Agro-climatic Regions Of India Research Articles

Integration of SPEI and machine learning for assessing the characteristics of drought in the middle ganga plain, an agro-climatic region of India.

Drought, as a natural and intricate climatic phenomenon, poses challenges with implications for both natural ecosystems and socioeconomic conditions. Evaluating the characteristics of drought is a significant endeavor aimed at mitigating its impact on society and individuals. This research paper explores the integration of the Standardized Precipitation Evapotranspiration Index (SPEI) and machine learning techniques for an assessment of drought characteristics in the Middle Ganga Plain, a crucial agro-climatic region in India. The study focuses on evaluating the frequency, intensity, magnitude, and recurrence interval of drought events. Various drought models, including Random Forest (RF), Artificial Neural Networks (ANN), and an ensemble model combining ANN and RF, were employed to analyze and predict drought patterns at different temporal scales (3-month, 6-month, and 12-month). The performance of these models was rigorously validated using key metrics such as precision, accuracy, proportion incorrectly classified, over-all area under the curve (AUC), mean absolute error (MAE), and root mean square error (RMSE). Furthermore, the research extends its application to delineating drought vulnerability zones by establishing demarcations for high and very high drought vulnerability areas for each model and temporal scale. Results indicate that the south-western part of the middle Ganga plain falls under the highly drought-vulnerable zone, which averagely covers 40% of the study region. The core and buffer regions of drought vulnerability have also been identified. The south-western part of the study area is identified as the core region of drought. Ground verification of the drought-vulnerable area has been done by using soil moisture meter. Validation metrics show that the ensemble model of ANN and RF exhibits the highest accuracy across all temporal scales. This research's findings can be applied to improve drought preparedness and water resource management in the Middle Ganga Plain. By identifying high-risk drought zones and utilizing accurate prediction models, policymakers and farmers can implement targeted mitigation strategies. This approach could enhance agricultural resilience, protect livelihoods, and optimize water allocation in this vital agro-climatic region.

Varietal suitability of grapes in different agro-climatic regions of India

Grape cultivation, in India, is dependent on a narrow range of table grape varieties, with more than 70 per cent cultivated area in Maharashtra alone, followed by Karnataka and Tamil Nadu. Therefore, to increase the scope of area extension under grape cultivation, the suitability of six coloured grape varieties was assessed for yield, quality and phenological parameters at four locations, i.e., Pune (Maharashtra), Arabhavi (Karnataka), Rajendranagar (Telangana) and Theni (Tamil Nadu) during 2019-2022. From the study, it was revealed that the ‘Manjari Shyama’ and ‘Red Globe’ yielded the maximum (13.7 kg/vine) as compared to the rest of the varieties. Variety ‘Manjari Shyama’ was found stable at all four locations for yield, bunch weight, 100-berry weight, berry diameter, TSS, acidity, sugar: acid ratio and days to veraison with the regression coefficient 1.22, 1.11, 1.01, 1.13, 1.35, 1.44, 0.88 and 0.79, respectively. The yield and bunch weight in ‘Red Globe’ was found to be more expressive under the favourable environment as compared to ‘Fantasy Seedless’ (5.59 kg/vine), ‘Nanasaheb Purple Seedless’ (6.13 kg/vine) and ‘Crimson Seedless’ (7.63 kg/vine), which were found lower.

The invasive mimosoid legume Dichrostachys cinerea (L.) Wight & Arn is nodulated by diverse strains of Ensifer and Bradyrhizobium in different agroclimatic regions of India

The invasive mimosoid legume Dichrostachys cinerea (L.) Wight & Arn is nodulated by diverse strains of Ensifer and Bradyrhizobium in different agroclimatic regions of India

Exploitation of biotic inducers for the management of important foliar diseases of sunflower (Helianthus annuus L.)

Sunflower (Helianthus annuus L.) is a unique crop grown for human consumption as edible oil and also for ornamental use. It has become a popular cut flower, easy to grow under varied climatic conditions requires 672.4 mm water requirement during growing season. Sunflower crop is native to North America and as of now we have the varieties, hybrids developed from the huge germplasm collections maintained at ICAR-Indian Institute of Oilseeds Research and also at co-ordinating centres under AICRP on sunflower situated at different agro-climatic regions of India. During the crop growing period, many fungal and viral diseases start affecting the crop from early stage up to flowering and milky stage leads to drastic losses in seed yield. In particular, necrosis, leaf spot and powdery mildew diseases are causing drastic yield losses in the cultivation. In this study, we have attempted the biotic inducers as seed treatment and foliar spray against this disease as an alternative to fungicide.

