Construction of SNP genetic maps based on targeted next-generation sequencing and QTL mapping of vital agronomic traits in faba bean(Vicia faba L.)

Owing to the limitation of a large genome size(~13 Gb),the genetic and gene mapping studies on faba bean(Vicia faba L.)are lagging far behind those for other legumes.In this study,we selected three purified faba bean lines(Yundou 8137,H0003712,and H000572)as parents and constructed two F2 populations.These two F2 populations,namely 167 F2 plants in Pop1(Yundou 8137×H0003712)and 204 F2 plants in Pop2(H000572×Yundou 8137),were genotyped using a targeted next-generation sequencing(TNGS)genotyping platform,and two high-density single nucleotide polymorphisms(SNP)genetic linkage maps of faba bean were constructed.The map constructed from Pop1 contained 5103 SNPs with a length of 1333.31 cM and an average marker density of 0.26 cM.The map constructed from Pop2 contained 1904 SNPs with a greater length of 1610.61 cM.In these two F2 populations,QTL mapping identified 98 QTLs for 14 agronomic traits related to the flowers,pods,plant types and grains.The two maps were then merged into an integrated genetic linkage map containing 6895 SNPs,with a length of 3324.48 cM.These results not only lay the foundation for fine mapping and map-based cloning of related genes,but can also accelerate the molecular marker-assisted breeding of faba bean.

Yield stability and relationships among stability parameters in faba bean(Vicia faba L.) genotypes

Sixteen faba bean genotypes were evaluated in 13 environments in Ethiopia during the main cropping season for three years(2009–2011). The objectives of the study were to evaluate the yield stability of the genotypes and the relative importance of different stability parameters for improving selection in faba bean. The study was conducted using a randomized complete block design with four replications. G × E interaction and yield stability were estimated using 17 different stability parameters. Pooled analysis of variance for grain yield showed that the main effects of both genotypes and environments, and the interaction effect, were highly significant(P ≤ 0.001) and(P ≤ 0.01), respectively. The environment main effect accounted for 89.27% of the total yield variation, whereas genotype and G × E interaction effects accounted for 2.12% and 3.31%, respectively.Genotypic superiority index(Pi) and FT3 were found to be very informative for selecting both high-yielding and stable faba bean genotypes. Twelve of the 17 stability parameters,including CVi, RS, α, λ, S2 di, bi, S(2)i, Wi, σ2i, EV, P59, and ASV, were influenced simultaneously by both yield and stability. They should accordingly be used as complementary criteria to select genotypes with high yield and stability. Although none of the varieties showed consistently superior performance across all environments, the genotype EK 01024-1-2ranked in the top third of the test entries in 61.5% of the test environments and was identified as the most stable genotype, with type I stability. EK 01024-1-2 also showed a17.0% seed size advantage over the standard varieties and was released as a new variety in2013 for wide production and named "Gora". Different stability parameters explained genotypic performance differently, irrespective of yield performance. It was accordingly concluded that assessment of G × E interaction and yield stability should not be based on a single or a few stability parameters but rather on a combination of stability parameters.

Genetic Diversity Analysis of Faba Bean (Vicia faba L.) Based on EST-SSR Markers

Faba bean （Vicia faba L.）, one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat （SSR） markers from expressed sequence tags （EST） provided a useful tool for investigation of its genetic diversity. The purpose of the present study was to investigate the genetic diversity of faba bean from China and Europe using EST-SSR markers. 5 031 faba bean ESTs from the NCBI database were downloaded and assembled into 1 148 unigenes. A total of 107 microsatellites in 96 unigenes were identified, indicating that merely 8.36% of sequences contained SSRs. The most abundant SSR within faba bean was tri-nucleotide repeat motif, and among all the tri-nucleotide repeats, the motif AAG/CTT was the most abundant type. Based on these results, 11 EST-SSR markers were used to assess the genetic diversity of 29 faba bean cultivars from China and Europe with two to three alleles per locus. The polymorphism information content value ranged from 0.0644 to 0.4278 with an average of 0.2919. Principal coordinate analysis （PCA） and phylogenetic clustering based on these 11 EST-SSR markers distinguished these cultivars into different groups. The results indicated that faba bean in China had a narrow genetic basis, and the additional sources of genetic cultivars/accessions should be introduced to enhance the genetic variability. The results of this study proved that the EST-SSR marker is very effective in evaluation of faba bean germplasm.

