Plant Disease Management

Wilt is an important disease of chilli crop causing significant reduction in yield. In the present study, the pathogenic fungus was isolated from the infected plant parts and was identified as Fusarium oxysporum f. sp. capsici based on the morphological and cultural features. In this context, an eco-friendly approach was followed by using plant extracts to control the pathogen. The antifungal effects of aqueous extracts of five plant species namely, Azadirachta indica, Ocimum sanctum, Zingiber officinale, Allium sativam and Allium cepa were tested in vitro against Fusarium oxysporum f. sp. capsici by poisoned food technique. The results revealed that all plant extracts showed significant (P<0.05) reduction in the growth of pathogen. Plant extracts at 10% concentration were significantly better in the inhibitory effect than those at 5% concentration. Among the different extracts at 10% concentration, Allium sativam was found to be the most effective (53%) in inhibiting the mycelial growth of the fungus followed by Azadirachta indica (47.7%) and Ocimum sanctum (36.3%). The least inhibitory effect was found in the crude extract of Zingiber officinale. Based on the above results, it could be concluded that Allium sativam and Azadirachta indica extracts can be used to control Fusarium oxysporum f. sp. capsici. These extracts are cost effective, non-hazardous and useful in maintaining ecological balance.

The purpose of this project is to investigate, describe, and define plant pests, diseases and disorders, vandalism in context with open public spaces and the historic and contemporary methods of identification, prevention, mitigation and control.
Without a thorough understanding of the susceptibility of planting schemes to pest, disease, disorders and vandalism and how to manage/prevent them, poor design will be inevitable.  Planners, developers, local authorities, etc, are looking towards environmental (sustainable) design for efficient, cost effective schemes.  Environmental design is “the philosophy of designing physical objects, the built environment and services to comply with the principles of the economic, social and ecological sustainability” (McLennan, 2004).

With a view to harvest superior quality lemon fruits, the experiment was carried out to study the impact of integrated use of inorganic fertilizer (N), organic manure (FYM) and biofertilizer (Azotobacter) on lemon cv. ‘Baramasi’ during 2009. The plant material was selected from Punjab Government Progeny Orchard & Nursery, Attari, Amritsar. There were nine nutrient management practices set in a Randomized Block Design replicated thrice. The present experiment showed that the substantial improvement in fruit quality could be achieved with the consortium of three classes of nutrient sources. FYM (75 Kg/tree), inorganic nitrogen (350g/tree) along with biofertilization (Azotobacter 18g/tree) proved to be the most judicious treatment in minimizing fruit cracking and maximizing fruit quality.

The efficacy of water extracts and essential oils of five locally available medicinal and aromatic plants viz. ginger (Zingiber
officinale Rosc), garlic (Allium sativum L.), lemongrass (Cymbopogon flexuosus Stud), Japanese mint (Mentha arvensis L.) and holy basil (Ocimum sanctum Linn.) were in vitro evaluated against the fungus Penicillium digitatum Sacc. and the green mold disease of citrus fruits (in vivo) at central laboratory of IAAS, Rampur, Chitwan during the winter season of 2007. This experiment was conducted in completely randomized design with five replications. Extracts were either tested alone, or in combination with vegetable (mustard) cooking oil or bee wax at different concentrations using mandarin fruit cultivar (local Suntala). Treated fruits were stored at 15 ± 1oC and 90-95 % relative humidity for 15 days. Further experimentation was carried out by lowering the concentration levels of the extract. All the extracts of various concentrations were effective as compared to control in inhibiting the growth and development of Penicillium digitatum Sacc. However the most effective one was
lemongrass oil in the management of green mold disease of citrus. A markedly increased ability of extracts was observed when extracts were used with bee wax in checking green mold disease of citrus fruits. The treatment comprising lemongrass oil and mint oil even at lower concentration level (0.01-0.04%) was also found equally effective as that of the fungicide treatment in controlling green mold on mandarin oranges.

