Very interesting responses indeed friends.  There is no doubt , we hardly perform sap analysis  as a practice for nutrient constraint diagnosis, if at all , we perform , we do not have sufficient  data on nutrient composition  of sap derived from non-fruiting terminals versus fruiting terminals vis-a-vis  conventional leaf analysis data. Very rightly put up by Dr Nazir , this is where the ouir research gap exists  with regard to field application as highlighted by Dr Hepperly . Strong calibration at base is neded something like leaf analysis or soil test -crop response -based data  generation . Fruit juice brix an excellent indicator of nutrient status as observed by Dr Hepperly . We tried juice analysis vis-avis leaf analysis data in citrus , but could not succeed , since concentration of micronutrients in juice is so little   that we could hardly derive any conclusion . But , extracting sap from different plant parts could be very strong option , as an analogue to leaf analysis . And such option should address more to field identification of nutrient constraints instead of destructive methods of plant parts analysis. In this regard, I fully endorse the opinion of Dr Hepperly , our utter failures in field application of such analytical work.

Dr Barbara  and Dr Hussein both are  right , SPAD meter has made some initial head in this regard , to be able to measure the chlorophyll concentration as a measure of nitrogen response. But , distinctly missing about the realm of other nutrients.  We need to know more from our other colleagues on this matter.

Is there any information available on the nutrient composition of sap obtained from different plant parts and establish which kind of tissues have higher concentration of nutrients.

Interesting response Dr Deka .Such information will surely cater the long existing gap in our understanding on sap analysis.

Sap analysis is surely field oriented and rapid diagnosis is possible non destructively. Unfortunately why so much of headways have not been made. If anyone can throw some lights in these issues, it will be really interesting to read those responses.

Sap analysis has value when you have a complete sap analyses database as a comparison. The sap analysis, per crop, needs to follow that crop, with corresponding yields, throughout the entire season. Multiple seasons is better.

You should do dual-analysis, leaf tissue and sap, and make another data-set of values using those comparisons

In our work, sap analysis alone has not been useful.

Thanks Richard. Can you please share your  published work with us for better understanding on the subject.

In my experience the biggest issues with analysis is that complete nutrient analysis is not performed so diagnosis lacking or erroneous.

Secondly while commercial laboratories have wonderful accuracy in their results they usually include a one US dollar option for recommendation based on analysis. Unfortunately this interpretation and suggestions are not worth the one US dollar. There is a big gap between the technician and the application in many of these laboratories and the interpretative summary are good mostly for laughs.

Our soil and plant laboratories are strong on getting creditable consistent results and weak on the interpretation and recommendation for application based on the results.

Sap analysis is wonderful if you already have some complete analysis behind you to have the diagnosis pinpointed. For example without soil analysis the plant analysis wanting and vice a versa However and unfortunately that is generally not the case. So many top institutions accumulate test results put them in computer formerly the file cabinet and without having the acumen and experience to use them effectively they call it day. They followed their procedure and believe their backside is protected.

I have worked in top for profit, non profit public and in government research and all in my experience are quite deficient in this regard. Lastly another real issue in all these is what is costs. Getting the monitoring and interpretation that would optimize our field situation can be expensive and is one of the reasons farmers are using it so little. In relation to getting hold of these very important issues the multiple analysis types give more insights in what is happening on are not there is most parts.

When it comes to sap analysis the use of Brix for fruit crops is wonderful as it gives a fast idea of the health of the plant and sugar is a huge factor for consumer acceptance of the final product. When it comes to all these without preventive diagnosis the prognosis is not an optimized crop result.

Even with all this critique the advances in this field have been astounding during my tenure.

One final thought while we have all the technology to optimally feed our people now and into future our application and extension of the basic research is woefully inadequate. If we follow the limiting factor strategy to improve our future we will need to up our game particularly in the area of extension applications.

Plant content of nutrients very important issue and I think we can take quick and simple idea about the state of the nutrients in the fields of plant using SPAD as a signal Dr.Barbara. which is a small device that can be used field though, but the experience was not accurate in the soil content, but could give an idea of the nutrients in the the plant only.