Adaptation of faba bean varieties for yield, for yield components and against faba bean gall (Olpidium viciae Kusano) disease in South Gondar, Ethiopia

Faba bean(Vicia faba L.) has an important place in the Ethiopian national diet. It is consumed in various forms and contributes to the improvement of soil fertility. However,its production and productivity are affected by biotic and abiotic constraints. Among the biotic constraints, the emerging faba bean gall disease, caused by Olpidium uiciae, is the major and most destructive disease wherever faba bean is grown. Field experiments were conducted at two locations(Farta and Tach Gayint districts) to evaluate the reaction of faba bean varieties to faba bean gall disease and to assess them for yield and yield components during the 2014 and 2015 main cropping seasons. Thirteen faba bean varieties and one local check were plantecd in three replications Lusing a randomized complete block design. The disease incidence and severity of faba bean gall were recorded(on a 1-9 scale) five tinmes at10-day intervals. A combined analysis of variance showed za significant difference(P < 0.05)among faba bean varieties with respect to the incidence and severity of gall disease at both locations. Disease incidence, severity, and AUDPC were lowest for variety Turmsa at both locatiOons, but this variety showed lhigh yield only at tlhe Farta location. 'The lhighest yields were obtained from varieties Degaga(1157.74 kg ha ') and Nc58(828.97 kg ha ') at Farta and Tach Gayint, respectively and these varieties slhowed low faba bean gall severity and AUDPC. Thus, higher-yielding faba bean varieties such as Degaga and Nc58 are recommended for faba bean production areas in northwestern Ethiopia.

Yield performance and optimal nitrogen and phosphorus application rates in wheat and faba bean intercropping

Yield performance in cereal and legume intercropping is related to nutrient management,however,the yield response of companion crops to nitrogen(N)input is inconclusive and only limited efforts have focused on rationed phosphorous(P)fertilization.In this study,two multi-year field experiments were implemented from 2014-2019 under identical conditions.Two factors in a randomized complete block design were adopted in both experiments.In field experiment 1,the two factors included three planting patterns(mono-cropped wheat(MW),mono-cropped faba bean(MF),and wheat and faba bean intercropping(W//F))and four N application rates(N0,0 kg N ha^(-1);N1,90 and 45 kg N ha^(-1) for wheat and faba beans,respectively;N2,180 and 90 kg N ha^(-1) for wheat and faba beans,respectively;and N3,270 and 135 kg N ha^(-1) for wheat and faba beans,respectively).In field experiment 2,the two factors included three P application rates(P0,0 kg P_(2)O_(5) ha^(-1);P1,45 kg P_(2)O_(5) ha^(-1);and P2,90 kg P_(2)O_(5) ha^(-1))and the same three planting patterns(MW,MF,and W//F).The yield performances of inter-and mono-cropped wheat and faba beans under different N and P application rates were analyzed and the optimal N and P rates for intercropped wheat(IW)and MW were estimated.The results revealed that intercropping favored wheat yield and was adverse to faba bean yield.Wheat yield increased by 18-26%,but faba bean yield decreased by 5-21% in W//F compared to MW and MF,respectively.The stimulated IW yield drove the yield advantage in W//F with an average land equivalent ratio(LER)of 1.12.N and P fertilization benefited IW yield,but reduced intercropped faba bean(IF)yield.Nevertheless,the partial LER of wheat(pLER_(wheat))decreased with increasing N application rates,and the partial LER of faba bean(pLER_(faba bean))decreased with increasing P application rates.Thus,LER decreased as N input increased and tended to decline as P rates increased.IW maintained a similar yield as MW,even under reduced 40-50% N fertilizer and 30-40% P fertilizer conditions.The estimated optimum N application rates for IW and MW were 150 and 168 kg ha^(-1),respectively,and 63 and 62 kg ha^(-1) for P_(2)O_(5),respectively.In conclusion,W//F exhibited yield advantages due to stimulated IW yield,but the intercropping yield benefit decreased as N and P inputs increased.Thus,it was concluded that modulated N and P rates could maximize the economic and ecological functions of intercropping.Based on the results,rates of 150 kg N ha^(-1) and 60 kg P_(2)O_(5) ha^(-1) are recommended for IW production in southwestern China and places with similar conditions.