Pulses have always used to be integral part of food since the vedic times (Achaya, 1998). Agri-archaeological researches have revealed that pulses have been grown in the Indian sub-continent for more than 6000 years. We find references to most of the pulses, in the scriptures of ancient India, that we cultivate today (Nene, 2000). Pulses constitute a very important source of dietary protein for majority of the Indian people, as they provide a perfect mix of vegetable protein component of high biological value when supplemented with cereals. It is also an excellent feed and fodder for livestock. These crops are also endowed with the ability to improve nutrient supply in soils through addition of organic matter (leaf drop) and nitrogen, by fixing atmospheric nitrogen, carbon sequestration, and soil amelioration. Since pulses have ability to have low water requirement and capability to withstand harsh climate, pulses have remained an integral component of sustainable crop production system in the dry areas. They offer good scope for crop diversification and intensification. This is more significant in view of the impending danger of non-availability of nitrogen as fertilizer from petroleum

The Alternaria leaf spot caused by A. brassicae (Berk.) Sacc is one of the destructive disease of Cauliflower in Konkan region of Maharashtra. In the present study, bio efficacy of seven fungicides tested under in vitro conditions against the pathogen. Among that, Mancozeb 75% WP (0.25 %) was completely inhibited the growth of the test fungus. It was followed by Propiconazole 25% EC (0.1%) which showed 96.29 per cent inhibition of the test fungus and was at par with Mancozeb. No sporulation was observed in Mancozeb 75% WP, Propiconazole 25% EC and Difenconazole 25% EC. Among the different fungicides tested under field conditions, all the fungicidal treatments were significantly superior over control after last spray. The treatment Mancozeb 75% WP was the most effective as it recorded minimum disease incidence (28 %). It was followed by Azoxystrobin 23% EC which recorded 29 % disease incidence.

Global food security is vulnerable due to massive growth of the human population, changes in global climate, the emergence of novel/more virulent pathogens, and demands from increasingly discerning consumers for chemical-free, sustainably produced food products. Bacterium- based biological control agents (BCAs), if used as part of an integrated management system, may satisfy the above demands. We focus on the advantages, limitations, problems, and challenges involved in such strategies.

This review presents a comprehensive and systematic study of the field of bacterial plant biostimulants and considers the fundamental and innovative principles underlying this technology. Plant biostimulants are an important tool for modern agriculture as part of an integrated crop management (ICM) system, helping make agriculture more sustainable and resilient. Plant biostimulants contain substance(s) and/or microorganisms whose function when applied to plants or the rhizosphere is to stimulate natural processes to enhance plant nutrient uptake, nutrient use efficiency, tolerance to abiotic stress, biocontrol, and crop quality. The use of plant biostimulants has gained substantial and significant heed worldwide as an environmentally friendly alternative to sustainable agricultural production. At present, there is an increasing curiosity in industry and researchers about microbial biostimulants, especially bacterial plant biostimulants (BPBs), to improve crop growth and productivity. The BPBs that are based on PGPR (plant growth-promoting rhizobacteria) play plausible roles to promote/stimulate crop plant growth through several mechanisms that include (i) nutrient acquisition by nitrogen (N2) fixation and solubilization of insoluble minerals (P, K, Zn), organic acids and siderophores; (ii) antimicrobial metabolites and various lytic enzymes; (iii) the action of growth regulators and stress responsive/induced phytohormones; (iv) ameliorating abiotic stress such as drought, high soil salinity, extreme temperatures, oxidative stress, and heavy metals by using different modes of action; and (v) plant defense induction modes. Presented here is a brief review emphasizing the applicability of BPBs as an innovative exertion to fulfill the current food crisis.

Early blight of tomato disease caused by Alternaria solani (Ell. & Mart.) is one of the most devastating
diseases of tomatoes. It is a potential tomato disease that is reducing production worldwide. To date,
various treatments have been adopted to minimize the disease. The present study was based on the
selection of chemical fungicides against A. solani in tomatoes that cause blight. The in vitro and in vivo
efficacy of chemical fungicides showed that minimal radial growth with a diameter of 0.51 cm gave
hexaconazole, followed by thifluzamide with a radial growth of 1.18 cm. In this study, five fungicides
were used at a concentration of 100 and 300 ppm. The maximum suppression of fungi was provided by
hexaconazole with 94.33% at a concentration of 300 ppm, fruits 35 / plant, fruit yield 1.224 kg / plant,
15.45 kg / plot, 252.50 q / ha.

This review presents a comprehensive and systematic study of the field of bacterial plant biostimulants and considers the fundamental and innovative principles underlying this technology. Plant biostimulants are an important tool for modern agriculture as part of an integrated crop management (ICM) system; helping make agriculture more sustainable and resilient. Plant biostimulants contain substance(s) and/or microorganisms whose function when applied to plants or the rhizosphere, is to stimulate natural processes to enhance plant nutrient uptake, nutrient use efficiency, tolerance to abiotic stress, biocontrol, and crop quality. The use of plant biostimulants has gained substantial and significant heed worldwide as an environment-friendly alternative for sustainable agricultural production. Presently, there is an increasing curiosity of industry and researchers in microbial biostimulants especially, bacterial plant biostimulants (BPBs) to improve crop growth and productivity. The B...

