eChapters

Introduction

Under arid and semi-arid regions of the world, major problems are salinity, alkalinity and calcareousness, which seems to further aggravate with changing climate scenario. Besides, most of the developing countries lies in this zone with flanging population resulting from shrinking of land resource and good quality of irrigation water. Globally area under saline/sodic soils is about 953mha covering 8% of the land surface. Resent estimates indicate that 6.7 mha area in India is affected by soil salinity and alkalinity and about 25% of ground water are sodic and/or saline in the country. There are two important approaches for utilizing saline alkali or calcareous environment. The first one is to modify the environment so as to suit the plant or modifying the plant and the second one is to substitute the plant species so as to suit the environment. However, second option is cost effective and most sustainable.

Vegetable production in our country is significantly influenced by the seasonality and weather conditions. Extends of abundance and deficiency in production and availability cause considerable fluctuations in the prices and quality of vegetables. Vegetable production, at present, is also characterized by a strong dependence on chemical plant protection with its all inherent environment and health hazards, both for growers and the consumers. Strinking a balance between all-season availability of high quality vegetables with minimum environment impact, and still to remain economically competitive in this time of globalization, is a major challenge for the modern technology of crop production. The crop productivity is influenced by the genetic characteristics of the cultivar and the management practices including nutrients, water and microclimate. Under open field cultivation, while the other factors could be taken care of, it is not possible to effect control on the microclimate around the plant.

Introduction

Fast and efficient dissemination of suitable technological information from the Agricultural Research System to the Farmers in the field and reporting of farmers’ feedback to the research system is one of the critical inputs in Transfer of Technology. Today India is at the verge of technology revolution with immense number of agriculture, home science and livestock technologies developed by the research institutes to enhance the agriculture and livestock production. These technologies have changed the total production of agricultural commodities in the country.

Apple codling moth: Cydia (Carpocapsa) pomonella: Tortricidae 

This is an international pest and is now seen in Kashmir, Himachal Pradesh and Tamil Nadu. This is a fruit borer whose moth is silvery white with a dark band on the margin of the forewing and light brownish hind wings with a fringed margin. The moths hold their wings roof-like over the body while at rest.

Citrus butterfly: Papilio demoleus, P. polytes : Papilionidae

The pest is distributed all over the world and has a host range that includes citrus and other rutaceae plants like Aegle marmelos. Adult has the head and thorax black with a creamy-yellow coloration on the underside of the abdomen. Wings are dull black, orna-mented with yellow markings and a distinct red patch on the hind wing. The underside is orange and yellow coloured and can be seen when it flirts for honey collection or just before egg laying. The Antenna is black and clubbed.

Mango Fruit fly : Bactrocera dorsalis : Tephritidae

This is probably the most economically important pest of mango. It can attack many crops like mango, guava, peach, apricot, cherry, pear, ber, citrus, banana, papaya, avocado, passion fruit, coffee, melons, jack fruit and strawberry. There are also related species that may cross infect. The adults are light brown small flies with a single pair of membranous transparent wings. The other pair is modified into halteres. Eggs are thrust into the skin of the mangoes when they are semi ripe. A drop of resin comes out of the ovipunctures and can be seen as a black mark. While purchasing mango, this can be used as an indication of the presence of the fruit fly eggs.

Spindle bug: Carvalhoia arecae :Miridae

Spindle bug is a serious pest multiplying rapidly with the close of monsoon. The adults are red and black and nymphs are greenish in colour with reddish brown patches. Both these stages colonize the top-most leaf axils at the base of the spindle. Adults and nymphs suck the sap from emerging spindle, tender leaves and other tender parts. For feeding they move out and later return to the axils again. At the site of feeding a longitudinal narrow, decolourised zone develops rapidly on either side of the puncture, along the length of the leaf blade. The decolourised patch gradually turns yellowish, then brownish, become stunted, twisted and malformed in a few days and dries up. In this way the tissues may break away and drop off in the wind leaving shot holes on the leaves. In cases of severe infestation the leaves get shred, stand erect and the palms become stunted.