Feminization of hunger in climate change: linking rural women’s health and wellbeing in India

ABSTRACT The links between climate change, food security and women’s wellbeing remain an under-investigated area. This paper contributes to this area through a thorough examination of how women experience food insecurity in farming households in rural India. The households are located in four agro-climatic regions in India. These regions experience varied climatic pressures, and this diversity allows us to explore a wider variety of women’s experiences in their attempts to maintain household food security as the climate changes. The study finds that women, even in comparatively more food-secure households, suffer from food insecurity. One of the reasons for this is that women’s food habits and mealtimes have altered in recent years due to the increase in their work pressures. The worst effects are to be found in drought-prone areas, and there are greater vulnerabilities among women-headed households, indicating that the impacts of climate change are exacerbated by cultural norms that further hinder the role of women in farm activities.

Measuring the agricultural sustainability of India: An application of Pressure-State-Response (PSR) model

Analyzing agricultural sustainability is essential for designing and assessing rural development initiatives. However, accurately measuring agricultural sustainability is complicated since it involves so many different factors. This study provides a new suite of quantitative indicators for assessing agricultural sustainability at regional and district levels, involving environmental sustainability, social security, and economic security. Combining the Pressure-State-Response (PSR) model and indicator approach, this study creates a composite agricultural sustainability index for the 14 mainstream agro-climatic regions of India. The results of this study show that the Trans-Gengatic Plain Region (TGPR) ranks first in agricultural sustainability among India’s 14 mainstream agro-climatic regions, while the Eastern Himalayan Region (EHR) ranks last. Higher livestock ownership, cropping intensity, per capita income, irrigation intensity, share of institutional credit, food grain productivity, crop diversification, awareness of minimum support price, knowledge sharing with fellow farmers, and young and working population, as well as better transportation facilities and membership of agricultural credit societies are influencing indicators responsible for higher agricultural sustainability in TGPR compared with EHR. Although, the scores of environmental sustainability indicators of EHR are quite good, its scores of social and economic security indicators are fairly low, putting it at the bottom of the rank of agricultural sustainability index among the 14 mainstream agro-climatic regions in India. This demonstrates the need of understanding agricultural sustainability in relation to social and economic dimensions. In a nation as diverse and complicated as India, it is the social structure that determines the health of the economy and environment. Last but not least, the sustainability assessment methodology may be used in a variety of India’s agro-climatic regions.

ANN-based PCA to predict evapotranspiration: a case study in India

Abstract The Penman–Monteith evapotranspiration (ET) model has superior predictive ability to other methods, but it is challenging to apply in several Indian stations, owing to the need for a large number of climatic variables. The study investigated an artificial neural network (ANN) model for calculating ET for various agro-climatic regions of India. Sensitivity analysis showed that the overall average changes in ET0 values for 25% change in the climatic variables were 18, 16, 14, 7, 5, and 4%, respectively, for Tmax, RHmean, Rn, wind speed, Tmin, and sunshine hours. The dominant climatic variables were identified from the principal component analysis (PCA) and ET0 was computed using an ANN with dominant climatic variables. The ANN architecture with backpropagation technique had one hidden layer and neurons ranging from 10 to 30 for all climatic variables and from 5 to 10 for PCA variables. The new ET models were statistically compared with Penman–Monteith ET estimate, and found reliable. PCA variables guaranteed an estimate of ET0 accounting for 98% of the variability. The average values of coefficient of determination, standard error of estimate, and percentage efficiency were observed as 0.96, 0.24, and 94%, respectively.

Phylogenetic diversity and plant growth-promoting activities of rhizobia nodulating fenugreek (Trigonella foenum-graecum Linn.) cultivated in different agroclimatic regions of India.

