Background Harvest index is an important component of grain yield and is typically reduced by reproductive stage drought stress in rice. Multiple drought response mechanisms can affect harvest index including plant water status and the degree of stem carbohydrate mobilization during grain filling. In this study, we aimed to dissect the contributions of plant water status and stem carbohydrate mobilization to harvest index. Pairs of genotypes selected for contrasting harvest index but similar biomass and days to flowering were characterized at ICAR-RCER, Patna, India and at IRRI, Philippines. Results Multiple traits were related with harvest index across experiments, including mobilization efficiency at both sites as indicated by groupings in principal component analysis, and plant water status as indicated by direct correlations. Biomass-related traits were positively correlated with harvest index at IRRI but biomass was negatively correlated with harvest index at ICER-RCER, Patna. We observed that some pairs of genotypes showed differences in harvest index across environments, whereas other showed differences in harvest index only under drought. Of all time points measured when all genotypes were considered together, the stem carbohydrate levels at maturity were most consistently (negatively) correlated with harvest index under drought, but not under well-watered conditions. However, in the pairs of genotypes grouped as those whose differences in harvest index were stable across environments, improved plant water status resulted in a greater ability to both accumulate and remobilize stored carbohydrate, i.e. starch. Conclusion By distinguishing between genotypes whose harvest index was improved across conditions as opposed to specifically under drought, we can attribute the mechanisms behind the stable high-harvest index genotypes to be more related to stem carbohydrate remobilization than to plant water status. The stable high-harvest index lines in this study (Aus 257 and Wanni Dahanala) may confer mechanisms to improve harvest index that are independent of drought response and therefore may be useful for breeding improved rice varieties.
Salmonella is a major pathogen worldwide causing acute foodborne outbreaks. Traditional identification methods, however, are time-consuming and faced complexity to detect contamination of bacteria in the food supply chain timely. We herein aimed to develop a method for rapid and robust detection of Salmonella Typhimurium in milk and chicken meat based on recombinase polymerase amplification (RPA) integrated with agarose gel electrophoresis (AGE). Three primers pairs were designed which function both in RPA as well as in polymerase chain reaction (PCR). A total number of 254 S. Typhimurium field isolates from various sources of North Eastern Region (NER) of India were evaluated using both RPA and PCR for validating the assay. The results were consistent in RPA and PCR-based detection using crude DNA obtained by a simple boiling method without any purification step. The RPA-AGE showed versatility functioning at 350C to 410C, and at the temperature of 370C, it only took 5 min of amplification to reach the test threshold of amplicon. The established method had both a good specificity and a sensitivity of 10fg DNA per reaction of 15µL volume. It showed high sensitivity when artificially inoculated in fresh chicken samples even at 10-9 fold dilutions containing 1.95 X 10 to 1.95 X 10 cfu/mL. There was no cross-reactivity with the other four Salmonella serovars and seven bacterial pathogens tested. To our knowledge, this is the first report of reliable serovar specific detection of Salmonella Typhimurium by RPA using crude DNA extracted by a simple boiling method.
Biotic stresses are major concerns for the world’s food security. These, commonly induced by diseases and/or insect pests, are one of the primary reasons for maize yield and quality losses. About 10% of the annual maize production is reduced because of biotic stresses globally. Diseases, particularly by fungal pathogens, lead to significant yield decline. Among the insect pests, the herbivorous insects are the major culprits of total yield losses. Moreover, the origin of new pathogens and insects, evolution of new races or strains with time due to climate change and development of pesticide resistance are the other major concerns. Development and deployment of stress-tolerant genotypes is the economically and environmentally viable option to manage biotic stresses. In contrast to the cereals like wheat and rice, quantitative resistance is more important in maize owing to its pollination mode and nature of causal organism. The quantitative trait loci (QTLs) or genomic regions imparting tolerance/resistance to pathogens and insect pests have been identified in maize. This chapter is an attempt to archive all these findings in a referable format to be useful for both students and researchers working in biotic stress resistance research area.
