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Browning is due to boron deficiency caused. In general, boron deficiency symptoms in the formation of the curd, the plant externally visible. In the early stages, immersion in water and curd in the stem region of the surface occurs. As plant growth, into the hollow, soaked in water covers the cavity inner wall tissue. In the absence of progressive steps, areas of brown or pink color are visible, and hence, it is also called brown or reddish-brown or dark brown rot affected by the bitter taste. D

Blossom end rot is a very common problem on green and ripe tomatoes. It started with light tan, water-soaked lesion, and then increased to black and tough. Although blossom blight itself caused only local damage, secondary biological invasions frequently lesions caused fruit rot complete.

Apart from insects, pests and diseases, physiological disorders are one of the major threats to fruit industry which cause financial losses global. Over-all, the problems rise due to unfavorable environmental conditions and improper cultural practices which affect the normal plant growth and development is called as physiological disorders of plant. Ladaniya (2008) stated that the physiological disorder is that it is a function of physiological processes fruit tissue abnormality or failure due to abiotic stress, such as temperature, relative humidity, water stress, chemicals/ nutritional excess and deficiency.

Physiological plant disorder is caused by non-pathological conditions such as poor light, weather damage, waterlogging or lack of nutrients affect the operation of the system caused. Physiological condition selected from diseases caused by plant pathogens such as viruses or fungi to distinguish. Although the physiological disorder symptoms may occur such as disease, they can often be prevented by changes in environmental conditions. However, once the nutritional deficiencies of plants showing symptoms, is likely to return that season yield will be reduced.

Small size grains namely millets are produced by extraneous grasses and the word millet is derived from ‘‘mille’ a French word synonymous to thousand indicating handful of millet grains in a handful measure contains thousand grains (Taylor and Emmambux, 2008). Small millets and pseudo cereals belong to Gramineae family and were major ancient foods of Asian and African continents while Western countries used them as only bird feed.

To constantly move towards advancement, points towards the addition to the tradition that converts to modernization. Today with the drawing waves risking health and diet of an individual, there is a constant demand of rolling back the traditional grains which lost its significance with the turning over of era. Family Amaranthaceae for a long time with the turn of events existed among the staple diets of people in different regions of Asia as China, Africa, America and some parts of India due to its complementary effects with different cuisines as well as the nutrient fulfillment (Olawuyi et al., 2016).

food, known to have been cultivated before 6000 BC in whole Andean region, Columbia, Peru, Equador, Bolivia before the conquest of Spanish. Incas have called this crop as a mother grain and was considered sacred. But in course of time, Catholics have suppressed the cultivation of crop after discovering it as a sacred drink during various religious ceremonies and hence the crop remained in the places where European could not reach (Vega Galvez, 2010).

Chia seed is an ancestral crop having fascinating history of 5500 years. It was the third most important grain of pre-columbian society. Chia seed is common name given to species of Salvia. Salvia hispanica, Salvia columbariae and Salvia polystachya are most important species among all Salvia seeds. Salvia belongs to family of Lamiaceaeis, first native to Mexico and later introduced to Spain by Hernan Cortes (Ortiz de Montellano, 1978), but in next 200 years 17 chia became virtually unknown to human and required research to establish the nutritional aspects of chia and reintegrate as food in modern diet.

Buckwheat (Fagopyrum esculentum Möench) is an annual pseudocereal crop belonging to the genus Fagopyrum of the family Polygonaceae. Its grains belong to cereals because of their similar use and chemical composition (Campbell, 1997). Among a number of buckwheat species nine species possed agricultural and nutritional trials common buckwheat (F. esculentum) and tartary buckwheat (F. tartaricum) are frequently cultivated around the world (Krkošková and Mrázová, 2005).

Amaranth crop stands in the group of pseudocereals and it is popular for its significant nutrient content as well as attractive inflorescence. The word Amaranthus came from a Greek word “Anthor” meaning eternal or unwilting. Amaranthus belongs to family of dicotyledonous plants Amaranthaceae and is one of the multipurpose rare plants whose leaves are consumed in the form 15 of vegetable while the grains are consumed as cereals. Amaranthus being an ancient crop has been included in the human diet since the pre-colonized South American civilizations.

In recent years, pseudocereals and alternative cereal substitutes are gaining attention from agriculture, processing and consumer point of views. The 14 justification for such changes can be found in the recent thought of reextending the range of starch rich seeds available in human diet, because from world-wide perspective cereals consumption is largely restricted to the cereals wheat, rice and maize (Venskutonis and Kraujalis, 2013). In upcoming years, the increase in population can lead to an unfavorable pressure on agriculture and nutrition needs.

