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Downy mildew is a devastating disease of canola. Two years study was conducted to find the impact of different nitrogen levels on disease severity of downy mildew with respect to leaf age on canola plants in field conditions. Three nitrogen levels (11.50 Kg acre−1, 23 Kg acre−1 and 34.5 Kg acre−1) were applied in soil when plants were 40 days old. In control, 0 Kg acre−1 N was applied. The diseased leaves from the lower, middle and upper part of the plant were tagged and data were recorded after 10 days interval. Disease severity differed significantly between the two experimental years. A significant increase in disease severity was recorded with leaf age irrespective of the N concentration applied. Nitrogen concentrations significantly accelerated the disease severity with the increase of age. Maximum disease severity was recorded in 34.5 Kg acre−1 N applied 100 days old leaves in both experimental years. [ABSTRACT FROM AUTHOR]

The effect of potassium phosphite (KPhi) on the photosynthetic parameters of cucumber plants inoculated withPseudoperonospora cubensiswas investigated in the present study. Cucumber plants were treated with KPhi before or after inoculation withP. cubensisand leaf samples were collected at different time courses for assessments. Results showed that in pathogen-inoculated plants Fv/Fm was decreased up to 3%. The rate of quantum photosynthetic was also decreased significantly in inoculated plants. Downy mildew led to a decrease in chlorophyll amount which in turn reduced the efficiency of photosystem II. In the KPhi-treated leaves, chlorophyll a and b decreased by 72% and 68%, respectively. Remarkable reduction in the efficiency of photosystem II as well as increased lipid membrane disruption, led to increased lipid peroxidation rate of the membranes up to 52%. The results of this study indicate the mitigating role of potassium phosphite in reducing the adverse effects of pathogen and maintaining the photosynthetic apparatus efficiency in cucumber plants. [ABSTRACT FROM AUTHOR]

Partially purified non-specific Lipid Transfer Proteins (ns-LTPs) of plant source were treated to pearl millet seeds at different concentrations for six hours. Among the tested, rice ns-LTP (100 μg/ml) showed a maximum seed germination of 94% and 1385 seedling vigour followed by maize and wheat. The treated seeds also enhanced growth parameters when compared to control plants. The maximum downy mildew disease protection of 56% was offered by rice ns-LTP (100 μg/ml) followed by maize and wheat which offered 52% and 47% protection, respectively. The ns-LTPs of maize and rice required minimum of three days after challenge inoculation to build up maximum resistance to downy mildew. The present investigation suggests that the ns-LTPs from plant source can be used as inducers in managing pearl millet downy mildew disease and also for plant growth promotion. [ABSTRACT FROM PUBLISHER]

The efficiency of some inducer resistance chemicals (IRCs) like bion, chitosan, humic acid and salicylic acid as well as the fungicides like Folu-Gold, Galben Copper, Previcure-N and Redomil Gold Mancozeb on management of sweet melon downy mildew, caused byPseudoperonospora cubensiswas evaluatedin vitroandin vivo. Also, the efficiency of the alternation between the sprayed two fungicides and IRCs on management of the disease and the produced fruit yield and its total soluble solids (TSS) under field conditions were assessed. The inhibitory effect of the IRCs and the tested fungicides on sporangial germination ofP. cubensisresulted in a significant reduction in the germinated sporangia. In addition, IRCs were less effective than the fungicides. Disease management revealed the same trend of thein vitroexperiment when they sprayed fungicides on sweet melon plants artificially inoculated with the sporangia of the causal fungus under greenhouse conditions. Furthermore, under field conditions, spraying sweet melon plants with the two tested fungicides was the most efficient in decreasing the disease and increasing fruit yield and its TSS, to somewhat, followed by the alternation between them and the tested IRCs. In addition, IRCs treatments showed the lowest efficiency in this regard. [ABSTRACT FROM AUTHOR]

The present study aimed to assess the efficacy of applied programmes and treatment methods against downy mildew (Plasmopara viticola). Two vine cultivars (Frankovka and Game) were tested in an experimental field (in Rahovec, Kosovo) for a two-year period (2010–2011). The fungicides used were Quadris (azoxystrobin), Antracol EP-70 (propineb), Dithan M-45 (mancozeb), Ridomil (metalaxyl), Curzate (cymoxanil), Bordeaux mixture (calcium hydroxide and copper sulphate) and Mikal (fosetyl-aluminium) applied three treatment methods. The evaluation of the disease severity was performed using the McKinney index. In both tested cultivars and in both treatment years (2010 and 2011), all of the programmes tested significantly reduced the severity of grape downy mildew compared to the control. The highest efficacy against grape downy mildew was achieved with the combined use of Ridomil and Dithan (programme 3); this treatment was more than 80% effective in both cultivars and in both years. [ABSTRACT FROM PUBLISHER]

