eChapters

Abstract

The J&K state, like other Himalayan states, is endowed with varied climates and agro-climatic situations and has the potential for improvement in a horticulture sector. Focus on selective issues based on the niches of the areas , strengthening the on-going programs of different developmental departments, site specific issues, backed up with latest technologies need to be identified which can have tangible and immediate impact on the farm economy. The horticulture section is doing well in Jammu and Kashmir state when compared with others food crops, since it fetches good price because of its nature of seasonality. The estimation of the potential profits can be drawn by the fact that a farmer producing wheat of 1 kg gets 10 times higher prices for the same produce in horticulture section. Considering this high potential, the concept of doubling farmer’s income can work magically with horticultural crops. There is a need of shift from traditional crops and cropping patterns. Technological interventions are required to strengthen the conditions of cold storage, adoption of farming system approach, instead of cropping system approach, incorporating element of diversification, promotion of cultivation of high value crops, efficient post-harvest management, value addition etc. popularization of technologies and schemes to achieve targeted growth in horticulture. Strengthening water resources through rainwater harvesting, soil moisture conservation and efficient utilization of stored/conserved rain water (micro-irrigation, fertigation). Promotion of niche commodities based on agro-ecological situations will benefit promotional efforts in horticulture development with increased benefit cost ratio.

Abstract

Climate models predict a global average increase of air temperatures in the range of 14^°C by 2100 (IPCC 2014) - a pace exceeding that of past climatic modifications. Change in temperature is expected to influence species occurrence and distribution with up to 37% of all extant species “committed to extinction” due to climate change. These predictions, however, do not include species interactions and evolutionary change which will significantly alter the fate of species. It is therefore important to improve our understanding of host-parasite interactions and subsequent evolution in response to environmental changes in general and temperature changes in particular. Globally livestock production systems are estimated to account for around 18% of emissions. The need of hour is to draw on recent advances in climatology and epidemiology of various parasitic diseases to consider how environmental changes linked with urbanization and climate change can alter the biology of hosts, pathogens and vectors. Climate change is leading to unusual flare-up of diseases, outbreak recurrences, range expansions, or invasion into novel territories and ecosystems, concomitantly with vector or host range shifts. Higher temperatures increase the invertebrate metabolic rate, egg production amount, and feeding frequency, reducing the duration of the development periods and impacting on the number of generations per year and population abundance effecting livestock and human health and socio-economic transformation

Abstract

The future food grain demand in India is projected to increase beyond 300 million tons by 2025. There are only two ways to meet the increasing food and other agricultural demands of the country’s rising population either expanding the net area under cultivation or intensifying cropping over the existing area. The net sown area of the country has risen by about 20 per cent since independence and has reached a point where it is not possible to make any appreciable increase. The option left is go for high cropping intensity for ahead of present of 137%. A major share of this increase is likely to come from increasing the number of crops produced per year on a given land using improved crop cultivars. Research indicates that maximum intensity of 400-500% is possible provided situation fulfills the requisite factors such as irrigation facilities, short duration varieties, mechanization and agrochemicals are available. The objective of increasing the cropping intensity will be achieved only by the inclusion of short duration varieties of cereals, identification of pulses and oilseed crops that can fit well in the cropping systems of different agro-ecologies that will ultimately improve crop productivity per unit of land making the efficient utilization of resources and will meet the objectives of crop diversification leading to food and economic security of the nation.

1.1 General

Renewable technologies are considered to be clean sources of energy. The optimal use of these resources minimize environmental impacts, produce minimum secondary wastes, and are sustainable based on current and future economic and social needs. Sustainable development requires methods and tools to measure and compare human activities’ and its environmental impacts for various products. Renewable energy sources (RES), which include biomass, hydropower, geothermal, solar, wind, and marine energies, supply 14% of the world’s total energy demand. Renewable resources refer to primary, domestic, and clean or inexhaustible energy resources. Large-scale hydropower energy supplies 20 % of the global electricity need. Wind power in coastal and other windy regions is a promising source of energy.

Renewable energy resources can make a decisive contribution to the economic, social and sustainable development of rural regions in developing countries, yet the consumption of fossil fuels is dramatically increasing along with improvements in the quality of life, the industrialization of developing nations, and the increase of the world’s population. It has long been recognized that excessive consumption of fossil fuel leads not only to a diminishing fossil fuel reserves more quickly, but also has a significant adverse impact on the environment. Such impacts result in increased health risks and the threat of global climate change. Changes to improve environmental conditions are becoming more politically acceptable globally, especially in developed countries. Society is slowly moving towards seeking more sustainable production methods, minimizing waste, reducing air pollution from vehicles, generating distributed energy, conserving of native forests, and reducing greenhouse gas emissions. Increasing consumption of fossil fuel to meet out current energy demands, however, has sounded alarms over regarding potential energy crisis. This has generated a resurgence of interest in promoting renewable alternatives to meet the developing world’s growing energy needs. Excessive use of fossil fuels has caused global warming from carbon dioxide emissions, therefore, promoting renewable forms of clean energy is eagerly required. To monitor the level of these greenhouse gas emissions, an agreement that has fulfills the objectives of the Kyoto Protocol was create with overall pollution prevention targets.

7.1 Introduction

A greenhouse is quasi-permanent structure, covered with a transparent or translucent material, ranging from simple homemade designs to sophisticated pre-g\fabricated structures, wherein the environment could be modified suitable for propagation or growing of plants. Materials used to construct a greenhouse frame may be wood, bamboo and steel or even aluminum. Covering can be glass or various rigid or flexible plastic materials. Depending on the covering material, different terminology have been used in the context of greenhouse structures as mentioned below:

Glasshouse: A greenhouse with glass as the covering material is called glasshouse

Polyhouse: It is a greenhouse with polyethylene as the covering material.

15.1 Introduction

The oceans cover 71% of the earth’s surface and it acts a natural collector and store of solar energy. On an average day, 60 million sq. km. of tropical seas absorb an amount of solar radiation equivalent in heat content to about 245 billion barrels of oil, if this energy could be trapped, large scale renewable source becomes available especially for tropical countries. The energy available in the ocean is clean, continuous throughout the year and renewable.

