V R Mageshen

Iodine is highly prone to leaching and volatilization which results in iodine depletion in soils. Numerous studies have focused on the process by which iodine is absorbed from the soil, but there is still paucity of knowledge on different fractions of iodine in soils. In our work, we assessed different fractions of iodine (Water Extractable, Exchangeable, Organic bound, Oxide bound and Residual iodine) in soil from different sources of chitosan and potassium iodate alone and combinations. The results suggested that combination of potassium iodate and chitosan complex has increased the iodine stability throughout the cropping period in different seasons. As electrostatic interaction between chitosan and iodate prevents volatilization and gradually stabilizes the availability of iodine, our findings offer more details on iodine mobility and behaviour in soil when it is used alone and combination with chitosan at different rates.

Background: Naturally occurring iodide iodine exhibits complex soil behavior. Even though higher plants don’t consider iodine a vitamin, living things need it. Iodine is part of the thyroid hormone, which is vital to human health and metabolism. Potassium is the most effective cation for tomato plants and has a crucial role in improving several post-harvest quality characteristics in tomato fruits as well as in almost all vegetables. Methods: In the present work, we assessed the growth, yield and quality (Ascorbic acid, Titrable acidity and soluble solids) of tomatoesfrom different sources of chitosan and potassium iodate alone and combinations. The field experiment was carried out in the Thondamuthur block of Viraliyur village in the Coimbatore district of Tamil Nadu in 2022. The experiments were performed in randomized block design with three replications in palaviduthi soil series using hybrid tomato “Shivam”. Result: The chitosan iodate complex and foliar application combination enhanced the growth, yield and quality of tomato. Potassium iodate alone applied to soil and foliar, improved fruit quality but did not prevent acid loss during ripening. Chitosan reduces respiration and oxygen permeability to preserve losses. Thus, potassium iodate chitosan complex was favoured for boosting plant growth, fruit yield and quality.

Background: Iodine is found in soils in both inorganic and organic forms [Iodate-(IO3-) and Iodide-(I-)]. Iodine is highly prone to leaching and volatilization which results in iodine depletion in soils. Crops cultivated in these soils will be lacking in iodine and humans and animals eating food grown in these soils will be deficient in iodine. Numerous studies have focused on the process by which iodine is absorbed from the soil, but there is still paucity of knowledge on different fractions of iodine in soils. Methods: In our work, we assessed different fractions of iodine (Water Extractable, Exchangeable, Organic bound, Oxide bound and Residual iodine) in soil from different sources of chitosan and potassium iodate alone and combinations. The incubation experiment was carried out in the department of soil science and agricultural chemistry, Tamil Nadu Agricultural University, Coimbatore in 2022. Potassium iodate and chitosan were applied in the form of soil alone, soil drenching and chitosan iodate complex at different stages of incubation. Result: The results suggested that combination and potassium iodate and chitosan complex has increased the iodine stability throughout the incubation experiment. As electrostatic interaction between chitosan and iodate prevents volatilization and gradually stabilizes the availability of iodine. Our findings offer more details on iodine mobility and behaviour in soil when it is used alone and combination with chitosan at different rates.

Background: Even though iodine is not an essential micronutrient for the plant, it is very much needed for a person's mental and physical development. Due to the presence of negative charge on iodine it is highly susceptible to leaching. Further iodine is also highly prone to volatilization loss due to biochemical and physiochemical properties of soil leading to iodine deficiency. Agronomic biofortification of iodine is one of the ways to address iodine deficiency globally. Numerous studies have focused on the process by which plants absorb iodine from the soil, but there is still paucity of knowledge on stability of biofortified iodine in fruits. Methods: In our work, we assessed iodine bioavailability (Cooking, soaking and digestion) in tomato fruit from different sources of chitosan and potassium iodate alone and combinations using main and residual crop trials. The field experiment was carried out in Thondamuthur block of Viraliyur village at Coimbatore district of Tamil Nadu in 2021. Potassium iodate and chitosan were applied in the form of soil, foliar, and chitosan iodate complex at different stages of plant growth. Results: The results suggested that combination and potassium iodate and chitosan complex has increased the iodine stability in fruits of main crop and also retained the iodine in residual crop. As electrostatic interaction between chitosan and iodate prevents volatilization and gradually stabilizes the bioavailability of iodine in fruits. Our findings offer more details on iodine mobility and behaviour in fruits when it is used alone and combination with chitosan at different rates.