Cucurbits are tremendous economically important vegetable crops and extensively cultivated in tropical and subtropical part of the world during both rainy and winter seasons. Biotic stresses are of paramount importance in causing economic losses in cucurbits. Downy mildew, a foliar disease caused by an Oomycetes,Pseudoperonospora cubensis(Berk. & Curt.) Rostow, is one of the most destructive pathogens of cucurbits especially in wet and temperate regions, with worldwide distribution. Isolates of pointed gourd and ivy gourd showed no symptoms with most of the cucurbits hosts except pointed gourd and ivy gourd.P. cubensisisolate of pointed gourd differed from other isolates and may belong to different pathotype. The results of this investigation suggest that high variability ofP. cubensisin terms of different pathotypes exists in the Gangetic Alluvial Region of West Bengal. Based on morphological characterisation, nine isolates ofP. cubensisare grouped into four clusters by using hierarchical cluster analysis. [ABSTRACT FROM AUTHOR]

Antipathogenic potential of 16 plants was evaluated in the form of aqueous extracts againstPeronosclerospora sorghi, causing downy mildew of sorghum. A novel method was developed in which conidial suspension and plant extracts were mixed individually and allowed to stand for 5 min and then used to inoculate the host by sprout-dip method. The sprouts thus inoculated were grown in pots, and disease incidence was observed. Three extracts (Parthenium hysterophorus, Duranta repensandOxalis latifolia) suppressed the disease at par with chemical fungicide (Mancozeb 75%). In form of spray,D. repensextract with tween-20 adjuvant (1.9% disease) performed closest behind mancozeb (0% disease), while negative control showed 21% disease incidence. Organic management of airborne inoculum of downy mildew of sorghum is feasible and preferable as compared to the use of chemical fungicides, considering human and environmental health concerns. Use of water extract keeps the technology simple so that it can be directly prepared and used by farmers. Short listing of three most effective water extracts would help in self-reliance of farmers, reducing their dependence on commercial products. [ABSTRACT FROM AUTHOR]

Nowadays, artificial intelligence solutions such as digital image processing and artificial neural networks (ANN) have become important applicable techniques in phytomonitoring and plant health detection systems. In this research, an autonomous device was designed and developed for detecting two types of fungi (Pseudoperonospora cubensis,Sphaerotheca fuliginea) that infect the cucumber (Cucumis sativusL.) plant leaves. This device was able to recognise the fungal diseases of plants by detecting their symptoms on plant leaves (downy mildew and powdery mildew). For leaves of cucumber inoculated with different spores of the fungi, it was possible to estimate the amount of hour post inoculation (HPI) by extracting leaves’ image parameters. Device included a dark chamber, a CCD digital camera, a thermal camera, a light dependent resistor lightening module and a personal computer. The proposed programme for precise disease detection was based on an image processing algorithm and ANN. Three textural features and two thermal parameters from the obtained images were measured and normalised. Performance of ANN model was tested successfully for disease recognition and detecting HPI in images using back-propagation supervised learning method and inspection data. Such this machine vision system can be used in robotic intelligent systems to achieve a modern farmer’s assistant in agricultural crop fields. [ABSTRACT FROM PUBLISHER]

Matured botanical compost ofCroton sparsiflorusandAzadirachta indicawere evaluated for promotion of sorghum downy mildew at the rate of 0.5% (w/w). Exceptionally high promotional rates of 26.9% (C. sparsiflorus)and 30.1% (A. indica)were observed as compared to negative control (8.8%). The enhancement of disease was higher than that obtained by the supply of recommended dose of urea (13.3%). As the pathogen (Peronosclerospora sorghi) is a biotroph and cannot multiply by using organics as nutrient source in the absence of a host, the mechanism of disease enhancement is inferred to be through stimulation of oospore germination by organic compounds. [ABSTRACT FROM PUBLISHER]

