Agro-climatic Regions Of India Research Articles

Sorption and desorption behavior of lead in four different soils of India

Sorption and desorption mechanisms of lead (Pb) were determined in four different soils collected from different agro-climatic regions of India. The soils were classified as: fine loamy mixed Typic- Dystrudepts, fine sandy loam Typic Ustochrepts, fine loamy Typic Ustochrept, and fine sandy loam Udic Haplustalfs. Seven different Pb solutions [Pb(NO3)2 dissolved in 0.01M Ca(NO3)2] in a range of 400 to 2000µgL-1 were applied to study the sorption amounts at 25(±2)oC and 45(±2)oC temperatures. With the increase in application rate and tempera-ture, sorption amounts of Pb increased; however, percentages of sorption of applied Pb were decreased. Sorptions were positively and significantly (p≤0.01) correlated with Langmuir adsorption isotherm. Thermodynamic parameters of sorption (i.e. Ko, ?Go, ?Ho, and ?So) were also determined at two tempera-tures, 25(±2)oC and 45(±2)oC. Increase in Ko with the increase in temperature indicated positive effect of temperature on Pb sorption. High absolute values of ?Go, and positive values of ?Ho, and ?So suggested that the sorption reaction was spontaneous and en-dothermic. Sorbed Pb were desorbed in Pb free 0.01M Ca(NO3)2 solutions at 25(±2)oC and 45(±2)oC. Desorption amounts increased with increase in the Pb application rate, but not always with the increase in temperature.

QTL mapping of 1000-kernel weight, kernel length, and kernel width in bread wheat (Triticum aestivum L.)

Kernel size and morphology influence the market value and milling yield of bread wheat (Triticum aestivum L.). The objective of this study was to identify quantitative trait loci (QTLs) controlling kernel traits in hexaploid wheat. We recorded 1000-kernel weight, kernel length, and kernel width for 185 recombinant inbred lines from the cross Rye Selection 111 × Chinese Spring grown in 2 agro-climatic regions in India for many years. Composite interval mapping (CIM) was employed for QTL detection using a linkage map with 169 simple sequence repeat (SSR) markers. For 1000-kernel weight, 10 QTLs were identified on wheat chromosomes 1A, 1D, 2B, 2D, 4B, 5B, and 6B, whereas 6 QTLs for kernel length were detected on 1A, 2B, 2D, 5A, 5B and 5D. Chromosomes 1D, 2B, 2D, 4B, 5B and 5D had 9 QTLs for kernel width. Chromosomal regions with QTLs detected consistently for multiple year-location combinations were identified for each trait. Pleiotropic QTLs were found on chromosomes 2B, 2D, 4B, and 5B. The identified genomic regions controlling wheat kernel size and shape can be targeted during further studies for their genetic dissection.

Genetic diversity of Macrophomina phaseolina isolates from certain agro-climatic regions of India by using RAPD markers

Genetic diversity analysis of Macrophomina phaseolina isolates obtained from different host range and diverse geographical locations in India was carried out using RAPD fingerprinting. Of the thirteen 10-mer random primers used, primer OPB-08 gave the maximum polymorphism and the UPGMA clustering could separate 50 isolates in to ten groups at more than 65% similarity level. The ten clusters correlated well with the geographical locations with exceptions for isolates obtained from Eastern and Western Ghats. There was a segregation of isolates from these two geographical locations in to two clusters thus, distributing 10 genotypes in to eight geographical locations. All the isolates M. phaseolina irrespective of their host and geographical origin, exhibited two representative monomorphic bands at 250 bp and 1 kb, presence of these bands suggests that isolates might have evolved from a common ancestor but due to geographical isolation fallowed by natural selection and genetic drift might have segregated in to subpopulations. Genetic similarity in the pathogenic population reflects the dispersal of single lineage in all locations in India.

Changes in dry land agriculture in the semi-arid tropics of India, 1975–2004

This paper examines the changes in dry land agriculture between 1975 and 2004, drawing both from macro-level data as well as the Village Level Studies (VLS) data of ICRISAT from six villages in Maharashtra and Andhra Pradesh. The long-term panel data facilitate an indepth analysis of cropping patterns, productivity levels, costs and returns of crop enterprises over time. The contrasting findings about increasing asset prices and declining returns to land and management puzzle the analysts. Equally implausible are the non-viability of agricultural enterprises on one hand and increasing incomes and living standards of the farm house holds on the other. Yet the SAT areas record highest incidence of poverty among the different agroclimatic regions of India. There is a clear dividing line between dry land agriculture and irrigated agriculture in terms of productivity levels, viability, indebtedness and poverty incidence. The government has come out with relief packages for farmers and employment guarantee programmes for the agricultural labourers in these areas. Besides such temporary palliatives, long-term policy biases which caused them need to be set right to make dry land agriculture in the SAT areas viable and competitive.