Millets like finger millet, foxtail millet, pearl millet, sorghum millet and other small millets are the ancient super grains and nutrition reservoirs for better health. In semi-arid regions, these are the important food and fodder crops, and primarily acquiring more importance in the world. 

Since our existence, we practiced to be fit and fine with the food as a single option traditionally to cure ourselves also which we come to know about their selection with long term experiences. It is a type of diet therapy where food works like medicine. Presently, we practice the same through medicinal diet therapy where selected foods and food supplements are suggested to be taken with medicine for longevity promotion and fit (Zou, 2016).

Fonio is an indigenous cereal crop of West Africa. Fonio grain belongs to genus Digitaria Haller that consists of 230 to 325 grass species, both annual and perennial. The fonio species is a part of Poaceae family, sub- family of Panicoideae, and the tribe of Paniceae. Fonio grains have a protective covering (husk) outside the kernel, similar to rice.

Teff (Eragrostis tef) popularly known as Williams love grass or super grain or annual bunch grass originated in Ethiopia, South Africa has recently gained popularity with widespread cultivation and consumption in India, USA, South Africa and Eritrea (Arendt and Zannini, 2013). It generates around 500 million USA dollars as income to local farmers of Ethiopia. It is the second most important cash crop (Minten et al., 2013). 

After long back of continuous steep turn down in cropping and consumption pattern of traditional grains, once again time is rolling back for them as is evident from available integrated meal or composite research formulations distributed all around the market. Today’s food market is segmented majorly with them and also emphasize more of healthy consumptions owe to adopted governmental strategy as a promotional trends such as subsidies, mid day meal programmes, selection of grain of the year by FAO, 2014 and revised labeling policies etc. are the real time examples. Present lifestyle, ongoing food habits, hike in grain prices, adulteration practices, demand in functional foods and many more reasons lead to the time which emphasizes on its own for consumption of traditional grains.

Plants have served as an important food source in the human diet since times immemorial. In recent times, available plant food sources are facing the threat of limitation due to many reasons viz., shrinking of agricultural land, changes in traditional lifestyles, population growth, rapid urbanization, changes in climate and a variety of plant diseases (Strange and Scott, 2005). Technological, development in agriculture and food processing are associated with both benefits and drawbacks impacting the human health globally with people suffering from chronic hunger, malnutrition to over-nutrition and nutritional imbalances.

The millets are a group of highly variable small seeded grasses, widely grown around the world as cereal crops or grains for both human food and fodder. These are important crops in semi-arid and tropical regions of the world (in particular in Afro-Asian countries) due to their resistance to pests and diseases, short growing season and productivity under heat and drought conditions. Finger millet (Eleusine coracana L.) is a small seeded annual cereal which belongs to the grass family, Poaceae. 

The non-glutinous, easily digestible and alkaline forming characteristics make millets superior in nutritional point of view. Among various cultivated millets 6 in India, barn-yard millet, little millet, brown top millet, guinea millet and kodo millet are the most important minor millets (Nazni and Karuna, 2016). The Barnyard millet, Sawa millet or Japanese barnyard produces a crop within six weeks and considered as the fastest growing minor millets among the all minor millet (Veena et al., 2005). Japanese millet or Barnyard has several existing varieties.

Foxtail millet (Setaria italica) is one of the oldest cultivated millet with several varieties throughout the world with grains varying in colour from pale yellow, to gray, white and red. Archaeologists say that foxtail millet is so old that no wild plant of the species is known to exist today. Foxtail millet is known with several names in different parts of world and India (Table 1). Foxtail millet is thought to be native to China and is commonly cultivated in several regions of Africa, India, Russia, USA and Europe. It is an annual grass with erect and robust culms.

Millets, represents groups of small seeded cereals and grasses cultivated in Asian countries from ancient time and used for domestic purpose as feed and food. Being capable to grow under adverse environmental conditions (high temperature, dry land with limited rain) millets are the main food commodity of low income groups in various developing countries around the world.

Small millets such as foxtail millet, proso millet, finger millet, barnyard millet, kodo millet, fonio millet, teff and little millet and pseudo cereals such as buckwheat,quinoa, amaranth and cockscomb and chia are the oldest crops and staple food for millions of people around the world. Small millets and pseudo cereals are the main source of fodder and feed material for livestock.

Since times immemorial, cereals have always been the main source of the food for human population. Although the three major cereal crops, i.e., wheat, maize and rice have dominated the scene of food production for human sustenance, but due to climatic changes, water shortages and weakening global food security, world's attention has been turning towards achieving a sustainable food supply through long-forgotten grains such as, various millets, which are also resistant to drought and heat. These grain crops have been utilized by the human population not only for food but also as fodder for their animals.

