Agronomic Strategies Research Articles

Plant Density and Time of White Lupine (Lupinus Albus L.) Relay Cropping with Tef (Eragrostis tef (Zucc.) Trotter) in Additive Design in the Highlands of Northwest Ethiopia

Agronomic strategies such as choosing the optimal row ratio and planting legume crops at the right time are crucial for enhancing crop productivity. A field experiment was conducted in 2016 and 2017 to assess the influence of plant density and lupine intercropping time on tef field productivity. The treatments were as follows: tef was planted at a 20 cm inter-row spacing, lupine was sown at 20 and 40 cm inter-row spacing (row ratio of 1 tef: 1 lupine and 2 tef: 1 lupine) and lupine intercropped three times (1, 2, and 3 weeks after tef planting). Randomized complete block design (RCBD) with 3 replications were used. Two sole tef and lupine were planted. The results revealed 40 cm inter-row spacing and delayed lupine intercropping (3 weeks after tef planting) provided the maximum tef grain yield of 1.80 t ha−1. The sole cropping of lupine produced the highest lupine grain yield (2.63 t ha−1). Lupine intercropping at 40 cm inter-row spacing and two weeks after tef planting resulted in the highest land equivalent ratio (1.54), tef equivalent yield (2.45 t ha−1), area time equivalent ratio (1.11), system productivity index (2.5), monetary advantage index (15206 birr ha−1), net benefit (65109 birr ha−1), and marginal rate of return (602%). Therefore, farmers in the northwest Ethiopian highlands should consider intercropping lupine two weeks after tef planting in-between two rows of tef as an effective intercropping system.

The impact of boron seed priming on seedling establishment, growth, and grain biofortification of mungbean (Vigna radiata L.) in yermosols.

Boron-deficiency in Yermosols is among the major constraints to mungbean productivity and grain biofortification in Pakistan. However, agronomic strategies such as boron (B) seed priming have potential to improve mungbean yield and grain biofortification. Moreover, deficiency to toxicity range for B is very narrow; therefore, it is pre-requisite to optimize its dose before field evaluation. A wire house experiment was planned out to reconnoiter the impact of seed priming with B on growth and quality of two cultivars of mungbean, i.e., ‘NM-2011’ and ‘NM-2016’. Four different B levels were used as seed priming, i.e., 0.01%, 0.05%, 0.1% and 1.0% B, (borax Na2B4O7.10H2O, 11.5% B) were tested, whereas hydropriming was regarded as control. Seed priming with 0.01% B significantly (p≤0.05) lowered time taken to start germination and time to reach 50% emergence, whereas improved mean emergence time, emergence index, final emergence percentage, number of leaves, dry and fresh weight of root, shoot, and total weight, root length, plant height, chlorophyll contents, number of pods and 100-grain weight, seeds per plant, grain yield per plant, B concentrations in stem and grain, grain protein, carbohydrate and fiber in both cultivars. Boron seed priming proved beneficial under a specific range; however, deficiency (hydropriming) and excess (above 0.01% B) of B were detrimental for mungbean growth and productivity. The cultivar ‘NM-2016’ had significantly (p≤0.05) higher yield due to prominent increase in yield related traits with 0.01% B priming as compared to ‘NM-2011’. In conclusion, B seed priming (0.01% B) seemed a feasible choice for improving mungbean growth, yield related traits and grain-B concentration of mungbean on Yermosols.

A Longitudinal Study of the Microbial Basis of Nitrous Oxide Emissions Within a Long-Term Agricultural Experiment

Much of the global nitrous oxide emissions are derived from agricultural management driving microbial N transformations. Crop rotation, no-till, and cover cropping are feasible conservation agronomic strategies used to prevent N losses to the environment, though their effect on soil microbial N cycling at the field scale remains relatively unknown. Our goal was to determine the effect of crop rotation (continuous corn [Zea mays L.], CCC; and continuous soybean [Glycine max (L.) Merr.], SSS), tillage (no-till, NT; and chisel tillage, T), and cover crops (cover crop mixture, CC; and no cover crop, NCC) on the quantification of functional genes related to the N cycle from different times throughout the growing season. The study was conducted during the growing season of the cash crops following the first season of cover crops introduced after 23 years of management. Using quantitative polymerase chain reaction (qPCR) techniques, we quantified nifH (N2 fixation), amoA (nitrification) and nirK, nirS, and nosZ (denitrification). Our results show that CCC increased nitrous oxide emissions by 44% compared to SSS and reduced soil pH by nearly 1 unit. The reduction in soil pH, coupled with an increase in fertilizer-derived ammonium, caused ammonia-oxidizing bacteria (AOB) and nirK copy numbers to increase. The SSS rotation showed opposite results. Bacterial denitrification via the nirK pathway was likely the N cycle mechanism behind nitrous oxide emissions in CCC. The cover crop mixture of cereal rye [Secale cereale L.] and hairy vetch [Vicia villosa Roth] reduced soil nitrate levels, though they did increase nitrous oxide emissions, likely due to priming and the inclusion of a legume in the cover crop mixture. Nitrous oxide emissions were affected by sampling date, crop rotation, and cover crop use, suggesting management factors that add abundantly available N alter the microbial N cycle directly or indirectly. Chisel tillage increased the abundance of all N cycle genes compared to no-till. Together, our work adds further insight into the microbial N cycle, especially nitrous oxide evolution, from three common conservation agricultural management practices, contributing to our understanding of key soil biogeochemical processes.