Experiments were conducted to evaluate selected inorganic salts alone and in combination with hot water for management of banana anthracnose disease. The efficacy of hot water treatment (HWT) and either sodium bicarbonate (SBC), sodium carbonate (SC) or sodium hypochlorite (SH) applied alone and in combination to suppress anthracnose disease was investigated in both naturally infected and artificially inoculated banana fruit cv. Kolikuttu during the storage. The in vitro efficacy of the selected salts on the inhibition of colony growth of the anthracnose fungal pathogen was also tested. Postharvest treatment involving fruit dipped for 30 min in 1% (w/v) SC following HWT (50°C, 3 min) reduced the severity of anthracnose, which was statistically similar (P > 0.05) with that of homai fungicide treatment. Among the tested salts, SC recorded the significantly highest (P < 0.05) in vitro inhibition of mycelial growth of anthracnose pathogen. Integration of SC with HWT could be a commercially acceptable and economically feasible non-fungicidal approach for the postharvest management of anthracnose during the storage of banana.

Field identification of greening disease is often difficult because the symptoms on affected trees are sometimes confused with that of zinc and other nutritional deficiencies. The citrus greening disease was detected from source Kinnow plants collected from citrus growing area of the state showing yellowing with green veins or green islands and yellow mottling by biological indexing.

The objective of this study was to determine the extent of adoption of Salt
tolerant variety BRRI dhan 47 in Noakhali district. Data were collected
from randomly selected 100 farmers via pre-tested interview schedule
during September 20 to October 10, 2012. After data collection, were
coded for processing and analysis. SPSS was used to perform the data
analysis. Percentage, mean, standard deviation were calculated.
Coefficients of correlation (r) were computed to find out the relationship
between adoption of BRRI dhan 47 and the selected socio-economic
characteristics of farmers. Majority of the respondents were middle aged
(48%), having primary level education (46%), medium family size (60%),
small farm size (51%), medium annual income (66%), very low
organizational participation (65%), low innovativeness (72%), medium
extension contact (64%), and medium knowledge on rice cultivation
(70%). Majority (53%) of the respondents had low adoption of BRRI dhan
47 whereas 42 % medium and only 5% under high adoption category.
Farmers’ education, farm size, annual income, innovativeness, extension
contact, and knowledge on rice cultivation showed significant and positive
relationship with adoption of BRRI dhan 47. Shattering problem, cost on
irrigation, natural calamities were the major problems faced by the farmers
in cultivating BRRI dhan 47. Proper extensions activities are needed to
disseminate BRRI dhan 47 to bring the uncultivated areas under rigorous
cultivation for ensure a better livelihood on the coastal farmers.

Trunk injection is a novel delivery method for plant protective compounds in agriculture, which could increase the sustainability of fruit production through target-precise disease control and thus minimal exposure of the environment to the compounds. We evaluated whether trunk-injected antibiotics, copper and structural plant resistance activator prohexadione-calcium (PC) can significantly reduce fire blight on apples due to translocation of these compounds into the canopy. After 1-2 spring injections of oxytetracycline (OX), kasugamycin (KS) and copper chelate (CC), using four replicates per treatment, we evaluated inoculated apple trees for blossom and shoot blight incidence. In a separate study, after one spray or one injection of PC, we evaluated randomly selected and inoculated apple shoots for shoot blight severity. At high disease pressure, OX, KS and CC significantly reduced blossom blight providing control of 60.6, 31.7 and 15.5-17.8%, respectively. Fire blight has spread ...