Tea tortrix/flushworm: Homona coffearia:Tortricidae

The tortrix is  an important pest of tea leaves. The larvae make leaf nests by webbing the leaves using silken threads and feed from inside. A single caterpillar makes several cases. Young larvae prefer tender leaves, while the older larvae are seen in mature leaves. The economic produce being the leaves, and since chemical control is not advised, especially during the picking phase, the pest becomes a management problem.

Aphids: Myzus persicae, Lipaphis erysimi and Brevicoryne brassicae Aphididae
 
Aphids suck the sap from potato foliage, causing wrinkling, cupping and downward curling of young leaves. The older leaves will become yellow, wilt and fall off.  They also excrete honeydew on which sooty mould develops covering affected parts with a thin superficial black coating that hinders photosynthetic activity of leaves resulting in stunted growth of plants. In addition, they also act as vectors, for transmitting potato leaf roll virus. Major damage by M.persicae and A. gossypii is through transmission of potato leaf roll virus.

Fruit flies: Bactrocera cucurbitae:Tephritidae

This pest is more serious in bitter gourd, snake gourd and to a certain extent on ridge gourd. Other cucurbits are attacked to a lesser level. Damage by this pest causes losing the fruit quality, rotting and fruit drop. The adults lay many eggs inside the fruit sing their big ovipositor that hatch out into worm like apodous maggots. Feeding by the maggots on the pulp of fruits result in rotting, yellowing and fruit drop. The dropped fruits allow pupation by the maggots in the soil from where they emerge out as adults and start egg laying on fresh frits.

Fruit borer: Helicoverpa armigera: Noctuidae

This is a medium sized moth yellowish brown in colour with a wing

span of about 3 cm and a body length up to 1.4 cm. There is a dark speck and a dark area on the outer margin of each forewing. The forewings also have greyish wavy lines and black spots of different sizes on the upper side.

11.1 Introduction

The analysis of variance is a powerful statistical tool for tests of significance.  The test of significance based on t-distribution is an adequate procedure only for testing the significance of the difference between two sample means. In a situation when we have three or more samples to consider at a time an alternative procedure is needed for testing the hypothesis that all the samples are drawn from the same population, i.e., they have the same mean. For example five fertilizers are applied of four plots each of wheat and yield of wheat on each of the plot is given we may be interested in finding out whether the effect of these fertilizers on the yields is significantly different or in other words, whether the samples have come from the same normal population. The answer to this problem is provided by the technique of analysis of variance. Thus basic purpose of the analysis of variance is to test the homogeneity of several means.

Introduction

Data are the most critical element of a GIS. It is reported that more than two thirds of the time and expenditure to develop a GIS is spent on data collection and organization. Understanding and appreciating the criticality of data is of paramount significance to practice GIS. This chapter is complementary to database concepts chapter discussed in Level II and deals with the fundamentals to start with and the concepts of building an information organization.

Data - A Definition and Certain Points to Ponder

“Data” are defined as a body of facts or figures, which have been gathered systematically for one or more specific purposes.”

Introduction

Data input or capture is the operation of encoding the data and incorporating in the database. The creation of a clean error free digital database is a complex and critical task determining the very usefulness of a GIS. GIS data represent not only where the graphic or cartographic features occur, but also the associated attributes of them.

Data input to a geographical information system involves

(a) Entering the spatial data (digitizing);

(b) Entering the non-spatial, associated attributes and

(c) Linking the spatial to the non-spatial data.

At each stage necessary verification and checking procedures shall be deployed to ensure an error free database.

Introduction

The term geographic information systems (GIS) has come to mean, variously, an industry, a product, a technology, and a science. As such, the term invokes different perceptions dependent on whether the viewpoint is that of the software developer, the system marketer, the data provider, the application specialist, or the academic researcher, among others. A newcomer to the field is likely to be bewildered by the multiple uses of the same term, or, seen alternatively, different definitions of the same term. For instance some find it distasteful to use of the conventional acronym GIS and prefer Geospatial Technology. With all the variety of perceptions predicting the future of GIS is a cumbersome business. The most certain inference we can gain from the available trends is, it is growing and is poised for further growth. Geotechnology along with Nanotechnology and Biotechnology is considered as of the three most promising growth industries for the near future.

