Background: Bacterial leaf blight can damage upland rice and reduce yield by 30-40%. Chemical pesticides harm ecosystems and can increase pathogen resistance. The objective of this research was to explore the potential of AMF, a biological agent, to enhance the resistance of local Acehnese-radiated mutant rice against bacterial leaf blight.&nbsp; 
 
Methods: Two-factor factorial design with three levels of AMF dosage (0 g, 10 g and 20 g per plant) and three upland rice lines (UA-01, UA-09 and UA-10). There were 9 treatment combinations replicated 3 times, resulting in 81 experimental units. 
 
Result: The intensity of the disease decreased significantly as the dosage of AMF increased and the maximum number of tillers increased substantially up to 20 g plant-1 AMF application. UA-10 strains exhibited the highest number of tillers per clump, while UA-09 strains had the lowest. The interaction between local Aceh rice varieties and AMF did not impact bacterial leaf blight intensity, maximum number of tillers and percentage of filled grain, except for AMF colonization on roots. The significance of AMF colonization varied among lines, with the highest AMF colonization observed in the UA-10 strain (20.64%) at an AMF dose of 20 g plant-1. AMF inoculation appeared to affect the percentage of filled grain positively.

Treating Radiation-induced Aceh Rice Germplasm with Arbuscular Mycorrhizal Fungi has been Shown to Effectively Address Bacterial Leaf Blight

<div>Background: Rice (Oryza sativa L.) gets affected by more than seventy diseases by the infection of bacteria, fungi and viruses. Among, bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv oryzae (Xoo) is the important disease around the rice cultivated areas and causing drastic yield losses ranging between 20 and 30 per cent. Among very few options for increasing yield potential in rice, genetic diversity among the genotypes plays an important role in selection of parents having wider variability for disease resistance.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 
Methods: The rice genotypes were screened using PDI for bacterial leaf blight (BLB) and subjected to D2 analysis for nine quantitative traits viz., plant height, number of productive tillers per plant, panicle length, days to fifty per cent flowering, number of grains per panicle, thousand grain weight, grain length, grain breadth and single plant yield.&nbsp; 
 
Result: On the basis of Mahalanobis D2 statistics, the thirty five genotypes are grouped into VIII clusters. The highest intra cluster distance was recorded for cluster II (41.16) followed by cluster VI (37.73). Out of thirty five genotypes screened under field condition using percentage disease index (PDI), CR 1009 found to be resistant with the lowest PDI value of 9.67 per cent. The genotypes Karsamba, TPS 4 and Kaivara samba registered highest PDI value of 70.67, 67.22 and 66.67 respectively. The BLB resistance in genotype dependent and not cluster based. The resistant genotype CR 1009 under field screening was positioned in VI cluster. The cluster II had susceptible genotypes karsamba and kaivarasamba. Thus, the identified genotypes can be utilized in recombination breeding to provide BLB resistance segregants.</div>

​​Genetic Diversity Analysis for Bacterial Leaf Blight Disease Resistance in Rice (Oryza sativa L.)

Background-Bacterial leaf blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most destructive diseases affecting rice production worldwide. Resistance breeding is considered a durable, effective, and eco-friendly approach to control BB. Several BB resistance (R) genes have been identified that confer resistance against various strains of Xoo. The dynamic nature of this pathogen needs proper knowledge of pathotype composition and its virulence among the diverse Xoo strains which is imperative for designing a resistance breeding program.

Methods-In this study, we conducted an extensive survey to collect BB infected samples from diverse rice-growing regions of Tamil Nadu. Further, the samples were identified as Xoo through morphological and molecular identification methods. The pathotyping and virulence profiling of Xoo isolates was carried out on a set of rice differentials consisting of 22 near-isogenic lines (NILs) of IR24 possessing different BB resistance genes under glasshouse conditions during Kharif 2021-2022.

Results-Based on the disease reaction in 22 rice BB differentials (IRBB lines), the Xoo isolates were grouped into six pathotypes (I II, III, IV, V, and VI). Further, the virulence analysis revealed that the near-isogenic lines possessing single R gene and gene pyramids were susceptible to about 20-88% and 4-20% respectively to Xoo isolates. R genes and their pyramids such as (Xa7, Xa21, Xa4+xa5+Xa21, Xa4+xa5+xa13 Xa4+xa13+Xa21, xa5+xa13+Xa21, and Xa4+Xa21+xa5+Xa21) were found to be effective against all the pathotypes in Tamil Nadu. The pathotype III was predominantly distributed (40%) over the Tamil Nadu. The isolates found in the pathotypes I and II are more virulent and in the pathotypes V, VI are less virulent.&nbsp; The current study identified the virulence nature of diverse Xoo isolates and the effectiveness of resistance (R) genes against the Xoo isolates. Therefore, the effective R genes identified in this study could be an effective source for resistance breeding program against BB in Tamil Nadu.

