You could have a look at the work by Martin Broadley: http://www.nottingham.ac.uk/biosciences/people/martin.broadley#lookup-publications - in particular this review: http://dx.doi.org/10.1111/j.1469-8137.2008.02738.x

Or you could look at the work on zinc by Ismail Cakmak: http://www.harvestzinc.org/publications - most recently http://dx.doi.org/10.1007/s11104-012-1369-2

But e.g. also the IPNI has recently published a review: http://www.ipni.net/article/IPNI-3269

More generally, you could also consider breeding for higher micronutrient concentrations: http://www.harvestplus.org/content/zinc-wheat

In addition to the Alex's recommendation, you could also look out for this paper for some pointers:

Agronomic biofortification of maize with selenium (Se) in Malawi (2012)

Allan D.C. Chilimba, Scott D. Young, Colin R. Black, Mark C. Meacham, Joachim Lammel, Martin R. Broadley, (Field Crops Research 125: 118–128)

And I think Allan D.C. Chilimba's PhD thesis (POTENTIAL FOR SAFE AND EFFICIENT BIOFORTIFICATION OF MAIZE CROPS WITH SELENIUM IN MALAWI) is freely available online at the Univ of Nottingham elibrary repository.

In addition to above recommendation, in short various strategies such as nutripriming, soil application and foliar applied of these micronutrients or thier combination to ameliorate the crop hidden hunger, improve crop productivity and for grain enrichment can be used. However, the rate or concentration of application of these nutrients can be reviewed from literature depending on the soil type and nutrient status.

In consideration of global zinc (Zn) and iron (Fe) malnutrition --particularly in poor segments of the society, currently micronutrient biofortification R&D is a hot topic worldwide. In our experience, wheat grain Zn concentration can be enhanced substantially -- even in Zn-deficient calcareous soils -- by soil application of Zn fertilizer, supplemented with foliar sprays of Zn. Ready reference: Zou CQ, YQ Zhang, A Rashid, H Ram, E Savasli, Z Arisoy, I Ortiz-Monasterio, S Simunji, ZH Wang, V Sohu, M Hassan, Y Kaya, O Onder, O Lungu, MY Mujahid, AK Joshi, Y Zelensky, FS Zang, and I Cakmak (2012) Biofortification of wheat with zinc through zinc fertilization in seven countries. Plant and Soil 361:43–55, doi: 10.1007/s11104-012-1369-2

A lot of effort has already been put in this field in India including work at our Institute (ARI, Pune). In addition to the work done outside India, you can also get information on work being done in India through following links.

Coordination of Biofortification Research and Development Activities in Grain and Tuber Crops to Enhance Nutritional Security in India

http://www.icrisat.org/DC-Projects/Coordination.pdf

Biofortification of wheat for micronutrients through conventional and molecular breeding approaches

http://www.iitr.ac.in/departments/BT/pages/Research+Summary.html

HarvestPlus, ICAR, and DBT Assess Progress on Biofortification ...www.isaaa.org › Knowledge Center › Crop Biotech UpdateCached

HarvestPlus, ICAR, and DBT Assess Progress on Biofortification: HarvestPlus, Indian Council of Agricultural Research (ICAR), and the Indian ...

Country Programs | HarvestPluswww.harvestplus.org/content/country-programs

One area not addressed in the answers given is the low bioavailability of certain micronutrients, such as iron and zinc, in staple food crops resulting from antinutrients in whole seeds and grains. Plant breeders also need to address this problem. Breeding for higher levels of promoter substances (enhancers of bioavailability) needs to be addressed which will require more research into this long neglected research area. The following references are recommended:

Welch RM, Graham RD. Agriculture: The real nexus for enhancing bioavailable micronutrients in food crops. Journal of Trace Elements in Medicine and Biology. 2005;18:299-307.

Graham RD, Welch RM, Bouis HE. Addressing micronutrient malnutrition through enhancing the nutritional quality of staple foods: Principles, perspectives and knowledge gaps. Advances in Agronomy. Volume 70 ed. Academic Press; 2001. p. 77-142.

