eChapters

Introduction

The book has been framed as a text book cum vegetable production manual for both under graduate and post graduate students of Agriculture/ Horticulture as well as commercial vegetable production professionals. This book has been oriented on different management practices of vegetable culture in open field condition viz., Classification of vegetable crops, Management of seedlings in the nursery, Water managent, Plant nutrient management, Pollination management, Integrated pest management, Biological management of diseases, Weed management and Production technology of different vegetable crops.

Classification of vegetable crops

Vegetables are defined as herbaceous plant origin material with generally low calorific value providing micronutrients, vitamins, antioxidants, fibre and induce alkaline reaction inside human body. Vegetable crops are not only botanically different but also their cultural and climatic adaptation shows wide variability. It is, therefore, necessary to classify the vegetable crops for their easy recognition. Vegetable crops can conveniently be classified “Botanically” for the purpose of vegetable breeding and according to “Method of culture” from the point of crop husbandry.

Botanical classification

The crops used for vegetable purpose in the world belong to 1200 species under 78 families and of them, more than 860 species under 59 families belong to dicotyledoneae and about 340 species under 19 families belong to monocotyledoneae. In the tropical and subtropical parts of the world, about 90 species of vegetable crops are cultivated, but hardly 20 of them are commercially important.

In the present botanical classification, over 140 different vegetable crops under 6 monocotyledoneae and 20 dicotyledoneae families have been included.

Quite a large number of vegetable crops are grown in the country either on a commercial scale or limited to backyards of homesteads. A few crops have similarity while others have dissimilarity in their climatic and soil requirements, parts used, method of cultivation etc. While describing individual vegetables, there is possibility of repetition in many aspects. In order to avoid repetition, it is essential to classify or group them into different classes/groups. Different methods of classification followed in vegetables are described below:

I. Botanical classification

Botanical classification is based on taxonomical relationship among different vegetables. Plant kingdom is divided into four viz. Thallophyta, Bryophyta, Pteridophyta and Spermatophyta. All vegetables belong to Division Angiospermae of Spermatophyta. It is further divided and two classes viz., Monocotylydoneae and Dicotylydoneae.

Quite a large number of vegetable crops are grown in the country either on a commercial scale or limited to backyards of homesteads.  A few crops have similarity while others have dissimilarity in their climatic and soil requirements, parts used, method of cultivation etc. While describing individual vegetables, there is possibility of repetition in many aspects. In order to avoid repetition, it is essential to classify or group them into different classes/groups. Different methods of classification followed in vegetables are described below: 

Olericulture, a Latin word, is used to designate the science, culture and management of vegetable crops. In India, about more than fifty vegetable crops are grown in different parts, depending on their climatic requirement. A number of vegetables have similarity in their method of cultivation, which makes the package of practices followed by the farmers for their cultivation very complicated and brings about a lot of repetition. Whichever the method is adopted for the classification of vegetables can systematize the preparation and presentation of the material to some extent and can avoid the unnecessary duplication of some of the principles and methods of vegetable cultivation. In different vegetables, different plant parts are used as food in different forms and they belong to different botanical families with varying cultural and climatic requirements but common insect-pests and diseases along with their common control measures.

Various methods may be used to classify all the vegetable crops into different categories but no single method of classification would be useful to serve the purpose for different groups of scientists like taxonomists, botanists, physiologists, horticulturists, agronomists, and breeders. Under field conditions, the classification based on cultural practices has been proved the best adaptable and very useful for the growers. Vegetable crops can be classified in the following ways for the convenience of different groups of scientist and growers:

Olericulture, a Latin word, is used to designate the science, culture and management of vegetable crops. In India, about more than fifty vegetable crops are grown in different parts, depending on their climatic requirement. A number of vegetables have similarity in their method of cultivation, which makes the package of practices followed by the farmers for their cultivation very complicated and brings about a lot of repetition. Whichever the method is adopted for the classification of vegetables can systematize the preparation and presentation of the material to some extent and can avoid the unnecessary duplication of some of the principles and methods of vegetable cultivation. In different vegetables, different plant parts are used as food in different forms and they belong to different botanical families with varying cultural and climatic requirements but common insect-pests and diseases along with their common control measures.

Various methods may be used to classify all the vegetable crops into different categories but no single method of classification would be useful to serve the purpose for different groups of scientists like taxonomists, botanists, physiologists, horticulturists, agronomists, and breeders. Under field conditions, the classification based on cultural practices has been proved the best adaptable and very useful for the growers. Vegetable crops can be classified in the following ways for the convenience of different groups of scientist and growers:

1. Classification of weeds based on life cycle (Ontogony)

(i) Annuals: Weeds that  complete their life cycle within a year or season are called annual weeds. They are associated with annual crops and propagated mainly through seeds. Annual weeds are subdivided according to the season of prevalence as follows:

(a) Kharif season  annuals or Kharif  weeds: The weeds that grow during the summer and complete their life cycle during Kharif or rainy season are called Kharif season annuals or Kharif weeds. The kharif weeds complete their life cycle during the warm wet season (i.e. from the month of June to September) and attain maturity with the onset of winter and finally dies.