Genetic diversity in Hirsutella thompsonii isolates based on random amplified polymorphic DNA analysis

Hirsutella thompsonii Fisher is a host-specific fungal pathogen of the diverse group of arthropods known as the Acari. It particularly affects eriophyid mites, and the identification of its isolates is a difficult task due to its pleomorphic nature. Seven isolates of H. thompsonii var. thompsonii and H. thompsonii var. synnematosa collected from various agro-climatic regions of India were subjected to PCR analysis using random decamer primers to differentiate between them. Random amplified polymorphic DNA analysis revealed that all of the isolates from the citrus rust mite, Phyllocoptruta oleivora Ashmead (Acari: Eriophyidae), clustered together, with the exception of one, HtCRMB. The only isolate of H. thompsonii from Aceria guerreronis keifer (Acari: Eriophydae), HtPDBC, clustered separately.

Genotyping safflower (Carthamus tinctorius) cultivars by DNA fingerprints

Carthamus tinctorius (2n = 2x = 24) (family Asteraceae), commonly known as safflower, is widely cultivated in agricultural production systems of Asia, Europe, Australia and the Americas as a source of high-quality vegetable and industrial oil. India ranks first in the production of safflower oil. Fourteen cultivars, widely cultivated in various agro-climatic regions of India, have been fingerprinted by RAPD, ISSR, and AFLP markers utilizing 36, 21 primers, and 4 primer combinations, respectively. On an individual assay basis, AFLP has proven to be the best marker system as compared with the other two markers applied as assessed by high discriminating power (0.98), assay efficiency index (33.2), marker index (18.2), resolving power (40.62), and genotype index (0.856). Thirty-six RAPD and 21 SSR primers could differentiate a maximum of eight and four cultivars, respectively, whereas, two AFLP primer combinations could fingerprint all the 14 cultivars. To understand genetic relationships among these cultivars, Jaccard's similarity coefficient and UPGMA clustering algorithm were applied to the three marker data sets. Mean genetic similarities ranged from 0.689 (AFLP) to 0.952 (ISSR). Correlation coefficient comparisons between similarity matrices and co-phenetic matrices obtained with the three markers revealed that AFLP displayed no congruence vis-a-vis RAPD and ISSR data. However, strong correlation was observed between RAPD and ISSR marker systems. This paper reports the start of molecular biology programme targeting nuclear genome of safflower, a major world oilseed crop about whose genetics very little is known.

Modeling Event-Based Temporal Variability of Flow Resistance Coefficient

During the storm duration, the effects of surface resistance on the developing and receding overland flow depths (hj) on different flow parameters like the overland flow resistance coefficient (Nj), flow velocities (vj), Reynolds number (Rj), and Froude number (Fj) have been studied for the six natural catchments (0.012–92.5 km2) located in different agroclimatic regions of India. The kinematic wave (KW) equations are used for simulation of overland and channel flows using explicit methods for developing numerical solutions for the estimation of flow parameters at short durations. For the complete storm duration hj-Nj relationships have been found to form hysteresis loops. To predict resistance coefficients, simple hj-Nj relationships have been worked out separately for the rising and depleting overland flow conditions. Computed hydrographs simulated by incorporating these equations in the KW model agree well with the observed ones. The overall applicability of the suggested approach is successfully demon...

Phenotypic and Genetic Diversity of Bacillus thuringiensis Strains Isolated in India Active Against Spodoptera litura

Bacillus thuringiensis strains isolated from different agroclimatic regions of India were found to harbor cry1 family genes. Of 831 strains 18 that were found to produce 130- and 68-kDa mol wt proteins in sodium dodecyl sulfate polyacry1amide gel electrophoresis were subjected to bioassay against second instar larvae of Spodoptera litura. According to the time response curve, while the highest toxic activity against S. litura was observed in PBT-782 with an LT50 of 25.46 h, strains PBT-372, PBT-574, PBT-801, and PBT-716 in descending order of merit had LT50 values of 36.81, 48.18, 50.35, and 73.53 h. The results of the field experiment testing the efficacy of different B. thuringiensis strains in controlling S. litura larvae infecting peanut plants showed that the chemical insecticide chlorpyriphos was the most effective in controlling S. litura throughout the study period. However, among B. thuringiensis strains, PBT-372 was superior. All the B. thuringiensis strains except PBT-689 were found to contain cry1Ac1-type gene. However, only nine strains contained cry1Aa1 gene. While cry1Ab1 was present only in PBT-372 and PBT-689, cry1Ca1 was present in PBT-574, PBT-688, PBT-689, and PBT-695. cry1Da1 was detected only in PBT-688 and PBT-692. None of the strains contained cry1Ba1 and cry1Ea1 genes. When polymerase chain reaction analysis using cry1Ca1 primer was performed, PBT-695 produced an unexpected 739-bp product, which showed 33% homology with cry1Ca1 gene between nucleotides 1819 and 2107. Our results indicated that among the field-collected B. thuringiensis strains, PBT-372 harbors multiple cry-type genes and could be employed for biological control of insects.