Renewable energy contribution to the available energy resources is very important to the country as it is presently facing an energy resources crunch. Out of the total installed capacity of approximately 370.106 GW as on March 2020, Renewable Power Plants including hydro-electric plant contribute 35.86 % of total installed capacity. However, with the present increase in demand, more attention is required to extract the renewable sources so that at least 50 to 60 % share for the total energy requirement by the renewable energy sources.

There are various forms of ocean energy such as Ocean Thermal Energy Conversion (OTEC), Wave Energy, Tidal Energy, Salinity Gradient Energy, Offshore Wind Energy, Marine Currents, Marine Biomass Conversion. Among these, the first three forms are likely to be technically viable for the future.

More recently Ministry of New and Renewable Energy (MNRE), Government of India hasdeclared Ocean Energy as renewable energy, and clarified to all the stakeholders that energy produced using various forms of ocean energy such as tidal, wave, ocean thermal energy conversion among others shall be considered as renewable energy.

MNRE reported that, the total identified potential of tidal energy is about 8000 - 9000 MW, with about 7000 MW in the Gulf of Cambay in Gujarat, about 1200 MW in Gulf of Kutch and less than 100 MW in Sundarbans. Primary estimates of wave energy potential along Indian coast are about 5 – 15 MW/m, so that theoretical estimates are around 40 – 60 GW. Ocean Thermal Energy Conversion (OTEC) has a theoretical potential of 180,000 MW in India subject to suitable technological evolution. As of date, there is not any installed Ocean Energy capacity in India.

16.1 Fuel Cell

Fuel cell is an electrochemical device that convert chemical energy of a reaction directly into electrical energy. The basic physical structure of a fuel cell consists of an electrolyte layer in contact with a porous anode and cathode on either side. A schematic representation of a fuel cell with the reactant or product gases and the ion conduction flow directions through the cell is shown in Fig. 16.1

Abstract

Food security to the increasing population on one side and the increasing export of food grains on the other side has lead to the immediate attention on to raise the food production in our country. The decreasing land availability for agriculture due to the increased degraded lands and use of agricultural lands for non agricultural purposes has still worsened the situation. In order to match with the food requirement from decreasing agricultural lands, Indian agriculture has been pushed towards indiscriminate use of farm inputs exploiting the non renewable natural resources without any concern to the environmental ill effects leading to further degrading of the situation. Even though the concept of sustainability is age old, the importance is felt recently. Sustainable use of resources at farm level can magnify the effect of conserving non renewable resources and reducing ill effects on the environment at state level and to the country. Sustained farm production is a key to manage our resources and environment. Adoption of new information technologies with the conventional agronomic practices to increase farm production is made inevitable due to our past experience. The advancement in the technology tools like Remote Sensing, Geographic Information System, Global Positioning System and Decision Support Systems have paved way for better and effective management of crop production at farm level. 46 Geospatial Technologies for Natural Resources Management

A systematic approach of management involving advanced technologies and conventional agronomic practices through understanding the factors like soil variability, weather parameters and crops that contribute for the sustainable farm production is need of the hour. The spatial and temporal variability of the farm production parameters are to be studied and mapped in relation to historical data of the farm for successful site specific management. Site specific management tools may improve decisions related to site conditions, thereby reducing the aspect of uncertainty in the management system. This approach of farm management using advanced technologies viz., Remote Sensing, Geographic Information System, Global Positioning System, Variable rate technology, crop production modeling and Decision Support System can enable sustainable farm production with beneficial effect on the environment in future.

Keywords : Remote sensing, GIS, Sustainable Farm production, Site Specific Management

Abstract

The present study discusses the cropping pattern changes in Andhra Pradesh agriculture will leads to crop diversification and crop concentration using with Geographical Information System (GIS). Crop data were compiled for the triennium ending period 1980-81, 1990-91, 2000-01 and 2004-05 from various statistical abstracts of Andhra Pradesh. For measuring the crop diversification indices, we have used the Herfindahle index and for crop specialization is measured by using the Location quotient method. The level of crop diversification in the some districts of the state in the eighties is very high. However with the advent of green revolution, there had been a moderate crop unification or crop concentration in the eighties. This trend of crop unification is found to be reversed after 1990-91, though the magnitude of the change is not very striking. The crop diversification is observed to differ across the districts. The level of crop diversification is high in the agricultural backward regions of Rayalaseema and Telangana districts and low in the agriculturally progressive Coastal Andhra districts. During the period 1990-91 to 2004-05, the major trends in crop concentration are increase in the concentration of rice in the districts where it is popularly grown and decline in the concentration of coarse cereal crops, pulses and oilseeds. The concentration of spice crops and fruits and vegetables are also on an increasing trend, which they are popularly grown in their respective districts.

Keywords : Cropping Pattern, Diversification, Location Quotient, Andhra Pradesh, GIS

Abstract

The rapid development and integration of spatial technologies viz., Geographical Information System (GIS), Remote Sensing (RS) along with Global Positioning Systems (GPS) provide functional alternatives to revolutionize the conventional entomological approaches like surveillance, spatial/temporal distribution of insect populations, pest distribution mapping and predictive modeling. Application of these technologies for insect problems is well established in the fields of forest, range land, medical and agricultural entomology elsewhere. Nevertheless, in India its field relevance in agricultural entomology is still limited owing to lack of proven field prototype studies and collaborative efforts among stakeholders. It’s time to gain real momentum to integrate these progressive technologies to formulate sustainable integrated pest management programs.

Key words: GIS, Remote Sensing, Insect Populations, Field Applications

Abstract

Soil quality assessment has been recognized as an important step towards understanding the long term effects of land management practices within agricultural watersheds. Potential soil quality issues include continued high rates of erosion, losses of organic matter, reductions in soil fertility and productivity, as well as chemical and heavy metal contamination. This case study addressed the spatial variability of soil properties and its quality at the watershed level using geostatistical methods. Soil samples from the 0- to 20-cm depth were collected on a 100- by 100-m grid across an 88-ha watershed at Sakaliseripalli village in the Nalgonda District in Andhra Pradesh State, India. Geostatistical analysis showed that most of the soil parameters were moderately spatially dependent. An assessment framework, that included a minimum data set, linear scoring technique, and additive indices, was used to evaluate the soil quality index (SQI). Through principal component analysis, cation exchange capacity, exchangeable Na percentage, DTPA-extractable Zn, available P, available water, and dehydrogenase activity have been emerged as the most important indicators for evaluating soil quality. A kriged map of SQI was prepared for the watershed. The SQI was found to be higher in irrigated systems than under rainfed conditions. In the study, potential soil loss calculated using the Universal Soil Loss Equation and crop yield were identified as the quantifiable management goals; the results indicated that soils having higher soil quality indices were more productive and less erosion prone.

