Several methods exist for evaluating plant nutritional status. Looking for visual deficiency symptoms is perhaps the simplest approach, but once symptoms appear, crop performance has already been compromised. Several other techniques have been developed. All of them require correlation studies to provide plant performance interpretations. Reflectance is a remote sensing technique that detects changes in light energy reflected by plant tissue. It has proven successful in detecting nutrient deficiencies but does not yet have the ability to discriminate among more than one deficiency. Chemical assays of leaf tissue, known as tissue tests, require destructive sampling but are the standard against which other assessments are compared. Sufficiency ranges provide concentrations of each nutrient that are considered adequate for crop growth and development. They consider nutrients in isolation. Other approaches have been developed to consider how the concentration of one nutrient in tissue impacts the concentrations of other nutrients. These approaches strive to develop guidelines for maintaining nutrient balance within the plant. All approaches require large data sets for interpretation.

Objective: The key objective of this research is to investigate the aroma profle of Kaffir lime (Citrus hystrix) leaves grown under greenhouse and peatlite soilless substrate conditions using the electronic nose system. Methodology: Fresh Citrus hystrix samples of recently matured (RML) and old (OL) leaves were analyzed using electronic nose. A total of 79 volatiles were identified and those equivalent to 90% were reported. Results: The RML and OL leaves had similar volatiles such as Citronellal, N-Nonanal, Myrcene, Pentyl Octanoate and γ-Terpinene with no significant difference in the concentration. Citronellal was the major volatile found more than 20% in both recently matured and old leaves. Recently matured and old leaves also had dissimilar volatiles such as 5-Propyldihydro-2(3H)-Furanone(32.9%), β-Pinene (7.6%), Terpinen-4-ol (2.4%), 1-Hexanol (1.3%) and (Z)-3-Hexen-1-ol-Acetate (1.0%) were only found in the recently matured leaves, whereas 1-Nonanol (30.8%), 3-Methyl Butanoic Acid(4.6%), p-Methyl Acetophenone (1.5%), Trans-Hex-2-Enyl Acetate (1.4%) and Methyl Eugenol (1.1%) were detected only in OL. Conclusion: The results are very useful in food and cosmetics industries to develop innovative products based on kaffirlime leaves/oil.

Aims: Ginger aromatic volatiles generally extracted and quantified by various laboratory techniques analysis and instruments. Possibility of few highly volatiles loss coupled with the formation of different compounds during various extraction process due to changes in the natural chemical profiles of the ginger tissue samples. Thus, a study was carried out to explore and quantify the distribution of various natural volatiles present in young, recently matured, matured and old leaves of ginger. Study Design: Ginger seedlings and plants were grown in 100% biochar substrate and fertigated with 50 mg.L-1 of 20% N:4.3% P:16.6% K water soluble fertilizer. Five months old ginger plant leaves were harvested and washed with distilled water and separated by various physiological leaf stages. Place and Duration of Study: Tennessee State University, Nashville, USA. Methodology: Aromatic volatiles were analyzed and quantified by using Alpha Soft V14 electronic nose. Volatiles with more than 1% concentration by fresh mass were 20, 21, 20, and 29 in young, recently matured, matured and old leaves respectively. Results: Young, recently matured, matured and old leaves of ginger showed major volatiles  like benzaldehyde, 1, 8- cineole, myrcene, butane-2, 3-dione, 1 S-α- pinene, Z-3-Hexen-1-ol acetate, butanol and 1-Propanal, 2-methyl- volatiles were identified. A significant variation in the composition, quantity and distribution of volatiles was found across the various leaf tissue samples of ginger. Conclusion: The distribution of aromatic volatiles in this study would provide better insight and guidance to the consumers for maximum utilization ginger plant tissues beside rhizome; as a source of aromatic volatiles. Utilization of other plant tissues especially could be considered as an important byproduct will definitely contribute to the sustainability of ginger production and marketing in the near future.