Fenugreek (Trigonella foenum-graecum Linn.), is an extensively cultivated legume crop used as a herb, spice, and traditional medicine in India. The symbiotic efficiency and plant growth-promoting potential of fenugreek rhizobia depend on the symbiont strain and environmental factors. We isolated 176 root-nodulating bacteria from fenugreek cultivated in different agroclimatic regions of India. MALDI-TOF MS-based identification and phylogenetic analyses based on 16S rRNA and five housekeeping genes classified the fenugreek-rhizobia as Ensifer (Sinorhizobium) meliloti. However, the strains represent separate sub-lineages of E. meliloti, distinct from all reported sub-lineages across the globe. We also observed the spatial distribution of fenugreek rhizobia, as the three sub-lineages of E. meliloti recorded during this study were specific to their respective agroclimatic regions. According to the symbiotic gene (nodC and nifH) phylogenies, all three sub-lineages of E. meliloti harboured symbiotic genes similar to symbiovar meliloti; as with the housekeeping genes, these also revealed a spatial distribution for different clades of sv. meliloti. The strains could nodulate fenugreek plants and they showed plant growth-promoting potential. Significant differences were found in the plant growth parameters in response to inoculation with the various strains, suggesting strain-level differences. This study demonstrates that fenugreek rhizobia in India are diverse and spatially distributed in different agro-climatic regions.

Genomic Diversity of Pigeon Pea (Cajanus cajan L. Millsp.) Endosymbionts in India and Selection of Potential Strains for Use as Agricultural Inoculants.

Pigeon pea (Cajanus cajan L. Millsp. ) is a legume crop resilient to climate change due to its tolerance to drought. It is grown by millions of resource-poor farmers in semiarid and tropical subregions of Asia and Africa and is a major contributor to their nutritional food security. Pigeon pea is the sixth most important legume in the world, with India contributing more than 70% of the total production and harbouring a wide variety of cultivars. Nevertheless, the low yield of pigeon pea grown under dry land conditions and its yield instability need to be improved. This may be done by enhancing crop nodulation and, hence, biological nitrogen fixation (BNF) by supplying effective symbiotic rhizobia through the application of “elite” inoculants. Therefore, the main aim in this study was the isolation and genomic analysis of effective rhizobial strains potentially adapted to drought conditions. Accordingly, pigeon pea endosymbionts were isolated from different soil types in Southern, Central, and Northern India. After functional characterisation of the isolated strains in terms of their ability to nodulate and promote the growth of pigeon pea, 19 were selected for full genome sequencing, along with eight commercial inoculant strains obtained from the ICRISAT culture collection. The phylogenomic analysis [Average nucleotide identity MUMmer (ANIm)] revealed that the pigeon pea endosymbionts were members of the genera Bradyrhizobium and Ensifer. Based on nodC phylogeny and nod cluster synteny, Bradyrhizobium yuanmingense was revealed as the most common endosymbiont, harbouring nod genes similar to those of Bradyrhizobium cajani and Bradyrhizobium zhanjiangense. This symbiont type (e.g., strain BRP05 from Madhya Pradesh) also outperformed all other strains tested on pigeon pea, with the notable exception of an Ensifer alkalisoli strain from North India (NBAIM29). The results provide the basis for the development of pigeon pea inoculants to increase the yield of this legume through the use of effective nitrogen-fixing rhizobia, tailored for the different agroclimatic regions of India.

Spatial analysis of area and carbon stocks under Populus deltoides based agroforestry systems in Punjab and Haryana states of Indo-Gangetic Plains

Various agroforestry systems are prevalent in different agro-climatic regions of India and occupy sizeable area. Populus deltoides (poplar) based agroforestry systems are very predominant in Indo-Gangetic Plains of northern India. These systems are not only meeting wood demand of wood-based industries but also contributing significantly in generating employment, reducing atmospheric CO2 vis-a-vis mitigating climate change. The present study aimed at estimating area under poplar plantations and assessment of biomass production and carbon stock at district level for selected districts of Punjab and Haryana states. High resolution multispectral remote sensing data (LISS-IV, spatial resolution- 5.8 m) have been used for mapping poplar area in these districts. Growth data (tree density, diameter at breast height) from farmers’ fields were collected for assessment of aboveground and total biomass. Poplar area in Hoshiarpur, Rupnagar, Ludhiana, Shahid Bhagat Singh Nagar, Yamunanagar, Kurukshetra and Karnal districts accounted for 3.19, 4.09, 1.02, 0.43, 7.25, 1.58 and 0.97%, respectively, of their geographical area. As percentage of agroforestry area, poplar area occupied 43.8% in four districts of Punjab and 53.4% in three districts of Haryana. Estimated carbon stock in total biomass of poplar plantations was 0.931, 0.481, 0.287, 0.040, 0.949, 0.256 and 0.229 million tonnes, respectively. CO2 equivalent C in aboveground and total biomass was estimated to be 7.854 and 9.946 million t, respectively, in all these seven districts. The proposed methodology based on object-oriented image classification showed promising results as far as mapping of agroforestry systems/species is concerned.