Effect of Seeds Size on Germination of Faba Bean Plant

The study was conducted in Al-Qassim region in February 2020 and the study aimed to know the effect of seed size on germination and some morphological parameters in Faba bean (Vicia faba L.) plant, by dividing the seeds into three sizes large 2.5 - 2.3 cm, medium 2.0 - 2.2 cm, and small 1.7 - 1.9 cm and planting them. The results showed that the germination percentage in the large seeds was the highest (100%), and the size of the seeds affected the length of the root and shoot as the large seeds gave the highest length for root (8.37 cm) and shoot (14.2 cm) compared to the medium and small seeds. So, for these results, the seed size is closely related to root and shoot length, number of leaves.

Accumulation of L-DOPA in various organs of faba bean and influence of drought, nitrogen stress, and processing methods on L-DOPA yield

Faba bean(Vicia faba L.)has been identified as a rich source of L-DOPA,which is used in treating Parkinson's disease.Biosynthesis and accumulation of active substances such as L-DOPA in plant tissues may interact with growing conditions and processing methods.Accumulation trends of L-DOPA in various faba bean organs and the effect of drought stress and N fertilization on L-DOPA content were studied in a field and two greenhouse experiments.The influence of various processing methods on L-DOPA content of faba bean tissues was evaluated.The highest L-DOPA content was detected in fresh leaves(22.4 mg g^(-1))followed by flowers,young pods,mature seeds,and roots.Regardless of processing method,L-DOPA concentration in faba bean tissues was significantly reduced when tissues were boiled or dried.Among various methods of processing,freezing had the lowest detrimental effect,reducing L-DOPA concentrations by 24.1%and 21.1%in leaves and seeds,respectively.Drought stress elevated L-DOPA concentration,and maximum L-DOPA(23.3 mg g^(-1)of biomass)was extracted from plants grown under severe drought stress.However,L-DOPA yield(L-DOPA concentration×biomass)was compromised,owing to the adverse influence of drought stress on dry matter production.No significant difference in L-DOPA concentration was detected among various N application rates.

Quantitative Analysis of Pathway Enrichment within Faba Bean Seeds RNA-Seq (<i>Vicia faba</i>L)

Faba bean (Vicia faba L) seeds are an important source of plant protein for humans and animals. A total of 15,697 Differentially Expressed Genes (DEGs) with pathway annotation were discovered in RNA-Seq of the faba bean seeds. A total of 75 significant KEGG pathways abundance were discovered and 9 pathways were conserved within all genotypes. 41 significant pathways were found to be partially conserved within comparisons of 2 to 6 pairs of genotypes and 25 significant pathways were unique to single pairs of genotypes. There were 8 specific significant pathways discovered related to the faba bean seed Hydration Capacity trait and 9 specific significant pathways discovered related to the PSbMV seeds staining trait. The DEGs demonstrated the genetic distance between these varieties was confirmed by the breeding pedigree selection information and a PCA graph clearly illustrated the genetic distance within these genotypes.

Heterotic Effect, Combining Ability and Significance of Synthetics over Line Cultivars in Faba Bean (<i>Vicia faba</i>L.) Grown under Semi-Arid Zones

The aim of this study was to investigate the amount of heterosis and performance of faba bean synthetic cultivars compared to line cultivars under semi-arid conditions. Five inbred lines in at least S6 generation were developed and used to develop F1s hybrid (in all possible combination excluding reciprocal), lines mixtures (Syn-0) and synthetic generations of Syn-1. Evaluation of the entries showed the lines to have high general and specific combining ability, high yield and high average degree of cross-fertilization (0.36);hetrosis relative to mid-parent for yield was 67%. Lines mixture from four inbred lines (Hudeiba/93, Bassabier, Ed-Damar and Shabah) gave the highest yield of 3.40 t/ha for Syn-0 and 3.96 t/ha for Syn-1. Compared to the average yield t/ha of the pure stand of the four lines (3.11 t/ha), the increase in yield of was 9% in sy-0 and 27% in Syn-1. Compared to the individual yield t/ha of the pure stand of the lines, the performance of Syn-0 surpassed that of the individual pure stands of the linesby 14% for Hudiaba/93 and Bassabier and 4% for Ed-Damar and 7% for Shabah, whereas the increase in performance of Syn-1 compared to pure stand of the lines was 32%, 25% and 21%, respectively. The results confirm the previous knowledge on yield increase with successive syn-generations in faba bean due to the effects of heterogeneity and heterozygosity. Such results could be used as a base for an effective breeding program for improvement of yield of faba bean grown under the semi-arid zones.