Bacterial Modulation of the Plant Ethylene Signaling Pathway Improves Tolerance to Salt Stress in Lettuce (Lactuca sativa L.)

Salinity has extensive adverse effects on plant growth and the development of new agronomic strategies to improve crop salt tolerance is becoming necessary. Currently, the use of plant growth promoting rhizobacteria (PGPR) to mitigate abiotic stress in crops is of increasing interest. The most analyzed mechanism is based on ACC deaminase activity, an enzyme that decreases the ethylene synthesis, an important phytohormone in plant stress response. We aimed to identify other PGPR mediated mechanisms involved in the regulation of salt stress in plant. We used three PGPR strains (ESL001, ESL007, SH31), of which only ESL007 demonstrated ACC deaminase activity, to evaluate their effect on lettuce plants under salt stress (100 mM NaCl). We measured growth and biochemical parameters (e.g., proline content, lipid peroxidation and ROS degradation), as well as expression levels of genes involved in ethylene signaling (CTR1, EBF1) and transcription factors induced by ethylene (ERF5, ERF13). All bacterial strains enhanced growth on salt-stressed lettuce plants and modulated the proline levels. Strains ESL007 and SH31 triggered a higher catalase and ascorbate-peroxidase activity, compared to non-stressed plants. Differential expression of ethylene-related genes in inoculated plants subjected to salinity was observed. We gained consistent evidence for the existence of alternative mechanisms to ethylene modulation, which probably rely on bacterial IAA production and other chemical signals. These mechanisms modify the expression of genes associated with ethylene signaling and regulation, complementarily to the ACC deaminase model to diminish abiotic stress responses.

Nipping-Agronomic Approach for Enhancing the Pulses Production: A Review

Pulses are an important protein source for vegetarian people across the world and they have a great potential to improve the human health, contribute to global food and nutritional security. Variety of pulses were grown in India with 25% of global production and 27% of global consumption. Though India is the largest pulses producer in the world, it imports around 3.5 million tons annually to meet the ever-increasing requirement. Less adoption of improved Agro techniques, low fertile soils and unpredictable environment conditions are major factor for low production of pulses. As a results of increasing population, the projected pulses requirement will be 32 million tons by 2030 which necessitate annual growth rate of 4.2%. With adoption of suitable agronomic strategies, the productivity has to be enhanced to meet the demand. This review work was done at Department of Agronomy, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India. Collected review and research papers were screened from various data base like TNAU e library, ARCC journals, google scholar, research gate and scopus used to write this paper. This review article documented information gathered on importance of pulses, area, production and productivity of pulses. Nipping is important agronomic practices that removes the apical bud dominance and promotes the lateral growth which turn better maintenance of source and sink relationship and enhance the pulses yield. Influence of nipping on growth and yield of various pluses crops has been discussed here.

Accumulation of essential mineral and toxic trace elements in crops and soils of vegetable cropping systems in central highlands of Sri Lanka

AbstractVegetables are widely cultivated in high rainfall and mountainous regions in Sri Lanka with poor soil conservation practices. Accumulation of essential mineral and toxic trace elements in the soils and widely cultivated vegetables of this region are poorly understood. One hundred soil and vegetable (i.e. cabbage, carrot and potato) samples were collected at the time of harvest and analysed for element concentrations. Soils contained high concentrations of essential mineral (N, P, K, Cu, Zn and Mn) and toxic trace elements (As, Cd and Pb). When comparing edible parts, cabbage contained the highest concentrations of mineral and toxic trace elements, and potato contained the lowest. Irrespective of the crop, edible parts contained high concentrations of N, P, K (14–35, 2–6, 15–24 g/kg, respectively), and Cu, Zn, Mn (2.5–6.7, 11–30, 8–147 mg/kg, respectively). Vegetables also contained As, Cd and Pb (0.04–1, 0.02–0.15, 0.02–0.26 mg/kg, respectively), but did not exceed the maximum permissible limits. Irrespective of the crop, 36–64 kg N, 6–11 kg P and 35–45 kg K per ha were removed with the harvest. According to the current rate of vegetable consumption by Sri Lankans (i.e. 240 g fresh weight (FW) per day), per capita consumption of 0.05–0.2 mg Cu, 0.45–0.65 mg Zn and 0.5–2 mg Mn per day through these vegetables was observed, i.e. 5–23% Cu, 7.5–11% Zn and 22–87% Mn of the recommended daily intake. Vegetables grown in the region served as a key source of essential mineral elements. However, agronomic mitigation strategies are needed to improve soil health and sustainability of these cropping systems.