Evaluation of HF crossbred bulls under field progeny testing programme at different agro-climatic regions in India

Adequate numbers of progeny tested bulls are not available in India and whatever small number of bulls are progeny tested, they have low repeatability as the progeny tests are based on small number of daughters mostly reared at the institutional farms. But extending the progeny testing programmes to the farmer's herds will sort out the issue of less number of progeny per bull. The first lactation records of 4,782 crossbred cows which were daughters of 121 bulls and calved over a period of 12 years from 1996 to 2008 were used to determine the genetic worth of HF crossbred bulls under different agro-climatic conditions and to assess their ranking. The average first lactation milk yield in field HF crossbred cows was 2806.51±56.06 kg. In this evaluation average number of progeny per bull was 39.5. The breeding value of bulls was estimated as 2,920.59 kg for 1st ranked bull and 2662.58 kg for 121st ranked bull. A total of 47 bulls (38%) showed higher breeding values ranging from 2,807.91 to 2,920.59 kg over and above the herd average. Among the fixed effects, the centre of field progeny testing programme and year of calving had significant effect on first lactation milk yield of daughters. The increasing trend of first lactation milk yield over years is a clear indication of a successful large scale progeny testing programme under field conditions.

Influence of weather patterns and air quality on ecological population dynamics of ectoparasites in goats.

Ectoparasitism has a damaging impact on the economy of goat production in India, but the factors influencing its distribution and dynamics are less explored. The present study was designed to investigate the influence of environmental factors like weather and air quality parameters on the occurrence of different types of ectoparasites in goats of two agro-climatic regions of India, viz. the Upper Gangetic Plain (UGP) and the Western Himalayas (WH). The prevalence survey for ectoparasitism among goats was conducted during the four distinct climatic seasons (winter, summer, monsoon, autumn) in both regions. The season-wise data of weather parameters (maximum and minimum temperature, relative humidity in morning and evening, sunrise and sunset time, mean daily temperature and relative humidity, daily variation in temperature and relative humidity, and day length) and air quality parameters (air quality index (AQI), particulate matter 2.5μm (PM2.5), particulate matter 10μm (PM10)) of both regions were analyzed in relation with the ectoparasitic prevalence pattern of corresponding regions. The results depict a noticeable correlation between the studied parameters and seasonal variation in the occurrence of each type of ectoparasites. This outcome on the interaction of studied parameters and ectoparasitism is intriguing and it opens a huge scope for future studies on the biometeorological aspects of host-parasite ecological interplay and evolutionary biology. The better understanding of climatological aspects of ectoparasite occurrences helps goat farmers in formulating appropriate timely intervention strategies for the economic control of ectoparasites, which in turn tackles ectoparasiticidal drug resistance and reduces threat of vector-borne diseases.

Correlation analysis for various growth and yield attributing traits in potato (Solanum tuberosum L.) genotypes

In the present study twelve potato genotypes collected from various agro-climatic regions of India were evaluated in three diverse environments viz., SKUAST-K, Shalimar, Krishi Vigyan Kendra, Budgam and MRCFC Khudwani during Kharif 2018. The experiments were laid out in complete randomized block design with three replications at each location. From the present study it was observed that economically important trait i.e., total tuber yield hectare-1 (q) showed positive and significant association with plant height (cm), plant spread (cm), number of stems hill-1, leaf area (cm2). Stem diameter (cm) and number of tubers plant-1, but positive and non-significant association with days to initiation of germination, indicating that improvement in yield could be brought about by selection of these component traits.