Bouis HE, Welch RM. Biofortification--A Sustainable Agricultural Strategy for Reducing Micronutrient Malnutrition in the Global South. Crop Sci. 2010 Mar 5;50:S20-S32.

Just by increasing the uptake of micronutrients by fertilization one may not be able to improve the nutritional status of wheat.Bioavailabilty of the micronutrients has to be improved. This can be improved by reducing the phytate contents of wheat as these are regarded as antinutrients. This can be achieved by either screening wheat varieties with low phytate content or developing transgenic wheat having phytase gene with endosperm specific promoter.Our recent publication entitled In vitro dephytinization and bioavailability of essential minerals in several wheat

varieties in Journal of Cereal Science 56 (2012) 741-746 might be useful.

Reducing phytate in seeds and grains may not be the best strategy to use. Phytate also performs beneficial functions in the human body and reducing it could lead to increases in non-communicable diseases. I support increasing promoters of iron and zinc bioavailability as an alternative strategy to reducing antinutrients.

For example, here is a very recent study on the anticancer properties of phytate:

Raina K, Ravichandran K, Rajamanickam S, Huber KM, Serkova NJ, Agarwal R. Inositol Hexaphosphate Inhibits Tumor Growth, Vascularity, and Metabolism in TRAMP Mice: A Multiparametric Magnetic Resonance Study. Cancer Prevention Research. 2013 Jan 1;6:40-50.

Dear Kumar: I don´t have experience on this, but usually the minerals you mention have low availability in alkaline soils. Probably the use of quelates or soluble formulations of these minerals can help increasing grain content of these minerals when sprayed at flag leaves, but if you try to add all together, I think you´ll face big risk of phytotoxicity. Going back to the effect of soil pH in nutrient availability, I am just thinking about the potential it can have certain mycorhizae, like Glomus intraradicens to solubilize certain nutrients due to the creation of a more acid environment and make them more available for the plant. There is extensive literature about its use to improve P availability, but could be worth to have a look at its potential effect on the absorption of the metals you are mentioning. I made a fast look at google and I didn´t find any clear mention about experiments directed to analyze this. I think it could be something to explore. Best regards, Jorge

Kumar,

your question is an interesting one, and as A. Rashid says, “currently micronutrient fortification R&D is a hot topic worldwide.” One technique that is being research to fortify fertilizer with micronutrients like Zn, is what is known as “seed core technology” where i.e., a zinc core is developed and then coated with other nutrient fertilizer i.e., urea. This technology involves a chemical process, and since I am not a chemist, I would not be able to explain it. I am just aware of the technology and do not know if it can be applied to other micronutrients (Cu, Mn and Fe). I will advise you to do some research on it, perhaps in the chemistry literature. Also I believe the Brazilians (EMBRAPA, Companhia Vale do Rio Doce (VALE)) have been doing research on this technology. As a matter of lead, I am providing a newsletter from the IZA and a short article on Biofortification of Spinach and Rice using Seed‐Core Zinc Technology. I hope this information helps.

Her is the other article I made reference on my previous post.

I suggest...

TAVARES, L. C. ; RUFINO, C. A. ; Brunes, A. P. ; Friedrich, F. F. ; BARROS, A,C.S.A. ; Villela, F. A. . Physiological performance of wheat seeds coated with micronutrients. Revista Brasileira de Sementes (Impresso), v. 35, p. xxx-xxx, 2013.

Tunes, L. M. ; Pedroso, D. C. ; TAVARES, L. C. ; Barbieri, A. P. P. ; BARROS, A,C.S.A. ; Muniz, M. F. B. . Tratamento de sementes de trigo com zinco: armazenabilidade, componentes do rendimento e teor do elemento nas sementes. Ciência Rural (UFSM. Impresso), v. 42, p. 1-6, 2012.

Citações:1

TAVARES, L. C. ; RUFINO, C. A. ; Dörr, C.S. ; BARROS, A,C.S.A. ; Peske, S. T. . Performance of lowland rice seeds coated with. Revista Brasileira de Sementes (Impresso), v. 34, p. 202-211, 2012.

