eChapters

Taxonomy

Taxonomy is the science that deals with the identification nomenclature and classification of organisms.

Nomenclature

It is the system of assigning names to the taxonomic groups or organism according to international rules.

Systematics

It is scientific study of organisms with the ultimate object of characterizing and arranging them in an orderly manner.

GENERAL CHARACTERISTICS OF FUNGI

1. Thallus

The body of the fungus is called as Thallus, which is without stem root and leaves. It maybe Plasmodial, Pseudoplasmodial , Pseudomycelial or Mycelial. A single thread like filament is called as hypha. A hypha is made up of a thin, transparent tabular wall filled or lined with a layer of protoplasm.

A group of hypha constituting the body of fungus is called as mycelium may be septate or aseptate. i.e coenocytic.

a) Coenocytic or Nonseptate or Aseptate Mycelium

When mycelium is not divided by cross walls called as Cornocytic mycelium.

Depending upon the nature of parasitism with the host plant, mycelium is either ecotophytic or endophytic.

b) Septate Mycelium

When mycelium is divided by cross walls or septa called as septate mycelium.

Plant diseases are classified on the basis of type of pathogenic or non- pathogenic causes of the disease. The classification is based on the plant pathogenic organisms as follows.

PARASITES

They include both biotic and mesobiotic agents. The diseases are incited by parasites under a set of suitable environment. Association of definite pathogen is essential with each disease.

i. Biotic agents: They are also called as animate causes. They are living organisms. Biotic agents include:

History in general reveals chronological account of important events, contribution of persons who significantly influenced the thinking of their era and the interpretations of the observed facts or phenomenon over the period of time. The progress in plant pathology leading to the major land mark in mycology, plant bacteriology, plant virology and plant disease control has been described in chronological order for easy and better understanding of the student in following sub-headings.

DEFINITION

The term Plant Pathology is derived from Greek words- pathos (suffering) + Logos (study) i.e. the study of the suffering plant. Plant Pathology has two phases broadly-

• Science- understanding of the disease i.e. the theoretical consideration of the suffering plants and how do pathogens invade, how do plants defend themselves, what causes symptoms etc.
• Art- the application of the science to the field problems i.e. Diagnosis and Control.

Plant pathology or phytopathology is the branch of agricultural, botanical or biological science which deals with the cause, etiology, resulting in losses and management methods of plant diseases.

Plant pathology can also be defined as the study of the nature, cause and prevention of plant diseases. Plant pathology is related to most of the old and new sciences like biology, physics, chemistry, physiology, mathematics, genetics, soil science, biochemistry, biotechnology etc.

Study of plant pathology includes the study of sciences viz, microbiology, bacteriology, virology, mycology, nematology, protozology, phycology, unfavorable environmental factors, nutritional deficiencies and flowering plant parasites.

Plants make up the majority of the earth’s living environment as trees, grass, flowers, etc. Plants are the only higher organisms that can convert the energy of sunlight into stored, usable chemical energy in carbohydrates, proteins and fats. Directly or indirectly, plants make up all the food on which humans and all animals depend. Plants however also gets sick, grow and exhibit various types of symptoms and sometimes whole plant die. It is not known whether diseased plant feel pain or discomfort. If a plant is looking different from its community then it is equal to be disease one. Any biotic or abiotic agents which induce the disease in plant is referred as the cause of diseases.The causative agents of disease in plants are pathogenic such as fungi, bacteria, viruses, protozoa and nematodes and environmental conditions such as lack or excess of nutrients, moisture, light, etc to presence of toxic chemicals in air or soil. These biotic constraints can, at times, seriously compromise food security, For example, potato late blight, caused by Phytophthora infestans, struck Europe like ‘a bolt from the blue’ in the 1840s. In Ireland, about a million people died of starvation and more than a million attempted to emigrate. The reasons for this calamity were the arrival in Europe of a virulent strain of the pathogen, the high dependence of much of the Irish population on potato for sustenance, the lack of resistance in the plant to the pathogen, and weather conditions favorable to epidemic development. There have been other disasters caused by plant diseases such as the Great Bengal Famine of 1943 and the southern corn blight epidemic of 1970-71 in the USA, to name but two. In the former, an estimated 2 million people died owing to the high dependence of most of the population on a single crop, rice, which was attacked by the fungus Cochliobolus miyabeanus. In the USA, by contrast, although in some genus, Cochlobolus heterostrophus, alternative sources of nutrition were plentiful so no one died, although the effect on the agricultural economy was severe.