Climate Change and Rice Yields in Diverse Agro-Environments of India. II. Effect of Uncertainties in Scenarios and Crop Models on Impact Assessment

Estimates of impact of climate change on crop production could be biased depending upon the uncertainties in climate change scenarios, region of study, crop models used for impact assessment and the level of management. This study reports the results of a study where the impact of various climate change scenarios has been assessed on grain yields of irrigated rice with two popular crop simulation models- Ceres-Rice and ORYZA1N at different levels of N management. The results showed that the direct effect of climate change on rice crops in different agroclimatic regions in India would always be positive irrespective of the various uncertainties. Rice yields increased between 1.0 and 16.8% in pessimistic scenarios of climate change depending upon the level of management and model used. These increases were between 3.5 and 33.8% in optimistic scenarios. At current as well as improved level of management, southern and western parts of India which currently have relatively lower temperatures compared to northern and eastern regions, are likely to show greater sensitivity in rice yields under climate change. The response to climate change is small at low N management compared to optimal management. The magnitude of this impact can be biased upto 32% depending on the uncertainty in climate change scenario, level of management and crop model used. These conclusions are highly dependent on the specific thresholds of phenology and photosynthesis to change in temperature used in the models. Caution is needed in using the impact assessment results made with the average simulated grain yields and mean changes in climatic parameters.

Biofuel Demand Estimation in The Rural Domestic Energy Sector of India

The major efforts and their limitations to formulate rural domestic energy requirements in India are discussed. Results of some of the recent efforts for quantifying biofuel consumption in rural areas are presented thereafter. Emphasis in this paper is on the recent efforts to collate and analyze results of energy consumption survey of 638 villages covering over 39,000 households. These are used to estimate biofuel use for different agro-climatic regions in India by estimating consumption at the district level in the rural domestic sector. The results are aggregated at the state level and they are compared with other estimates for India. The range of consumption aggregated at the national level is found to vary widely (93-252 million tonnes/yr of firewood, 54-107 million tonnes/yr of animal waste and 36-99 million tonnes/yr of agricultural residues). Reasons for the wide disparity in the results is briefly discussed.

Biofuel Demand Estimation in the Rural Domestic Energy Sector of India

The major efforts and their limitations to formulate rural domestic energy requirements in India are discussed. Results of some of the recent efforts for quantifying biofuel consumption in rural areas are presented thereafter. Emphasis in this paper is on the recent efforts to collate and analyze results of energy consumption survey of 638 villages covering over 39,000 households. These are used to estimate biofuel use for different agro-climatic regions in India by estimating consumption at the district level in the rural domestic sector. The results are aggregated at the state level and they are compared with other estimates for India. The range of consumption aggregated at the national level is found to vary widely (93–252 million tonnes/y of firewood, 54–107 million tonnes/y of animal waste and 36–99 million tonnes/y of agricultural residues). Reasons for the wide disparity in the results is briefly discussed.

Variation in Yields and Quality of Geranium (Pelargonium graveolens L' Hér. ex Aiton) under Varied Climatic and Fertility Conditions

ABSTRACT Experiments were conducted to study the response pattern of geranium (Pelargonium graveolens L' H' r. ex Aiton) to fertilizers, and the variation of essential oil constituents under varied agroclimatic regions in India (one temperate and two semi-arid tropical locations ranging in altitude from 542 to 2200 m above mean sea level and in soil pH from 5.1 to 8.0). The essential oil yields were higher at lower altitude regions than at higher altitudes. The oil produced from plants grown in the temperate climate of high altitude location was richer in menthone, citronellol, nerol and geraniol, while the oil produced from plants grown at lower altitude locations was richer in isomenthone, linalool, citronellyl formate and an unidentified compound. Maximum biomass and essential oil yields were obtained at all the locations with an N dose of 120 kg/ha. While response of geranium to P and K was observed at the high altitude location, the response was absent at the other two locations. The essential oil co...