Magnaporthe oryzae, the rice blast fungus, is one of the most dangerous rice pathogens, causing considerable crop losses around the world. In order to explore the rice blast-resistant sources, initially performed a large-scale screening of 277 rice accessions. In parallel with field evaluations, fifty-two rice accessions were genotyped for 25 major blast resistance genes utilizing functional/gene-based markers based on their reactivity against rice blast disease. According to the phenotypic examination, 29 (58%) and 22 (42%) entries were found to be highly resistant, 18 (36%) and 29 (57%) showed moderate resistance, and 05 (6%) and 01 (1%), respectively, were highly susceptible to leaf and neck blast. The genetic frequency of 25 major blast resistance genes ranged from 32 to 60%, with two genotypes having a maximum of 16 R-genes each. The 52 rice accessions were divided into two groups based on cluster and population structure analysis. The highly resistant and moderately resistant accessions are divided into different groups using the principal coordinate analysis. According to the analysis of molecular variance, the maximum diversity was found within the population, while the minimum diversity was found between the populations. Two markers (RM5647 and K39512), which correspond to the blast-resistant genes Pi36 and Pik, respectively, showed a significant association to the neck blast disease, whereas three markers (Pi2-i, Pita3, and k2167), which correspond to the blast-resistant genes Pi2, Pita/Pita2, and Pikm, respectively, showed a significant association to the leaf blast disease. The associated R-genes might be utilized in rice breeding programmes through marker-assisted breeding, and the identified resistant rice accessions could be used as prospective donors for the production of new resistant varieties in India and around the world.
Environmental pollution, resource dwindling, and soil degradation questioned the sustainability of contemporary agricultural production systems. Organic farming is advocated as a sustainable solution for ensuring food security without compromising environmental sustainability. However, poor farm productivity quizzed the sustainability of organic production systems. Hence, a field study was carried out in the Sikkim region of the Indian Himalayas to assess the efficacy of conservation-effective tilling and diversified cropping on system productivity, profitability, environmental quality, and soil nutrient balance in organic farming. Three tillage systems, namely, (i) conventional tillage (CT), (ii) reduced tillage (RT), and (iii) zero tillage (ZT), and four maize-based diversified cropping systems (maize–black gram–toria, maize–black gram–buckwheat, maize–rajmash–toria, and maize–rajmash–buckwheat) were tested using three times replicated split-plot design. The ZT system recorded 13.5 and 3.5% higher system productivity over CT and RT, respectively. Of the four diversified cropping systems, the maize–rajmash–buckwheat system recorded the maximum system productivity (13.99 Mg ha−1) and net returns (3,141 US$ ha−1) followed by the maize–black gram–buckwheat system. Among the tillage practices, ZT recorded the significantly high eco-efficiency index (EEI; 1.55 US$ per kg CO2-eq emission) and the lowest greenhouse gas intensity (GHGI; 0.15 kg CO2-eq per kg production). Of the diversified cropping systems, the maize-rajmash-buckwheat registered the lowest GHGI (0.14 CO2-eq per kg production) and the highest EEI (1.47 US$ per kg CO2-eq emission). Concerning soil nutrient balance, after three cropping cycles, the soil under ZT recorded significantly higher available N (340.0 kg ha−1), P (16.6 kg ha−1), and K (337.3 kg ha−1) over the CT system at 0–10 cm soil depth. Similarly, the soil under the maize–black gram–buckwheat system had the maximum bio-available NPK. Thus, the study suggests that the cultivation of the maize–black gram/rajmash–buckwheat systems under ZT and/or RT would increase farm productivity, profitability, and soil fertility with minimum GHGI in organic farming under the Eastern Himalayan region of India.