Keyword : Principal Component analysis, SQI, Watershed, Geostatistics, Potential soil loss

Abstract

Agroforestry is an integrated self-sustainable land use management system that is not only capable of producing food from marginal agricultural land but also capable of maintaining and improving the quality of environment. It plays a vital role in achieving integrated rural and urban development. But reliable data on number of trees and area under agroforestry is not available as methodology for estimation of even area under agroforestry is not yet standardized. In this paper, a methodology for estimation of number of trees under agroforestry using high resolution satellite data has been proposed and estimation of number of trees as well as area under agroforestry in Ludhiana district of Punjab State has been done using the proposed methodology. Land use/land cover map of the district has also been generated using ERDAS IMAGINE software. It has been observed from the accuracy assessment that the estimates of number of trees as well as area under agroforestry obtained using the proposed methodology under this study are very reliable. Therefore, the proposed methodology may be replicated for estimating number of trees as well as area under agroforestry in other parts of the country.

Keywords: Agroforestry; Estimation of number of trees, Area estimation; Remote Sensing; GIS

Abstract

The sustainable management of plant genetic resources is of great concern as increasing population and rapid technological strides are putting enormous pressure on this country’s nutritional and food security. Management of plant genetic resources at national level generates and uses enormous data and analysis of these data is crucial to the effectiveness of PGR management process and can add significantly to the value of genetic resources. A GIS is a database management system that can simultaneously handle data representing spatial objects and their attribute data. GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. It can play an important role in the management of large and complex PGR datasets. The article analyses the potential uses of GIS in plant genetic resources management in India covering various activities such as germplasm exploration and collection, characterization and evaluation, plant health management, documentation and conservation.

Key words : plant genetic resources, germplasm, conservation, documentation, DIVA-GIS,

Abstract

The social and economic development of any state is interlaced with the manner of its natural resource management. The unplanned use and overexploitation of resources are results in various kinds of land degradation, biomass deterioration and siltation of tanks. In addition, the low per capita availability of land, erratic and uneven distribution of rains, undulating topography, improper management, traditional cropping programmes and recurrence of droughts having cumulative effect leading to low productivity and high risk particularly in dryland farming. Further, developing dry land agriculture through sectoral approach did not bring in the desired results, as the efforts were not integrated. However, in nature all the resources are inter-linked and thus, the integrated developmental approach is the best solution for optimal development of any area. Further, development based on administrative units such as district, taluk, block and village have resulted in imbalance and sometimes, no overall development in some areas. Considering this, natural resources management through Geo- informatics tools like, remote sensing, GIS, GPS and other sensor based techniques are the possible ways for making agriculture sustainable. The paper mainly highlights theimportance of application of latest technologies in agriculture along with some field level case studies.

Keywords: Remote sensing, GIS, Watershed, CAPE, Precision agriculture

Abstract

GIS in marine fisheries has taken off much later than its application in land. But the strides made in this field since 1990’s has been quite significant, as many serious mapping studies and modeling initiatives have been recorded. With the third dimension added to the 2D spatial data, the marine GIS have all the ingredients of making it a fertile domain for research for decades to come. Most of the studies and products pertaining to GIS in fishery management had been revolving around mapping of habitats, geo-referencing of catch and effort data and modeling linking oceanographic and biogeochemical factors with living resources. Satellite remotely sensed information like ocean colour can act as a surrogate to fish biomass. Further remotely sensed SST, wind and other parameters can be effectively modeled to predict fish abundance, their habitat and related aspects. This manuscript pours into the various products and outputs based on GIS in marine fisheries around the world and the Indian initiatives.

Key words: GIS, marine resources, oceanography, primary productivity and climate change

1.0 Introduction

Geographic Information Systems (GIS) have been one of the most prolific scientific enhancements in recent past, which by virtue of out of box expansion of traditional database concept have opened up an entirely new vista of knowledge and opportunities. It’s probably one such unique application where information collation and analysis happen hand in hand resulting in palpable mining of data in perspective. A formal introduction to GIS would define it as a collection of computer hardware, software, data and personnel designed to collect, store, update, manipulate, analyze and display geographically referenced information. By virtue of its conceptualizations, there are no single GIS; systems can be assembled in an infinite number of ways. This is one such field, which probably always seeks the frontiers of innovations in the fields of ICT and modeling.

Indifferent stage: Primordia are present for both sexes (gonads and mesonephric and paramesonephric ducts), although genetic sex is determined at fertilization.

Gonads : are structuarally indistinguishable prospective testis and ovaries. The first sign of gonadal development is a swelling called the gonadal ridge on the medial side of the middle part of the mesonephros. It enlarges due to arrival of primary germ cells. Cells of mesonephric tubules invade the ridge to form clusters and besides surround germ cells resulting in gonadal cords.

The primordial germ cells of these gonads arise from the endodermal cells of the yolk sac. These migrate to the gonadal ridge through the dorsal mesentry. Migration of primordial germ cells from the yolk sac endoderm into the gonadal ridges initiates testicular (if SRY gene is present) or ovarian development. The primordial germ cells form the sex cells, called gonadal blastema. The somatic blastema (non-germ cell) forms the other parenchymal elements of the gonads. The germ cells are capable of amoeboid-like movement.

Cardiovascular system consists of heart and blood vessels which include both arteries and veins. Blood vessels formation occurs in two stages i.e vasculogenesis and angiogenesis. Splanchnic mesodermal cells lining the yolk sac form clusters, referred to as blood islands. Vasculogenesis, the formation of blood vessels from blood islands of of Pander, commences during the third week of gestation in domestic animals first in yolk sac and later in the allantois.Development of blood vessels involves a complex series of events during which endothelial cells differentiate, proliferate, migrate and become organized into vascular network. Angiogenesis describes budding and sprouting of new vessels from existing vessels. This process a fundamental requirement for embryological development, continues postnatally.

Somites are derived from paraxial mesoderm and they are located lateral to the developing notochord and neural tube. During the third week of gestation in domestic animals, the outlines of somites first become visible and in the fifth week of gestation the somite formation is completed. Somites differentiate into sclerotome, myotome and dermatome. They form skeletal, muscular and dermal elements i.e, vertebral column, muscles and dermis respectively.