Fusarium oxysporum f. sp. ciceri, F. solani and Rhizoctonia solani were isolated from the wilted chickpea (Cicer arietinum) plants. To manage the wilt complex cultural practices, use of biocontrol agents and fungicides were tried under in vitro and in vivo conditions. Sowing of chickpea at different dates revealed that early sowing (10th Oct.) resulted in maximum disease incidence (32.20%), whereas, late sowing (24th Nov.) the minimum (13.35%). Twenty and 50 cm row to row spacing resulted in maximum (29.17%) and minimum (17.35%) disease incidence respectively. In vitro evaluation of biological control agents revealed the superiority of Trichoderma viride. Trichoderma over Trichoderma virens in controlling the pathogens. Carbendazim at 100, 200, 500 ppm caused maximum per cent inhibition of the pathogens under in vitro conditions. Fungicides applied as seed treatment reduced disease incidence significantly. Seed treatment with carbendazim increased seed germination (71.24%), though it was at par with carbendazim + mancozeb (62.21%) and mancozeb (61.46%). Seed coating with T. viride resulted in minimum disease incidence (9.24%), however, it was at par with T. virens (9.72%). Maximum yield (10.10 q/ha) was recorded with the application of carbendazim, followed by carbendazim + mancozeb (9.77 q/ha) and T. viride (8.10 q/ha).

To optimize the number and timing of trunk injections for season-long control of apple scab (Venturia inaequalis), we evaluated 1-2 and 4 seasonal and cross-seasonal injections of potassium phosphites and synthetic fungicides and quantified residues in leaves and fruit. Phosphites accumulated in the canopy at the highest concentrations, aligned well in time with scab suppression, and gave better leaf scab control of 41.8-73.5% than propiconazole (16.9-51.5%) or difenoconazole + cyprodinil (5.4-17.4%). More injections of phosphites controlled leaf scab better than fewer (23.7% vs. 48.2%), and more fungicide injections resulted in 21.9-51.1% better leaf scab control than fewer. Leaf scab control with phosphites was 3.2-13.9% better with 4 cross-seasonal compared to 4 seasonal injections, while 1-2 seasonal compared to 1-2 cross-seasonal injections improved scab control for 4.2-22.1%. On shoots, injected phosphites provided comparable or for 4.4-10.5% and 22.3-41.4% better scab control than spray standards. On fruit, injected phosphites slightly improved control compared to sprayed phosphites or the sprayed fungicide standard (33.4-40.8%). Two seasonal injections of phosphites controlled shoot scab 5.7% better than 9 spray applications. Five sprays of difenoconazole + cyprodinil controlled scab better than their injections. Fruit residues of phosphites reached 2.8 ppm and declined in all treatments except in 2 seasonal injections and phosphite sprays. Cyprodinil and difenoconazole fruit residues reached 0.02 and 0.07 ppm and declined sharply towards the end of the season. These were far below the USA, Codex, and EU MRL-s of 1, 0.8 and 0.5 ppm for difenoconazole, and 1.7, 2 and 1 ppm for cyprodinil, respectively.

Trunk injection is a novel delivery method for plant protective compounds in agriculture. It could increase sustainability of fruit production through target-precise disease control. We evaluated trunk-injected antibiotics, copper chelate (CC), and prohexadione-calcium (PC) in control of fire blight on apples. After 1-2 spring injections of oxytetracycline (OX), kasugamycin (KS) and CC, we evaluated inoculated apple trees for blossom and shoot blight incidence. In a separate study, after spraying or injection of PC, we evaluated shoot blight severity after inoculation. At a high disease pressure, OX, KS and CC provided blossom blight control of 60.6, 31.7 and 15.5-17.8%, respectively. The same compounds provided control of shoot blight incidence of 60.7, 42 and 24.5-33.9%, respectively. The results indicate that shoots initially accumulate more of the injected compound than flowers, due to their higher transpiration driven by larger green tissue area. Sprayed PC reduced shoot blight severity for 25.6% and caused expected reduction of shoot length, while trunk-injected PC failed to cause any of these effects. This indicates that PC did not translocate into the canopy due to its strong binding in the xylem. With the development and use of injectable formulations, proper dosing, and optimal injection timing, delivered compounds could have more time for accumulation in the canopy and thus provide better fire blight control. Hence, trunk injection could become an effective option for fire blight control on apple trees.

Root-knot disease caused by Meloidogyne spp. poses a worldwide threat to agriculture as well as environment due to excess use of chemical nematicides for its management. Recently Arbuscular mycorrhizal fungi (AMF) have achieving importance as biocontrol agent for the managements of Root-knot disease. In this aspect, present study was focused on the effect of AMF (Glomus intrareadices) against Root-knot disease of tomato (Lycopersicon esculentum) caused by Meloidogyne incognita. Observations of G. intraredices against M. incognita were taken at 10, 20 and 30 days after M. incognita second stage juveniles (J2) inoculation on tomato roots, which were pre-colonized by G. intraradices. A significant effect was observed on  plant growth (length and biomass) and nematode induced (root galls, egg masses, egg and adult females) parameters in nematode inoculated G. intraradices colonized plants as compared to non-colonized plants at all the three harvesting periods. The finding of present study indicates the potential of G. intraradices as a potential biocontrol tool for the management of root-knot disease and can be used in the place of environmentally hazardous chemical nematicides.