Optimization of Protease Production by Bacillus mojavensis A21 on Chickpea and Faba Bean

Response surface methodology (RSM) was employed to optimize the medium composition and culture conditions for the production of alkaline proteases by Bacillus mojavensis A21 on uncommon substrates: chickpea (CF) and faba bean (FF) flours. A significant positive influence of temperature, CF, FF, incubation time and inoculums size on the protease production was evaluated by Plackett Burman Design. Among these, CF was the most influential factor. The enhancement of protease to 9127 U/ml was achieved with the optimization procedure on the medium composed of (g/l): CF, 40;FF 30, NaCl 2.0;KH2PO4 1;K2HPO4 1;CaCl2, 0.1;MgSO4 0.1. The cultures were conducted for 72 hours with an IS of 2%, at 30&degC, an agitation speed of 150 rpm and an initial pH of 8.0. More interestingly, the optimization was accomplished using two cheap and local fermentation substrates, CF and FF, which could result in a significant reduction in the cost of medium constituents. The maximum alkaline protease production was 9127 U/ml after 72 h of incubation and showed 5-fold increase in protease production over the initial level.

Impact of Bee Pollination on Yield of Faba Bean (<i>Vicia faba</i>L.) Grown under Semi-Arid Conditions

The effect of honeybee (Apis mellifera carnica) on yield was investigated in open-pollinated faba bean cultivars and three inbred generations produced from them (once-selfed, twice-selfed, and thrice-selfed). All entries were grown in cages under two pollination conditions: presence of bees (cross-pollination) or absence of bees (self-pollination). The open-pollinated generations gave the highest performance in the presence and absence of bees. In the presence of bees, the open-pollinated and their inbred entries gave higher performance in all of the studied traits than in the absence of bees;the average improvement in yield and its components was 22%. The highest improvement percentage in yield performance was shown by more inbred entries (thrice-selfed > once-selfed), indicating that in faba bean populations, the performance of inbred generations was chiefly associated with the tripping of flowers, which is usually governed by successfully fertilized flowers, i.e., plants result from selfing in faba bean population needs to be visited by pollinating insects (bees) to set more seeds. It concluded that honeybee has an important role in increasing faba bean yield in semi-arid conditions;hence, it is important to provide a pollinator friendly environment for their foraging places and nesting sites to secure food supply.

Influences of Ridge Width and Foliar Spraying of Amino Acids Compounds on Yield and Quality of Two Faba Bean Cultivars

A two-year study was carried out at the Agricultural Experiments and Research Station, Faculty of Agriculture, Cairo University, Giza, Egypt, during 2015/2016 and 2016/2017 seasons to evaluate seed yield and quality of two faba bean cultivars to different rates of amino acids compounds under narrow and wide ridges. Two faba bean cultivars Sakha 1 and Masr 3 were grown in two ridge widths 60 and 120 cm and received five rates of amino acids compounds (Power mix at rates 1.5 cm&#8901;L&#8722;1 “Pm1” and 3.0 cm&#8901;L&#8722;1 “Pm2”, Super mix at rates of 3.5 cm&#8901;L&#8722;1 “Sm1” and 7.0 cm&#8901;L&#8722;1 “Sm2”, as well as, water only “control treatment”). The treatments laid out in a split split plot distribution in randomized complete blocks design in three replications were used. Ridge width was randomly assigned to the main plots, faba bean cultivars were allocated in sub-plots and amino acids compounds were allocated in sub sub-plots. Shoot chemical composition and photosynthesis pigments, as well as, chemical composition in seed traits of faba bean were tested in the laboratories of Plant Physiology Section, Agricultural Botany Department, Faculty of Agriculture, Cairo University, Giza, Egypt. Wide ridge had higher nitrogen (N), phosphorus (P), potassium (K), total sugars and total free amino acids concentrations in faba bean shoot and seeds in addition to chlorophyll a (Chl a) and chlorophyll b (Chl b) in faba bean shoot, as well as, most seed yield attributes than those of the narrow one. Faba bean cultivar Sakha 1 had higher values of seed yield, yield attributes and quality than Masr 3 that achieved higher seed antioxidants. Also, amino acids compounds affected significantly all studied traits of faba bean plants. Pm2 recorded the highest values of chemical composition in faba bean shoot and seeds. Moreover, Pm2 gave the highest seed yield and yield attributes compared to others. The interaction between ridge width and faba bean cultivar was significant for total sugars and carotenoids concentrations in faba bean shoot and 100-seed weight, as well as, seed N content. Also, the interaction between ridge width and amino acids compound had significant effects on shoot and seed N, P, K concentrations, number of pods plant&#8722;1 and seed yield ha&#8722;1, as well as, total soluble phenols and total free amino acids concentrations. Moreover, the interaction between faba bean cultivar and amino acids compound had significant effects on shoot Chl a and b concentrations, number of seeds pod&#8722;1 and seed yield plant&#8722;1, as well as, seed N, total soluble phenols and total free amino acids concentrations. Wide ridge x faba bean cultivar x amino acids compound interaction had significant effects on photosynthesis pigments, number of seeds pod&#8722;1 and seed yield ha&#8722;1, as well as, seed N, total sugars, total soluble phenols and total free amino acids concentrations. High seed yield and quality were recorded by growing faba bean cultivar Sakha 1 in wide ridge with foliar spraying at rate of 3.0 cm&#8901;L&#8722;1 of power mix. On the other hand, growing faba bean cultivar Masr 3 in narrow ridge with foliar spraying at rate of 3.5 cm&#8901;L&#8722;1 of super mix had good antioxidants in faba bean seeds.