Small millets and Pseudo cereals are staple food for millions of small and marginal farming community and household in developing and under developed countries. They are major source of fodder and feed material for livestock. They are nutritionally alike or superior to major cereal grains with additional advantage of proteins (gluten-free), enhanced fiber, lower glycemic index and bioactive phyto chemicals made them an appropriate balanced health food.

An atom consists of a positively charged nucleus surrounded by a cloud of negatively charged electrons. The positive nuclear charge is due to the presence of protons which carry a mass of 1 and a charge of +1. Besides protons in the nucleus, there are neutrons which are heavier than protons. They carry no charge. Comparatively electrons have no mass (1836 times lesser than that of a proton) but they carry a charge of –1. Hence, the whole mass of an atom is likely to be concentrated in the nucleus.

Research related to biochemical analysis has been greatly benefited due to the development of chromatographic technique, since this technique makes it possible to resolve mixtures of closely related substances on a milligram to picogram range and to identify individual components by comparison with reference standard compounds. Chromatography ‘gives information where other analytical means have failed’ [Tswett, M. (1906) The macro-chemical and micro-chemical detection of carotene. Ber. Deut. Botan.Ges. 24 : 384- 393].

Mass spectrometry (MS) is a powerful and versatile analytical technique through which mass of an atom, or a molecule is assessed. It helps for identification and structure elucidation of various complex compounds. The instrument used is known as Mass Spectrometer. It serves the purpose of qualitative identification, confirmation as well as the quantification of an atom or a molecule. MS identification is conclusive because the mass spectrum of each substance is unique. In general, MS instruments are composed of a sample inlet, an ionization source, a molecule accelerator, a detector, an amplifier, and a recorder (Figure 7.1)

Interaction of radiant energy, exhibiting the properties of both waves and particles, with matter is dealt in spectroscopy. Matter may be defined as material, existing in solid or liquid or gaseous phase, which is composed of molecules, atoms, or ions. Atoms, molecules, and ions, irrespective of their physical state, remain in constant motion in a matter. Molecules may rotate, vibrate, and move from place to place in space. While radiant energy interacts with matter, these molecular motions are influenced to some extent. It is observed that radiations from ultraviolet and visible range of electromagnetic spectrum lead to the movement of bonding electrons from lowest energy state (ground state) to higher energy state (excited state) in the molecules, while absorption of IR radiation causes the molecule to vibrate more. Such changes, referred to as transition, are responsible for changing the molecular energy level.

Electrophoresis is an important separation technique for the charged molecules. Biologically important molecules, such as amino acids, peptides, proteins nucleotides, nucleic acids which carry electrical charge as they possess certain ionizable functional groups may be separated and identified from a mixture with the help of this technique. Some compounds that are non-polar in nature and do not possess any charge may be transformed to charge carrying derivatives. Thus, phosphate derivatives of carbohydrates may be separated and characterized utilizing electrophoretic techniques.

Centrifugation is a technique that promotes accelerated settling of particles in a solid-liquid mixture by the application of centrifugal force. The device that accelerates the separation with the help of centrifugal force is known as ‘Centrifuge’. The centrifuge consists of a fixed base or frame and a rotating part in which the mixture is placed and is then spun at high speed.

Indicators are the natural or synthetic chemical compounds that are used to detect the equivalence point in a volumetric analysis where unknown compound in a solution form is quantitatively estimated with the help of a known standard solution. The equivalence point, also known as the stoichiometric end point, is the point or stage of a titration reaction where the equivalent amount of the reacting substances are mixed together, and this point is identified by monitoring the rate of change in pH, conductivity, flow of current, adsorption, fluorescence, changing of solution colour, occurrence or disappearance of turbidity, flocculation or deflocculation, etc.

Volumetric analysis, also known as titrimetric analysis, is an analytical method of estimating the concentration of a known solute (analyte) in a solution by measuring the volume of a second known solution of known concentration (standard solution), that reacts completely with the known solute of unknown concentration. The prerequisite of titration is that the two different analytes, present in solution form, must involve in a fast chemical reaction. The standard solution is more commonly known as ‘titrant’ and the solution whose concentration needs to be determined is frequently called ‘titrand’.

Acids are chemical substances that are sour in taste and highly corrosive. The term ‘Acid’ was derived from a Latin word ‘acidus’, meaning ‘sour’. They emit sharp odour and transform litmus colour from blue to red. They lose their properties when alkalis are added to them. However, in this process, alkalis also lose their alkaline properties.