Groundwater contributes 98.5% of the remaining fresh water available for use is stored in groundwater and only 0.98% of fresh water is available at surface, viz. rivers, lakes, ponds, and so on. However, over time, aberrations in rainfall patterns and overuse of aquifers resulted in groundwater recharge (GWR) depletion and water level has fallen in most parts of India resulting in severe drought like situations in several parts of the country. This can be resolved mainly through linking surface water with groundwater resources for GWR. It is reported that by considering 60% and 30% of surface runoff combined with river bed recharge and natural recharge through rainfall, the net GWR varied from 0.33 to 1.66 m and 0.16 to 1.06 m above mean sea level, respectively. In plain dryland conditions and hills and plateau regions, GWR rates are approximately 11–18 and 11–16% of average annual rainfall. Through water harvesting structures, the total GWR is about 38.53% of total GWR. Therefore, assessment of GWR potential is essential to develop linkages of surface water to groundwater for integrated water resource management.
The industrial revolution followed by technological development successively paved the way to a new era in human civilization. In no case, this revolution will decline, thus, making anthropogenic environmental pollution a major global issue. In the present scenario, e-waste accumulation and management is seriously a daunting task that needs to be tackled efficiently. Traditional methods because of their disadvantages have fuelled the use of biological tools to recover the precious metals present in e-waste and to promote the studies of bioleaching and biodegradation processes. In this context, recently, microbial exopolysaccharides (EPSs) become the emerging topic among environmentalists and biotechnologists due to its eco-friendly nature and diverse applications. Besides its tremendous uses in pharmaceutical industries, the food sector, pesticides, plastics, and many more, it also has to offer its potential use in e-waste bioremediation. The bioactive microbial EPS is a high molecular weight biopolymer having both homo- and hetero-polysaccharides. The biosorption mechanism which is important in the sequestration of heavy metal ions from the environment by this biopolymer is due to the net negative charge associated with this compound. Besides addressing e-waste pollution, this review critically analyzes the role of EPS in the sustainable and economic management of this burning issue. Moreover, it documents and compares the latest research, innovations, and advancements in the field of EPS-mediated e-waste bioremediation.
The eastern Himalayas, one of the important hotspots of global biodiversity, have a rich diversity of wild edible fruit trees. The fruits of these tree species have been consumed by the tribal people since time immemorial. However, there is limited information available on the biochemical and antioxidant properties of the fruits. Therefore, the present investigation was undertaken to study the physico-chemical and antioxidant properties of the nine most important wild fruit trees. Among the species, Pyrus pashia had the maximum fruit weight (37.83 g), while the highest juice (43.72%) and pulp content (84.67%) were noted in Haematocarpus validus and Myrica esculenta, respectively. Maximum total soluble solids (18.27%), total sugar (11.27%), moisture content (88.39%), ascorbic acid content (63.82 mg/100 g), total carotenoids (18.47 mg/100 g), and total monomeric anthocyanin (354.04 mg/100 g) were recorded in H. validus. Docynia indica had the highest total phenolic content (19.37 mg GAE/g), while H. validus recorded the highest total flavonoids and flavanol content. The antioxidant activities of the different fruits ranged from 0.17 to 0.67 IC50 for DPPH activity and 3.59–13.82 mg AAE/g for FRAP. These fruits had attractive pigmentation of both pulp and juice and were a good potential source for the extraction of natural edible color in the food industry. The fruits also possess high market prices;Prunus nepalensis fetched $ 34.10–$ 141.5 per tree. Therefore, these fruits are rich sources of antioxidants, pigments and have a high market value for livelihood and nutritional security.
