eChapters

2.1 INTRODUCTION

Owing to a varied agro-ecological and eco- edaphic condition prevalent in one or other part of the country, quite a large number of crops are grown in different parts of India. India is rich in bio-diversity with four hotspots out of twenty-five in the world. About 356 domesticated plant species having economic and botanical importance and 326 species with their wild relatives are found in Indian sub-continent. Besides the above, 9500 other plant species are also available. More than 50 different types of fruits, 50 different types of vegetables, 95 types of spices and condiments, medicinal and aromatic plants, plantation crops and ornamental crop plants have been recorded. To avoid confusion and identity, the horticultural plants are grouped into different categories based on similarity or dissimilarities. Grouping of the crop plants with similar characteristics is referred as classification.

Grouping plants in different categories on the basis of similarities and dissimilarities is referred to as classification, which helps for study of these crops in various perspectives. India is endowed with a rich diversity of horticultural plant wealth due to varied agro-climatic conditions. Number of fruits, vegetables, ornamental crops, spices, condiments, plantation crops, etc. is under commercial cultivation in different parts of the country under different sets of growing conditions.

The systematic study of all these crops becomes a difficult and more repetitive part. To avoid it; classification of horticultural crops on different aspects has been made to deal with all these plants separately. Classification of horticultural crops has been made in different groups on similarity or dissimilarity of attributes. Plants having similarity in either of the traits are placed under one group. The overall objective of the classification is to categorize the horticultural plants and make the recollections very easy and convenient.

There are number of diseases which attacks crop plants. Therefore It is mandatory to classify plant disease into more manageable and more specific group based on several criteria for easy and better understanding. Let us discuss one by one.

1. On the basis of type of infection

On the basis of type of infection disease can be classified into two types

Introduction
Plant diseases pose significant challenges in agriculture, affecting crop yields, quality, and overall plant health. To manage these diseases effectively, it is essential to classify them systematically. Accurate classification helps researchers and farmers understand the nature of the diseases, identify the causal agents, and implement appropriate control measures. This chapter explores various ways to classify plant diseases based on different criteria, such as the causal organism, symptoms, host range, type of crops infected, and whether the diseases are infectious or non-infectious.
Basis of Classification
On the basis of various criteria, plant diseases can be classified into the following categories:
1. Causal Organism
2. Symptoms
3. Host Range
4. Crop Plants Infected
5. Infectious vs. Non-infectious Diseases

There are thousands of diseases, which attack crop plants. Classification can be made based on several criteria. The various ways of classifying diseases of plants are given below.

A. Based on Type of Infection

1. Localized disease- affecting only a part of the plant; leaf spots and anthracnoses caused by different fungi.

2. Systemic disease- affecting the entire plant.

B. Based on Symptoms

Rusts, smuts, wilts, blights, cankers, mildews, rots, damping-off, die-back, scab etc.

There are thousands of diseases, which attack crop plants. Classification can be made based on several criteria. The various ways of classifying diseases of plants are given below.
A. Based on type of infection
1. Localized disease: Affecting only a part of the plant; leaf spots and anthracnoses caused by different fungi.
2. Systemic disease: affecting the entire plant.
B. Based on symptoms: Rusts smuts, wilts, blights, cankers, mildews, rots, damping-off, die-back, scab etc.
C. Based on the host plant
1. On the basis of host e.g. Diseases of apple, diseases of wheat, diseases of rose, diseases of coconut, diseases of coffee, diseases of cotton.
2. On the basis of host group- e.g. cereal crop disease, pulse crop diseases, oilseed crop diseases, root crop disease, forage crop disease, plantation crop disease etc.

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.

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:

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.

