprays of micronutrient liquid fertilizer and the lowest was related to the control (113 cm) without foliar application (Fig. 1e). The increment of plant height in foliar treatments was probably due to a signi cant increase in stem length due to an increase in internode distance in result of enhanced production of plant growth hormones, which plays a critical role in zinc content that increased cell division and photosynthesis rate. Arif et, al (2012) reported that integrated application of zinc and boron has been the best fertilizer balance for further growth and yield response of rice and also increased plant height, number of tillers, panicle length, number of seeds per plant, number of fertile spikes, and dry weight.
Regarding the panicle length, which is directly related to the number of grains, the results of combined analysis of statistical data during two consecutive years of experiment showed that the effect of micronutrient fertilizer foliar application treatment on the length of panicle was not signi cant (Table 4). This was while the interaction effect of foliar application and year also had no signi cant in uence. Also, according to the results of comparing the two-year average of the data, the highest cluster length was related to T3 (30.8 cm) and the lowest was related to the control (28.1 cm) (Fig. 1f). It seems that increasing the transfer of nutrients and minerals and increasing the productivity of these elements along with regulating plant hormone levels, enhancement of cell division due to increasing concentration of plant growth regulators within plant tissue has a signi cant in uence on cluster length in micronutrient foliar application treatments. Also in a similar study by Zayed et. al (2013) reported that plant dry weight, leaf area index, chlorophyll content along with plant height and cluster length showed a signi cant increase compared to the control after receiving micronutrients.
According to the outlets, there was a signi cant difference (at the level of 1% probability) between plant dry weight of foliar and control treatments as a result of combined analysis ( Table 4). The highest plant dry weight was related to T5 and the lowest amount was related to the control (Fig. 1g). Obviously, increasing plant dry weight is directly related to increasing plant height, increment of the number of tillers per plant and also increasing the volume of the root system, which can be caused by improving the growth rate of rice plant as a result of receiving micronutrients through leaf that affect the plant metabolism. In a search in the present study, Hossein Abadi et al. (2006) also reported that the results showed that micronutrients can only partially increase plant dry weight by improving growth conditions and affecting wheat yield.

Leaf greenness
The difference in leaf color diagram number was signi cant according to the results of combined analysis of variance at the level of 1% probability (Table 4). But the interaction of foliar application and year was not signi cant for this trait. Based on the results of comparing the average data during two years, T4 (number 3.84) had the highest number of leaf color diagram for Shiroodi cultivar and the lowest value was related to the control (number 2.5) (Fig. 1h). The facilitating processes related to nitrogen metabolism, improving the rate of decomposition and synthesis, as well as accelerating nitrogen reduction reactions are some of the factors that have contributed to the signi cance of leaf color diagram in foliar spraying treatments compared to the control. The results indicate an increase in the productivity of basal nitrogen fertilizers that used in the investigation. In this regard, Maralian et al. (Maralian et al., 2008) also reported that micronutrient foliar application had a signi cant effect on traits such as LCC, number of tillers and number of fertile tillers at a probability level of 1 percent.

Grain yield and its yield components
Total grain yield was signi cantly lower (at the level of 1% probability) compared to micronutrient treatments when nutrients were not used (Table 4). This trend was similar to the statistical results on traits such as number of tillers and number of panicles per plant. However, there was no signi cant difference between grain yield of micronutrient treatments. The comparison of the biennial average of the data showed that the highest grain yield was related to T4 (4257 kg / ha) with four sprays and the lowest was related to the control (3499 kg / ha) (Fig. 1i). In connection with the effective factors in increasing the grain yield of rice plants, in which the foliar application of micronutrients may have played a direct role, it can be facilitated by the inoculation process, which is manganese roles, grain formation and maturation which boron it is effective, activation of enzymes responsible for protein synthesis which is zinc role. Furthermore, facilitate the reduction of nitrate and sulfate processes, which are the role of iron, and to accelerate the metabolism of carbohydrates in which copper is effective. In this regard, Mahendra et al. (2017) stated that the application of zinc sulfate signi cantly affected the number of tillers, plant height, number of seeds per panicle, 1000-seed weight, harvest index and biological yield. There has also been a signi cant increase in the availability of primary and secondary macronutrients.
The 1000-grain weight was also affected by zinc, iron, manganese, boron and copper and a signi cant difference was observed between foliar and control treatments at the level of 1% probability (Table 4). Also, the interaction effect of foliar application and year showed a signi cant difference. In this regard, comparison of data averages over the two years showed that the highest 1000-grain weight was related to T4 with (29.8 gr) and the lowest was related to control (25 gr) (Fig. 1j). It is likely that increasing the productivity of macronutrients in which iron, boron and manganese directly affect, and increasing the fertility of clusters, have played the largest role in enhancement the 1000-grain weight and signi cance of micronutrient treatments. In this regard, showed that with increasing the amount of element application, 1000-grain weight, the number of seeds per panicle, the amount of available Zn in corn grain, grain protein percentage and grain yield increased.
In this experiment, the effect of different times of micronutrients foliar application on the rice harvest index was signi cant at the level of 1% probability (Table 4). The highest harvest index was related to T4 (42%) which was not signi cantly different from other foliar spraying treatments. The lowest harvest index was related to the control (34%) (Fig. 1k). By affecting the yield-related indices and yield components of rice, it is obvious that the harvest index, which is directly related to grain yield, has also been affected by micronutrient spraying. Therefore, it is possible that increasing grain yield as well as 1000-grain weight had a direct in uence on the signi cance of the harvest index. In this regard and in a similar study, Ghasemi et al. (2013) reported that the highest harvest index and maximum 1000-grain weight were obtained under the interaction of three factors for treatment with zinc, iron and manganese sulfate fertilizers.