Introduction India’s north-eastern hill region (NEH) is one of the biodiversity hotspots, inhabited by several tribal communities still maintaining their traditional food habits. Much of their food resources are drawn from wild sources. Materials and methods Fourteen species of wild edible plants of high ethnic importance were collected from remote localities of Nagaland and Meghalaya states of the NEH region of India for nutritional profiling. Nutritional profiling of leaves of six species comprising Gynura cusimbua, Garcinia cowa, Herpetospermum operculatum, Plukenetia corniculata, Trichodesma khasianum , and Elatostemma sessile is conducted first time under present study. Samples were analyzed as per the Official Method of Analysis (AOAC) and standard methods. Results and discussion The range of variation in proximate composition was observed for moisture (72–92%), protein (1.71–6.66%), fat (0.22–1.36%), dietary fibre (5.16–14.58%), sugar (0.30–3.41%), and starch (0.07–2.14%). The highest protein content (6.66%) was recorded in Herpetospermum operculatum , followed by Trichodesma khasianum (5.89%) and Plukenetia corniculata (5.27%). Incidentally, two of these also have high iron (>7.0 mg/100 g) and high zinc (>2.0 mg/100 g) contents, except Trichodesma khasianum , which has low zinc content. High antioxidant activities in terms of gallic acid equivalent (GAE) by the cupric ion reducing antioxidant capacity (CUPRAC) method ranged from 1.10 to 8.40 mg/100 g, and by the Fluorescence recovery after photobleaching (FRAP) method ranged from 0.10 to 1.9 mg/100 g, while phenol content ranged between 0.30 and 6.00 mg/100 g. These wild vegetables have high potential because of their nutritional properties and are fully capable of enhancing sustainability and improving ecosystem services. Efforts were also initiated to mainstream these resources, mainly for widening the food basket of native peoples.
Nitrogen (N) is an important macronutrient needed for grain yield, grain N and grain protein content in rice. Grain yield and quality are significantly determined by N availability. In this study, to understand the mechanisms associated with reproductive stage N remobilization and N partitioning to grain 2 years of field experiments were conducted with 30 diverse rice genotypes during 2019-Kharif and 2020-Kharif seasons. The experiments were conducted with two different N treatments; N deficient (N0-no external N application, available soil N; 2019-234.15 kgha-1, 2020-225.79 kgha-1) and N sufficient (N120-120 kgha-1 external N application, available soil N; 2019-363.77 kgha-1, 2020-367.95 kgha-1). N application increased the NDVI value, biomass accumulation, grain yield, harvest index and grain N accumulation. Post-anthesis N uptake and N remobilization from vegetative tissues to grain are critical for grain yield and N harvest index. Rice genotypes, Kalinga-1, BAM-4234, IR-8384-B-B102-3, Sahbhagi Dhan, BVD-109 and Nerica-L-42 showed a higher rate of N remobilization under N sufficient conditions. But, under N deficiency, rice genotypes-83929-B-B-291-3-1-1, BVD-109, IR-8384-B-B102-3 and BAM-4234 performed well showing higher N remobilization efficiency. The total amount of N remobilization was recorded to be high in the N120 treatment. The harvest index was higher in N120 during both the cropping seasons. RANBIR BASMATI, BAM-832, APO, BAM-247, IR-64, Vandana, and Nerica-L-44 were more efficient in N grain production efficiency under N deficient conditions. From this study, it is evident that higher grain N accumulation is not always associated with higher yield. IR-83929-B-B-291-3-1-1, Kalinga-1, APO, Pusa Basmati-1, and Nerica-L-44 performed well for different N use efficiency component traits under both N deficient (N0) and N sufficient (N120) conditions. Identifying genotypes/donors for N use efficiency-component traits is crucial in improving the fertilizer N recovery rate and site specific N management.