The connective tissue, cartilage and bone all differentiate from mesenchyme which arises chiefly from mesodermal somites and lateral layer of somatic mesoderm while connective tissue of alimentary canal and lower respiratory tract is derived from splanchnic mesoderm. Mesenchyme is a spongy meshwork composed of branching cells spaces between which are filled by ground substance. The supporting tissues, connective tissue, cartilage and bone are derivatives of mesenchyme in which ground substance is gelly like, stiff and firm respectively.

Maize is the only cereal crop which is being used as human food, animal feed and as a source of large number of industrial products. In Odisha traditionally maize is a Kharif season crop and second most important crop next to paddy during Kharif season in terms of both area and production. The Rabi maize is cultivated under irrigated condition, and accounts only 7% of total area and production of the State. While only 24% of the Kharif maize area have irrigation facilities. Irrespective of the season, it is that is the fourth most important food grain crop with respect to area in the state which is next to rice, mungbean and urdbean. Even though maize is grown as a sole crop in the state but, some farmers are also adopting maize based inter-cropping and the major recommended/adopted inter-crops are arhar, cowpea, yam, runner bean, greengram and blackgram. The comparative analysis of compound annual growth rate (CAGR) of area, production and yield of the major crops is the state was done for the years 2004-05 to 2013-14. The CAGR study of major crops revealed that no other major crop including rice has the impressive growth rate a like maize in the state (Fig. 1).

Maize is a miracle crop and is popularly known as “Queen of Cereals” due to its very high yield potential. It’s a leading crop worldwide in terms of area, production and productivity and is suitable to diverse agro-climates. Its extent of adaptability is unmatched by any other crop. Due to this adaptability to diverse climates, maize had been grown by many generations in different parts of the world. Earlier, the primary utilisation of maize was focused towards human consumption and even today it is a staple food of many underprivileged societies especially in African countries and certain tribal pockets in India. It is playing an important role as a cheap source of carbohydrate in daily meals due to high productivity and wider adaptability. With the passage of time the productivity increased due to conscious selection towards high yield by farmers and researchers. This enhanced production and productivity opened new doors of utilisation of this wonderful crop. Maize found its place as a feed crop for economically important anima ls like chicken and swine. This shift towards feed industry got encouragement by change in the food habits of people. Looking at the recent consumption pattern of maize as a food crop displays declining trend. As per a NSSO survey (2014) maize consumption in rural areas in India has seen a decline of around 35% from 3.7 kg/year in 2004-05 to 2.4 kg per year in 2009-10, and further declined to 1.56 kg during the year 2011-12. Continued efforts towards yield enhancement and decline in human consumption made its way to utilise surplus maize in economically viable industrial products. Maize is a crop where every part of its plant can be utilised to produce food and non-food products. Oil, starch, glucose, dextrose and sorbitol are few important products produced by processing of maize grains. Apart from these, maize has been very widely used for production of ethanol which is used as a fuel in many developed countries. Direct utilisation of maize grains in poultry and other feed industries is on the rise with increasing demand of such foods. Maize oil is of high quality and is being widely used in developed countries. Maize is a major source of industrial starch which finds its way to diverse utilization such as food and beverage, pharmaceutical, textile, paper and other industries. Processing of maize is done by two ways- Dry Milling and Wet Milling. Wet milling produces starch, gluten and husk and Dry Milling produces corn meal, germ, grits and animal feed. Apart from these processed products, maize is also being developed to be utilised as a biopharmaceutical crop. Maize crop is being bioengineered to extract products of therapeutic and medicinal importance. Such a diverse utilisation of maize has generated a necessity to improve morpho-physiological traits which are important with respect to its industrial utilisation. In the present chapter, we will discuss various aspects of maize improvement for industrially important traits which will include oil, starch, methionine, biofuel and biopharmaceuticals.

Vector data consists of points, lines and polygons with x, y coordinates known as vertices representing the geographic location i.e. latitude and longitude. Vector data depicts the shape of the spatial feature. Points consist of single x, y locations. Examples of points are tower location, sampling location, etc. Lines represent 1 – dimensional features like roads, streams, etc., and are composed of many or at least two connected points or vertices. Polygons denote 2 – dimensional features like boundaries with three or more vertices that are connected and closed. The vector data are represented in the following figure (fig. 5.1).

Ornamental pot plants should be potted in small pots according to the size of the plants. Any kind of pot/container which can hold medium and provide aeration is suitable. The most common container is the plastic or clay pots. Plastic pots should be preferred because it retains moisture longer than mud pots. Plants should not be disturbed frequently and re-potting done only when absolutely necessary.

Potting media

Different types of growing media may be used for ornamental pot plant cultivation, but it is crucial that it must retain a certain amount of moisture and be well draining. Different plants require different substrate in which they would thrive. Conditions of the plant experiences in nature should think before choosing the media. Tropical plants require more water naturally compare to subtropical and temperate ones. For irrigating with sprinkling can or hose, it is better to use materials that drain well and decompose slowly while for drip irrigation heavy potting material should be used. The most important thing is to match watering habits to the potting material. Growing conditions play a most significant role in deciding on a medium. If there is no problem in providing a constantly humid environment due to climate or if growing in a greenhouse, the moisture retention on thepart of media is less of a concern. Ambient temperatures play a role here, as well, as warmer temperatures tend to increase the evaporation of water and along with the drying rate of the medium. The personal tendencies and how much time might be spending to water plants is another significant factor in choosing a medium. The combination of potting materials that will work best for garden plants mainly on Plant structure and root structures:

Ikebana

Flowers are generally known as the symbol of beauty around the world. Many people stick flowers in vases to wreath their rooms, houses and other places. Japanese FlowerArrangement is essentially different from the Western style of flower arrangement. The western style involves symmetrical arrangement of flowering plants in a vase whereas, the Ikebana, which means “flowers kept alive”, is much more intricate, complex and asymmetric. This style of flower arrangement is one of the famous cultural traditions of Japan known around the world. Generally, all Japanese flower arrangement styles are lumped together as ikebana but we cannot say they are all the same. Ikebana is a disciplined art form in which nature and humanity are brought together. Though it is a creative expression, it has certain rules governing its form. The main rule is that all the elements used in construction must be organic, be they branches, leaves, grasses, or flowers. The artist’s intention behind each arrangement is shown through a piece’s colour combinations, natural shapes, graceful lines and the usually implied meaning of the arrangement. They arrange flowers to recreate nature in miniature to see individual flowers which have been left behind. Ikebana is like one of the ways to communicate with nature. Another aspect present in ikebana is its employment of minimalism. That is, an arrangement may consist of only a minimal number of blooms interspersed among stalks and leaves. The structure of a Japanese flower arrangement is based on a scalene triangle delineated by three main points, usually twigs, considered in some schools to symbolize heaven, earth and man and in others sun, moon, love & earth. The container is also a key element of the composition and various styles of pottery may be used in their construction. Over time, the ways and styles have changed but there is still the basic idea of ikebana remain same.

