What is Plant Biometry?  

Biometry is the science that deals with the statistical investigation of biological observations and phenomena. It is very important in the development of sound and effective agricultural research practices. It is a Greek-derived word wherein 'bio' means life and 'metrics' means 'to measure'. Thus, it is generally defined as the combination of statistics and science. Water Weldon introduced this term. This method is applied in several fields of science, including botany, health, social and physical sciences, and humanities.  

Application of Biometry in Agriculture 

In research and analysis, the biometrical analysis uses statistics or mathematics to evaluate biological data or observations. It can help in the correct determination of the results obtained after experiments. Nowadays, computational technology is widely used in automated biometric systems to store and carry out the statistical calculations of a large set of data using computers.   

In agricultural biology, it contributes to the research in crop production, breeding programs, nutrition, and biological pest control. In addition, this unit provides consultancy services and assistance in data collection, experimental designs, and data analysis. 

The leaf fossils and climate in a given flora can be studied and scored by Climate Leaf Analysis Multivariate Program (CLAMP) in plant biotechnology. In addition, the advances in imaging and microscopy allow for the application of quantitative methods to investigate the morphological structure of plants. 

Plant Breeding 

Plant breeding is a method where the crop yield and plant growth can be increased along with its improved quality by introducing new varieties of plants in the market. To get a stable and healthy plant, it should uptake essential nutrients for its overall development. New planting methods such as the soilless cultivation of Pepino plants have led to greater vegetative and reproductive growth due to the high accumulation of nutritious substrates in the parts such as leaves. 

Methods 

In these programs, genetic variability is a prerequisite. Thus, the conserved plant genetic resources are taken from the gene banks to identify the desirable traits in the plant materials that can undergo this procedure in a well-adapted environmental situation. 

Earlier all the experiments of Botany were based on the manual and visual methods of inspection. Thus, resulted in the limited perspective of seeing through the problem. However, with advances in mathematical and computational techniques in the laboratory, such as artificial intelligence, pattern recognition, and computer vision, there has been a new insight into plant biology. Thus, experimentation procedures became easier and gave accurate and reliable results with a piece of in-depth information. 

The physiology of the plant species development and the impact of biotic and abiotic factors of the environment on its growth is crucial to know. It will help the farmers to follow proper management practices to improve crop yield. The anatomical measurements and biometry offer a deep understanding of the growth of a plant in different environments. 

Modern studies also involve allometry of plant species in which the growth rate of their parts with their overall growth is learned. It helps to get an insight into their reproduction, morphology, evolution, and physiology. Thus, there is a major contribution of allometry in the study of plant life.  

Use of Statistics in Plant Breeding

Statistics is a branch of science that comprises data collection, arrangement, analysis, interpretation, and presentation. This approach is widely used in the majority of fields such as biology, astronomy, physics, mathematics, and economics. 

Further, the statistical studies can be branched into quantitative biology, biostatistics, or biometry. All three subdivisions deal with implementing mathematical methods in finding solutions for biological issues by data analysis and interpretation of the biological data. 

The researchers are studying introductory statistics courses to make use of statistics to address the problems in research. For example, in plant biometry, students learn topics such as data, sampling, population, Chi-square test, analysis of variance, t-test, simple linear regression, correlation, probability, measurement of gene frequency (Hardy Weinberg equilibrium), and measures of dispersion (standard deviation, standard error, coefficient of variation).    

The application of statistics in plant breeding involves: 

• The mathematical reduction of the research data to make a descriptive summary of the plant sample. 
• To draw out a statistical inference of the particular characteristics of the flora population from the collected data. 
• To compare the experimental data sets and estimate the parameters of the population. 

The statistical methods used may vary from simple central tendency measures (mean, median, and mode) to complex multivariate analysis. Moreover, the scientific hypothesis created from the interpreted data is further tested. 

It is observed that in a crop field, all the same species are not identical. In particular vegetation, all the crops may not respond the same in different plots. It will also show some variations in its leaves. Thus, it is not easy to get a concrete conclusion. Such questions of scientific interest in the observed data can be tackled with biomathematical data that helps in providing a clear description of the experimental results. 

Application of Biometrics in Plant Breeding 

• The inheritance of any trait in a population helps get information about how the character is inherited and distributed among the population. 
• To know whether the characters show any correlation between them and their degree of correlation. 
• A Chi-square test (to measure the degree of association between two parameters) can be carried out to know whether Mendelian genetics is being obeyed or not. 
• The informative statistical methods (parametric and non-parametric tests) can be done for the test of significance to justify any agricultural practices (such as irrigation and use of fertilizers). 
• ANOVA (Analysis of Variance) test can be done to prove hypothesis from data. For example, in the crop field, it can be used to review the effects of applying two or more fertilizers. 
• The laws of probability are required to be understood and applied to study genetics in a population and forecast the chances of getting a certain result. Therefore, probability distributions (discrete or continuous) wherein the distribution of frequencies is based on the expected frequencies obtained from mathematical computation of certain hypotheses are used. 
• Alleles of a particular gene can also be studied in different populations with the factors that change or maintain the frequencies of a genotype in populations. 

Study of Plant Biometrics 

• The leaf size, shape, patterns, arrangement, venation can be visualized. Biometric methods can be enacted on two main parts of the leaf anatomy: 
• Outline of a leaf- It comprises information about width, height, signatures, symmetry, curvatures, a center of mass, and complexity. 
• Leaf veins- The number of bifurcations, length of the veins, and the angle of ramifications can be measured. 
• In the taxonomy protocol, species identification depends on the information mentioned above about the species. These species are used to determine a set of features, and the grouping is then based on these characteristics. 
• The species of plants can be identified and grouped according to their taxonomy. In addition, the computer visualization of the shape of vegetative structures can help in the recognition and characterization of species faster. 
• Individual measurements such as height, width, stem count, distance to the nearby plants, the circumference of stem, leaf density can all be checked for all the samples in a population. 
• The comparative study of the field growth of different grass species (including alien and native) in monocultures. 
• Modeling methods for relative growth rate study. 

Limitations 

• Only the collective data can be used for statistical measurements. Individual data cannot be used directly. 
• It is mostly applicable for a large population than for the small sample size of the population. 
• All the conclusions derived from the collected data rely on the availability of the sample data. Therefore, if the sampling is biased, it may result in errors in the results. 
• Experts or trained individuals can only handle the statistical tools. 

Context and Applications 

This subject matter is significant for all the researchers and other people engaged in plant improvement and agronomy. It provides details about the statistics and plant breeding. The information related to the term biometry is also provided with its role in the agricultural sector (especially for breeders). Therefore, a student can opt for the study of biometry program who are intended to later go for Ph.D. (Doctor of Philosophy) in Biological Sciences, thereby increasing their job opportunities in quantitative biological research. 

The information is helpful for students of:  

• Master of Science in Environmental Science.  
• A modular course of Biometrics in Agronomy.  
• Master of Science degree program. 

Related Concepts 

1. Data meaning, interpretation, and presentation 
2. Biostatistics: definition, characteristics, and methods 
3. Role of statistics in biological sciences