Introduction Developing an intensive sustainable model and feeding a rising population are worldwide challenges. The task is much more daunting in the North Eastern Himalayas, where, low productive maize ( Zea mays )- fallow is the main production system in the upland. To increase farm productivity, nutritional security, and energy dietary returns while maintaining environmental sustainability and economic viability, short-duration crops must be included in the maize–fallow system. Methods A field study was conducted in sandy clay loam soil with a randomized complete block design with three replications for three continuous years (2018–2021) under organic management with two crop management practices, viz. , (i) conservation agriculture and (ii) conventional agriculture, and six crop diversification options, viz. , (i) maize–sweet corn ( Zea mays saccharata )–vegetable pea ( Pisum sativa ) (M-SC-VP), (ii) maize–sweet corn-mustard ( Brassica juncea ) (M-SC-M), (iii) maize–sweet corn–lentil ( Lens culinaris ) (M-SC-L), (iv) maize–sweet corn–vegetable broad bean ( Vicia faba ) (M-SC-VB), (v) maize (local)–vegetable pea (M-VP), and (vi) maize (local)–fallow (M-F). Results The results showed that, the average system productivity was 5.3% lower for conventional agriculture than conservation agriculture. System carbohydrate, protein, fat, dietary fiber, and dietary energy were ~6.9, 6.8, 7.8, 6.7, and 7%, higher in conservation agriculture than in conventional agriculture, respectively. Similarly, system macronutrients (Ca, Mg, P, and K) and system micronutrients yield (Fe, Mn, Zn, and Cu) were, 5.2–8% and 6.9–7.4% higher in conservation agriculture than in conventional agriculture, respectively. On average, over the years, crop diversification with M-SC-VP/M-SC-VB intensive crop rotation had higher system productivity (158%), production efficiency (157%), net returns (benefit–cost ratio) (44%), and dietary net energy returns (16.6%) than the local maize–vegetable pea system. Similarly, the M-SC-VP/M-SC-VB system improved the nutritional security by improving Ca, Mg, P, K, Fe, Mn, Zn, and Cu yield by 35.5–135.7% than the local M-VP system. Discussion Conservation agriculture with M-SC-VP/M-SC-VB rotation showed significantly ( p < 0.05) higher productivity, carbohydrate yield, protein yield, fat yield, and dietary fiber production. It is concluded that conservation agriculture improved soil health and performed better than conventional agriculture in maize-based intensive cropping systems. Overall results indicate that crop diversification with M-SC-VP/M-SC-VB can potentially increase calorie and protein consumption and farm profitability.
Drought is a multidimensional stress that affects the grain nutritional quality of high yielding rice genotypes. The present study evaluated the impacts of stage-specific (seedling, vegetative, and reproductive stages) and cumulative (multi-stage) drought on ionome, starch, and protein contents in grains of two rice genotypes of eastern Indo-Gangetic plain, viz. Sahbhagi Dhan and IR64 with contrasting drought tolerance. The study showed drought to negatively affect the physiological and nutritional traits of rice grains. Following the study, stage-specific and multi-stage drought caused significant reduction in grain size, test weight, starch, amylose, amylopectin, and total soluble protein contents of rice grains. Drought during different developmental stages of rice caused significant variations in micro- (Cu, Fe, Mn, Na, Zn) and macro-nutrient (P, K, Ca, Mg) contents in the grains. Stage-specific and cumulative drought exposure of the rice genotypes also governed the ionomes in grains resulting in specific ionomic networks. Hierarchical cluster analysis showed two discrete clusters for elements as well as different drought treatments in the studied rice genotypes, which supported the results obtained from the principal component analysis, displaying five clusters based on stage-specific and multi-stage drought treatments. Variation in drought treatments and elements in different rice genotypes also altered the ionomic interactions represented by differential ionomic networks. In this study, Sahbhagi Dhan maintained the morphological and nutritional qualities of grains across the drought treatments and therefore, can be used as a suitable donor in breeding for stage-specific and cumulative drought tolerance with superior grain quality for eastern Indo-Gangetic plain.