Competitive Relationships and Yield Advantage of Intercropping Faba Bean with Sugar Beet under Bio-Organic Additives and Mineral Nitrogen Fertilizer Rates

A field experiment was conducted at El-Serw Agricultural Research Station, Damietta Governorate, Egypt during 2016/2017 and 2017/2018 seasons to reduce mineral N inputs of sugar beet with increased land use efficiency and profitability under intercropping conditions. Seven treatments included five treatments (90 kg nitrogen “N” + 30 m3 farm yard manure “FYM”/fad, 80 kg N +30 m3 FYM/fad, 70 kg N +30 m3 FYM/fad and 400 g of Cerealine + 30 m3 FYM/fad for intercropping faba bean cultivar Spanish with sugar beet cultivar Gloria) and two treatments (90 and 20 kg N/fad for solid culture of sugar beet and faba bean, respectively, as recommended mineral N fertilizer rate) were compared in a randomized complete block design with three replications. Solid culture of sugar beet with the application of recommended rate (90 kg N/fad) gave the highest top, root and sugar yields/fad, as well as the percentage of purity compared with the other treatments in both seasons. Intercropping faba bean with sugar beet plants with application of 90 kg N + 30 m3 FYM/fad gave the highest number of leaves/plant, leaf area/plant, root length, root diameter and root weight/plant followed by intercropped sugar beet plants that fertilized with 80 kg N + 30 m3 FYM/fad compared with the other treatments in both seasons. On the other hand, intercropped sugar beet that received 400 g of Cerealine + 30 m3 FYM/fad had the highest percentages of T.S.S. and sucrose followed by 70 kg N + 30 m3 FYM/fad compared with the other treatments in both seasons. Solid culture of faba bean with the application of 20 kg N/fad gave the highest plant height, number of seeds/pod and seed yield/fad, meanwhile the highest number of branches/plant and pod length were achieved by intercropping faba bean with sugar beet with application of 90 kg N + 30 m3 FYM/fad followed by intercropped faba bean plants that fertilized with 80 kg N + 30 m3 FYM/fad compared with the other treatments in both seasons. However, intercropped faba bean plants that fertilized with 70 kg N + 30 m3 FYM/fad gave the highest number of pods per plant, number of seeds per pod, seed index and seed yield per plant compared with the other treatments in both seasons. Land equivalent ratio (LER), land equivalent coefficient (LEC) and relative crowding coefficient (RCC) were high by intercropping faba bean with sugar beet with the application of 80 kg N + 30 m3 FYM/fad indicating yield advantage was achieved. The value of aggressivity (Agg) of sugar beet was negative for all combinations indicating that sugar beet is dominated component in the present study. Intercropping faba bean with sugar beet with the application of 80 kg N + 30 m3 FYM/fad achieved higher total income and monetary advantage index (MAI) than the other treatments. Growing sugar beet plants in both sides of beds (1.2 m width) with one faba bean row in middle of sugar beet beds with the application of 80 kg N + 30 m3 FYM/fad decreased mineral N fertilizer rate by 10.00% of the recommended sugar beet mineral N fertilizer rate, as well as increased land usage and profitability for Egyptian farmers compared with sugar beet solid culture.