Seroprevalence of Trypanosoma evansi Infection in equine population of India

Equine trypanosomosis caused by Trypanosoma evansi, is prevalent across all agro-climatic regions of India, and has a significant direct and indirect impact on equine productivity particularly on the performance of working equids. The impact of the disease is often overlooked due to unavailability of epidemiological status of disease and impact on livestock productivity. In the present study, an antibody-ELISA was used for seroprevalence study of T. evansi in Indian equine population. A total of 19467 serum samples were screened from twenty-one states of India collected during 20092020. Out of these, 1215 serum samples were found positive for the presence of antibodies against T. evansi from equids of sixteen states with varying prevalence. The seroprevalence for T. evansi infection ranged from 2.30%-15.02% in different states with an overall seroprevalence of 5.67% (5.35%-6.00% at a 95% confidence interval). The results indicated that Surra is prevalent in equids in majority of states of India. The disease was found prevalent in most of the states of India throughout the year with sporadic outbreaks in equines.

Estimation of genetic diversity in Terminalia Arjuna genotypes represents the different agroclimatic regions of India

Estimation of genetic diversity in Terminalia Arjuna genotypes represents the different agroclimatic regions of India

Feeding status of free-range scavenging chickens in different agro-climatic regions of India

ABSTRACT1. The aim of this study was to determine the nutritional status of backyard chickens reared under 4 different agro-climatic conditions (tropical, humid subtropical, cool-temperate and semi-arid) of India during different seasons of the year and to compare their nutritional status with those reared under confined feeding system (CFS). In each season, 15 adult and 15 grower chickens were slaughtered for collecting content of crop and gizzard to assess the nutritional status from different agro-climatic conditions.2. The dry matter content of crop and gizzard was higher (P < 0.01) in chickens reared under backyard conditions compared to those reared under CFS.3. Higher (P < 0.01) crop and gizzard contents were recorded during winter compared to the rainy season. The proportion of grains in the crop during summer and winter season was higher compared to rainy season. Further, there were more insects present in the crop during the rainy season and winter compared to summer.4. The proportion of insects was higher in chickens reared in humid, subtropical and cool temperate regions compared to semi-arid conditions. The consumption of grasses was higher in cool-temperate regions as compared to those reared under other areas.5. Crude protein (CP), Ca, P and gross energy (GE) content of the crop were higher in chickens reared under CFS compared to those reared in backyard systems and CP in the crop contents was lower in backyard chickens reared in humid subtropical and semi-arid regions compared to other areas. Similarly, lower (P < 0.01) Ca levels were seen in crop and gizzard contents from birds reared in semi-arid Rajasthan, and P and GE were lower in tropical wet and dry Telangana (TWT) compared to the chickens reared in the backyard conditions in other regions.6. Based on the results, the nutrient intake for birds utilising the scavenging feed resource base (SFRB) in the TWT region was below the requirements of backyard chickens from the other regions selected in the present study. GE and CP were critically deficient in the SFRB of the TWT region. Therefore, evolving location-specific supplementary diets using locally available feed resources to meet nutrient requirement of backyard chickens is required for optimising production potential.

Pathogenic and molecular variability among Brassica isolates of Alternaria brassicae collected from different agro-climatic regions of India

The Alternaria blight is one of the most destructive fungal disease of Indian mustard causes severe damage to the crop. Ten isolates of A. brassicae were collected from various agro-climatic location of India viz., Uttar Pradesh (Ab 1 ), Madhya Pradesh (Ab 2 ), Uttarakhand (Ab 3 ), Bihar (Ab 4 ), Jharkhand (Ab 5 ), West Bengal (Ab 6 ), Haryana (Ab 7 ), Rajasthan (Ab 8 ), Chhattisgarh (Ab 9 ) and Gujarat (Ab 10 ) and characterized for pathogenic and molecular variations. All the isolates showed high level of variability. The incubation period of the isolates was recorded on B. juncea 3 to 4 days, B. carinata 6.17 to 6.83 days, B. napus 5.17 to 6.00 days, B. nigra 4.17 to 5.17 days and in B. campestris it was ranged from 3.17 to 4.00 days. The results revealed that the maximum PDI was noted on Brassica juncea followed by B. campestris var yellow sarson, B. nigra , B. napus and B. carinata . Based on PDI ten isolates could be classified into three groups in which group one consist of isolates Ab 3 , Ab 6 , Ab 7 and Ab 5 . Isolates Ab 8 , Ab 2 and Ab 4 fall in second group; while group three include isolates Ab 1 , Ab 9 and Ab 10 . The dendrogram analysis identified two major clusters with 82 per cent similarity. One cluster (group I) comprised of 3 isolates (Ab 1 , Ab 10 and Ab 2 ). Whereas, another cluster (group II) comprised of Ab 3 , Ab 6 , Ab 7 , Ab 5 , Ab 4 , Ab 8 and Ab 9 at 86 per cent similarity. The three isolates (Ab 3 , Ab 6 and Ab 7 ) of group II showed 100 per cent similarity based on molecular basis.