When iodine levels in the soil are inadequate, resulting in limited crop uptake and as a result, a population with insufficient iodine intake. Iodine deficiency can be avoided by biofortifying commonly consumed crops with iodine. Tomato is the best crop for biofortification study as it is having the capacity to store excess iodine in pholoem. The field experiment was carried out in Thondamuthur block of Viraliyur village at Coimbatore district of Tamil Nadu in 2021. The purpose of this study was to determine the effect of biofortication of iodine in residual tomato growth, yield, quality and iodine content. Potassium iodate and Chitosan were applied in the form of soil, foliar and Chitosan iodate complex at different stages of plant growth. The results revealed that the soil fertilization of potassium iodate alone resulted in lower uptake of residual iodine in fruits because the iodine was susceptible to high volatilization and less phyto-availability. While foliar spray alone increased the residual iodine content in roots and stem. However, residual higher iodine accumulation in the tomato fruits was achieved through the combination of foliar and iodine Chitosan forms. As electrostatic interaction between Chitosan and iodate prevents volatilization and gradually increases the bioavailability of iodine from soil to fruits. Based on the discussion, biofortification of iodine through potassium iodate Chitosan complex paved the way for the improvement of growth, yield, quality and iodine content in fruits. Hence, biofortification of iodine through iodate Chitosan complex increased the iodine content in tomato fruit and introducing it in our daily diet may be helpful to reduce iodine deficiency disorder.

In Soil Test Crop Response (STCR) based Integrated Plant Nutrient System (IPNS) technology, the fertilizer doses are tailored as per the requirements of estimated crop yield taking into account the nutrient requirement of the crop, and the contribution of nutrients from the soil, fertilizers and organic manures. In this study, a field experiment was carried out in the Bahour soil series of Puducherry to study the quality of Okra in response to STCR-based manure and fertilizer application. The experiment was carried out with ten treatments viz., farmer’s practice, FYM alone @ 12.5 t ha-1, blanket recommendation, STCR-NPK alone @ 160, 170, and 180 q ha-1, and STCR-IPNS @ 160, 170, and 180 q ha-1 and control replicated thrice. The fruit samples were collected at 5th, 12th, and 19th pickings and were analyzed for quality parameters. Application of STCR + IPNS – 180 q ha-1 improved the quality parameters such as mucilage (4.54%), protein (1.84%), and starch (4.95%) and ascorbic acid (13.99 mg per100g) content of Okra. The STCR-IPNS technology ensures sustainable crop production and economical use of expensive fertilizer.

A field experiment was conducted to investigate the potential of iodine biofortification in tomato fruits by fertilizing potassium iodate in soil, foliar form and chitosan complex forms. While foliar spray alone increases iodine content in leaves (95%), chitosan iodate complex alone and soil application alone increased iodine contentin roots(11% and 16%) and stems (19% and 27%). However, higher iodine accumulation (3%) in tomato fruits was achieved through the combination of foliar and iodine chitosan forms, as electrostatic interaction between chitosan and iodate prevents volatilization and gradually increases the bioavailability of iodine from soil to fruits. The transfer factor was higher for iodate and chitosan complex from soil to plant. Further, the average and relative distribution of iodine in plants revealed that the chitosan iodate complex and foliar spray combination is proven to be the most effective, as it keeps adequate amounts of iodine in roots, stems, and leaves while also increasing iodine content in final fruit. Biofortifying iodine through iodate chitosan complex increases iodine content in tomato fruit and introducing it in our daily diet may help to reduce iodine deficiency