For plant analysis to be meaningful, collection of particular plant part(tissue) at the right stage of growth is very important. A research worker in soil fertility is generally interested in finding out the nutrient uptake by crop at different stages. The stage at which nutrient uptake is to be studied will vary with different crops. One may also be interested in collecting a plant sample when some abnormality is observed in the plants and a nutrient deficiency or toxicity is suspected. In such cases no time should be lost in collecting the sample otherwise secondary reactions that often take place in the mineral content of plants will conceal the real cause of deficiency or toxicity. In such cases only the affected plants are to be sampled as compared to general sampling technique described below.

For research projects each plot receiving differential fertilizer or some other treatment is to be sampled separately. For general advisory purposes one sample would be good enough for the entire field (not exceeding 2 hectares). One should, however, take care that the sample comes from a field or a part there of having a uniform stand. If a field is patchy and differences in stand and plant growth are obvious, each such area should be sampled separately.

Stomach

Horse

The stomach of horse is a simple stomach. It is ‘J’ shaped sac with its right part very much shorter than the left part. It is situated in the dorsal part of the abdominal cavity behind the diaphragm and liver mainly to the left of the median line. The parietal surface faces craniad and dorsad and to the left. It is related to the diaphragm and liver. The visceral surface faces caudad and ventrad and to the right. It is related to the small intestine and colon. Its lesser curvature is short and the greater curvature is extensive. The left extremity is called the saccus caecus. It lies ventral to the sixteenth or seventeenth rib. It is related to pancreas and terminal part of greater colon caudally and to the base of the spleen laterally. The right extremity is the pylorus. It is smaller and is continued by duodenum. The stomach is fastened by several ligaments which include the gastro-phrenic ligament, the gastro- pancreatic ligament, the greater omentum, the lesser omentum and the gastro-splenic ligament. The capacity of the equine stomach is about 8 to 15 liters.

The wall of the stomach consists of four coats, the serous, muscular, submucous and the mucous. The mucous membrane is clearly divided into two parts by sinuous ridge called the margo plicatus. The part which is towards the left extremity is nonglandular while that towards the right extremity is glandular.

Animal Biotechnology

Biotechnology is defined as “the application of biological organisms, systems or processes to manufacturing and service industries” (Coombs, 1984).

It is also defined as “the application of scientific and engineering principles to the processing of materials by biological agents to produce goods and services” (Coleman, 1986).

Animalbiotechnologyis the application of scientific and engineeringprinciples to the processing or production of materials by animals to provide goods and services to human kind.

Abstract

Gender equity is more pronounced in livestock sector where more than 70% participation is from women side as compared to 33% in agricultural farming. About 75 million women are engaged in livestock sector. In India, livestock production is largely in the hands of women. In fact animal husbandry is becoming feminized. At present about 22% of milk and 2% percent of meat is processed into value-added products for trade while in developed countries it is above 90% and 60%, respectively. Traditional dairy products not only have established market in India but also great export potential because of strong presence of Indian diaspora in many part of the world. Value addition to dairy foods would provide health benefits to the consumers and improve the scale of economy in the dairy industry. Nearly half of the milk produced in India (50-55%) is utilized for the manufacture of value-added milk products but only 22% of the total milk produced is processed by the organized dairy sector. Conversion of surplus milk into indigenous milk products in and around production areas is least expensive and more profitable. Most of the animal farming activities such as cleaning of barn, washing of animals and hygienic maintenance, fodder collection, feeding, watering, and health care, management, milking, collection of dung for fertilizer and fuel, care of sick, pregnant and lactating animals, milking, household-level processing and value addition (ghee, curd, khoa, lassi and desi butter-making) are undertaken by women. However adoption of value-added livestock products as an entrepreneurship is scarce activity because of lack of training and financial liberties.

Abstract

84 per cent of the Indian rural women livelihood depends on agriculture. It is estimated that 52-75 per cent of the Indian women engaged in agriculture are illiterate. Prevalence of anaemia among pregnant women ranges between 50%-90%. From these facts it infers that ghost of food and nutritional security haunts the rural women health and prosperity. Female participation in the economic activities also determines the sex ratio because the work determines the worth in the society. It has been observed that in those families where women participate in economic activities, this problem is not severe as compared to those families which do not participate in economic activities. Diverse areas of entrepreneurship exists in rural India for women empowerment. This potential can be realized through policy and infrastructure support from the government and by strengthening proactive synergies among various farm and non-farm sectors activities. Although we are proud of the Indian women in the global arena yet we have peer into the atrocities against them in the name of female foeticide, gender inequality, sexual harassment, dowry system and many more evils with promotion of involvement in socio-economic enterprises, if rural transformation is to be achieved.

Tending is the term applied to pre-harvest silvicultural treatment of forest tree crops at any stage after initial planting or seeding. In other words, tending is the intermediate treatments that forest vegetation receives after establishment of regeneration and prior to final harvest of the stand. These tending operations can occur throughout the life of the forest stand, but do not include efforts directed at establishing regeneration. Tending operations play a fundamental role in the improvement of quality and stability of forest stands. Tending the trees after planting creates favourable conditions for both the plants’ survival and to stimulate a healthy, vigorous growth. Tending operations keep the plants from being suppressed by natural vegetation. It essentially covers operation on the crop itself and competing vegetation. Weeding, cleaning and thinning are important tending operations. Even improvement felling comes under tending operations but regeneration felling is not a tending operation. The major objectives of tending are to maintain sanitation, provide sufficient growing space, and more light, water, nutrients, etc. to the tree crops.

