Studies on the Effect of Temperature on the Development of Soft Rot of Cabbage (Brassica oleracea var. Capitata) Caused by Erwinia carotovora sub Sp. Carotovora

Soft rot is one of the destructive diseases of vegetables including cabbage worldwide. Since the temperature is one of the important factors for destructive nature of disease during storage and transportation, experiments were conducted to standardize optimum temperature for the growth of pathogen which revealed pathogen could grow at all the temperatures from 15 to 40°C. Marked higher growth was recorded at 30°C and considerable growth was at 25 and 35°C. During the study of effect of temperature on soft rot disease after 4 and 6 days of storage at different temperatures it was concluded that 30-35°C mostly favor the soft rot in cabbage and thus emphasis is to be given to prevent the disease during the prevailing temperatures in the region, in order to prevent losses due to the disease in cabbage and other hosts of the same pathogen

Growth response and nutrient uptake of blue pine (Pinus wallichiana) seedlings inoculated with rhizosphere microorganisms under temperate nursery conditions

Microbial inoculants (Trichoderma harzianum, Pseudomonas fluorescens,Laccaria laccata) inoculated either individually or in combinationsignificantly improved the growth and biomass of blue pine seedlings. The ECM fungus Laccaria laccata, when inoculated individually, showed significantly higher plant growth, followed by Pseudomonas fluorescens and Trichoderma harzianum. The combined inoculation of rhizosphere microorganisms showed synergistic growth promoting action and proved superior in enhancing the growth of blue pine than individual inoculation. Co-inoculation of L. laccata with P. fluorescens resulted in higher ectomycorrhizal root colonization. Uptake of nutrients (N, P, K) was significantly improved by microbial inoculants, tested individually or in combination. Combined inoculation of L. laccata with T. harzianum and P. fluorescens significantly increased in N, P and K contents in blue pine seedlings as compared to control. Acid phosphatase activity in the rhizosphere of blue pine seedlings was also enhanced by these microorganisms. L. laccata exhibited higher acid phosphatase activity followed by P. fluorescens

Effect of Silver Ions on Ethylene Metabolism of Mustard Grown Under Irrigated and Non- irrigated Conditions

A field experiment was conducted during the winter season of 2004-2005 at the Experimental farm of Aligarh Muslim University, Aligarh, India on mustard (Brassica juncea L. Czen and Coss, cultivar Alankar) under irrigated and non -irrigated  conditions to evaluate the application of 0  and 200 µl/L  ethrel (E200) or 1 mM silver thiosulphate (S) at flowering stage along with a basal  uniform application of 80 kg N ha-1 on leaf area, plant dry mass, net photosynthetic rate and seed yield. Silver thoisulphate, which inhibits the physiological action of ethylene was used in the experiment with ethrel. Ethrel is a source of ethylene and its effects are manifested through physiological action of ethylene. Ethrel 200 µl/L (E200) treatment enhanced leaf area, net photosynthetic rate, plant dry mass and seed yield by 10.6, 9.1, 7.7 and 11.6% over S treatment. So silver thiosulphate (S) reduces the physiological action of ethrel (source of ethylene) in this study. This clearly indicates that silver ions used in this experiment in the form of silver thiosulphate inhibits the action of ethylene metabolism in mustard

Biopesticides: Ecofriendly and biorational alternatives to vegetable production and environmental sustainability

Insect pests, nematodes and plant diseases of vegetables are generally controlled by frequent applications of chemical pesticides with an objective to increase crop productivity and obtain greater profit in conventional farming. With consumers' awareness and perception, vegetables without residue of chemicals are being preferred in local and export markets. For this purpose, plant-derived crude products or formulated pesticides can be eco-friendly, effective and economical for an average producer. Several pressures have accelerated the search for more environmentally and toxicologically safe and more selective and efficacious pesticides. Biopesticides, including microbial pesticides, entomopathogenic nematodes, baculoviruses, plant derived pesticides, and insect pheromones are receiving increased exposure in scientific annals as alternatives to chemical pesticides and also as key components of integrated pest management (IPM) systems. The reality, however, is that biopesticides currently represent only a small fraction (1.3%) of the world pesticide market. However, the growth rate for biopesticides over the next 10 years has been forecast at 10–l5% per annum in contrast to 2% for chemical pesticides. It is imperative to make aware the farming community regarding the use of biopesticides to reduce the environmental pollution

Efficient Plant regeneration through leaf, In vitro Flowering and Biochemical studies during morphogenesis of Solanum nigrum L.