CCM-200 Chlorophyll Content Meter

http://www.optisci.com/ccm200.htm?gclid=CO-82J6k_8kCFQqdGwodDnUCvw

Anoop Kumar Srivastava we are a private consulting group, also a fertilizer manufacturing company. Organic & conventional.

As such we do not publish our product research. Sorry.

I can assist you in whatever means possible if you ask.

Dr. Anoop Kumar placed a very good question that has a practical aspect in diagnosis of nutrient status in growing plants. No doubt this is very good technique but it has not been standardized properly because it needs standardization for each set of soil, water, climate, crop and cultivation practices. Commercial recommendations cannot work properly, as our learned experts have pointed out. Every one has to develop its own data base and correlation coefficient. It needs a long term study of at least 3-5 years. You have to correlate sap analysis with yields and soil analysis. Some good correlations when developed will be very good to serve to address the deficiency of a nutrient by aerial spray. Thus, major losses of yield can be avoided.  

Very interesting responses indeed friends.  There is no doubt , we hardly perform sap analysis  as a practice for nutrient constraint diagnosis, if at all , we perform , we do not have sufficient  data on nutrient composition  of sap derived from non-fruiting terminals versus fruiting terminals vis-a-vis  conventional leaf analysis data. Very rightly put up by Dr Nazir , this is where the ouir research gap exists  with regard to field application as highlighted by Dr Hepperly . Strong calibration at base is neded something like leaf analysis or soil test -crop response -based data  generation . Fruit juice brix an excellent indicator of nutrient status as observed by Dr Hepperly . We tried juice analysis vis-avis leaf analysis data in citrus , but could not succeed , since concentration of micronutrients in juice is so little   that we could hardly derive any conclusion . But , extracting sap from different plant parts could be very strong option , as an analogue to leaf analysis . And such option should address more to field identification of nutrient constraints instead of destructive methods of plant parts analysis. In this regard, I fully endorse the opinion of Dr Hepperly , our utter failures in field application of such analytical work.

Dr Barbara  and Dr Hussein both are  right , SPAD meter has made some initial head in this regard , to be able to measure the chlorophyll concentration as a measure of nitrogen response. But , distinctly missing about the realm of other nutrients.  We need to know more from our other colleagues on this matter.

You are very right Dr. Anoop, sap analysis is deficient field of research and work done so far does not touch the level it required in a systematic way to devise it as a new useful diagnostic technique. The young scientists can take up this field of research for specific conditions. 

Exactly Dr Nazir.  What could be the precise reasons for not  touching upon such issues which  are more field oriented and probably require lesser efforts ?

Let me enclosed my editorial on this issue highlighting various issues of nutrient constraints diagnosis , how far it is useful . I need yours further feedback please  ( PDF enclosed).

Is there any study comparing the sap analysis based fertilization versus soil analysis based fertilization versus leaf analysis based fertilization. Or applying fertilizer and then monitoring their response through leaf soil  and analysis for nutrients preferably other than Nitrogen.

Friends , you will be surprised to know while exploring the literature on sap analysis, I came to know that   NovaCropControl   company in Netherland is extending advisory on sap analysis -based fertilizer recommendation  for the last 10 years ( www.novacropcontrol.nl/en.). 

Many attempts in the past have been made to compare the efficacy of sap analysis versus leaf analysis . What are the factors that govern the effectiveness of sap analysis ( PDF enclose for further reading ). Sap analysis in vegetables ( DOI : 10.17660/Acta Hortic.2001.563.11) has shown that sap analysis can very well overtake conventional leaf analysis with respect to certain nutrients , especially with respect to recommendation for time of top-dressing of nitrogen . hope these two PDFs will be very useful  to our friends. In another study , while comparing the conventional leaf analysis with sap analysis, petiole extract  was observed very competitive to leaf analysis (PDF enclosed)

Sir,

SAP analysis gives only the momentary results. On irrigation and on receipt of rain the contents will dilute. And vice-versa under dry condition.  It can only be used for supplemental nutrition through foliage. Best method for fertilizer recommendation is soil testing.