The first two of these heartbreaking examples demonstrate with brutal clarity that in areas of the world where a large proportion of the population is dependent on a single crop or a few crops, they are at risk should that crop fail owing to one or more devastating diseases. At the present time, the threat is partially great in developing countries, where populations are growing fastest, poverty is endemic , the population depends upon on locally produced staples, and the infrastructure of extension and R&D is often poorly resourced. The losses due to weeds, disease and insects have been estimated to around 40% in the developing and underdeveloped countries. If the post harvest losses (15-20%) are also added , the situation becomes even more alarming.

The transition from conventional to organic farming requires numerous changes. One of the biggest changes is in the mindset of the farmer. Conventional approaches often involve the use of quick-fix remedies that, unfortunately, rarely address the cause of the problem. Transitioning farmers generally spend too much time worrying about replacing synthetic input with allowable organic product instead of considering management practices based on preventative strategies. Here are a few steps new entrants should follow when making the transition to organic farming:

20.1. Understand the Basics of Organic Agriculture and the Organic Farming Standards

Since organic production systems are knowledge based, new entrants and transitional producers must become familiar with sound and sustainable agricultural practices. Transitional producers should be prepared to read appropriate information, conduct their own trials and participate in formal and informal training events. As mentioned, switching from conventional to organic farming is more than substituting synthetic materials to organic allowed materials. Organic farming is a holistic system that relies on sound practices focused on preventative strategies. Since there are often few organic remedies available to organic producers for certain problems, prevention is the key element in organic production.

In food production remarkable progress has been made in the last fifty years in agricultural production and self – sufficiency (Food security) has been reached. Yet nutritional security seems to be a distant goal. With depleting natural resources and increasing threat to the environment, sustainable crop production is attracting the attention of the scientists, farmers and administrators. Due to over exploitation of natural resources and indiscriminate use of agro chemicals, green revolution also brought in quite a lot of miseries which focus the urgent need to have EVERGREEN REVOLUTION that is sustainable, leading to food and nutritional security to the rural poor. At this juncture it will be more appropriate to practicing organic agriculrure through the integration of traditional wisdom and modern scientific knowledge in synergy with nature.

19.1. Eco-friendly Technologies for Rice Cultivation

A sound package of eco-friendly technologies to grow rice is being successfully adopted by a few progressive farmers in Puliangudi village in Tirunelveli district of Tamil Nadu. “The technologies work well with indigenous rice varieties such as Kitchili Samba. The cost of cultivation is substantially reduced and the organic rice fetches a premium price in the market,” says Mr. P. Gomathinayagam, a pioneer in organic farming in Puliangudi.

In India, there are two accreditation systems for authorizing Certification and Inspection agencies for organic certification. National Programme on organic Production (NPOP) promoted by Ministry of Commerce is the core programme which governs and defines the standards and implementing procedures. National Accreditation Body (NAB) is the apex decision making body. Certification and Inspection agencies accredited by NAB are authorized to undertake certification process. The NPOP notified under FTDR act and controlled by Agricultural Processed Foods Export Development Authority (APEDA) looks after the requirement of export while NPOP notified under APGMC act and controlled by Agriculture Marketing Advisor, Directorate of Marketing and Inspection looks after domestic certification. Currently 20 certification agencies have been authorized to undertake certification process.

National Programme on Organic Production

National Program on Organic Production (NPOP) was launched during 2001 under the Foreign Trade & Development Act (FTDR Act). The document provides information on standards for organic production, systems criteria, and procedures for accreditation of Inspection and Certification bodies, the national organic logo and the regulations governing its use.

