Sexual Reproduction in Flowers – Parts of flowers

Pre-fertilization: structures and events The hormonal and structural changes in plant lead to the differentiation and development of floral primordium. The structures and events involved in pre- fertilization are given below Male Reproductive part – Androecium Androecium is made up of stamens. Each stamen possesses an anther and a filament. Anther bears pollen grains which […]

Continue Reading

Sexual Reproduction In Plants

Sexual reproduction involves the production and fusion of male and female gametes. The former is called gametogenesis and the latter is the process of fertilization.recall thesexual reproduction in algae and bryophytes. They reproduce by the production of gametes which may be motile or non motile depending upon the species. The gametic fusion is of three […]

Continue Reading

Vegetative Reproduction Methods – Studymaterial

Vegetative reproduction Natural methods Natural vegetative reproduction is a form of asexual reproduction in which a bud grows and develops into a new plant. The buds may be formed in organs such as root, stem and leaf. At some stage, the new plant gets detached from the parent plant and starts to develop into a […]

Continue Reading

இயற்கை விவசாயி அய்யா நம்மாழ்வாரின் வாழ்க்கை வரலாறு

நம்மாழ்வார், தஞ்சை மாவட்டத்தில் 06 ஏப்ரல் 1938 ஆம் ஆண்டு பிறந்தார். இவரின் தந்தை ச. கோவிந்தசாமி மற்றும் தாயார் அரங்கநாயகி என்கிற குங்குமத்தம்மாள் ஆகியோர்கள் ஆவார்.(சான்று த.ரெ.தமிழ்மணியின் நம்மாழ்வார் வாழ்க்கைக் குறிப்பு நூல்) இவர் அண்ணாமலைப் பல்கலைக்கழகத்தில் விவசாயத்தில் இளங்கலைப் பட்டம் பெற்றார். 2007 ஆம் ஆண்டு காந்திகிராம பல்கலைக்கழகம் இவருக்கு அறிவியலில் மதிப்புறு முனைவர் பட்டம் தந்தது. கோவில்பட்டி மண்டல மழைப்பயிர் ஆய்வகத்தில் 1960ஆம் ஆண்டு ஆய்வு உதவியாளராக பணியில் சேர்ந்து ஆய்வகங்களில் நிலவும் […]

Continue Reading

DISEASES OF SUGARCANE – Agricultural study materials

DISEASES CAUSAL ORGANISM Red rot  Colletotrichum falcatum Whip smut Ustilago scitaminea Sett rot or pine apple disease Ceratocystis paradoxa Rust Puccinia erianthi Gummosis Xanthomonas campestris pv. vasculorum Mosaic Sugarcane mosaic virus Grassy shoot Mycoplasma like organism [MLO] Iron chlorosis Iron deficiency Ratoon stunting Clavibacter xyli Witch weed Striga angustifolia [Partial root parasite] 1. RED ROT […]

Continue Reading

DISEASES OF JUTE – Agricultural study materials

Root rot and stem rot Macrophomina phaseolina Bacterial wilt Pseudomonas solanacearum 1. ROOT ROT and STEM ROT – Macrophomina phaseolina Symptoms The fungus attacks the stem at the nodal region, causing shredding of the bark. In mature plants, necrotic lesions on the leaves appear at the apex and along their margins. Pycnidia are formed on […]

Continue Reading

DISEASES OF COTTON – Agricultural study materials

DISEASES CAUSAL ORGANISM Fusarium Wilt Fusarium oxysporium f.sp.vasinfectum Verticilium Wilt Verticillium dahliae Grey mildew or Areolate mildew Ramularia areola Root rot Rhizoctonia bataticola Anthracnose Colletotrichum capsici and Glomerella gossipii Leaf blight Alternaria macrospora Boll rot -Complex disease F.monoliforme, C.capsici, A.flavus, A.niger Stenosis or Small leaf Phytoplasma (Mycoplasma like organism) Bacterial blight Xanthomonas campestris pv. malvacearum […]

Continue Reading

DISEASES OF JATROPHA – Agricultural study materials

DISEASES CAUSAL ORGANISM Root rot Macrophomina phaseolina Powdery mildew Oidium sp. Leaf spots   Alternaria sp. Cassava Mosaic Disease (CMD)  Cassava mosaic gemini virus (CMG) 1. Root rot – Macrophomina phaseolina Symptom Symptoms include yellowing of foliage, reduced leaf size, and eventual death of the plant due to root rot. The affected tissues show shredding of […]

Continue Reading

DISEASES OF LINSEED – Agricultural study materials

DISEASES CAUSAL ORGANISM Rust Melamspora lini Wilt Fusarium oxysporum f.sp. lini Powdery mildew Oidium lini Alternaria leaf spot Alternaria lini Septoria leaf spot Mycosphaerella linorum 1. Rust –Melamspora lini Symptoms The rust may attack all the aerial parts of the plant including the capsules. Diseased plants produce bright orange uredo pustules on both surfaces of […]

Continue Reading

DISEASES OF CASTOR – Agricultural study materials

DISEASES CAUSAL ORGANISM Seedling blight Phytophthora parasitica Rust Melampsora ricini Leaf blight Alternaria ricini Brown leaf spot Cercospora ricinicola Bacterial leaf blight Xanthomonas campestris pv. ricini 1. SEDLING BLIGHT – Phytophthora parasitica Symptoms The disease appears as circular, dull green patch on both the surface of the cotyledonary leaves. Later it spreads and cause rotting. […]