A series of efforts have been made to initiate the work on post harvest grain technology in India. The history of post harvest grain technology in India goes back as early as 1888 when COATS published several papers from Calcutta related to biology of stored grain pests. The first professional was appointed in the year 1905, known as Imperial Entomologist, Harold Maxwell Lefroy adorned with this post. Lefroy (1906) for the first time gave a tentative list of storage insects, which was further supplemented by Fletcher (1914). The problems of grain storage were discussed at the entomological meetings held at Pusa, Bihar in the years 1917, 1919 and 1923. The first step towards establishing an Institute in India was in the year 1950 when Central Food Technology Research Institute (CFTRI) was established at Mysore (Karnataka) with a mandate to train personnel and evolve technology related to food processing and preservation. The Central Warehousing Corporation was set up on 2^nd March 1957 under the Agricultural Produce (Warehousing and Development) Act 1956. The Food Corporation of India was established on 1^st January 1965.

In India, the farmers in traditional bulk and bag storage for food, feed and seed stored about 65-70 per cent of the total food grains and seed purposes till next harvest. Rest 30-35 per cent are procured and stored by food grain organizations, like Food Corporation of India (FCI), Central Warehousing Corporation (CWC), State Warehousing Corporations (SWCs), cooperatives, rural godowns and other state government agencies. In 1958, the Department of Food established a centre at Hapur known as Grain Storage Research and Training Centre (GSRTC) with the main objective to train the personnel of state government engaged in food procurement, storage and distribution. This centre was upgraded during 1968-1973 with the technical and financial assistance of UNDP and GSRTC and redesigned as Indian Grain Storage Institute (IGSI). The field stations at Ludhiana and Bapatla (later shifted to Hyderabad in March, 1979) were established in 1968-69. Subsequently, three stations were also established at Jabalpur (1980), Udaipur (1981) and Jorhat (1981).

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.

The first four stages are the immature stages and are known as juvenile stages. The female lays eggs in soil or in plant tissues, singly or in groups as egg mass that hatch out into juveniles which are almost similar to adults appearance. The first moult occurs within the egg shell and the second stage juvenile comes out by rupturing the egg shells as J₂. In case of Xiphinema index, the juveniles are reported to emerge from the egg before the first moult. The juvenile cuticle is shed after each moult.

The egg

The nematode eggs are oval in shape. The eggs are covered by three membranes, the external protein layer which is the secretion of uterus wall, the middle chitinous layer or the true shell secreted by egg itself and the inner lipid layer (vitelline layer). The chitin content in the egg shell vary in different species of nematodes.

The concept of gene has undergone several refinements since its discovery in 1866 by Mendel. Most genes encode one polypeptide and can be operationally defined by the complementation test. The complementation or cis-trans test provides an operational definition of the gene. It is used to determine whether mutations are in the same gene or in different genes. Intragenic complementation may occur when a protein is a multimer containing at least two copies of one gene product. The concept of gene has evolved from a bead on a string, not divisible by recombination or mutation to a sequence of nucleotide pairs in DNA encoding one polypeptide chain. The unit of genetic material not divisible by recombination or mutation is the single nucleotide pair. Historically several experimental developments have occurred to facilitate understanding of the structure and function of gene and these are briefly described in a chronological order as follows to have better understanding of the gene concept as it evolved. However, before discussing evidences supporting various gene concepts, it is better to summarize important stages in the evolution of the gene concept.

Abstract

The present investigation was carried out in okra consisting of 11 diverse genotypes (8 lines & 3 testers) and their 24 F1 hybrids. Phenotypic and genotypic correlation indicated positive association of average fruit length with average fruit weight while negative association between days taken to first flower with number of fruits per plant. The maximum positive direct effect on yield was due to number of fruits per plant followed by average fruit weight. The F₁ hybrid VRO-6 × Parbhani Kranti exhibits highest negative heterobeltiosis for days taken to 1^st flowering while D-1-87-5 × Pusa A-4 and Arka Abhay × Parbhani Kranti are earliest heterobeltiotic hybrids for days taken to 1st harvest. The hybrid Arka Abhay × Pusa A-4 represents highest heterobeltiosis for average fruit length, number of fruits/ plant and average yield. Among all parents, only Akra Abhay exhibits better GCA effect. The highest SCA effect for average yield observed in VRO-6 × Arka Anamika, while VRO-6 × Pusa A-4 for per cent infestation of YVMV. The cross Arka Abhay × Pusa A-4 incurred the highest net returns/ ha and B: C ratio (3.21) followed by that of D-1-87-5 × Parbhani Kranti and the parent Hisar Unnat gave the higher net returns/ ha with B: C ratio of 2.02 among the parents. These elite hybrids may be tested for yield and other quality traits under different agro-climatic conditions for commercial exploitation of hybrid vigour.

Abstract

Onion (Allium cepa L.) and garlic (Allium sativum L.) are important members of the family Amaryllidaceae. Bulbs, which are the edible component in both onion and garlic grow underground and are of nutritional and medicinal importance. These underground bulb vegetables are affected by many diseases caused by different microorganisms like fungi, bacteria, nematode and viruses causing huge economic loss. Stemphylium leaf blight caused by Stemphylium vesicarium, is the major fungal disease affecting their productivity of the edible bulbs adversely.The fungus primarily attacks the leaves but can affect bulbs in storage. Initial infection is characterised by appearance of small greyish white oval spots on the leaves. These spots are often surrounded by a yellowish halo with irregular margins. Fungal pseudothecia may over-winter in contaminated plant material or may survive in the soil having plant debris and ascospores are the primary inoculums in the following season. Spores require rain or persistent dew to cause infection. This disease can spread rapidly when environmental conditions are favourable for spore development. Suitable integration of more efficient treatments like fungicides, bio agents in combination with appropriate cultural control provide better management of the Stemphylium blight disease

1. pH meter

pH meter/electrode systems are the most common method of measuring pH in the biology laboratory. Although more expensive and more complicated to use than chemical indicators, pH meters provide greater accuracy, sensitivity, and flexibility. When used properly, pH meters can measure the pH of a solution to the nearest 0.1 pH unit or better, and they can be used with a variety of samples.

Agriculture Scenario

It has been seen since last few decades there is huge decrease in the production of the agricultural production. Three factors which can be held responsible for the increase of agricultural production per hectare:

1. Overall increase in efficiency due to the merger of farms and a more efficient redistribution of farm land.
2. More efficient cultural practises and better quality and availability of inputs (fertilizer, pesticides).
3. Genetic improvement of crops.