This chapter mainly attention to the management of the diseases of different grain crops, vegetables, flower crops, oil crops, and others. The diseases were very harmful to produce the quality crops/fruits and this paper study on the common name and scientific name of the common diseases/causal organisms in different plants. This paper investigated the use of biochemical, chemical, and biological insecticides in the field and also with the cultural practices in the seedbed, field, and storage condition. The farmers used balance fertilizer and also used chemical insecticides to minimize crop damage. It has been estimated that of the average at 36.5% of total losses, 14.2% are caused by disease, 15.1% by insects, and 6.2% by weeds. This chapter has efforted the prescription to the disease’s management in farmer fields. Hence, I think if this book is available for all agriculturists and farmers then they will benefit.

To investigate patho-dyanamics of Erwinia tracheiphila on Cucurbita pepo with biochemical, molecular characterization and eco-friendly management approaches. Variability study of Erwinia tracheiphila was done by collecting the isolates from different places in Odisha. Disease severity was calculated and analyzed from 2016-18 to predict trend of emergence and disease progress. Molecular detection of pathogen was done through 16S rRNA sequencing. Biochemical characterization and identification of pathogenic nature of Erwinia tracheiphila was performed through Ortho-Nitrophenyl β-Galactoside, Esculin hydrolysis, Citrate and Malonate utilization in the presence of different carbohydrate molecules. Efficacy of eight different plant oils were tested by in-vitro inhibition zone (IVIZ) assay against Erwinia tracheiphila as eco-friendly management approaches. Analysis of disease severity data from 2016-18 ranged between 29% to 33%. Molecular detection of causal pathogen was further confirmed by 16S rRNA region sequencing with 99% identity of NCBI-GenBank published Erwinia tracheiphila (MK356446 and MK356441) database and phylogenetic analysis. The results of IVIZT revealed that the clove oil treatment showed maximum inhibitory effect on the growth of Erwinia tracheiphila followed by mustard oil and neem oil. Sesamum oil showed the lowest efficacy against Erwinia tracheiphila. Optimum temperature range between 25-28°C, 80-85% relative humidity and 150-180 mm average rainfall triggered the disease progress and turned to be a severe one under experimental agro-climatic situation. Biochemical characterization and molecular detection of causal isolate confirmed the pathogen as Erwinia tracheiphila, causing wilt disease of Cucurbita pepo. This study also revealed the potential efficacy of clove oil and mustard oil against Erwinia tracheiphila as compared to other selected plant oils.

Many diseases of viral etiology have been identified affecting tomato
production worldwide, causing important qualitative and quantitative losses. Among the main viral diseases, there are the ones caused by the genus Tospovirus and the genus Potyvirus. The Tospovirus (family Bunyaviridae) are responsible for the disease known as “vira-cabeça”, causing severe annual losses, mainly in horticultural crops. Species of this genus have a worldwide distribution and a great number of species infecting a vast array of hosts. The main resistance factor employed in tomato breeding for broad spectrum resistance to different tospovirus species is the Sw-5 gene. Plants that harbor this gene express hypersensitivity reactions that restrict the viral systemic infection. However, the ‘breaking’ of this resistance gene has already been reported in different parts of the world. Apart from tospoviruses, species of the genus Potyvirus represent a constant threat to tomato culture. A new species of this genus, Pepper yellow mosaic virus (PepYMV), was initially identified in pepper but it is also capable of infecting tomatoes, causing up to 100% losses. The search for resistance sources for PepYMV on tomato have already started, but the explored germplasm still represents a reduced number of accessions. This thesis shows the evaluation of germplasm collections seeking to  identify new resistance sources to PepYMV and to the
neotropical species of tospoviruses. Beyond that, a co-dominant marker for the Sw-5 gene was developed, capable of identifying resistant individuals through a simple PCR. A preliminary analysis of the avirulence component of the Sw-5/Tomato spotted wilt virus (TSWV) interaction was also done, using constructions containing independent TSWV genes, isolates BR-01 (avirulent for the Sw-5 gene) and GRAU (capable of breaking the Sw-5 gene resistance), using a platform based on transgenic Nicotiana benthamiana expressing the Sw-5 gene. In relation to the identification of the new resistance sources (Chapters 2 and 3, respectively), accessions of S. habrochaites showed to be promising sources of resistance to both PepYMV
and Potato virus Y (PVY). On the other hand, accessions of S. peruvianum confirmed this species as the main source of resistance factors to tospoviruses. An accession of S. chilense and a selection of an accession of 4 S. lycopersicum, showed good resistance/tolerance levels to the tospovirus species tested. Both analyses where compared to screenings that where previously done. The Sw-5 specific marker (Chapter 4) was evaluated with a broad array of accessions, showing a profile capable of identifying resistant and susceptible accessions in all situations. Therefore, this marker represents an efficient new tool for assisted selection systems and its future potential use for isolation or detection of  alleles or analogous genes in tomato and other solanaceous species. The avirulence component analysis showed that none of the viral genes that where evaluated (Nsm, the glycoprotein precursors, N and Nss) seems to be related in an independent manner with the induction process of the Sw-5 gene recognition mechanism. None of the genes tested was able to induce typical hypersensitive reaction observed when tomato genotypes containing this resistance gene are challenged by TSWV. The strategy used in this study also demonstrated that the biological model represented by transgenic N. benthamiana expressing an active copy of the Sw-5 gene is suitable for analyzing the mechanisms involved in tospovirus resistance. In addition, this system can also be used to investigate Sw-5-resistance breaking isolates.