Chitosan Seed Priming Improves the Yield and the Root System of Faba Bean(Vicia faba L.)Short Title:Chitosan Impact on Yield of Faba Bean

Faba bean is an important legume crop with food and feed applications.Since 2015,the culture of faba bean has decreased in France.Poor yield caused by climate change is proposed as one of the main reasons.Chitosan is a promising biopolymer with empirically proved impact on germination and disease tolerance of faba bean.However,the impact of chitosan seed priming on germination and yield of this plant is not experimentally studied.We followed chitosan primed faba bean seeds,from sowing until maturation,using germination,fruit and grain parameters.We observed that chitosan seed priming ameliorated several yield related traits.Germination rate,length of radicle and seedling,radicle dry matter,number of pods/plants,number of grains/pods were increased in chitosan primed faba beans.Total grain mass/plant increased up to 47%in treated plants.The probable underlying mechanisms,namely,root enhancement nitrogen metabolism,and elicitation of immune system are discussed.We conclude that,chitosan seed priming with compatible commercial preparations could be a potential solution to recompensate the loss of yield under variable climate conditions.

Nanoparticle Treatments Based on Zinc Oxide and Moringa oleifera Leaf Extracts Alleviate Salinity Stress in Faba Bean (Vicia faba L.)

Salinity stress limits crop growth and productivity, including legumes in various regions worldwide. The impact of foliar-applied zinc nanoparticles (ZnNPs) and combined zinc nano-loaded with moringa extracts (ZnONPs) on salt tolerance in faba beans (cultivar, Giza-716) grown under saline soil (50 and 100 mM NaCl) was investigated. Moringa oleifera extract has been used as a chelating agent to synthesize zinc oxide nanoparticles. The crystalline structure, morphology, and chemical composition of ZnO nanoparticles were studied using various characterization techniques, including UV-visible spectroscopy (UV), Fourier Transform Infrared Analysis (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Morphological, chemical, and biochemical parameters of plants at 60 and 90 days after sowing were assessed. Salinity stress caused a remarkable reduction in growth traits, photosynthetic pigments and proline levels of the faba bean. Foliar spray with ZnNPs and ZnONPs on faba bean grown under saline soils promoted plant growth parameters (i.e., shoot length, numbers of leaves, relative water content, shoot and roots fresh and dry weights), photosynthetic pigments (Chl a, b, total chlorophyll, and carotenoids), proline and mineral elements (Na+, K+, Ca2+, and Zn2+) compared to control. However, at 100 mM NaCl, there were no significant variations in the mentioned parameters. This study suggested that there is potential for foliar spraying with ZnNPs and ZnONPs in improving growth parameters, photosynthesis efficiency and biochemical aspects of faba bean plants under saline conditions.

Assessment of Factors Influencing Chocolate Spot (Botrytis fabae) Disease Epidemics of Faba Bean (Vicia faba L.) at Tach Gayint District in North Western Ethiopia

Faba bean (Vicia faba L.) is one of the oldest domesticated food legumes that have been cultivated for at least 5000 years. It is a multi-purpose crop that plays an important role in the socio-economic life of farming communities in Ethiopia. Chocolate spot disease, caused by Botrytis fabae is one of the yield limiting factors of this crop resulting in yield losses up to 68% in Ethiopia. A field survey was conducted in Tach Gayint district South Gondar Administrative Zone during the 2020/2021 main cropping season to assess the importance of the chocolate spot disease of faba bean. A total of 60 faba bean farmer fields were assessed in six (6) Kebele Administrations and most farmer fields were affected by chocolate spots. But the status of disease incidence and severity was varied. Significant differences among locations were observed due to altitude, soil type, planting density, date of planting, crop growth stages and farm history of the fields. Independent variables like Altitude, farm history, crop growth stage, date of planting and planting density were significantly associated with both disease incidence and severity when entered first and last into a model. The finding indicates that the lowest plant density and late planting of the crop reduce the incidence and severity of the disease.