First Report of an Association of Multispecies Phytoplasmas with Mango Phyllody and Little Leaf Disease from Western India

HomePlant DiseaseVol. 103, No. 10First Report of an Association of Multispecies Phytoplasmas with Mango Phyllody and Little Leaf Disease from Western India PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of an Association of Multispecies Phytoplasmas with Mango Phyllody and Little Leaf Disease from Western IndiaKiran Kirdat, Vipool Thorat, Tushar Ghole, Pramod Takawale, and Amit YadavKiran KirdatNational Centre for Microbial Resource, National Centre for Cell Science, Pashan, Pune 411 021, IndiaSearch for more papers by this author, Vipool ThoratNational Centre for Microbial Resource, National Centre for Cell Science, Pashan, Pune 411 021, IndiaSearch for more papers by this author, Tushar GholeNational Centre for Microbial Resource, National Centre for Cell Science, Pashan, Pune 411 021, IndiaSearch for more papers by this author, Pramod TakawaleBAIF-Development Research Foundation, Urulikanchan, Pune 412 202, IndiaSearch for more papers by this author, and Amit Yadav†Corresponding author: A. Yadav; E-mail Address: [email protected]http://orcid.org/0000-0002-4882-9075National Centre for Microbial Resource, National Centre for Cell Science, Pashan, Pune 411 021, IndiaSearch for more papers by this authorAffiliationsAuthors and Affiliations Kiran Kirdat1 Vipool Thorat1 Tushar Ghole1 Pramod Takawale2 Amit Yadav1 † 1National Centre for Microbial Resource, National Centre for Cell Science, Pashan, Pune 411 021, India 2BAIF-Development Research Foundation, Urulikanchan, Pune 412 202, India Published Online:7 Aug 2019https://doi.org/10.1094/PDIS-03-19-0599-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Mango (Mangifera indica L., family Anacardiaceae) trees with malformed vegetative tissues at branch nodes and phyllody in panicles with thicker and stunted peduncle were observed in Pune region, Western India, in February and March 2018. Although the etiology of mango malformation disease is established by performing Koch’s postulate, confirming species of Fusarium are the causative agents (Chakrabarti 2011; Crespo et al. 2014), the observed symptoms, namely, excessive vegetative growth resulting in “bunchy top” appearance with shootlets bearing small, scaly leaves and leafy girdles, however, were also suggestive of phytoplasma infection. The growing symptomatic tissues were collected from one seedling, two panicles, and four branch nodal tissues from separate plants. Eight other asymptomatic samples were also collected. To confirm the presence of phytoplasmas, 2 g of malformed tissue from symptomatic plants was used for total DNA extraction using the CTAB method. The DNA was also extracted from asymptomatic plants. The phytoplasma 16S rRNA gene was amplified from 50 ng of DNA using primers P1/P7 followed by nested primers R16F2n/R16R2. The 16S rRNA gene of phytoplasma was detected in a symptomatic seedling, one nodal tissue, and one panicle sample, except in one symptomatic nodal tissue and a panicle. This may be owing to unevenly spread low phytoplasma titer, as known from previous studies (Abeysinghe et al. 2016; Caicedo et al. 2015). No amplification was observed in asymptomatic samples. All symptomatic samples were also tested for the presence of Fusarium DNA using universal PCR primers ITS1/ITS4; however, none of the samples tested positive, nor was fungal mycelium observed when sections of symptomatic tissue stained with cotton blue were observed under the microscope. The obtained 16S rRNA gene sequences from a symptomatic panicle (MH744151), nodal tissue (MH744152), and seedling (MH744153) samples showed 99.30% sequence similarity with ‘Candidatus Phytoplasma asteris’ AYWB (CP000061), 16SrI group (aster yellows); 99.53% with ‘Ca. P. balanitae’ Balanites triflora (AB689678), 16SrV group (elm yellows); and 98.57% with ‘Ca. P. aurantifolia’ WBDL (U15442), 16SrII group (peanut witches’ broom), respectively, when analyzed using EzTaxon database and iPhyClassifier. So far, unknown phytoplasma associated with malformed mango inflorescence was reported from Egypt using electron microscopy (El-Banna et al. 2007), and ‘Ca. P. asteris’ (group 16SrI) was PCR detected from Pakistan (Fahmeed et al. 2009). These results suggest that polyphagous sap-sucking insect vectors must be involved in phytoplasma transmission from other alternate plant hosts to mango, and further studies are required. India produced over 19 million tons of mangoes, which is over 40% of the world’s production, and exported over U.S.$60 million worth of mangos in 2016 to 2017. To our knowledge, this is the first formal evidence of the association of multispecies phytoplasma strains with a mango malformation disease in India. The malformation is a severe disease of mango that causes serious damage to the seedlings and flowering tissue, resulting in severe economic losses. It is therefore essential to understand the etiology of mango malformation disease associated with phytoplasmas beyond the existing knowledge by collecting additional samples from different agro-climatic regions of India, ultimately for the better management of the disease.The author(s) declare no conflict of interest.