Fruits and vegetables are more perishable and generally have a higher value compared to cereals, making them very important in terms of minimizing waste and improving employability in the food industry. The losses in fruits and vegetables are significant, but through effective post-harvest processing, these losses can be reduced, and surplus produce can be better utilized. This processing involves a variety of techniques that prepare fruits and vegetables for conversion into processed foods. The food preservation and processing industry has evolved from being a luxury to an essential sector, playing a crucial role in conserving and enhancing the utilization of fruits and vegetables. To prevent waste during peak seasons and ensure availability during off-seasons, modern methods of storage and processing are necessary. These techniques allow for both large-scale and small-scale processing, extending the shelf life of produce for better distribution. The ultimate goal of food processing is to apply systematic techniques to preserve, process, package, store, and distribute food in a way that ensures a steady supply of diverse and nutritious food options, thereby improving food intake and nutritional standards, particularly during periods of low availability.
For effective preservation and processing, key prerequisites include cleaning, grading, and sorting the produce based on its maturity level. This ensures that only the highest quality fruits and vegetables are used in the processing chain, maintaining food safety, nutritional value, and consumer acceptability throughout the year.
CLEANING OF AGRICULTURAL COMMODITIES
Blanching is a unit operation used in food processing to remove contaminating materials from food and prepare the surface for further processing. In vegetable processing, blanching serves the additional purpose of cleaning the product. This process involves briefly exposing the food to heat, typically by immersing it in hot water or steam, which helps to remove dirt, enzymes, and microbial contamination. By doing so, blanching not only improves the quality of the food but also prevents microbial growth during storage or delays in processing. This early removal of contaminants ensures that the remaining bulk of food is preserved and remains safe for consumption throughout its shelf life.

There is no single factor as important in the production of fine quality dairy products as absolute and complete cleanliness.

R.B. Barrett

It is not enough to provide milk for man, it must be high quality milk. It would be impossible to provide man with milk and milk products of superior quality if we were unable to remove milk soil and to kill residual microorganisms. Respectively, these are the processes of cleaning and sanitizing.

To successfully provide the atmosphere for proper food safety, the basics must be thoroughly understood. The basics of food safety begin with good understanding of sanitation processes, food-handling procedures that protect from, or eliminate cross contamination problems and specific attention to inspection of and follow up for all processes. Food safety activities need to be programmed into available time of day scheduling just as production requirements do. Whether special personnel or separate shifts handle cleaning responsibilities or you clean as you go on the production line, time must be made available. Safe products leaving the facility must be the watch word of all employees involved with the process.

In order to ensure safe food supply a high level of sanitation should be maintained throughout the food production chain. The word ‘sanitation’ is derived from the Latin word “sanitas” which means “health”. To further apply this word to the food industry, sanitation is the creation and maintenance of hygienic and healthful conditions when processing, preparing and handling food. Sanitation is the application of science to provide wholesome food handled in a hygienic environment by healthy food handlers to prevent contamination by food spoilage microorganisms. Effective sanitation refers to the mechanisms, which accomplish these goals.

Cleaning and sanitisation are the two processes employed in dairy industry to ensure hygiene and product safety. The safety of milk and milk products is a very important aspect and every attempt should be made, during processing, to minimize contamination through handling and processing equipments. The accumulated dried milk solids (milk stones) consist largely of calcium phosphate, milk proteins (precipitated, coagulated and baked on by heat) and insoluble calcium salts from water and washing detergents. The surface can also contain biofilms, which are formed by the incorporation of bacteria into the accumulated inorganic and organic materials that attach to most surfaces. With time and in the presence of nutrients, a biofilm and the bacteria within the biofilm will grow and become strongly attached to the surface. The removal of dairy soil, milk stones as well biofilms is the prime objective of the cleaning process. International Dairy Federation (IDF) defines a clean surface as one which is free from residual film or soil that will not contaminate the food products coming in contact with it.

While cleaning refers to the removal of soil from the surface of the equipment, sanitisation implies destruction of all pathogenic and almost all non-pathogenic organisms. Cleaning and sanitisation are complimentary processes. Either of the processes alone will not achieve the desired result, which is to leave the surface as free as possible from soil and viable organisms. In actual practice cleaning and sanitisation overlap to some extent, as during cleaning a high proportion of bacteria are destroyed and others get removed in the detergent solution. Inadequate or faulty cleaning and sanitisation can have serious consequences, as milk is a prefect nutrient in which bacteria can multiply. A thorough understanding of the cleaning methods is, therefore, necessary for economic production of high quality food products.