At this moment over 6 billion people need to be fed and it is expected that in the year 2050 more than 10 billion people will inhabit the earth (FAO, 1996). Moreover, demands per capita will rise when standards of living in developing counties improve. As a consequence there will be a huge increase in the demand for food, and production will need to triple in the coming 40 years. A continued effort to secure agricultural production in the future will therefore be vital. Reduction of losses caused by a-biotic and biotic stress will be a key issue. Scenario studies on world food security generally assume that a large increase in production will be achieved by genetic improvement of crop species and biotechnology. History has indeed shown a continuous increase in crop yields, resulting from plant breeding efforts. However, in the light of the speed at which the human population develops, and taking into account the expected reduction of available arable land due to climate change and human intervention, it may be necessary to accelerate the rate at which genetic improvement is achieved. Modern biotechnology provides new tools that can facilitate development of improved plant breeding methods and augment our knowledge of plant genetics. The knowledge that is obtained with these new tools can be used to contribute to an enhanced food security throughout the world.

Also Referred to as Microsatellites

SSR markers are based short sequences of nucleotides (2-6 units in length) that are repeated in tandem:

Di-nucleotide repeat: CACACACA

Tri-nucleotide repeat: ATGATGATGATG

It is believed that when DNA is being replicated, errors occur in the process and extra sets of these repeated sequences are added to the strand. Over time, these repeated sequences vary in length between one cultivar and another.

What are Retrotransposons?

The presence of mobile elements, capable of moving from one region of the genome to another, has been known and thoroughly studied since the 1950’s. These elements are capable of exciding and inserting themselves from one region of the chromatin to another, through their peculiar terminal repeat regions. This process is mediated by enzymes encoded by the transposon itself.

Retrotransposons are a class of mobile elements, widespread in plant genomes, where they account for a significant part of noncoding DNA. Barley, for example, contains thousands of copies of the Bare-1 element, dispersed throughout the euchromatic regions of chromosomes and exhibiting sequence identity higher than 95% to each other.

Unlike other classes of mobile elements, retrotransposons insert into the genome via an RNA intermediate, synthesized by their own reverse transcriptase, without the loss of the parental copy. Unique sequence properties show that retrotransposons of the Ty1-copia group are close to retroviruses, and their mode of integration in the host genome is also very similar.

The number and exact point of insertion of retrotransposons may differ from one individual to another and this can be exploited to characterize individuals, varieties or species, depending on how recent the transpositional event is. Furthermore, insertion of a retrotransposon is an irreversible event, a characteristic that can be helpful when tracing an ancestry.

Introduction

The western blot (alternatively, protein immunoblot) is an analytical technique used to detect specific proteins in a given sample of tissue homogenate or extract. It uses gel electrophoresis to separate native or denatured proteins by the length of the polypeptide (denaturing conditions) or by the 3-D structure of the protein (native/non-denaturing conditions). The proteins are then transferred to a membrane (typically nitrocellulose or PVDF), where they are probed (detected) using antibodies specific to the target protein.

There are now many reagent companies that specialize in providing antibodies (both monoclonal and polyclonal antibodies) against tens of thousands of different proteins. Commercial antibodies can be expensive, although the unbound antibody can be reused between experiments. This method is used in the fields of molecular biology, biochemistry, immunogenetics and other molecular biology disciplines.

Other related techniques include using antibodies to detect proteins in tissues and cells by immunostaining and enzyme-linked immunosorbent assay (ELISA).

The method originated from the laboratory of George Stark at Stanford. The name western blot was given to the technique by W. Neal Burnette and is a play on the name Southern blot, a technique for DNA detection developed earlier by Edwin Southern. Detection of RNA is termed northern blotting and the detection of post-translational modification of protein is termed Eastern blotting.

No breeding work has so far been done on kewda except selection of some promising morphotypes. Varietal improvement in kewda by breeding poses problems mainly due to dioecious nature and long life cycle of the plants, besides heterozygosity. Lack of promising strains is a major drawback. The wild growing population of kewda has a measure of variation and this has never been documented and utilized, which naturally offer a good scope for improvement of kewda by resorting to selection and subsequently propagating them vegetatively. Since a wide range of variation is available and the plants are mostly propagated by vegetative means, it is worthwhile to collect genetic stocks, access variability in morphological characters and attempt a breeding programme after selecting the desirable types for high flower production as the ultimate economate economic value of the plantations depends on the quantity of flower production to be used industrially in the distillation units.

Both dryland crops and irrigated crops experience an assortment of ecological or environmental stresses which include abiotic viz., drought, water logging, salinity, extremes of temperature, changes in atmospheric gases and biotic viz., insects, birds, other pests, weeds, pathogens. Dryland crops are more vulnerable to stress in the present context of changing climatic scenarios. The ability to tolerate or adapt effectively by challenging these stresses is a very complicated phenomenon would be due to various plant interactions occurred in the specific environment. Both biotic and abiotic stresses occur at various stages of plant growth and development and frequently more than one stress concomitantly affects the crop. It is difficult to distinguish effects of these stress factors on the performance of crop plants with respect to yield and quality of harvested products. This is of special significance of maximizing productivity of dryland crops in changing climate scenarios, with complex consequences for ecologically and environmentally sound Indian agriculture. In order to successfully meet this challenge, one should understand the various aspects of stresses in view of the current development and to promote a competitive dryland production system.

Introduction

Flat plate collector is the heart of a solar heat collection system designed for delivery of heated fluid in the low to medium temperature range (5o70oC above ambient temperature) for applications, such as water heating, space heating, drying and similar industrial applications. The flat plate collectors absorb both beam and diffuse radiation. The absorbed radiation is converted into heat which is transferred to water or air flowing through the collector tubes or duct, respectively. Such collectors do not require tracking of the sun and little maintenance is required.

The conventional flat plate solar air heater, shown in Fig. 7.1, consists of a flat blackened absorber plate, a transparent cover (such as a glass cover) at the top and insulation at the bottom and on the sides. The air to be heated flows through the rectangular duct below the absorber plate. The glass cover transmits a major part of solar radiation incident upon it to the absorber plate where it is converted into heat. The glass is, however, opaque to longwavelength radiation and thus it does not allow the infrared radiation from the heated absorber plate to escape.

Karwa et al. (2002) have presented the following deductions of heat collection rate and pumping power equations for the flat plate solar air heater.