2.1. Based on life span

2.1.1. Annual weeds

Classifying wool is crucial in the textile sector for upholding quality standards, enhancing processing techniques, and ensuring that wool satisfies particular market demands. Precise classification aids in choosing the appropriate wool type for a variety of products, ranging from apparel to carpets, and guarantees uniformity and performance across diverse applications.
Classification of Wool: Wool is categorized in a manner akin to hides and skins, based on its intended application. It is divided into three primary types according to fibre length: combing wool, clothing wool, and carpet wool. Long fibres are combed and twisted to produce worsted yarn, whereas shorter fibres are carded and blended in various directions to create woollens. Carpet wool is characterized by an average fineness of 30 to 50 μm and a medullation percentage between 15% and 68%. The quality of wool is influenced by factors such as breeding conditions, climatic conditions, diet, and overall care. For example, excessive moisture can strip natural grease, while colder climates lead to tougher, heavier fibres. Consequently, wool can be classified in two distinct manners:
A. By the sheep from which it is sourced, and
B. By fleece

Wool is a fibre basically composed of amino acids and have excellent absorbency, moisture regain capacity, tend to warm the human body if used in form of cloths and others, good in elasticity and resiliency but poor in resistance to alkali but acid tolerance is good. To get better utilization of wool, they may be classified into various categories based on their origin, fleece quality, fineness of wool fibres etc.

Weeds are diverse plant species of the ecosystem which can survive adverse condition and reproduce quickly. The global compendium of plants has listed 28000 species as weeds. According to Holm et al (1977) about 8000 weeds species have been reported from agricultural fields in 124 countries and of these, 250 species are considered to be problematic. It is also to be noted that weeds from 12 families constitute 68% of the world’s worst weeds. Within these 12 families, weeds from poaceae, asteraceae and cyperaceae constitute 44% of the world’s worst weeds.

Nanotechnology has emerged as a transformative interdisciplinary field, enabling the design and manipulation of materials at the nanoscale with exceptional physical, chemical, and biological properties. Nanoparticles (NPs), the most fundamental components of nanotechnology, exhibit unique size-dependent characteristics such as high surface area-to-volume ratio, enhanced reactivity, and tunable functionalities that make them valuable in diverse applications including agriculture, medicine, and environmental management. This chapter provides a comprehensive overview of the classification, synthesis, and characterization of NPs. NPs are categorized based on origin, composition, dimensionality, and morphology, encompassing organic, inorganic, and composite forms. The synthesis of NPs follows two major approaches—top-down and bottom-up—employing physical, chemical, and biological methods. Conventional techniques such as ball milling, laser ablation, and chemical reduction are discussed alongside emerging green synthesis strategies that emphasize sustainability and biocompatibility. Characterization techniques including UV–Visible spectroscopy, DLS, SEM, TEM, FTIR, XRD, and AFM are highlighted for determining nanoparticle

2.1 Quantitative Classification

It the data are classified on the basis of phenomenon which is capable of quantitative measurement like age, height, weight, prices, production, income expenditure, sales, profits, etc., it is termed as quantitative classification. The quantitative phenomenon under study is known as variable.  For example the daily incomes of different retail shops in a town may be classified as under.

Classification of Living Organisms

The classification of living organisms has passed through several changes and has reached the present stage with the gradual assimilation of more and more knowledge about them. The classification is mainly based on the morphology, anatomy, life style, habits, habitats, metamorphosis and such other characteristics. Though the concept of classification of living organisms was perhaps started by Aristotle between 384 - 322 BC, it was the Swedish Scientist Carl Linnaeus (1788), who presented the classification, which was acceptable to most of the Taxonomists. He propounded the binomial nomenclature of naming each and every organism of animal and plant origin with a genetic and species name. In his classification he was consistent in using Latin names for all the organisms.

Floriculture is the aesthetic branch of horticulture that deals with the cultivation of ornamentals, annuals, biennials and perennial plants as well as with their marketing. Flowers symbolize beauty, purity, peace and love. In India, it is a dynamic and expanding industry showing an impressive annual growth rate.

Extensive studies have shown that much of the humified material in soil is finely bound to colloidal clay. However, it is uncertain to what proportion of the clay surface in any given soil is coated by organic substances as this will depend on the organic matter content and the type and amount of clay.

The ways in which organic substances are retained in soil are as follows:

1. As insoluble polymeric complexes of humic and fulvic acids.
2. As polymeric complexes of humic and fulvic acids bound together by di- and trivalent cations such as Ca²+, Fe³+ and Al³+.