Cleaning and sanitation are essential for maintaining microbiological safety in ice cream manufacturing, particularly because contamination can occur after pasteurization and freezing does not eliminate all microorganisms. This chapter explains contamination routes, hygienic zoning, cleaning systems, sanitization practices, HACCP principles, and microbiological expectations within an ice cream plant. It examines CIP and COP systems, detergent components, cleaning factors, high-risk equipment and surfaces, and post-pasteurization contamination control. Particular emphasis is placed on preventing biofilms and controlling contamination at filling equipment, tanks, pipelines, feeders, drains, packaging areas, and personnel interfaces. The chapter provides practical sanitation guidance to support food safety, product stability, regulatory compliance, and consumer protection

Cleaning, drying, and aeration are essential processes in the management of stored agricultural products to maintain their quality and reduce the risk of spoilage. These practices are particularly important in preventing the growth of molds, the infestation of pests, and the deterioration of the product during storage.
Cleaning is the first step in the storage process. It involves removing any debris, dust, dirt, and residues from both the stored products and storage facilities. Proper cleaning eliminates potential sources of contamination, such as pests, molds, and bacteria, which can thrive in the presence of organic matter. It also ensures that the grain or other stored product is free from contaminants that could affect its quality and marketability.
Drying is equally crucial to prevent moisture-related issues. Excess moisture can lead to mold growth, fungal infections, and insect infestations. Drying reduces the moisture content of the grain or product to safe levels, typically below 14% for grains, which helps preserve their quality during storage.
The drying process can be carried out using natural sunlight or mechanical dryers, depending on the volume of the product and available resources. Properly dried products are less prone to spoilage and can be stored for longer periods. Aeration involves the circulation of air through stored products to maintain optimal temperature and humidity levels. By controlling the environment, aeration helps prevent the buildup of heat and moisture, both of which can lead to product deterioration.
It also reduces the risk of insect infestations by keeping the grain cool and dry. Aeration systems typically use fans or ventilation channels to ensure continuous airflow, especially in large-scale storage facilities. Together, these processes form a comprehensive approach to maintaining the quality and safety of stored agricultural products.

13.1 Introduction

Climate change is emerging out to be the greatest challenge to humanity. Climate change may be a change in the mean of the various climatic parameters such as temperature, precipitation, relative humidity, atmospheric gases composition etc. and in properties over a longer period and a larger geographical area. It can also be referred to as any change in climate over time, whether due to natural variability or because of human activity. Climate change is a global challenge threatening sustainability of agriculture and its impact is realized more in the fragile and vulnerable ecosystems. The resource poor small and marginal farmers are more prone to climatic aberrations than other farmers. Predicted population growth over the next 50 years will raise food demand globally higher (Trostle 2008), which is complicated by environmental changes such as climate, biodiversity, water availability, land use, atmospheric and other pollutants, and sea level rise (Misselhorn et al. 2012). Climate change has emerged as a serious global environmental issue having impact on all forms of life. It increases the greenhouse gases like carbon dioxide, nitrous oxide, ozone and methane which may cause impact in terms of increased temperature, more demand for water and increase in biotic and abiotic stresses. It has direct impact on agriculture and horticulture. Due to climate change, low production of horticultural crops is featured. Due to severe cold wave, horticultural crops suffer a yield loss of 10-100% depending upon crop and variety (Hazarika 2013). Mitigation strategies aim to reduce the impact of changes to climate and the associated risks from anthropogenic (human) processes. Adaptive capacity is defined as ‘‘the ability of a system to adjust to climate change (including climate variability and extremes), to moderate potential damages, to take advantage of opportunities, or to cope with the consequences’’ (IPCC 2001, p. 982).

Introduction

We have now started to feel the impacts of climate change, as a threat to our health, directly as heat stress on our bodies, and indirectly as it damages crops, and causes storms, floods and wildfires (IPCC, 2022). People working in fields or factories, or in the open, suffer the most. Buildings are our first defense as we learn to adapt to these changes. Resilient buildings that provide passive cooling can protect us better from heat waves, buildings designed to withstand storms and f loods can provide better shelter, and net-zero buildings that produce and store their own energy can enable critical operations when the electric grid is down.

Growth and development of any horticultural crop is mostly depending upon two chief natural factors i.e. climate and soil, which decides success or failure. Therefore, understanding about climate and soil requirements for different horticultural crops for optimum growth and development is a prerequisite for profitable farming.

There is often confusion between weather and climate. Weather describes the condition of the atmosphere over a short period of time e.g. from day to day or week to week. It is current atmospheric conditions including temperature, rainfall, wind, humidity, sky condition at a given place. Climate on the other hand, is the average condition of weather over a longer period of time. Climate is the sum of all the statistical weather information that helps to describe a place or region.

Climate includes different factors namely temperature (minimum & maximum),