Dr Rajakumar , some of the studies carried out in the past do not really reveal , how much nutrients in the plant is actually metabolically active , what fraction of nutrient pool inside the plant is actually contributing towards plant performance  , and how quickly you come to know about the genesis of nutrient deficiency  , all these have been claimed to be better diagnosed through plant -based analysis, of them , leaf analysis as of now  cannot be challenged, more so form perennial crops followed by annual crops. Our main hurdle in whole exercise  is to save our time on analytical procedure and data generation as very rightly highlighted by Dr Hepperly and Dr Nazir . We have utterly failed to interpret such data into plant responsive recommendations.    We are looking for any such methodology which can act as field oriented   technique to be able to reveal the  nutrient constraints at field at the expense of least time so that growers are in a position to implement the recommendation within the current season crop. I have already flashe dsome PDFs about the effectiveness of sap analysis  vis-a-vis conventional leaf analysis. Kindly have a look at them , you will find them a total revelation .

 Dr Deka , to respond to your querry , I am enclosing a PDF studying the comparison of leaf analysis versus sap analysis in sugarcane . Better use of N from fertilizer is required for crop management, and in order to achieve it, adequate N nutrition monitoring is necessary. Sap extract analysis is a sensitive technique that has been adopted in other crops to tackle this objective, and can be used for sugarcane. The aim of this

study was to evaluate the behavior of N and the response of sugarcane after N fertilization, using sap and leaf tissue analysis. The study was undertaken in two experimental areas in 2012/2013 season, using ratoon cane, following application of 0, 50, 100, and 150 kg∙ha−1 of N. The youngestvisible leaves were sampled from sugarcane at five time points between 0 and 150 days after fertilization,

to evaluate the nitrate, ammonium, and total N content of sap extract, and total N content of leaf tissue. At the first sampling point (30 days after N fertilizer application), mineral N in sap increased as a result of N fertilization in medium-textured soil, and remained high until 120 days after fertilization in clayey soil. The total N content of sap followed a similar behavior. Stalk yield was only observed to increase in sugarcane grown in the clayey soil. Sap analysis proved to

be an efficient method for monitoring N status in sugarcane grown in different soil types.

So , there are studies , which with further inflow of knowledge on sap analysis  suiting to  varied application in various crops , will probably make sap  analysis , a promising alternative to conventional leaf analysis as far as early diagnosis of nutrient constraints is concerned. Dr Rajakumar , I am waiting for your further  feedback on the issue.

Very interesting responses from our colleagues. Can one share the information on results of sap analysis for nutrients other than nitrogen. It will be real revelation?

My Very Warm Greetings to all my RG friends for 2016

Dr Deka , I agree with you , there very limited literature with regard to micronutrients , either diagnosis or concentration of micronutrients in different parts of the plant . However , whatever literature , I could find , I am sending some links. those I am furnishing here a sunder:

https://books.google.co.in/books?.isbn.940095055/

www.LaMotte.com/en/soil/multiparameter-outfits/5261-01.html.

Also find one PDF for further reading please.

Friends , just I got the complete protocol for sap analysis by Huchmuth published in Hort Technology 1994(3): 218-234. This protocol takes into account the influence of leaf parts , time of day , number of samples, etc . An interestingly the sap concentration of K  in crop like potato petiole was observed to as high as 50-60g/kg as efficiency range . Like that the efficiency range of N and P is also suggested . I am enclosing one PDF  for further reading of  sap analysis protocol .

Very interesting information Dr Srivastava on protocol of sap analysis.

Our experience was that the data we were provided, by university & consulting groups, never was quite similar to what we saw. It was still important to develop our own history of analysis!

Thanks Dr Deka for complimentary remarks.