Pathotyping and Virulence Analysis of Xanthomonas oryzae pv. oryzae Causing Bacterial Blight of Rice in Tamil Nadu

<div>Background: Continuous rice cultivation has a negative effect on sustainable rice production. Crop rotation can increase the yield and soil quality. This study aimed to provide information on the morpho-physiological fingerprints of rice cultivars in different crop rotation systems. 
 
Methods: Twelve rice cultivars were evaluated in terms of their morpho-physiological in three crop rotation systems, i.e., rice-rice-rice, maize-maize-rice (M-M-R) and vegetable-vegetable-rice, at the Agrotechnology Innovation Center, Universitas Gadjah Mada at Berbah District, Sleman Regency, Special Province of Yogyakarta, Indonesia, from December 2020 to June 2021. 
 
Result: The results revealed an interaction between rice cultivars and the crop rotation system, with the effects observed on the nitrogen, phosphorus and potassium contents in the leaf tissue (NC, PC and KC, respectively), crop growth rate, total dry weight per clump, empty grain per clump (EG) and grain weight per clump (GWC). The increase in NC, PC and KC positively affected the increase in GWC. The GM 8 cultivar in the M-M-R crop rotation system showed lowest EG of 3% and highest GWC of 133.90 g clump-1.</div>

Studies on Morpho-physiological Fingerprints of Rice Cultivars in Rice Crop in Rice-Rice-Rice, Maize-Maize-Rice and Vegetable-Vegetable-Rice Cropping Systems

<div>Rice is a plant that has been intensively breed, especially in Asia, most of the population&rsquo;s staple food is rice. There were Many types of rice varieties have been developed for high yeald production. Different rice diseases arise that many treat to reduce production. Such as curvularia spotting disease caused by the fungus Curvularia sp. Infection of Curvularia species causing leaf spots, leaf blights, kernel root, grain deformation and other diseases are well known globally. It was discovered that the small brown oval spots on the Ciherang rice variety cultivated in Bali, Indonesia was caused by Curvularia verruculosa. This disease could reduce the rice yield up to almost 50%. The application of commercial fungicide by the local farmers has not been satisfactorily successful in term of controlling the disease but instead bring damages to the environment and the soil as well. Farmer&rsquo;s safety is also another serious issue. The current studi develop a natural and green fungicide to check the efficacy of Piper caninum extract against the fungi. Research in the laboratory uses a completely randomized design and research in the field uses a randomized group design.The method of making leaf extracts uses maceration method. Diffusion well technique showed a strong inhibition of the abstract against the C. verruculosa with 22mm inhibition. Zone with a total inhibition of 4% extract concentration. The minimum inhibitory concentration (MIC) was low of 0.5%. Scanning electron images of the treated fungi showed hollow and wrinkled mycelia morphology indicating lysis of the cell has occurred. P. caninum leaf extract at a concentration of 3% provides the highest obstacle to the intensity of C. verruculosa disease, whereas in the treatment of leaf extract concentration p. caninum 4% intensity of C. verrucuosa disease has decreased because rice plants are toxic at a concentration of 4%. Further research is needed regarding the treatment of P. caninum leaf extract against C. verruculosa in rice fields.</div>

<div>Inhibitory Activity of Piper Caninum Leaf Extract against Curvularia Spotting Disease on Rice Plants</div>

<div>Background: Pigeonpea [Cajanus cajan (L.) Millsp] is one of the primary grain legume crops grown in India for its high quality vegetable protein, animal feed and fodder. It is affected by various fungal and viral diseases. Among these, leaf blight caused by Alternaria alternata is one of the most destructive diseases and recently the disease of minor importance becomes major one in Tamil Nadu. Use of resistant cultivar is the most effective, economically viable and eco-friendly tool for combating the plant diseases. The micronutrients play a key role in many physiological and biochemical functions of the plants which influences plant pathogenic interaction. The micronutrients viz., Zn.Mn,Cu and Fe found to have greater impact on reducing the plant disease severity. Developing integrated disease management strategy involving disease resistant variety, micronutrient and fungicide application would be the best sustainable method for controlling the pigeonpea leaf blight. 
 