TAVARES, L. C. ; OLIVEIRA, S. ; Lemes, S. E. ; Villela, F. A. . Tratamento de sementes com nutrientes. Seed News, v. 1, p. 16-21, 2012.

LEITE, R. F. C. ; SCHUCH, L. O. B. ; AMARAL, A. S. ; TAVARES, L. C. . Rendimento e qualidade de sementes de arroz irrigado em função da adubação com boro. Revista Brasileira de Sementes (Impresso), v. 33, p. 785-791, 2011.

I am DR.T.Senthivel,Dean & Agronomist, Faculty of agriculture & Animal Husbandry, Gandhigram Rural Institute- Deemed University, Gandhigram, Tamil Nadu, India

Technologies available for grain enrichment to ameliorate the mineral malnutrition

First , Testing of soil and based on soil test values on available macro and micro nutrients we have apply fertilizers

Second, some soil are deficient in particular micro nutrients and we have to take necessary steps to supply the same

Third, adoption of Integrated Nutrient management(INM) approach by using Organic manures, recommended N, P &K, Micro nutrients, bio fertilizers etc.,

Finally, use of biological organic growth regulators such as neem based products, pancha kavya and other organic sources of micro nutrients to wheat crop.

Refer: WWW. tnau.agriportal.com for further information

We have to make a distinction between micronutients which are bioavailable and those which are required for plant growth. All micronutrient fertilizer applications may it be foliar or otherwise are required for increasing crop productivity. Increase in micronutrient uptake does not necessarily mean biofortification. We have to ensure its availability to human body. It is well known that phytates chelate these micronutrients and phytates are not digestible. Therefore one strategy is to reduce degrade phytates in the wheat seed endosperm thus relaesing FE and Zn with increased bioavailability.

As regards cancer, there are enough phytates that we consume in legumes and other vegetables.

Thanks to all for a brain-storming session on biofortifiction of wheat.

What about the role of farm yard manure along with fertilisers in mineral- enrichment of wheat grains? Can we have some more ideas?

Dear Pardeep

As our friends said we can do this under field conditions. It is practically done by mixing this fertilizers with some herbicides or fungi and insecticides and then spry over the plants.

Warm Thanks (from the core of my heart) to all the researchers from around the globe for keeping up the spirit of knowledge-sharing for the cause of science! This indeed is a beautiful forum for sharing ideas. Quoting a great scientist, " We indeed are small kids picking pebbles form here and there when the vast ocean of knowledge is flowing before our eyes!"

Dear Kumar,

We, in Egypt have soils with low to very low contents of Zn, Mn, Fe and Cu. As soil pH

is over 7.5 in almost all soils, we are using foliar fertilization to counteract deficieny effects. It leads to better growth and yield increases, but very little increase in mineral contents in grains. The reason is: In order to have effect on growth and yield, spay should be done during the growth period. However, as we have also deficiencies in

these elements and particular Zn in humans, we were interested in biofortification as we were interested in increasing yields. We found that spraying wheat durung the Milky-Stage with microelemnts increases the content in the grains. This means that spraying should be done more than one time, then it becomes an economic question. Can the farmer afford doing it or not?

Yes Sir, Spraying on crop is much more cheaper than soil applications. Moreover, farmers are recommended usually more than two sprays to correct the micro-nutrient deficiencies. The need of the hour is to work-out the growth-stage specific sprays, their concentration and the form of the fertilisers to be applied.

Please cite this article as: Fan, D., Hodges, D.M., Zhang, J., Kirby, C.W., Ji, X., Locke, S.J., Critchley, A.T.,

Prithiviraj, B., Commercial extract of the brown seaweed Ascophyllum nodosum enhances phenolic antioxidant

content of spinach (Spinacia oleracea L.) which protects Caenorhabditis elegans against oxidative and thermal stress,

Food Chemistry (2010), doi: 10.1016/j.foodchem.2010.06.008 While this does not cover micronutrients, it does look at antioxidants, and may also impact Mn and Fe