Rapid postharvest physiological deterioration (PPD) in cassava (Manihot esculenta Crantz) tuber is a significant concern during storage. The freshly harvested tubers start spoiling within 24 to 72 h. Accumulation of H 2 O 2 is one of the earliest biochemical events that occurred during PPD, which was detected using the 3,3 diaminobenzidine (DAB) in two contrast cassava genotypes, MNP Local A (29-57 µg g −1) and Sree Prakash (64-141 µg g −1). Accumulating the fluorescence hydroxycoumarin compounds emitted by the cassava tubers observed under an ultraviolet (UV) lamp showed significant variations at 0, 3, 6, 9, 12, and 15 days of storage. The total phenolics and carotenoids significantly and negatively correlated with PPD progression; however, the anthocyanin and flavonoids positively correlated with the PPD-anchored ROS accumulation. The primary compound, Phthalic acid, di(2-propylpentyl) ester, was identified in both the cassava tubers, Sree Prakash (57.21 and 35.21%), and MNP Local A (75.58 and 60.21%) at 0, and 72 h of PPD, respectively. The expression of PPD-associated genes APX-2, APX-3, PAL, and AP was higher at 6-12 days of PPD, which signified the synthesis of ROS turnover and phenylpropanoid biosynthesis. A significant, strong, and positive correlation was established between the secondary metabolites and PPD signaling gene expression, which was inversely correlated with hydroxycoumarin and H 2 O 2 Frontiers in Microbiology 01 frontiersin.org Wahengbam et al. 10.3389/fmicb.2023.1148464 accumulation. MNP Local A tubers exhibited longer storage life of 15 days with a low PPD score, higher metabolites synthesis, and gene expression. The PPD-resistant lines may be used to augment cassava breeding strategies for large-scale commercial and industrial use.
Climate change has become a reality and the agriculture sector is directly confronted by its ill effects. The poor dwellers of hilly tracts of the north-eastern region of India are totally dependent on rainfed agriculture practicing shifting cultivation, the most primitive way of crop cultivation in the history of humankind which is still practiced by 240 million indigenous people of the world. The present study is aimed to integrate local perspectives on the global phenomenon of climate change as we compare shifting cultivators’ (n = 600) climate change perceptions with meteorological data for a holistic understanding of adaptation decisions in shifting cultivation. Climatic trends are analyzed from the precipitation and temperature data of the India Meteorological Department. Study results show that shifting cultivators’ climate change perceptions align well with climatic trends for temperature-related events though some inconsistencies exist for precipitation events. Further, the significance and strength of the association between shifting cultivators’ climate change perceptions and their adaptation decisions are statistically tested by Chi-square and Cramer’s V respectively. Results reveal that three-fourths (~ 76%) of the respondents made alterations in the shifting cultivation calendar as an adaptation strategy to climate change. Adaptation decisions pertaining to the sowing and post-sowing activities (weed control, crop protection, and harvesting) are more strongly associated with climate change perception compared to pre-sowing activities (selection and clearing of forested hilly lands). This study identifies the appropriateness of the climate change perceptions of shifting cultivators and recommends their inclusion for the effective formulation of policies regarding climate risk management.
Background Cabbage butterfly, Pieris brassicae (Linnaeus) (Lepidoptera: Pieridae), is one of the most important pests of cabbage and other cruciferous crops and accounts for > 40% yield reduction in the crops. An investigation on the baseline susceptibility of P. brassicae to Bacillus thuringiensis ( Bt ) Cry toxins in Meghalaya was evaluated for future exploitation in Bt resistance monitoring. Two different Cry toxins, Bt Cry1C and Cry2Ab, were screened against 11 different field populations of P. brassicae from the state of Meghalaya. LC 50 was evaluated based on the response of larval mortality of P. brassicae using the leaf-dip bioassay method. Results The baseline-susceptibility tests conducted on P. brassicae in 11 different field populations from Meghalaya revealed that Smit population strains seemed to show less tolerance to both the Bt Cry toxins (Cry1C and Cry2Ab). Compared to the Cry1C toxin, Cry2Ab was found more potent against P. brassicae . The median lethal concentrations, LC 50 72 h, varied from 0.535 to 1.725 µg/ml for Cry2Ab and 0.546–1.803 µg/ml for Cry1C toxin. The screening using leaf-dip bioassay resulted in a tolerance ratio of 3.3-fold and 3.2-fold for Cry1C and Cry2Ab, respectively. The most tolerant strains of P. brassicae from Umiam and Pepbah regions were observed to show discriminating concentrations of 19.30 µg/ml for Cry1C and 24.03 µg/ml for Cry2Ab (LC 99 , 72 h). Conclusions The Cry2Ab toxin was found to be more virulent than Cry1C toxin for P. brassicae . Certain candidate discriminating concentrations for Cry1C and Cry2Ab can be used as benchmarks for future resistance monitoring of P. brassicae to Bt Cry toxins.