An effective and simple technique to obtain conidial inoculum ofPeronosclerospora sorghihas been devised, which confers many advantages over the conventional method. Systemically infected sorghum leaves were packed into folds of paper-towel. The end of folded paper-towel containing cut-ends of leaves was dipped in 3 cm deep water in a container. The container was exposed to moist field conditions at night and sporulated leaves were harvested with chilled distilled water in the morning to obtain the inoculum. Advantages of the technique include lower cost and effort, rapid harvesting and daily production of inoculum for up to seven consecutive days from same leaves. Though conventional method of plating leaf pieces in Petri plates proves superior in terms of the amount of sporulation, paper-towel method has the edge under working conditions. [ABSTRACT FROM PUBLISHER]

Uncomposted dried, powdered biomass of 38 selected botanicals was evaluated as soil amendments in a pot experiment for their potential to suppress downy mildew of sorghum caused by soil-borne oosporic inoculum ofPerenosclerospora sorghi. A negative control showed 11.1% disease incidence. Six botanicals proved effective in form of dry biomass powder at 0.5% (w/w) amendment rate to control infection by oospores (Allium cepa0%, Lantana camara1.6%, Polyalthia longofolia0%, Hyptis suaveolens1.5%, Eucalyptus globulus0% andNerium oleander1.6% of disease incidence). Dry powders are not only effective in disease suppression but confer additional benefits over composts like reduced bulk, increased shelf-life, consistent composition and results. [ABSTRACT FROM AUTHOR]

The biomass of 10 selected botanicals was evaluated as soil amendments, in the form of composts and dry powder biomass, to compare their potential to suppress downy mildew disease caused by oosporic inoculum of Perenosclerospora sorghi. Eight botanicals (Allium cepa, Lantana camara, Polyalthia longifolia, Hyptis suaveolens, Azadirachta indica, Nerium oleander Eucalyptus globulus and Tamarindus indica) proved effectively in the form of dry biomass powder at 4% (w/w) rate to control infection by oospores, while two (Croton sparsiflorus and Tagetes erecta) promoted it. In the form of composts (2% rate), the efficacy of botanicals was generally found reduced with the appearance of more disease than negative control in case of all botanicals except one (A. cepa). At the 4% compost rate, only four botanicals namely, A. cepa, P. longifolia, H. suaveolens and L. camara were found to suppress the disease. At higher amendment rates of 6, 8 and 10%, six botanicals suppressed the disease. Dry powders are not only superior in disease suppression but confer additional benefits like reduced bulk, increased shelf life, consistent composition and results. [ABSTRACT FROM AUTHOR]

Antipathogenic potential of 38 plants was evaluated in the form of aqueous extracts against Peronoclerospora sorghi, causing downy mildew of sorghum. Conidial suspension and plant extracts were mixed individually and allowed to stand for 5 min and then used to inoculate the host by sprout-dip method. The sprouts thus inoculated were grown in pots, and the disease incidence was observed. Eight plant extracts (Cicer areatinum, Datura metel, Croton sparsiflorus, Parthenium hysterophorus, Nerium oleander, Chromolaena odorata, Duranta repens and Oxalis latifolia) at 20% concentration performed at par with chemical fungicide (Mancozeb 75%) by exhibiting total suppression of disease incidence to 0%, when compared with 64.1% of negative control. Organic management of air-borne inoculum of downy mildew of sorghum is feasible and preferable when compared with chemical control methods, considering human and environmental health concerns. The use of water extract keeps the technology simple so that it can be directly prepared and used by the farmers. Short-listing of eight most effective water extracts would help in self-reliance of farmers, reducing their dependence on commercial products. [ABSTRACT FROM PUBLISHER]