Introduction

The sun is an abundant source of solar energy (average value on horizontal surface 6 kW m^-2 day^-1), which is freely available. This huge source of energy is non-polluting and inexhaustible in nature. It has the potential of supplementing the conventional energy sources to a great extent. There is acute shortage of conventional energy sources, which affects the overall development. Work on the utilization of such a huge, non-polluting and everlasting energy source has been carried out at CAZRI, Jodhpur for various domestic, industrial and agricultural applications in order to supplement the energy demand. This includes the development of a lot of solar thermal devices, such as, solar still, solar dryer, solar cooker, animal feed solar cooker, solar candle device and cool chamber. The details of some of these devices are given as following.

Introduction

The thermal performance of a building refers to the process of modeling the energy transfer between a building and its surroundings. For a conditioned building, it estimates the heating and cooling load and hence, the sizing and selection of HVAC equipment can be correctly made. For a non-conditioned building, it calculates temperature variation inside the building over a specified time and helps one to estimate the duration of uncomfortable periods. These quantifications enable one to determine the effectiveness of the design of a building and help in evolving improved designs for realizing energy efficient buildings with comfortable indoor conditions. The lack of proper quantification is one of the reasons why passive solar architecture is not popular among architects. Clients would like to know how much energy might be saved, or the temperature reduced to justify any additional expense or design change. Architects too need to know the relative performance of buildings to choose a suitable alternative. Thus, knowledge of the methods of estimating the performance of buildings is essential to the design of passive solar buildings.

5.1 APOMIXIS

Apomixis is derived from two Greek words “Apo” (away from) and “mixis” (the act of mixing or mingling). It refers to the occurrence of an asexual reproductive process in the place of normal sexual processes involving reduction division and fertilization. During sexual reproduction, developmental steps occurring inside the ovule produce the female gametophyte (embryo sac) and following a double fertilization event give rise to embryo and endosperm structures. Apomixis can be best described as the reference to the asexual process. In some species, embryo sac is produced not as a result of meiosis and fertilization but by certain asexual processes. The occurrence of such asexual reproductive process in the place of normal seed reproductive processes of reduction division and fertilization is known as Apomixis. Such seedling plants produced in this manner is known as apomicts. ’’Apomixis’’ is used synonymously with ’’agamospermy’’ (Stebbins 1950), referring to the asexual production of seed.

Apomixis (asexual seed formation) is a phenomenon in which a plant bypasses the most fundamental aspects of sexual reproduction—meiosis and fertilization—to form a viable seed. Plants can form seeds without fertilization, and the seed genotype is consistent with the female parent. The development of apomictic technology would be revolutionary for agriculture and for food production as it would reduce costs and breeding times and also avoid many complications typical of sexual reproduction (e.g., incompatibility barriers) and of vegetative propagation (e.g., viral transfer). The application of apomictic reproductive technology has the potential to revolutionize crop breeding. Apomixis is widely distributed among higher plants. More than 300 species belonging to 35 families are apomictic. It is most common in Gramineae, Compositae, Rosaceae and Rutaceae. Among the major cereals maize, wheat and pearl millet have apomictic relatives. Apomixis is reproduction where only one parent passes genes to the offspring (King, 2006). Apomictically produced offspring are genetically identical to the parent (clones).The method is mostly seen in plants, especially flowering plants. Apomixis was defined by Hans Winkler (2008) as the replacement of the normal sexual reproduction by asexual reproduction, without fertilization. Propagation from cuttings or leaves, is not apomixis. Natural replacement of the seed by an asexual method is apomixis.

INTRODUCTION

Potato (Solanum tuberosum L.) is one of the major food crops whichrecorded total globalproduction of 388.1million metrictonnes(mt) in 2017-18. Out of the major staple food crops, potato production (388.1mt) is exceeded only by maize (1077.98 mt), wheat (761.88 mt) and rice (494.88 mt) (FAOSTAT, 2017). According to the three years (2012-2014)averages,globally, India ranks 3^rdin area and 2^ndin terms of production nextto China. Thenutritional quality, high productivity and acquiescence for inclusion in intensive cropping systems of this shortduration crop reflects its great potentialin modern agriculture to feed theexponentiallyrisingpopulationin the developingcountries. But, theintensive cultivation of potato crops urges increased use of fertilizers, pesticides and other chemicals leading to high input costs with plateauingyields. Blanket dose of fertilizers as well as imbalance use of nutrientsnot only increases the cost of farm inputs but also degrades soil condition and causes severe environment pollution. Indiscriminate use of insecticide as well as fungicide is verycommon in potato crop which contaminate the environment and deteriorate product quality. Therefore, the chemical inputs need to be optimised based on actual requirement of the crops for sustainable crop production. Furthermore, potato production is associated witha high tillagepractices, number of tillage operation would depend on soiltype, previous crop etc.

INTRODUCTION

Potato is an important horticultural food crop which has the potential to meet food demand of the fast growing human population across the world, including India. This is going to be the future food crop for the millions especially in the third world countries. However, this crop is highly prone to wide range of diseases and pests that are considered to be the main bottle neck in potato production across the globe. Amongst the biotic stresses, late blight caused by oomycete Phytophthora infestans (Mont.) de Bary has historically been an important disease of potatoes and tomatoes worldwide. In the mid 1800, late blight caused widespread crop failures throughout Northern Europe including Ireland where it was responsible for the Irish famine. Since then, it has spread far and wide and now occurs wherever potatoes are grown. Losses due to P. infestans have been estimated to € 12 billion per annum of which the losses in developing countries have been estimated around € 10 billion per annum (Haverkort et al., 2009). In India, average annual losses to the tune of 15% have been estimated which amounts to 7.95 million tons of potatoes (Current production is 53 MT). Disease appears every year in epiphytotic form in hilly regions whereas in the plains, although it usually appears every year but its intensity is low (traces to 25%). It is only in few years that it assumes epiphytotic form leading to crop losses to the tune of 40%. Recently, late blight has become a serious problem in kharif grown potatoes and tomatoes in Karnataka state (Sharma et al., 2015). Phytophthora infestans is considered as re-emerging pathogen due to regular emergence of its novel strains with increased virulence and its appearance in new locations with surprising intensity. Management of this devastating pathogen is challenged by its remarkable speed of adaptation to control strategies such as genetically resistant cultivars.