Dr Laskar you  are absolutely right . Any diagnostic norm , including sap analysis , we need to have our own dataset to domesticate those diagnostic values in tune with regional preferences that comprise of soil type , climate , crop type, manageemnt practices , rootstock-scion combination 9 in case of perennial crops), plant parts , yield targets, samplinf time , size , sampling position depending upon type of crop....But most important of all is , how far , the developed diagnostic values cater to the diagnosis at field level. this is the most missing part ?

DO WE NEED TO DEVELOP SOME CORRECTION FACTOR /CALIBRATION QUOTIENT FOR LEAF ANALYSIS VERSUS SAP ANALYSIS  for better suitability of sap analysis , friends i call upon you to respond on this issue ?

The information on  micronutrients for sap analysis , still we have not made much headways. 

Yes, I also strongly feel in addition to developing crop oriented sap analysis norms but need strong comparison data with  other established means of identifying nutrient deficiencies.

One thing is true: better nutrient/fertilizer management is critical for conservation of our water resources. Too often salt-type fertilizers used in incorrect amounts leach into ground-water or wash-off fields into streams, rivers and lakes....polluting them beyond use. No where is that better seen than in the Salinas Valley in California where groundwater has nitrate & phosphate levels high enough to cause birth-defects.

So any tool that helps manage especially nitrate is welcome!

Thanks Abhishek  for very interesting response coupled with suitable link and PDF. You are dead right , sap analysis is a very sensitive method of nutrient constraint diagnosis, considered very near to real time diagnosis of nutrient constraint . But looking at the extreme effect of the seasonality of the crop , diagnostic avlues are difficult to assign so far .... especially with respect to N, P, K ( For micronutrients , hardly any efforts made) . The values of sap analysis is further very distinctively affected by soil water as well as crop water deficit . But , none the less , despite all these limitations , sap analysis is realistic in terms of diagnosing the nutrient constraint as and when it emerges..  

This is an excellent paper regarding the suitability of sap analysis vis-a-vis conventional leaf analysis. i thought , let em share this piece of information with all of you . the abstract of the work goes as under:

Fertigation management requires rapid and accurate methods to determine nutrient concentrations in soil solution and in plant sap. This study was developed to evaluate the performance of cardy-ion meters (CIM) for the determinations of NO3-, K+ and Na+ concentrations in soil solution and tomato plant sap, for fertigation management purposes. Tomato was cultivated in a greenhouse with different levels of N, K and Na in the irrigation water. Soil solution was collected by suction at the 15 cm depth with porous ceramic cups and the concentrations of NO3-, K+ and Na+ were determined by CIM and also in the laboratory by standard methods. At the end of the cropping season, 50 leaf samples were also collected and concentrations of the nutrients in the petiole sap were analyzed by CIM and compared to the amounts of total-N, K and Na in the dry matter of the leaves. Concentrations in soil solution and plant sap determined by CIM presented good correlations with measurements in soil solution and in leaf dry matter, respectively, analysed by standard methods. The use of CIM is advantageous due to the quickness of the analyses and the low cost.9 Source : Folegati et al 2005, Sci. Agric. 62 , http://dx.doi.org/10.1590/S0103-90162005000100002 )

very useful information shared by prof, and other experts.

prof the file you uploaded is worth sharing. Thank you

Thanks Hussain for appreciating . Infact , it is a two way process. Hope , we will keep the same tempo going ..

Question is how far sap analysis stands out in relation to other conventional methods of nutrients constraint diagnosis if this is answered sap analysis could be metabolically active indicator of nutrient concentration .

Do we need any change in current strategy for developing any correction factor while comparing sap analysis against leaf analysis or soil analysis.? 

Interesting response Dr Shirgure . Our friends will surely give their valuable inputs on such an interesting issue...

Such correction factor if at all developed need to be fine tuned at the farm level. Since the agropedological conditions will be different. 

Thanks Abhishek  for your meaningful feedback , but  sap analysis has very limited utility  for micronutrients , may be because of their immobility within the plants. We will appreciate some discussion on this issue...

Can we use any sensor nutrient based to increase the utility of the sap analysis especially for micro-nutrients ?