In this investigation, Murashige and Skoog (MS) medium when supplemented with 6-benzylamino purine (BAP) or Kinetin produced high frequency of in vitro shoot directly from in vitro raised Solanum nigrum leaves without any callusing stage. Among the plant growth regulators (PGRs) the best response was noted at 2.0 mgl-1 BAP and 1.5 mgl-1 kinetin. Shoot formation and multiplication were more pronounced on dorsal leaf surface (0.5-1.5 cm2) compared to ventral. Biochemical studies including soluble protein, sugar and amino acid were carried out in order to know the differences in reserves of some biochemical entities. Nearly all parameters were high in samples derived from dorsal leaf, which was grown in MS augmented with 2.0 mgl-1 BAP or 1.5 mgl-1kinetin. The present investigation also describes first successful induction of in vitro flowering in S. nigrum, which can augment selective hybridization. Finally, the in vitro raised shoots were treated with various concentrations of auxins for obtaining roots, the rooted plantlets were transplanted with 100% survival in field conditions

Productivity and economic evaluation of Willow (Salix alba L.) based silvopastoral agroforestry system in Kashmir valley

Performance of two fodder crops namely, sorghum (Sorghum vulgare L.) and maize (Zea mays L.) was investigated with Willow (Salix alba L.) to evaluate productivity and economics of the silvopastoral agroforestry system in Kashmir valley. The experiment was laid out by planting two year old willows at 2.0m × 2.0m spacing and dividing the main plot into sub-plots of size 8m × 2m each with 5 replications in randomized block design (RDB). The intercrops of sorghum and maize were maintained at 20cm × 10 cm spacing and supplied with recommended doses of fertilizers. The economics of the willow plantation intercropped with fodder crops was compared with sole willow farming by the benefit-cost ratio and net present worth. The study revealed the differential behaviour of Salix alba regarding growth parameters (height, diameter and girth) by different intercrops and various fodder intercrops with respect to yield, above ground biomass, dry matter production and soil nutrient status (pH, organic carbon, available nitrogen, phosphorus and potassium). The willow based silvopastoral system was estimated to have benefit-cost ratio of 2.71 with maize and 2.68 with sorghum, while as sole crop the willows accrued a benefit-cost ratio of 2.66. The study is useful in discovering growth of willows, productivity of fodder crops and soil nutrient status under various silvopastoral agroforestry systems for maximizing economic gains. The findings envisaged evidences in favour of adopting willow based silvopastoral agroforestry instead of sole tree farming and the knowledge of interactions will be helpful in proper management of the system for sustained multiple productions

On cospectral signed digraphs

The set of distinct eigenvalues of a signed digraph S together with their respective multiplicities is called its spectrum. Two signed digraphs of same order are said to be cospectral if they have the same spectrum. In this paper, we show the existence of integral, real and Gaussian cospectral signed digraphs. We give a spectral characterization of normal signed digraphs and use it to construct cospectral normal signed digraphs

Effect of ethrel and nitrogen on nitrate reductase activity, photosynthesis, biomass and yield of mustard (Brassica juncea L. Czern and Coss)

      The plants of mustard (Brassica juncea L. Czern and Coss; cultivar Alankar) were treated with 200 µL/L ethrel (2-chloro ethyl phosphonic acid) at flowering stage (60 d after sowing) along with basal application of nitrogen 40, 60, and 80 kg N ha-1. Effect of ethrel and nitrogen on leaf area index (LAI), net photosynthetic rate (PN), nitrate reductase (NR) activity and plant dry mass were recorded at 80 and 100 d after sowing. At harvest pods plant-1, 1000 seed mass and seed yield were recorded. Ethrel 200 µL/L x 80 kg N ha-1 treatment enhanced all the characteristics studied during the experiment

Genome-wide association analysis to delineate high-quality SNPs for seed micronutrient density in chickpea (Cicer arietinum L.)

Chickpea is the most important nutrient-rich grain legume crop in the world. A diverse core set of 147 chickpea genotypes was genotyped with a Axiom(®)50K CicerSNP array and trait phenotyped in two different environments for four seed micronutrients (Zn, Cu, Fe and Mn). The trait data and high-throughput 50K SNP genotypic data were used for the genome-wide association study (GWAS). The study led to the discovery of genes/QTLs for seed Zn, Cu, Fe and Mn, concentrations in chickpea. The analysis of seed micronutrient data revealed significant differences for all four micronutrient concentrations (P ≤ 0.05). The mean concentrations of seed Zn, Cu, Fe and Mn pooled over the 2 years were 45.9 ppm, 63.8 ppm 146.1 ppm, and 27.0 ppm, respectively. The analysis of results led to the identification of 35 SNPs significantly associated with seed Zn, Cu, Fe and Mn concentrations. Among these 35 marker-trait associations (MTAs), 5 were stable (consistently identified in different environments), 6 were major (explaining more than 15% of the phenotypic variation for an individual trait) and 3 were both major and stable MTAs. A set of 6 MTAs, MTAs (3 for Mn, 2 for Fe, and 1 for Cu) reported by us during the present study have been also reported in the same/almost same genomic regions in earlier studies and therefore declared as validated MTAs. The stable, major and validated MTAs identified during the present study will prove useful in future chickpea molecular breeding programs aimed at enhancing the seed nutrient density of chickpea