A q-deformed nonlinear map

A scheme of q-deformation of nonlinear maps is introduced. As a specific example, a q-deformation procedure related to the Tsallis q-exponential function is applied to the logistic map. Compared to the canonical logistic map, the resulting family of q-logistic maps is shown to have a wider spectrum of interesting behaviours, including the co-existence of attractors -- a phenomenon rare in one dimensional maps.Comment: 17 pages, 19 figure

IXPE Mirror Module Assemblies

Expected to launch in 2021 Spring, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Astrophysics Small Explorer Mission with significant contributions from the Italian space agency (ASI). The IXPE observatory features three identical x-ray telescopes, each comprised of a 4-m-focal-length mirror module assembly (MMA, provided by NASA Marshall Space Flight Center) that focuses x rays onto a polarization-sensitive, imaging detector (contributed by ASI-funded institutions). This paper summarizes the MMAs design, fabrication, alignment and assembly, expected performance, and calibration plans

Prioritization of candidate genes in "QTL-hotspot" region for drought tolerance in chickpea (Cicer arietinum L.)

A combination of two approaches, namely QTL analysis and gene enrichment analysis were used to identify candidate genes in the "QTL-hotspot" region for drought tolerance present on the Ca4 pseudomolecule in chickpea. In the first approach, a high-density bin map was developed using 53,223 single nucleotide polymorphisms (SNPs) identified in the recombinant inbred line (RIL) population of ICC 4958 (drought tolerant) and ICC 1882 (drought sensitive) cross. QTL analysis using recombination bins as markers along with the phenotyping data for 17 drought tolerance related traits obtained over 1-5 seasons and 1-5 locations split the "QTL-hotspot" region into two subregions namely "QTL-hotspot_a" (15 genes) and "QTL-hotspot_b" (11 genes). In the second approach, gene enrichment analysis using significant marker trait associations based on SNPs from the Ca4 pseudomolecule with the above mentioned phenotyping data, and the candidate genes from the refined "QTL-hotspot" region showed enrichment for 23 genes. Twelve genes were found common in both approaches. Functional validation using quantitative real-time PCR (qRT-PCR) indicated four promising candidate genes having functional implications on the effect of "QTL-hotspot" for drought tolerance in chickpea.Sandip M Kale, Deepa Jaganathan, Pradeep Ruperao, Charles Chen, Ramu Punna, Himabindu Kudapa, Mahendar Thudi, Manish Roorkiwal, Mohan AVSK Katta, Dadakhalandar Doddamani, Vanika Garg, P B Kavi Kishor, Pooran M Gaur, Henry T Nguyen, Jacqueline Batley, David Edwards, Tim Sutton and Rajeev K Varshne

Customized fertilizers for higher yield and income: Evidences from on-farm validation in coconut – tuber crop intercropping system

Fifteen on-farm experiments were conducted in tropical tuber crops intercropped in coconut gardens in Thiruvananthapuram, Kollam and Pathanamthitta districts, Kerala, during 2018-2021 for the validation of customized fertilizers formulated from on-station developed Site-Specific Nutrient Management (SSNM) practices. The validation experiments were done under the aegis of ICAR-Central Tuber Crops Research Institute, Thiruvananthapuram, in a project funded by Coconut Development Board, Kochi, Kerala.Three treatments viz., T1: SSNM technology using customized fertilizers (CF) (SSNM), T2: present POP recommendation (POP) and T3: farmer's practice (FP) was evaluated in cassava, elephant foot yam and greater yam intercropped with coconut. System productivity and profitability were worked out for the different treatments based on yield and income from coconut and tuber crops in the respective treatments. Pooled analysis indicated that the coconut yield under intercropping with tuber crops under SSNM using CF was higher by 12-23% in comparison to coconut monocrop maintained unscientifically by the farmers. Tuber yield under CF proved superior over POP by 9.3% and FP by 37.4%. On an average, the net income from coconut-tuber crop intercropping system under SSNM using CF was ₹ 270396 per ha, whereas it was ₹ 198047 in POP and ₹146358 in FP and significantly outperformed sole coconut (₹ 7764).Thus, the results of the validation experiments indicated that the use of customized fertilizers in tuberous intercrops offered resilience with higher system productivity and profitability from coconut gardens

Organic management of tuberous intercrops for resilience, higher yield and profit from coconut plantations: Insights from validation experiments in Kerala, India

Fifteen on-farm experiments were conducted in tropical tuber crops intercropped in coconut gardens in Thiruvananthapuram, Kollam and Pathanamthitta districts, Kerala, during 2018-2021 for validation of organic production technologies. The validation experiments were performed under the aegis of the ICAR-Central Tuber Crops Research Institute, Thiruvananthapuram, in a project funded by the Coconut Development Board, Kochi, Kerala. Three treatments viz., T1: organic farming technology (OF), T2: POP recommendation (POP) and T3: farmer's practice (FP) were evaluated in cassava, elephant foot yam and greater yam intercropped with coconut. System productivity and profitability were worked out for the different treatments based on yield and income from coconut and tuber crops in the respective treatments. Pooled analysis indicated that the coconut yield under intercropping with tuber crops in organic mode was high by 7-13% in comparison to monocrop of coconut maintained by the farmers. Tuber yield under organic management was superior over POP by 14% and FP by 27%. On an average, the net income from coconut-tuber crop intercropping system under organic management was ₹ 2,36,133 ha-1, whereas it was ₹ 1,56,904 ha-1 in POP and ₹ 1,32,706 ha-1 in FP and significantly outperformed sole coconut (₹ 7,764 ha-1). Thus, the results indicated that organic management of coconut-tuber crop system offered resilience with higher system productivity and profitability