Annual and seasonal variations in gross primary productivity across the agro-climatic regions in India.

Gross primary productivity (GPP) is a vital ecosystem variable that is used as a proxy to study the functional behaviour of a terrestrial ecosystem and its ability to regulate atmospheric CO2 by working as a carbon pool. India, having the potential terrestrial ecosystem dynamics to absorb the atmospheric carbon dioxide to some extent, is one of the least-explored regions in terms of carbon monitoring studies. The current study evaluates the applicability of a newly developed, quantum yield-based, remote sensing data-driven diagnostic model called the Southampton Carbon Flux (SCARF). This model was used to estimate the annual and seasonal variability of the terrestrial GPP over the Indian region with a spatial resolution of 1 km during 2008. This modified version of the conventional production efficiency model successfully predicted GPP using meteorological variables (PAR, air temperature and dew point temperature), the fraction of photosynthetically active radiation and quantum yield of C3 and C4 plants as the key input parameters. The annual GPP values were in the range from 0 to 4147.55 g C m-2 year-1, with a mean value of 1507.32 g C m-2 year-1. The maximum and minimum GPP were during the summer monsoon and pre-monsoon, respectively. The seasonal and annual distributions of GPP over the study area obtained using the SCARF model, and the MODIS GPP product (MOD17A2H) were similar. However, MODIS was found to underestimate the GPP in all regions and an overestimation in eastern Himalaya region. The study reveals that environmental scalars, specifically water stress, are the pivotal controlling variables responsible for the variation of GPP in India. The estimates of the GPP in different regions of the study area were made using SCARF, and an eddy covariance technique was similar. The SCARF model can be used to estimate GPP on a global scale. SCARF appears to be a better model in terms of the simplicity of the algorithm, performance and resolution. Thus, it may give higher accuracy in carbon monitoring studies.

Assessment of variability in lignan and fatty acid content in the germplasm of Sesamum indicum L.

Information on the variability available in lignan and fatty acid content in the oilseed crop of Sesamum indicum has been limited. This article presents and discusses the composition, quantity, and variability available for the two traits in the sesame germplasm that are grown in diverse agro climatic regions of India. HPLC and GC analysis of sesame seeds harvested over a period of three crop seasons revealed a considerable amount of variability in lignan and fatty acids. The antioxidant lignans sesamol, sesamin and sesamolin were observed to be in the range of 0.16-3.24, 2.10-5.98 and 1.52-3.76mg/g of seed, respectively. Similarly oleic and linoleic acids, respectively, have ranged from 34.71 to 45.61% and 38.49 to 49.60%. The black sesame seeds were found rich in sesamin, sesamolin, total lignan content and oleic acid and are thus identified nutritionally and pharmaceutically more important than white and brown seeds. Pearson statistics showed a strong correlation between the components within a particular trait and also some correlation was found between the traits. The study revealed promising cultivars for use in sesame breeding aimed at improving lignan and fatty acid contents, and can be thus directly used in human foods, nutrition, health and welfare.