Model organisms are widely used in biological researches to describe basic biological processes. When selecting living organisms as models to work with, a wide range of characteristics are used which include: 1) rapid development with short life cycles, 2) small adult size, 3) ready availability and 4) tractability. 

Nematode associated with insects are referred as entomophilic, entomogenous and entomophagous nematodes. Generally they belong to the superfamilies Tylenchoidea, Rhadbitoidea, Oxyuroidea and Mermithoidea of the phylum Nematoda.

Plant parasitic nematodes can be controlled by several methods. The nematode control aims to improve growth, quality and yield by keeping the nematode population below the economical threshold level. The control measures to be adopted should be profitable and cost effective. It is essential to calculate the cost benefit ratio before adopting control measures.

Black pepper (Piper nigrum) is indigenous to the tropical forests of Western Ghats of South India. The crop is grown in Kerala, Karnataka, Tamil Nadu, Andra Pradesh and Assam.

Crossandra (Crossandra undulaefolia) is one of the important commercially grown flower crop in Tamil Nadu. In recent years there is a marked decline in the cultivation of this crop in Madurai, Dindigul, Coimbatore, Salem, Thiruvannamalai and Tiruchirappalli districts. The common problem with the crop is death of plants in patches during the second and third year. This is due to the nematode-fungal complex disease in the crop.

Potato is one of the most important vegetable crop grown in India. It thrives best in cool climate. Therefore it is a summer crop in the hills and a winter crop in plains.

Citrus is an important fruit crop and ranks third in area which is followed by mango and banana. They are grown in 105,396 hectares in India. Among the oranges, mandarin oranges, limes and sweet oranges are very popular while lemons, grape fruits, pummelos, sour and bitter oranges are of minor importance. The Citrus spp. are grown in larger extent in the states
of Maharashtra, Karnataka, Kerala, Tamil Nadu, Andhra Pradesh, Punjab, Haryana, Rajasthan, Assam, Orissa and Bihar.

Plant parasitic nematodes cause serious damage to rice crop. Thirty two species belonging to 13 genera were observed in association with the crop. Among them few are considered to be important. They are the rice white - tip nematode (Aphelenchoides besseyi), rice stem nematode (Ditylenchus angustus), rice root nematode (Hirschmanniella oryzae), root-knot nematode
(Meloidogyne graminicola) and the cyst nematode (Heterodera oryzicola).

Plant parasitic nematodes favour the establishment of secondary pathogens viz., fungi, bacteria, virus etc. The nematodes alter the host in such a way that the host tissue becomes suitable for colonization by the secondary pathogens. Even though the nematodes themselves are capable of causing considerable damage to the crops, their association with other organisms aggravate the disease.

Most of the plant parasitic nematodes affect the root portion of plants except Anguina spp., Aphelenchus spp., Aphelenchoides spp., Ditylenchus spp., Bursaphelenchus cocophilus and B. xylophilus. Nematodes suck the sap of the plants with the help of stylet and causes leaf discolouration, stunted growth, reduced leaf size and fruits, lesions on roots, galls, reduced root system and finally wilting.

The nematode feeding on plant can be divided into above ground feeders and below ground feeders.

Sampling for nematode communities has been the basis for the development of appropriate control strategy. The major purposes of sampling for nematodes include population estimation for general detection, advisory or predictive programme, disease diagnosis and also for research purposes.

Plant parasitic nematodes cause serious problems in sustained crop production. For a successful management of nematodes, their morphology, biology and host - parasitic relationship should be thoroughly studied. A thorough study is achieved only when its taxonomical position is known. Thus, in a simple way taxonomy can be defined as the theroretical study of classification of an
organism.

Life cycle of nematode has six stages. The egg stage, first stage juvenile (J1), second stage juvenile (J2), third stage juvenile (J3), fourth stage juvenile (J4) and the adult stage.

Eventhough nematodes occupy nearly every habitat on earth, they are remarkably similar in morphology and life stages. Despite their structural complexity, certain basic principles are common to all nematodes. Nematodes are triploblastic, bilaterally symmetrical, unsegmented, pseudocoelomate, vermiform and colourless animals.

In light of the high population of nematodes, N.A. Cobb (1915) who is considered to be the father of American Nematology, provided a dramatic description of the abundance of nematodes. He stated, “if all the matter in the universe except the nematodes were swept away, our world still would be dimly recognisable.

Agricultural crops are being affected by a wide range of organisms such as insects, mites, fungi, bacteria etc. Another important and unseen enemy is known as plant parasitic nematodes. The study on nematodes is known as Nematology.