Methods: Twenty four pigeonpea genotypes along with two local varieties viz., CO5 and CO6 were evaluated in the field for their resistance against Alternaria alternata leaf blight disease, consecutively for three years from 2015-16 to 2017-18 using the disease resistance scale ranging from 0 to 9. Field experiments were also conducted for three consecutive Kharif season from 2015 to 2018 to evaluate the efficacy of the foliar application of different micronutrients and combination fungicide viz., carbendazim 12% + mancozeb 63% on the incidence of leaf blight disease.&nbsp; 
 
Result: A total of 24 pigeonpea genotypes were screened for their resistance against leaf blight under field condition. Among these, four genotypes viz., BDN2, IPA 8F, IPA 15F and MA6 were found resistance and nine genotypes were moderately resistant and remaining 11 genotypes showed susceptible reaction to leaf blight. The results of the field experiment on micronutrient and fungicide application revealed that foliar spraying of MnSO 4 @0.2% on 30 days after sowing and carbendazim 12%+ mancozeb 63%@ 1g / lit on 45 days after sowing recorded the lowest leaf blight incidence of 8.1 PDI (Per cent Disease Index) with the highest disease reduction of 76.9% as against 35 PDI in the untreated control plot. The above treatments also recorded the highest grain yield of 905 kg/ ha as against 703 kg/ in the untreated control.</div>

<div>Management of Alternaria Leaf Blight in Pigeonpea through Host Plant Resistance and Micronutrient Application</div>

<div>Background: Leaf blight caused by Exserohilum turcicum (E. turcicum) is commonly or generally found on sorghum grown in the sub-tropics and tropical lowlands during summer. The pathogen is easily wind disseminated and apparently most consistent in their occurrence and severity across the diverse sorghum growing environments. The sweet sorghum variety SSV 74 was released by University of Agricultural Sciences, Dharwad for kharif season mainly for fodder purpose. This variety is also good for ethanol production and jaggery making. However, for the last several years this variety was showing its susceptibility to the leaf blight caused by E. turcicum and causes heavy losses both in fodder and its quality. Even though there are reports of the presence of leaf blight caused by E. turcicum on the grain sorghum, no precise information is available on the presence of the leaf blight on sweet sorghum in India as well as in the world and no information is available about the magnitude of losses caused by this disease. Hence, the experiment was conducted to assess the losses caused by the E. turcicum. 
 
Methods: An experiment on loss assessment in sweet sorghum due to leaf blight caused by E. turcicum was carried out at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, during kharif 2017 using randomized complete block design (RCBD) with three replications and seven treatments. Six treatments were imposed with hexaconazole at 0.1% besides a treatment with unsprayed control. 
 
Result: Lowest per cent disease index (PDI) (24.76%) as well as area under disease progressive curve (789.61) was observed in treatment involving six sprays of hexaconazole at 0.1% followed by five sprays, (PDI: 27.51%, AUDPC: 815.32) and four sprays T4 (PDI: 32.57%, AUDPC: 908.80). Highest fodder yield (46.47 t/ha), brix value (12.47%), crude fibre content (28.22%), leaf ash content (23.08%) and crude protein content (5.29%) was observed in treatment with six sprays of hexaconazole at 0.1%. With respect to the per cent increase over control, 17.47-37.20 per cent increase in fodder yield, 7.4-21.17 per cent in brix value, 11.64-9.66 per cent in crude fibre content, 12.74-62.91 per cent in leaf ash content and 4.36-13.00 per cent in crude protein content was observed at one spray to six sprays with hexaconazole at 0.1 per cent, respectively.</div>

Assessment of Losses in Sweet Sorghum Genotype (SSV 74) due to Leaf Blight caused by Exserohilum turcicum (Pass.) Leonard and Suggs

<div>Background: Potato (Solanum tuberosum) is main crop in subtropical and temperate regions as vegetable crop. It is affected by Phytophthora infestans causing a devasting disease late blight. The chemical pesticides used against this disease in this present scenario cause pollution (soil as well as water) and adversely affect beneficial soil micro-flora, grazing animals and human beings.&nbsp; 
 
Methods: An experiment was designed at the Department of Botany, K.V. Subharti College of Science, Swami Vivekanand Subharti University, Meerut (UP), India during 2017-2018. Three bacterial bioagents, Pseudomonas isolate 1 and 2 and Bacillus species was isolated from infected phylloplane and used against late blight pathogen, P. infestans. The efficacy of antagonistic bio-agents tested against mycelial growth, zoospore and zoosporangial germination of P. infestans by dual culture method and detached leaf method. 
 