Conclusion
The results revealed that the micronutrients application effect was signi cant about plant dry weight, grain yield, 1,000 grains yield and harvest index. Also, the interaction of the year and foliar application was signi cant about seed Zn content, chlorophyll b and 1,000 grains yield. According to statistical data, it can be concluded that T4 with 4257 kg/ha grain yield compare to control yield 3499.1 kg/ha that indicated 20 percentage approximate enhancement about foliar application treatments, four leaf spraying with 2 liters/ 1000 liters of water dosage of micronutrients could affect grain yield and yield components of rice (shiroodi cv.) signi cantly through increasing the number of tillers/plant, improvement of panicle length and increasing the number of grains/ panicle. The micronutrients supply through leaves is more effective procedure in the eld of rice nutrition compare to soil application method due to higher absorption velocity. The substantial micronutrients supply through foliar application can be more effective nutritional procedure, due to the higher e ciency of this method compared to soil application of them. Due to the low mobility of micronutrients in the soil structure in results of the physicochemical constraints (like abnormal pH and EC in the most farms, which are due to improper use of soil-based fertilizers at the beginning and middle of the growing season), leaf spraying of essential nutrients is a determinative factor about plant nutrition and increment of the rice production.

Declarations Ethical Approval and Consent to participate
Hereby, all of the participants approved the content and achievements of the investigation and, we will undertake the results responsibilities of the paper.

Consent for publication
We (the article authors) announce our complete consent for the survey and publication of the present paper in the Rice Journal.

Availability of supporting data
The corresponding author is responsible for providing the supplementary data and information for further process by editorial broad.

Competing interests
We approved that the paper content and achievements will not have any con ict with another investigation.

Funding
The authors con rmed that the participants did not receive any fund and nancial support during the research procedure.

Authors' contributions
The rst author had determinative and operational role during the investigation implementation. The second and third authors had supervision role for the paper correct execution.   Figure 1 The bar diagram for micronutrients foliar application effect on the seed Zn content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.

Figure 1
The bar diagram for micronutrients foliar application effect on the seed Zn content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the chlorophyll a content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.

Figure 2
The bar diagram for micronutrients foliar application effect on the chlorophyll a content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the chlorophyll b content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.

Figure 3
The bar diagram for micronutrients foliar application effect on the chlorophyll b content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the carotenoids content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the carotenoids content of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the plant height of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the plant height of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the panicle length of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the panicle length of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the plant dry weight of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the plant dry weight of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the leaf greenness of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.

Figure 8
The bar diagram for micronutrients foliar application effect on the leaf greenness of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the grain yield of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test. The bar diagram for micronutrients foliar application effect on the grain yield of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.

Figure 10
The bar diagram for micronutrients foliar application effect on the 1,000 grains weight of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.

Figure 10
The bar diagram for micronutrients foliar application effect on the 1,000 grains weight of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.

Figure 11
The bar diagram for micronutrients foliar application effect on the harvest index of rice (cv. shiroodi). The foliar application treatments (T1 one foliar application to T7 with seven foliar application) considered with seven days interval. Means with different letters in each bar are signi cantly different using LSD test.