Introduction

Famous French postmodern philosopher Jean Baudrillard commented on information once. “Information can tell us everything. It has all the answers. But they are answers to questions we have not asked, and which doubtless don’t even arise.” This seemingly paradox observation fits contemporary Internet age perfectly. Internet is a vast repository of information of all kinds and is bursting on its seams. The seeker needs to search with monumental grit and determination to have a full handle on the range of information available for any particular search. A search string for GIS returns more than 1185000 results, in a mere 0.26 seconds. Recommending a comprehensive resource list is not possible as new material gets continually added by way of additions and updates. However for a beginner the list given below will be handy. The flip side is GIS has innumerable resources and a broad range of content. Software vendors, organizations, individuals, universities and companies have provided a wealth of information. The readers are exhorted to make use of the materials to improve their understanding of the subject.

IPGRI founded in 1974 is the world’s largest international institute dedicated solely to the conservation and use of plant genetic resources. It is located at Rome in Italy. The institute is funded by the Consultative Group on International Agricultural Research (CGIR) which is an informal association of 45 public and private sector donors. CGIAR supports a network of 16 International Agricultural Research Centres. The Group was established in 1971. It is cosponsored by the Food and Agriculture Organization (FAO), the World Bank, United Nations Development Programme (UNDP), and the United Nations Environment Programme (UNEP).

Biodiversity is the foundation stone of human survival on the earth. Very appropriately, the theme of the World Food Day celebration, 16 October, 2004 was “Biodiversity for Food Security” Biological diversity is fundamental to agriculture and food production. Scientists have identified so far about 1.4 million of the plant and animal species that exist on earth. A rich variety of cultivated plants and animals serves as the foundation for agricultural biodiversity. Yet people depend on just 14 mammal and bird species for 90 % of their food supply from animals. Just four plant species, namely, wheat, maize, rice and potato provide half of our energy from plants (FAO, 2004).

India is located between 8^°- 38^° N and 68^°- 97^ºE and exhibits extreme variation in altitude — from sea level to heights above vegetational limits in the Himalayas (ca 4500 m), and climate — from monsoon- tropical in south to temperate and alpine in the north-western Himalayas and extremely arid to semi-arid in the north-western plains. It is floristically extremely rich with about 33 percent of its botanical wealth (over 15,000 species of higher plants) being endemic. There are about 141 endemic genera distributed over 47 families. Further, of the 4,900 endemic species, larger percentage is localised in the Himalayas (about 2,532 species) than in other regions, namely, the peninsular tract (1,788 species), and the Andaman and Nicobar Islands (185 species). It is also estimated that floristic richness is maximum in the north-eastern region, which holds about 50 percent of India’s total species diversity, i.e., more than 7,000 species, and is considered as the cradle of flowering plants. Of 990 species of orchids, 700 species occur in this region (Nayar, 1989). This, thus, makes the Indian region botanically unique and interesting (Arora, 1991).

Certified seed must meet certain seed standards in order to ensure an adequate level of seed purity along with the reasonable level of seed germination so that the farmer gets a good stand of the crop conforming to the varietal description. The components of the seed standard are as follows :
     The minimum percentage of pure seed 
     The maximum permissible limit for inert matter 
     Other crops seeds  
     Weed seeds 
     The maximum permissible limit for objectionable weeds 
     The maximum permissible limits of seeds of other distinguishable varieties (ODV) 
     Maximum permissible limits of seeds infected by seed bone diseases 
These standards are ensured in the seed crop by strictly adhering to field standards and careful harvesting, threshing, seed drying and then brining the same to the seed processing /seed conditioning plants. The Indian minimum seed standards for different crops are given in Tables 24.1-24.3 (Agarwal, 1995).