Continue Reading

DISEASES OF SAFFLOWER – Agricultural study materials

Rust Puccinia carthami Leaf spot Cercospora carthami Leaf blight Alternaria carthami 1. RUST- Puccinia carthami Symptoms The pustules (uredosori) are chestnut brown in colour and scattered throughout the leaves. Later, black teliosori are formed on the leaves. Stem girdling occurs in older plants and rust pustules also appear on roots. Uredia and telia are produced […]

Continue Reading

DISEASES OF SUNFLOWER – Agricultural study materials

DISEASES CAUSAL ORGANISM Rust Puccinia helianthi Leaf blight Alternaria helianthi Root rot or charcoal rot Macrophomina phaseolina Head rot Rhizopus nigricans 1. RUST – Puccinia helianthi Symptoms Small, reddish brown pustules (uredia) covered with rusty dust appear on the lower surface of bottom leaves. In severe infection, numerous pustules appear on leaves leading to yellowing […]

Continue Reading

DISEASES OF GINGELLY OR SESAME – Agricultural study materials

DISEASES CAUSAL ORGANISM Leaf blight Alternaria sesami Leaf spot or white spot Cercospora sesami Leaf and stem blight Phytophthora parasitica var sesami Root rot or charcoal rot Macrophomina phaseolina Wilt Fusarium oxysporium f.sp.sesami Powdery mildew Erisiphe cichoracearum Bacterial blight Xanthomonas campestris pv.sesami  Bacterial leaf spot Pseudomonas sesami Leaf curl Nicotiana virus Phyllody Mycoplasma – like […]

Continue Reading

DISEASES OF MUSTARD / RAPE SEED – Agricultural study material

White rust Albugo cruciferarum Leaf blight Alternaria brassicae 1. WHITE RUST / BLISTER- Albugo cruciferarum Symptoms Isolated, raised and shiny white pustules develop on leaves and stem. In severe cases, the entire plant may remain dwarf and only small leaves are formed. The pathogen is an obligate parasite. Mode of spread and survival The infection […]

Continue Reading

DISEASES OF GROUND NUT – Agricultural study materials

DISEASES CAUSAL ORGANISM Tikka early leaf spot Cercospora arachidicola Tikka late leaf spot Phaeoisariopsis personata Rust Puccinia arachidis Crown rot / Collar rot Aspergillus niger and A. flavus Dry root rot Macrophomina phaseolina Stem and pod rot Sclerotoum rolfsii Anthracnose Colletotrichum dematium Bacterial wilt Pseudomonas solanacearum Bud necrosis or ring mosaic Tomato spotted wilt virus […]

Continue Reading

DISEASES OF BLACK GRAM / GREEN GRAM, SOYBEANS, COW PEA

1. LEAF CURL – Tomato spotted wilt virus [TSWV] Symptoms The infection starts as chlorosis of lateral veins near the leaf margins and margins slowly curl downwards. The infected leaves are brittle and plants produce a few small and malformed pods. Vector  The disease is transmitted by Thrips viz., – Frankliniella schultzi, Thrips tabaci and […]

Continue Reading

DISEASES OF BENGAL GRAM / CHICK PEA – Free Study Material

1. WILT – Fusarium oxysporum f.sp. ciceri Symptoms The disease occurs in seedling stage and flowering stage. Infected seedlings show yellowing, drying of leaves, browning of vascular bundles and finally wilting of plants. Mode of Spread and Survival  The disease spreads through irrigation water and farm implements. The pathogen survives as chlamydospores in the soil […]

Continue Reading

DISEASES OF RED GRAM / PIEGON PEA – Agricultural study materials

1.  WILT – Fusarium oxysporum f.sp. udum Symptoms The characteristic symptoms of the diseases are yellowing and dropping of leaves followed by drying of the plant and dark – streaks under the bark of roots and base of the stem. The vascular tissues exhibit brown discolouration and partial wilting of roots. The symptoms appear when […]

Continue Reading

DISEASES OF PULSES – Agricultural study materials

Common Pulse Diseases COMMON DISEASES CAUSAL ORGANISM Dry root rot Macrophomina phaseolina Leaf spot Cercospora canescens Powdery mildew Erysiphe polygoni Rust Uromyces phaseoli-typica Anthracnose Colletotrichum lindemuthianum Bacterial blight Xanthomonas phaseoli Yellow mosaic Yellow mosaic virus Leaf crinkle Leaf crinkle virus RED GRAM / PIEGON PEA Wilt Fusarium oxysporum f.sp. udum Stem blight Phytophthora drechsleri f.sp. […]

Continue Reading

DISEASES OF MINOR MILLETS

TENAI / FOX-TAIL MILLET Blast Pyricularia setariae Leaf spot or leaf blotch Helminthosporium setariae Smut Ustilago crameri Downy mildew or green ear Sclerospora graminicola KUDIRAIVALI Smut Ustilago crus-galli VARAGU / KODO MILLET Head smut Sorosporium paspali-thunbergii Ergot or sugary disease Claviceps paspali PANIVARAGU / SMALL MILLET Rust Uromyces linearis SAMAI Smut Sphacelotheca destruens Downy mildew […]

Continue Reading