Pearl millet [Pennisetum glaucum (L.) R. Br.] has the seventh largest annual production in the world giving it significant economic importance. Although generally well adapted to the growing conditions in arid and semi-arid regions, major constraints to yields are susceptibility to downy mildew disease caused by the oomycete Sclerospora graminicola (Sacc.) Schroet. Induction of resistance against downy mildew disease of pearl millet has been well established using various biotic and abiotic inducers. The present study demonstrated the comparative analysis of the involvement of the important defence enzymes like β-1,3-Glucanase, chitinase, phenylalanine ammonia-lyase (PAL), peroxidase (POX), polyphenol oxidase (PPO) and lipoxygenase (LOX) during induced systemic resistance (ISR) mediated by inducers like Benzo(1,2,3)-thiadiazole-7-carbothionic acid-S-methyl ester (BTH), Beta amino butyric acid (BABA), Chitosan and Cerebroside against pearl millet downy mildew disease. Native-PAGE showed six POX isozymes in all categories of uninoculated pearl millet seedlings and maximum intensity of bands was noticed in resistant seedlings. After inoculation in Cerebroside-treated seedlings, there were seven isoforms, POX-4 was not present in any other seedlings. Native-PAGE analysis showed the presence of five PPO isozymes in all categories of uninoculated pearl millet seedlings and after inoculation seven isoforms of PPO-7 were noticed, and the intensity of banding was more in resistant and Cerebroside-treated seedlings. The isoforms PPO-3 were present as an extra band after inoculation in all seedlings. Isoform PPO-7, though found in all seedlings, was very prominent in Chitosan- and Cerebroside-treated seedlings. β-1,3-Glucanase Native-PAGE analysis showed the presence of only one isozyme in all categories of uninoculated/inoculated pearl millet seedlings. Glu-1 isozyme was very prominent in all seedlings including resistant and susceptible seedlings. Among the induced resistant seedlings, highest intensity was observed in Cerebroside-treated seedlings. Native-PAGE analysis showed the presence of three LOX isozymes in all categories of uninoculated pearl millet seedlings, and the intensity of banding pattern was very low in BTH-treated seedlings. LOX-1 and LOX-2 were very prominent in resistant, Chitosan- and Cerebroside-treated seedlings. Upon inoculation, one extra band, LOX-3, was exclusively noticed in Cerebroside-treated seedlings. In inoculated seedlings, LOX-1, LOX-2 and LOX-4 were very prominent in Chitosan Cerebroside-treated seedlings compared to other seedlings. [ABSTRACT FROM AUTHOR]

In the present investigation, downy mildew resistant and susceptible pearl millet genotypes were characterised using seed protein and isozymes at pre- [45 days after sowing (DAS)] and post-infection (57 DAS, i.e. 7 days after infection) stage, as well as molecular markers at seedling stage without infection. Native polyacrylamide gel electrophoreis (PAGE) isozyme banding pattern of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and esterase showed some inducible band(s) due to disease infection and differentiated resistant and susceptible genotypes. Total seed protein profiling revealed the presence of two unique protein of ∼97 and ∼100 kDa in resistant genotypes. Randomly amplified polymorphic DNA (RAPD) analysis did not show any specific marker for disease resistant and susceptible genotypes. However, inter-simple sequence repeat (ISSR) markers showed six markers in resistant genotypes viz., UBC-825 (900 bp), UBC-827 (900 bp), UBC-857 (1000 bp, 700 bp, 375 bp and 200 bp). Moreover, a single unique band UBC-857 (400 bp) was present in only susceptible genotypes. Overall pooled analysis of isozymes, protein profiling, RAPD and ISSR data showed two distinct clusters of resistant and susceptible genotypes. These results suggested that seed protein profiling and ISSR markers may be used for large scale screening of germplasm for disease reaction trait. [ABSTRACT FROM PUBLISHER]

In this study, the ascorbic acid content, lipid peroxidation product, reactive oxygen generation and scavenging enzyme activities were determined in pearl millet [Pennisetum glaucum (L.) R.Br.] leaves. These parameters were analysed at two stages: (i) pre-infection [45 days after sowing (DAS)] and (ii) post-infection [7 days after infection (DAI), i.e. 57 DAS]. Lipid peroxidation product (malondialdehyde content) was recorded higher in compatible interaction at pre-infection stage while it was increased in incompatible interaction at post-infection stage. Resistant genotypes had higher ascorbic acid content at both the stages of analysis. Superoxide dismutase (SOD) activity was higher in susceptible genotypes at pre-infection but after infection it was found to be higher in resistant genotypes. Ascorbate peroxidase, catalase (CAT) and lipoxygenase activities were higher in resistant genotypes at both the stages of analysis. Native PAGE isozyme banding pattern of SOD, CAT, APX and esterase showed some inducible band(s) due to disease infection. [ABSTRACT FROM AUTHOR]