Nearly 50% of the population across the globe is at risk of malnutrition with respect to zinc (Zn) in areas where a cereal based dietary system dominates. The present study estimated daily Zn intake in humans through field experiments in reclaimed sodic soil, utilizing waste crop residue (CR) in conservation tillage where CR played a vital role in enhancing Zn uptake in rice and wheat grains. Zn dynamics, its bioavailability, interaction with soil properties, and plausible contribution in dietary intake were studied extensively to supplement the research. A higher mobility factor (2.70%) and plant available Zn resulted in its higher uptake in rice (58.2 mg kg-1) and wheat (67.2 mg kg-1) under zero tillage in rice followed by zero tillage in wheat where CR was retained on the surface (ZTR-ZTW+CR). Daily Zn intake was found to be maximum (0.651 mg kg-1 day-1) under ZTR-ZTW+CR, demonstrating zinc sufficiency. Thus, this study may help in formulating actionable policies for combating both nutritional security and environmental hazards due to CR burning.
The most crucial factor in crop production is soil fertility; thus, it directly influences food security. Therefore, to ensure food security, soil fertility level needs improvement. Though, poor cultivation practices led to soil infertility across the Gangatic region, making even more need to identify and implement sustainable farming practices. In this light, this experiment was undertaken to study the dynamics of soil nutrients in different agroforestry systems (AFS) as a sustainable farming practice concerning seasonal and depth-wise variations. The experiment was conducted in the Samastipur district of India, which comes under the Gangatic plain. Three AFS, including Kadamb ( Anthocephalus cadamba Miq.), Simarauba ( Simarouba glauca DC), and Litchi ( Litchi chinensis Sonn.) based AFS along with one fallow land were taken under investigation. Soil samples were collected from three depths (0-15cm, 15-30cm and 30-45cm) during four seasons (Summer, Autuam, Rainy and Winter). Data revealed that agroforestry development had significantly increased soil nutrients (11-19%) in all seasons and depths. The month of June reported higher availability of nutrients over December. Soil depth had significant influence on soil nutrient availability, irrespective of treatments. The variation of available nutrients among the soil layer was more in agroforestry systems over fallow land. This study will help the researchers to understand the influence of seasons and depths on the movements and transformation of soil nutrients.
A sapota varietal experiment was conducted under rainfed conditions for 15 fruiting seasons (2003–2018) with three phases of 5 years each with varieties: ‘Murabba’, ‘Cricket Ball’, ‘Bhuripatti’, ‘Kalipatti’, ‘Jhumakiya’, ‘Mahayoti’, ‘PKM-1’, ‘DHS-1’ and ‘DHS-2’. Based on the initial five fruiting seasons (Phase I), ‘Murabba’ and ‘Jhumakiya’ were found to be promising, while in Phase II and III, ‘Murabba’ and ‘Cricket Ball’ had significantly higher yields. The cumulative yields in Phase I correlated poorly to overall cumulative yields (2003–2018). However, yields during Phase II and III strongly correlated to the overall yields for sapota varieties. This showed that recommending a sapota variety based on 10 years of data is equally effective as that of 15 years, indicating the scope of shortening of varietal recommendation duration. Our study also indicated a significant increase in the fruit weight and pulp content (%) with increasing tree age. ‘DHS-1’, ‘DHS-2’, and ‘Murabba’ produced the largest fruits. The pooled data showed that sapota variety ‘DHS-1’ and ‘Murabba’ had significantly higher pulp (%). The variety × phase interaction was also a significant source of variability among all characteristics except for number of seeds, TSS and acidity. The stability analysis based on regression coefficient (bi) revealed that all the sapota varieties had a stable yield with a regression coefficient near to one. After the evaluation, it was found that ‘Murabba’ and ‘Cricket Ball’ performed best among the varieties compared and is suitable for commercial cultivation in the East India Plateau (EIP) region of India.