Experiments were carried out to evaluate five different plant extracts against lentil stemphylium blight (Stemphylium
botryosum Walr.) at the Grain Legume Research Program, Rampur, Chitwan, Nepal during two winter seasons (2011/
12 and 2012/13) using CRD in laboratory and RCBD in field conditions. Water extract of Acorus calamus at higher
dose (8% W/V) was able to check the growth of the pathogen completely in-vitro. The mycelial growth inhibition
(%) of Xanthoxylum armatum and Lantana camera at 8% concentration in PDA were 31.17 and 24.56 respectively.
In the field experiment during 2011/12, extracts were sparingly effective for a short period. However the disease
control (PDC) was higher in X. armatum treated plot (31.60%) followed by A. calamaus (28.69%) and L. camera
(27.61%) when compared to unsprayed plot. The following year (2012/13) field experimental results also verified the
effect of plant extracts against the disease. The lower Disease (%) Index (PDI) was obtained from the plots treated
with A. calamus (35.33%) and X. armatum (35.55%). Higher crop yield was recorded from the plot treated with A.
calamus (987.39 kg/ha) followed by X. armatum (972.78 kg/ha). Two years’ experimental results revealed that A.
calamus and X. armatum were effective botanicals to manage lentil Stemphylium blight.

Field studies were undertaken at Offinso in the Ashanti Region of Ghana during the 2015/2016 growing season to evaluate growth, root and dry matter yields of an improved cassava variety (Bankyehemaa) treated with poultry manure (PM), NPK 15-15-15 and NPK 23-10-10 fertilizers. The treatment structure was a 3 x 4 factorial, laid out in a Randomized Complete Block Design with three replications. Three levels of fertilizer (600 kg/ha NPK 15-15-15, 600 kg/ha NPK 23-10-10 and 2 t/ha PM) were applied at 6, 8, 10 and 12 weeks after planting. The parameters measured included plant height, fresh and dry shoot weights, number of stems per plant, stem girth, fresh and dry root yields and total dry matter yield. The data collected were subjected to analysis of variance using the Genstat Statistical package. Main effects of fertilizer type and time of fertilizer application on most of the parameters measured were not significant. However, the interaction effects of the two factors were significan...

Rice blast caused by Magnaporthe grisea is turn to be one of the most severe pathogen under change in climatic condition in coastal region of SouthEastern India. Severity of the pathogen was not overwhelming previously. An investigation was carried out in several villages of different districts of Andhra Pradesh and Odisha under the RAWEP programme of Centurion University of Technology and Management with compared to meteorological data support from IMD, Bhubaneswar, Odisha. Different meteorological factors consider under this study were maximum temperature (T max), minimum temperature (T min), relative humidity maximum (RH max), relative humidity minimum (RH min), rainfall (RF). Among the three cultivated rice varieties, Pooja and Samba mahsuri (BPT-5204) are the most susceptible blast varieties (5.71% and 4.85%) compared to Swarna (MTU 7029) with a disease incidence level of 1.23%. Outcome of this investigation also revealed that the most crucial two (T max and RH max) factors dir...