Biochemical characterisation of pearl millet genotypes was carried at pre- (45 DAS) and post-infection (57 DAS i.e. 7 days after infection) stages. Total phenol content at pre-infection stage did not show inherent resistance or susceptibility. While the total phenol content was found to be higher in susceptible genotypes at post-infection stage, qualitative analysis of phenol through high-performance thin layer chromatography showed absence of ferulic acid in resistant genotypes at pre-infection stage. Peroxidase (POX) activity was higher in susceptible genotypes at both the stages of analysis. Constitutive activity of phenylalanine ammonia lyase was higher in resistant genotype whereas induced activity was recorded higher in susceptible genotypes. Native poly-acrylamide gel electrophoresis isozyme banding pattern of POX showed some inducible band(s) due to disease infection in resistant and susceptible genotypes. [ABSTRACT FROM AUTHOR]

Genotypic diversity among 46 isolates of Sclerospora graminicola collected from seven states in India during 1992-2005 was determined through pathotyping and AFLP analysis. A high level of variation was observed among the isolates for downy mildew incidence, latent period and virulence index. Based on the reaction on a set of nine pearl millet lines, 46 isolates were classified in 21 pathotypes. Quantitative differences in virulence levels of the test isolates were assessed by calculating the virulence index (disease incidence × latent period - 1). A dendrogram generated by the average linkage cluster analysis of virulence index clustered the 46 isolates into eight groups. Region-specific grouping of five isolates from Gujarat and six from Rajasthan was observed within two distinct groups. Temporal variation was also observed among the isolates collected from the same location and same host over the years. A total of 297 bands were scored following selective amplification with three primer combinations E-TT/M-CAG, E-AT/M-CAG and E-TG/M-CAT and all of them were polymorphic. Cluster analysis of AFLP data clustered the test isolates into seven groups. Analysis of molecular variance indicated that variation in the S. graminicola populations was largely due to differences among the isolates within the states. [ABSTRACT FROM AUTHOR]

Field trials in which seed dressing with Apron Star 42 WS (metalaxyl-M) was tested on five pearl millet cultivars were laid at Gashua (Sahel) and Maiduguri (Sudan Savanna) for three wet seasons (1998-2000). Using the split-plot design, seed dressing and cultivars were tested in main- and sub-plots, respectively. Results showed that at each location and season, there was significantly high seedling emergence and grain yield but lower downy mildew incidence as a result of seed dressing with metalaxyl-M compared with check. Among the cultivars tested, SOSAT C-88 had significantly lower downy mildew incidence and the highest grain yield during the three seasons. Dressed with metalaxyl-M, other cultivars had lower downy mildew and higher grain yield than undressed check. It is therefore important that pearl millet should be dressed with metalaxyl as routine practice before cultivation in the arid area of Nigeria. [ABSTRACT FROM AUTHOR]

In this investigation, four local inbred maize (Zea mays L.) genotypes CM-500, NAI-127, NAI-129 and SKV-10 were evaluated in the field against Peronosclerospora sorghi during two seasons, i.e., Kharif and Rabi, 2005. The results indicate that genotype SKV-10 was found highly resistant to downy mildew recording 1.0% of disease during both seasons. Whereas NAI-129 had low incidence (10.2 and 13.0% respectively for Kharif and Rabi) of downy mildew compared to CM-500 (97.2 and 99.4% respectively for Kharif and Rabi). The characterization of soluble seed proteins by SDS-PAGE indicates CM-500 as highly susceptible to downy mildew and revealed considerable variation among the genotypes. It is evident from the dendrograms that CM-500 and NAI-127, as well as NAI-129 and SKV-10, were genetically closely related, consistent with the compatible and incompatible reaction of these genotypes to downy mildew. [ABSTRACT FROM AUTHOR]

The osmoconditioning effect on pearl millet seeds was tested with different concentrations among which 1% showed an optimum effect. Seeds osmoprimed with mannitol for 3 h followed by overnight drying offered maximum germination of 99% and seedling vigour of 1465 followed by PEG and glycerol. All the three osmopriming agents recorded a significant increase on growth parameters like height of the plant, leaf area, number of tillers per plant. The results indicated that mannitol offered a maximum positive effect followed by PEG and glycerol. Notably, osmopriming has advanced five days of flowering and also has a positive effect on number and length of the earheads. The osmoconditioning agent increased the 1000 seed weight significantly over the untreated control. When the osmoprimed seeds were germinated and inoculated with downy mildew pathogen, the maximum protection of 61.76% was observed in mannitol treatment followed by PEG and glycerol under greenhouse conditions. Osmopriming has promoted seed germination percentage, seedling vigour index and growth parameters in pearl millet and also reduced downy mildew incidence. [ABSTRACT FROM AUTHOR]