Production of nutritious fodder for livestock remains a challenge especially in arid and semiarid regions of the world. Cereal–legume inter-cropping with integrated use of organic and inorganic nutrient sources could be a viable option for achieving higher fodder tonnage in aforesaid ecologies. Therefore, the present study was undertaken to determine the impact of cereal-legume intercropping and integrated nutrient management on productivity, forage quality, and land use efficiency (LUE). The experiment was conducted in a split plot design where four planting ratios as monocropped maize (SM), monocropped cowpea (SC), maize intercropped with cowpea in 1:1 (1M:1C), and 2:1 (2M:1C) row ratio were allotted in the main plot and five nutrient management practices as absolute control (NM0), 100% recommended dose of fertilizer (RDF) + Zn (NM1), 125%RDF + Zn (NM2), (75%RDF + Zn + farm yard manure (FYM) + plant growth promoting rhizobacteria (PGPR) (NM3) and 100%RDF + Zn + FYM (NM4) were allotted in subplot. Monocropped maize fertilized with 75%RDF + Zn + PGPR + FYM and 100%RDF + Zn + FYM produced significantly maximum dry matter yield (DMY) (138.3 and 135.7 q ha−1, respectively) which statistically at par with maize intercropped with cowpea in 2M:1C ratio under 75%RDF + Zn + PGPR + FYM (127.6 q ha−1). Maize and cowpea intercropped in 1M:1C ratio fertilized with 75%RDF + Zn + PGPR + FYM or 100%RDF + Zn +FYM gave highest crude protein, ether extract, and ash yield, digestibility and energy, and lowest fiber fractions. The intercropped treatments showed higher LUE with 8–12% yield advantage over monocropping. Therefore, intercropping of maize and cowpea in 1M:1C ratio with application of 75%RDF + Zn + PGPR +FYM or 100%RDF + Zn + FYM could be recommended to enhance the productivity, forage quality, and LUE in semiarid conditions of North-Western India.
Bacterial leaf blight (BLB) disease of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the significant constraints for rice production. A study was carried out to analyze the virulence, genetic diversity, and population structure of Xoo isolates collected from different rice ecosystems of Karnataka, India. The taxonomic identity of all 54 isolates was confirmed using a Xoo-specific PCR assay. The virulence assay on a set of twenty-eight near-isogenic differentials identified nine pathotype groups (KPthX-1 to KPthX-9). Among them, KPthX-6 was highly virulent, whereas KPthx-2 was less virulent. Differentials with four and five resistance (R) genes (Xa4+xa5+xa13+Xa21, Xa4+Xa7+xa13+Xa21, and Xa4+xa5+Xa7+xa13+Xa21) were effective against all the pathotypes. Further, genetic diversity was deduced using a universal marker set, JEL-1, and JEL-2, complementary to a conserved repetitive sequence IS1112. The amplicon size and numbers varied from 100 bp to 3 Kb and 1 to 25. Based on the amplicon counts, Jaccard's co-efficient and phylogenetic analyses were carried out and categorized the 54 isolates into three clusters (I to III). Cluster-II contains the maximum number of isolates (27), followed by cluster-I (23 isolates) and cluster-III (one isolate). The structure analysis categorized the isolates into five subgroups, viz. SG1, SG2, SG3, SG4, and SG5 indicate the existence of five subpopulations. The present study has identified the genetic and virulence diversity of the Xoo population and reported the effective R gene/s for different rice ecosystems, which can be used in the breeding program for the eco-specific management of BLB of rice.
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ICAR RCER ICAR PARISAR, 800014, Patna, BIHAR, India
Head of institution
Dr Ujjwal Kumar