Result: The present study focused on use of bio-agents or antagonistic bacteria to control late blight pathogen showed concentration biased potential inhibitory activity against mycelial growth, zoospore and zoosporangial germination.&nbsp;It means higher the concentration of bacterial isolate, greater the inhibitory effect on various tested parameters. Among the three tested antagonistic bioagents, Bacillus showed maximum zone of inhibition to late blight pathogen. The proved that the Pseudomaonas and Bacillus as potential antagonistic agent for ecofriendly sustainable management of pathogenic mycoflora, P. infestans.</div>

<div>Efficacy of Bacterial Isolates against Causal Agent of Late Blight of Potato, Phytophthora infestans</div>

Six genotypes viz., Palam Basmati-1, Palam Red Rice, HPR 1068, Arize 6129, HPR 2143 and Kasturi Basmati were evaluated to assess the crop/ yield losses by paddy leaf folder, Cnaphalocrocis medinalis at CSK Himachal Pradesh Krishi Vishvidyalaya, Rice and Wheat Research Centre, Malan, during Kharif 2012. The leaf infestation (47.1%) at maturity stage was significantly lower in HPR 2143 as compared to other varieties. However, Kasturi Basmati was having significantly higher leaf infestation (77.2%) as compared to Arize 6129 (59.2%), HPR 1068 (57.7%), Palam Red Rice (57.0%) and HPR 2143 (47.1%) and was found at par with Palam Basmati-1 (73.3%).Yield data revealed that the grain yield was higher in protected plots as compared to unprotected plots irrespective of the varieties. The highest grain yield was recorded in protected plots of Arize 6129 (76.45 q/ha) followed by Kasturi Basmati (59.07 q/ha), HPR 1068 (57.15 q/ha), Palam Basmati-1 (56.52 q/ha), HPR 2143 (52.84 q/ha) and Palam Red Rice (46.22 q/ha). The grain yield varied from 35.26 to 53.40 q/ha in the unprotected plots. Assessment of yield losses revealed that the maximum per cent avoidable losses was found in Kasturi Basmati (37.9%) and least in HPR 2143 (11.9%).&nbsp;

Assessment of yield losses of rice caused by paddy&nbsp;leaf folder, Cnaphalocrocis medinalis Guenee

<div style="text-align: justify;">Background: Low nutrient content in ultisol soils and the result of Maydis leaf rot are a major problem in efforts to increase corn productivity in Southeast Sulawesi Province, Indonesia. The use of organic materials and biological agents is one of the solutions in increasing disease resistance and corn productivity in the environmentally friendly ultisol lands. This study aims to assess the effectiveness of the biological agent Biofresh combined with various types of organic material to increase resistance to Maydis leaf rot and maize productivity in ultisol lands.</div><div style="text-align: justify;">Methods: Research in April-August 2017 in Southeast Sulawesi, Indonesia. With 21 units of experiments using a random block design with 7 treatments in combination of Biofresh with organic material &lsquo;Bokashi&rsquo;. consists of: B0 = Inorganic fertilizer; B1 = Organic material of cow dung; B2 = Biofresh Biological Agent; B3 = Biofresh biological agent combined with cow dung organic matter; B4 = Biofresh biological agent combination with bokashi cow dung and straws; B5 = Biofresh combination of biological agents with bokashi cow dung and soybean Sitter; B6 = Biofresh Biological agent combination with all Cow, straw and soybean bokashi.</div><div style="text-align: justify;">Result: The results showed that the combination of Biofresh with organic material in the form of bokashi at a dose of 5 tons ha-1 was very effective in increasing the durability and productivity of corn plants in ultisol land. The combination of Biofresh biological agents with bokashi containing cow&rsquo;s feses, straw, and soy litter can reduce Maydis leaf blight leaf blight disease by 47.36% and increase production by 53.54%. Disease suppression index is positively correlated with maize crop productivity in Ultisol land.</div>

<div style="text-align: justify;">Increase Resistance to Maydis Leaf Blight and Productivity of Maize in Ultisol Soils with A Combination of Organic Material and Biological Agents Biofresh</div>