If a plant shows a symptom which could develop due to deficiency of more than one nutrient, how would you find out experimentally, the real deficient mineral element?

To determine experimentally the real deficient mineral element causing a symptom that could develop due to the deficiency of more than one nutrient, you can conduct a series of controlled experiments using a technique called nutrient solution culture or hydroponics. Here's a general procedure:

1. Prepare Nutrient Solutions: Prepare several nutrient solutions, each containing a complete set of nutrients except for one specific mineral element (the one you suspect to be deficient). Ensure that all other environmental factors, such as light, temperature, and pH, are controlled and consistent across treatments.

2. Establish Treatment Groups: Divide identical plants showing the symptom into separate treatment groups, with each group receiving a different nutrient solution lacking one specific mineral element. Include a control group that receives a complete nutrient solution to compare against.

3. Monitor Plant Response: Observe and monitor the plants over a defined period, noting any changes in symptom severity and overall plant health. Document the appearance of new symptoms or the alleviation of existing symptoms in response to different nutrient treatments.

4. Analyze Plant Tissue: At the end of the experiment, harvest plant tissue (e.g., leaves) from each treatment group and the control group. Analyze the tissue samples to determine the concentrations of various mineral elements using techniques such as atomic absorption spectroscopy or inductively coupled plasma mass spectrometry.

5. Compare Nutrient Levels: Compare the nutrient concentrations in the tissue samples from plants exhibiting symptoms with those from plants in the control group. Identify any significant differences in the concentration of specific mineral elements between symptomatic and asymptomatic plants.

6. Confirm Deficiency: If plants showing symptoms exhibit significantly lower concentrations of a particular mineral element compared to the control group, it suggests that the deficiency of that mineral element is likely responsible for the observed symptoms. Repeat the experiment if necessary to validate the findings.

By systematically manipulating the nutrient composition of the growth medium and analyzing the resulting plant responses, you can determine the specific mineral element that is deficient and causing the observed symptoms. This experimental approach allows for the identification of the real deficient nutrient element, even in cases where symptoms may overlap or be ambiguous due to the potential involvement of multiple nutrients.