Organic matter is of immense importance in forming good aggregates in a wide range of soil types, particularly those representing Mollisols, Alfisols, Ultisols and Inceptisols. Organic matter is somewhat less important in the Oxisols where hydrous oxides may play apredominant role. These relationships are depicted in Fig. 13.

Fig. 13.1: Relationship between OM and the formation of soil aggregates

Aggregates do not directly influence plant growth, but they alter the physical and chemical environments in which plant roots grow through their effects on porosity, aeration, moisture retention, etc., when well-irrigated, even fine- textured soils permit adequate exchange of gases with the atmosphere. The polysaccharides of soil have received the greatest attention in producing stable aggregates, but other organic substances bonded to clay through association with Fe or Al may also be involved.

ABSTRACT

Sedimentological studies such as textural, heavy mineral and clay mineralogy have been carried out for Warkalli Formations at Varkala, situated in the southern part of Kerala, India. The X-ray diffraction study reveals that kaolinite is the only clay mineral present in all the samples with trace amounts of gibbsite and goethite. The higher amount of kaolinite and gibbsite indicates warm and humid paleoclimatic conditions. The textural analysis shows that the sediments are moderate to poorly sorted, nearly symmetrical to fine skewed and lepto to mesokurtic in nature. A plot of skewness against sorting shows fluvial trend. The major heavy minerals present in the samples are magnetite, ilmenite, rutile, sillimanite, anatase and zircon. It can be inferred from these studies that these sediments would have been deposited in a lagoon by fluvial action. During that time, the source region has experienced tropical humid climate with mean annual precipitation (MAP) above 200 cm and intensive chemical weathering. Heavy mineral assemblage indicates medium to high grade metamorphic source rocks.

15.1 Introduction

It is important that we understand some terms like clay, mineral, clay mineral, activated clay, and nanocomposite clearly. In fact, “clay” is a soil separate consisting of particles of <2 µm (equivalent to <0.002 mm) in equivalent diameter (Brady & Weil, 2002; pages 18-19) in both USDA and International systems. While in nanotechnology, uniqueness of micro- and nana- aggregates is of crucial consideration. (In Chapter 8: The Colloidal Fraction (Brady & Weil, 2002) size dimensions of minerals are given eliminating any chance of confusion.) Now let us look at some definitions provided in the Glossary of the Clay Minerals Society (CMS) Nomenclature Committee – Clay Science Project (www.clay.org; August 2011).

Structure of Crystalline Clays

Soil clay minerals are of two types: crystalline and amorphous. Crystalline clays are made up of sheets of octahedra and tetrahedra of O and OH. Clays with alternating sheets of aluminium octahedra and silicon tetrahedra, are called, “1:1 clays” or “diphormic clays”. A sheet of octahedra is sandwiched between two sheets of tetrahedra in 2:1 clays which are called as, “triphormic clays”.

The building blocks of clay crystals are called “unit cells”. The geometry of octahedra has 3 voids in each half unit cell, equivalent to 6 negative valences. In order to nullify these 6 negative valences, 6 positive valences are needed. The 6 negative valences can be nullified by 3 divalent cations, one each in the three voids, or by 2 trivalent cations, leaving the third void empty. When trivalent cations such as Fe³+ and Al³+ fill two of the three voids, the clays are called, “dioctahedral clays”. When three divalent cations such as Fe , Mg and Mn fill up all the three voids, such clays are called, “trioctahedral clays”.

2.1 Clean Cultivation

This type of cultivation is extensively followed in India. It involves regular ploughing of the land followed by removal of weeds. Tilling the orchard soil regularly provides a weed free environment in the orchard. Traditional tillage with the spade or hoe involves shallow cultivation and partial burying of weeds. Use of animals for ploughing reduces the labour cost but some superficial tree roots get damaged in ploughing. Tractor drawn tool can be used during initial years when the orchard trees are not fully grown. Branches hanging low, spreading in the inter-row spaces hinders the movements of the tractor even in widely spaced rows at maturity in most of the orchards. Under such situations small power tillers can be used. Tillage controls weeds partly through burying weeds and partly through exposing underground parts of weeds to desiccation. The land around the trunk must be cleaned separately with the help of spade as it is difficult to operate a power implement in the vicinity of the trunk. This is very instrumental in saving soil moisture. It has immense effects on the soil properties. Cleaning removes the protecting layer of vegetation and exposes the soil surface to weathering, and thus reduces the frequency of additions of organic matter to soil. Cultivation physically disturbs soil, mixing upper and lower layers. In this management system, the interspace between the trees is kept clean by tillage by removal of weeds. Clean cultivation by tillage influences the soil aggregate size and stability, porosity and pore size distribution, and the development of sub-surface layers of high bulk density (hard pans). The first change that occurs with tillage is the disruption of established soil pore continuity (Chan and Mead 1989). Organic carbon and nitrogen decline to a new equilibrium value depending on tillage intensity, cropping system and climate.