Downy mildew of pearl millet incited by Sclerospora graminicola (Sacc.) Schroet. The experiment was conducted to test the eight fungal and three bacterial antagonists against S. graminicola sporangial production, spore germination and in the management of the disease. Pearl millet seeds were treated with a talc-based formulation of Trichoderma spp. and Pseudomonas fluorescens and a peat-based formulation for Bacillus subtilis. The seeds were treated with Trichoderma spp. at 4 g/kg, P. fluorescens at 10 g/kg and B. subtilis at 30 g/kg and then dried in the shade for 12 h. These seeds were then exposed to the sporangial shed of S. graminicola and were sown in infected soil in pots. These were compared with the standard check of seed treatment with Apron 35 SD (2 g/kg) and seed treatment with Apron 35 SD+ foliar spray with Ridomil MZ 72 wp. A suitable control was maintained. The number of plants showing downy mildew infection was recorded 30, 45 and 65 days after sowing. The results showed that seed treatment with Apron (2 g/kg) + foliar spray of Ridomil (0.6%) significantly reduced the incidence of downy mildew incidence to the minimum of 4.50% from 53.33% in the control. This was followed by P. fluorescens (9.50%). [ABSTRACT FROM AUTHOR]

Grapevine downy mildew is the most devastating disease throughout the world causing huge monetary losses. Twenty medicinal plant extracts and six phylloplane microfloras were evaluated for their efficacy against sporangial germination of grapevine downy mildew pathogen Plasmopara viticola in vitro. The results revealed that the Neem Seed Kernel Extract (NSKE) at 5% significantly inhibited the sporangial germination (75.36%) of P. viticola. Among the phylloplane microflora Pseudomonas fluorescens was highly effective in reducing the sporangial germination (64.26%). Post inoculation spraying of NSKE (5%) and P. fluorescens (0.2%) effectively inhibited the disease development in the greenhouse. Three sprays with NSKE (5%) and phylloplane P. fluorescens (0.2%): first spray after initial appearance of disease and the second and third at 10 day intervals were found to be promising in reducing disease incidence in the field. [ABSTRACT FROM AUTHOR]

Abstract The effect of seven intra row spacing (10, 20, 30, 40, 50, 60, 70 cm) on the incidence and severity of downy mildew of pearl millet and yield components of a local pearl millet variety (Zango) were studied under field conditions in 2002 and 2003 at Samaru, Nigeria. Intra row spacing did not have significant effect on the incidence and severity of the disease but significantly increased plant height, panicle length and weight, 1000-grain weight and grain yield. [ABSTRACT FROM AUTHOR]

The effect of various levels of nitrogen (0.0, 30.0, 60.0, 120.0) and phosphorus (0.0, 6.5, 13.0, 36.0) on the incidence and severity of downy mildew of pearl millet and yield of two pearl millet varieties (Zango and GB8375) were studied under field conditions in 2000 and 2001 respectively. Both nitrogen and phosphorus significantly increased incidence and severity of the disease in the two varieties. Grain yield and 1000 grain weight of the varieties also increased with nitrogen and phosphorus levels. [ABSTRACT FROM AUTHOR]

Methanolic extracts of forty plant species commonly growing across India were collected and have been screened for antisporulant activity against Sclerospora graminicola (Sacc.) Schroet., the causative agent of pearl millet downy mildew. The collection represented 38 genera of 30 families. The methanolic extracts of nine species did not show any effect, whereas the activity of the extracts of Clematis gouriana, Evolvulus alsinoides, Mimusops elengi, Allium sativum and Piper nigrum were commensurable to that of the marketed botanical fungicides. The extracts of 11 species (Agave americana, Artemisia pallens, Citrus sinensis, Dalbergia latifolia, Helianthus annus, Murraya koenigii, Ocimum basilicum, Parthenium hysterophorus, Tagetes erecta, Thuja occidentalis and Zingiber offinale) exhibited remarkable antisporulant effect even after 10-fold dilution of the crude extracts while in the case of remaining 15 plants the crude extracts loosed activity after 10-fold dilution. The antisporulant activity of commercialised Azadirachta preparation (Nutri-Neem) was more pronounced than that of Reynutria based one (Milsana) and Sabadilla (veratrin), however, these botanical preparations held off the extracts of C. gouriana and E. alsinoides and synthetic fungicides. [ABSTRACT FROM AUTHOR]

Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight. [ABSTRACT FROM AUTHOR]