Gender analysis and empowerment of women and men in Cassava (Manihot esculenta) production in Kerala

Women’s participation is vitally important in agriculture so also in cultivation of tuber crops. In Kerala, cassava is cultivated mostly in homestead farming with active participation of the women. Gender analysis was conducted to map the profile characteristics and empowerment of men and women. Hundred respondents doing cassava cultivation were selected from Thiruvananthapuram and Pathanamthitta districts of Kerala. Majority (61.53%) of the women and men (68.57%) had medium level of participation in cassava cultivation. The overall empowerment index of men (0.86) was more than women (0.78). Employment generation and economic benefits in cassava cultivation for men and women were also assessed

Fine mapping of the “QTL-hotspot” region for drought tolerance in Chickpea (Cicer arietinum L.)

Chickpea (Cicer arietinum L.) is the third most important grain legume cultivated in the arid and semi-arid regions of the world. Drought is one of the major constraints leading up to 50% production losses in chickpea. In order to understand the basics of drought tolerance, two recombinant inbred line (RIL) mapping populations (ICC 4958 × ICC 1882 and ICC 283 × ICC 8261) segregating for root traits were developed and a promising “QTL-hotspot” region was reported on these populations. With an objective to fine map this region, two approaches were adopted, i) genotyping-by sequencing (GBS) and ii) skim sequencing. GBS approach enabled identification of 828 single nucleotide polymorphism (SNP) markers. A high-density genetic map was developed, comprising 1,007 marker loci including 49 SNP markers in the “QTL-hotspot” region and spanning a distance of 727.29 cM. QTL analysis using the extended genetic map along with precise phenotyping data generated earlier, re-estimated the “QTL-hotspot” from 29 cM to 14 cM. In addition, these 49 SNPs were converted into cleaved amplified polymorphic sequence (CAPS)/derived CAPS (dCAPS) markers which can be used in marker assisted breeding. An ultra-high-density bin map was developed using 53,223 SNPs obtained through skim sequencing approach and its analysis with the phenotyping data, split the “QTL-hotspot” region into two sub-regions namely “QTL-hotspot_a” of 139.22 kb with 15 genes and “QTL-hotspot_b” of 153.36 kb with 11 genes. To validate and find more recombination in these regions, a large mapping population was developed. Flanking SNP markers of the two regions were converted to KASPar assays and screened on 1,911 F2 lines. Progeny testing on F2:3 lines revealed the role of “QTL-hotspot_a” in controlling 100-SDW. A total of 15 candidate genes were reported in this region. In summary, the refined region will help in precise introgression of the “QTL-hotspot” in breeding program for yield improvement under drought conditions and the reported genes can be used for further cloning studies to dissect the molecular basis of drought tolerance in chickpea

Analyzing the trade competitiveness of Indian coconut sector in the liberalization regime

Coconut export sector in India of late gained an outward orientation, especially since the Coconut Development Board was elevated to the status of export promotion council in the year 2009. In the recent period, the growth rate experienced in the coconut based value added products has been stupendous. Since there is an attempt for global value chain up-gradation at the production node of the sector, it is imperative to analyse our strengths in the world market in comparison with the major competitors. We have used the Revealed Comparative Advantage (RCA) methodology to analyse India’s competitiveness in the exports of major coconut value added products traded across the world. The study revealed that, as far as the coconut value added products are concerned, India is comparatively a very small player with paltry export market shares. The analysis of RCA revealed that comparative advantage of India is lower than the major coconut exporting countries like Philippines, Indonesia and Sri Lanka. The Philippines is the dominant player with highest RCA indices in most of the coconut value added product lines. The study suggests the need to formulate plausible strategies to reach the overseas market and capture the optimal share in market segments. Though we have a strong domestic market base, it is an indubitable fact that in the near future due to the evolving trade agreements even in the domestic sector we may confront fierce price competition from the overseas imports. Hence we need to chalk out modalities and execution plans to elevate our export competitiveness and comparative advantage

Yield estimation in cocoa with partial harvest data

Methodology for estimation of crop production varies depending on the nature and duration of the crop. Perennial crops like cocoa, where the harvest is done throughout the year at different intervals, crop cutting experiments are laborious and time consuming. In this study, a methodology for early estimation of cocoa yield based on a few observations is proposed. A model based on observations on number of pods present on the tree during the beginning of major harvest season and after six months have been proposed to estimate the annual yield of cocoa. The accuracy of the methodology was validated using the test data. Subsequently, yield estimation of cocoa in major cocoa growing districts of Kerala and Karnataka were carried out. The effect of irrigation type, major cropping systems and age of the cocoa garden on the yield were also studied using Hierarchical linear modelling approach. The study revealed that cocoa yield in coconut based cropping system is better than any other systems