Realizing that nematodes cannot be eliminated, and that we must live with them, the overall goal is to keep the population density as low as possible. The economic threshold is the density of nematodes where the losses incurred exceed the cost of nematode management. It is not advisable to depend on a single method to control nematodes. Efficient management requires judicious and careful integration of several which will result in reduction of nematode populations. Important components of non chemical methods of nematode management program are considered in this chapter.

17.1. Organic Amendments

Manure and fertilizer applications are essential part of growing any crop. Besides supplying required essential nutrients theyhelp in many ways directly or indirectly by suppressing harmful organisms including phytonematodes. The use of organic amendments against nematodes was demonstrated by Linford et al., in as early as 1938. FYM and cattle urine have found to reduce nematode population. Biogas plant waste slurry was found to be effective for nematode management. Compost of water hyacinth, oilcakes, cellulose amendments like sawdust, wheat straw, rice husk, rice hull ash, green manuring with legumes, green leaf incorporation are useful to keep nematode populations low. Non - edible oilcakes like those of neem, karanj, mahua, caster, cotton as well as edible oilcakes groundnut, mustard sesame, coconut have been recommended at 2 - 2.5 t/ha for reduction of root knot and other nematode population in soil. Miscellaneous substances like decaffeinated tea waste, rice hull ash, chicken manure, tannery and food and fruit processing waste, market and domestic organic refuse, dead vegetation and crop stalks, wood shaving, etc. have been recommended for root knot nematode management. Castor leaves (40g/kg) along with NPK at 75:25:37.5 kg/ha achieved reduction of M. javanica population on tomato.

Paddy is cultivated about 45 m ha in India, less than 1% is under organic cultivation.

16.1. Varieties

Good quality fine varieties like Ponni, Super ponni, insect and disease resistant varities must be selected for getting higher yield and returns.

16.2. Seeds

Organically produced seeds only must be used.

16.3. Seed Treatment

For 1 kg of seeds 20 g Azospirillum, Pseudomonas and 10 g Phospobacteria must be used with rice gruel.

Panchagavya spray @ 1% for treating the seeds.

15.1. IFS Components Tested for Wetlands

Area Allocation;

In 1 ha of land

75 % - Cropping

10 % - Fodder cultivation

3 % - Goat shed

12 % - Fish pond

Possible Integrations:

14.1. Water Source Identification

• In places where Ficus religiosa tree is found, underground water will be more.
• Underground water will be more in places where the neem tree with more knots is found.
• In places where termite hills are found, underground water will be more.
• Farmers are practicing traditional method of using neem stick, metals etc. for finding the water resource in underground for digging wells. While they are walking with this stick on hand it will be rottate automatically at the place where underground water is surplus.
• Some farmers are using the magnetic stones for identifying water sources. Magnet is tied with a thread and held like a pendulum while walking over the fields. The magnet will rotate automatically at the place where underground water is more and this is taken as the indication for digging wells.

13 1. Rishi Krishi

Drawn from Vedas, the Rishi Krishi method of natural farming has been mastered by farmers of Maharashtra and Madhya Pradesh. In this method, all on-farm sources of nutrients including composts, cattle dung manure, green leaf manure and crop biomass for mulching are exploited to their best potential with continuous soil enrichment through the use of Rishi Krishi formulation known as “Amritpani” and virgin soil. 15 kg of virgin rhizosperic soil collected from beneath of Banyan tree (Ficus bengalensis) is spread over one acre and the soil is enriched with 200 lit Amritpani.

It is prepared by mixing 250 g ghee into 10 kg of cow dung followed by 500 g honey and diluted with 200 lit of water. This formulation is utilized for seed treatment (beej sanskar), enrichment of soil (bhumi sanskar) and foliar spray on plants (padap sanskar). For soil treatment it needs to be applied through irrigation water as fertigation. The system has been demonstrated on a wide range of crops i.e. fruits, vegetables, cereals, pulses, oilseeds, sugarcane and cotton.

12.1. General Practices for Storage

• Lime juice is mixed with grains and then sun dried before storage to prevent insect pests (Farmers in Nigeria).
• Seeds are safely stored in earthern pots after mixing with the leaves of neem and Vitex negundo (Farmers in Gujarat, India).
• Drying seeds and grains of all the crops on the new moon day before storing to avoid pest attack.
• Store seed materials in earthen pots which are kept on the ‘Paran’ directly above the furnace in kitchen. The smoke acts as a repellent.
• Grains, trees etc. harvested on full moon day are raqre prone to storage pest attack.
• Mixing the dried leaves of neem with seeds while storing them.

Change in weather affects growth and development of plants. The extent of these effects depends upon the range or severity of change of weather. It is very much possible to change the weather in relatively small area to reap better harvest. Micro weather modification is defined as, “The manipulation of weather elements at increasing or decreasing the duration, intensity, quality etc., for desired effects at microlevel of crop under investigation”.

The climate near the ground can be managed partly by influencing the moisture status and temperature of the upper soil layers, e.g. by mulching and partly by action above the ground e.g. by shading or use of wind breaks.

Soil regeneration is about bulding or making topsoil. It is a particular form of ecological regeneration within the field of restoration ecology is the act/idea of replenishingthe top soil with beneficial nutrients casing natural methods. Time required from inorganic to organic would be about 60 to 200 days depending upon the situation. Once the inorganic fertilization is stopped, following actions facilitate quick conversion:

• Apply Farm yard/Poultry manure available in the farm as a basal dressing.
• Sow 25 kg of multi varietal seeds (MVS) in one acre.
• Allow it to grow up to 60 days.
• Inoculate the soil with the bio-agents like Azospirillum, Phosphobacterium, Pseudomonas flouresens, Trichoderma viride on 30 days after sowing (DAS).
• Incorporate in situ 60 DAS (30 t ha^-1 biomass is generated on 60 DAS) green manures.

9.1. ITKS for Seed Treatment and Sowing

• Yield of almost all the crops depends on seed quality.
• Even if it is a quality seed, it should be a dried one because well dried seeds will have higher longevity and keeping quality.
• It better to change the seeds at least once in two years.
• To maintain the seed viability and prevent it from outside damage, the outer shell is not separated.
• The seeds are generally stored along with the leaves of neem (Azadirachta indica), pungam (Pongamia pinnata), notchi (Vitex negundo) and thumbai (Leucas aspera).
• Six weeks nursery period is enough for six months duration of the crop.
• Shallow sowing is followed in dry lands.
• Severing the broadcasted seeds in dry lands with soil.
• Dragging, over the fields, the thorny branches with weight over them for covering seeds the sown on dry lands.
• It is better to start planting from ‘Sani moolai’ (north east) of the field to get higher yields.
• It is better to perform sowing and planting operations during evening hours.

8.1. Documented ITKs on Moisture Conservation

The ITKs were documented under following specific categories

• Agronomic Measures
• Tillage
• Bunding & Terracing (Mech. & Vegetative barrier)
• Land Configuration
• Soil Amendment / Mulching
• Erosion Control & Runoff Diversion Structures
• Water Harvesting, Seepage Control & Ground Water Recharge

7.1. Rice

• Treatment of paddy seeds in diluted bio gas slurry for 12 hours increases resistance of seedlings to pests and diseases.
• During panicle formation in paddy, the flowers of Cycas circinalis are placed on sticks in paddy fields @ 4/ac. Its unpleasant odor repels ear head bugs.
• About 30 kg of tamarind seeds are applied for an acre of paddy field 1 day after transplanting to boost up the crop growth and yield.
• Soaking the paddy seeds in diluted cow’s urine before sowing, considerably reduces the incidence of leaf spot and rice blast
• Presoaking of paddy seeds in milk increases its resistance against ‘tungro’ virus and ‘stunt’ virus
• For control of red leaf spot disease in paddy, the seeds are soaked in ‘Pudina’ leaf extract (Mentha sativa) for 24 hours
• ‘T’ shaped bamboo stands are placed in many places in the paddy fields so that birds can sit on them and feed on the larvae and adults of rice pests.
• Sowing on eighteenth day (Aadipperukku) of Tamil month Aadi (Jul-Aug.) ensures good harvest.
• Daincha (Sesbania spp.) seeds are sown on paddy main fields when paddy nursery is raised and the grown up daincha is ploughed in-situ during field preparation.
• Plough the main field for four to six times for better yield.