A framework assessing the footprints of food consumption. An application on water footprint in Europe

Innovative sustainable food systems should be defined to meet the future food demand (both in terms of quality and quantity) and to overcome the threats that current food systems are posing to the natural capital. To achieve this ambitious goal, the transition to sustainable food habits should be supported by methodological frameworks and modelling tools promoting human and environmental health. The proposed framework provided a standardized system-based approach for the analysis of environmental impacts of food systems, assessed in terms of use of natural resources (water and ecological footprint) and GHG emissions (carbon footprint). The framework is applied to the assessment of water footprint of cradle-to-gate European food consumption, resulting in an average water footprint consumption of 3291 (±557) litre (per day per person). The case study showed the potentiality of our framework as a support tool for policy making in designing specific incentives for the reduction of environmental impacts related to the agri-food sector, as well as in the evaluation of agronomic strategies in the light of pursuing the environmental sustainability of food commodities production. The main novelty presented in the case study is to use food consumption data coming from surveys harmonized across European countries to assess the real food demand.

Genotypic differences in root traits to design drought-avoiding soybean ideotypes

Soybean (Glycine max (L.) Merr.) may contribute to the agro-ecological transition of cropping systems in Europe, but its productivity is severely affected by summer drought. The crop is mainly grown in southern and continental parts of Europe, whereby increasing drought and heat waves are expected in the near future. Agronomic strategies, such as early sowing, require cultivars with enhanced early plant growth traits under suboptimal conditions. Moreover, efficient water uptake by root delays dehydration and promotes drought avoidance. In general, changes in root morphology and root architecture are important pathways for plant adaptation to water stress conditions. This paper reviews the cultivar differences in soybean for root morphological and architectural traits especially during early growth stage. Previous works reported cultivar differences for root traits in soybean but they did not deal with cultivars commonly grown in Europe on which little information is available to date. Genotypic differences in available early-stage root traits can be used as a framework to design soybean ideotypes less vulnerable to drought. To this aim, high-throughput phenotyping supported by digital methods and crop modelling offer new avenues for the exploration of target root traits involved in drought avoidance.

Agronomic Strategies to Reduce the Arsenic Content in Rice in Environments Conducive to High Arsenic in Grains from Argentina

Agronomic Strategies to Reduce the Arsenic Content in Rice in Environments Conducive to High Arsenic in Grains from Argentina

Mediterranean viticulture in the context of climate change

The exposure of viticulture to climate change and extreme weather conditions makes the winemaking sector particularly vulnerable, being one of its major challenges in the current century. While grapevine is considered a highly tolerant crop to several abiotic stresses, Mediterranean areas are frequently affected by adverse environmental factors, namely water scarcity, heat and high irradiance, and are especially vulnerable to climate change. Due to the high socio-economic value of this sector in Europe, the study of adaptation strategies to mitigate the negative climate change impacts are of main importance for its sustainability and competitiveness. Adaptation strategies include all the set of actions and processes that can be performed in response to climate change. It is crucial to improve agronomic strategies to offset the loss of productivity and likely changes in production and fruit quality. It is important to look for new insights concerning response mechanisms to these stresses to advance with more effective and precise measures. These measures should be adjusted to local terroirs and regional climate change projections for the sustainable development of the winemaking sector. This review describes the direct climate change impacts (on phenology, physiology, yield and berry quality), risks, and uncertainties for Mediterranean viticulture, as well as a set of canopy, soil and water management practices that winegrowers can use to adapt their vines to warmer and drier conditions.

Review: Biofortification of Cereals with Zinc through Agronomic practices

In the developing world, Zinc deficiency is a bigger most socio-economic concern for the human and constraints for crop production. The deficiency of micronutrients in humans is generally overlapped with the deficiency in the soil. Mostly zinc deficiency is prevalent due to the consumption of cereals because their grains are genetically low in zinc concentration. The zinc deficiency is mostly occurred in soil due to cropping intensification. Intensification of zinc deficiency in humans mainly occurred due to the regular consumption of cereals as a staple food. Zn plays a key role to regulate the different functions in plants, animals, and humans. In humans, especially zinc is required for the immunity boost up. Therefore, a rapid and complementary approach is required for the biofortification of cereal crops to control zinc deficiency in the developing world. In this scenario, the breeding strategy is cost-effective, competent, and requires a lot of time to biofortified the cereals; but, on the other hand, agronomic biofortification is one of the most competitive approaches and rapid strategies. In the agronomic strategies of biofortification, (I) the priming of cereal seeds increases the germination ability and their strength/resistance against biotic & abiotic stressors (II) Soil and foliar application of zinc fertilizer (ZnSO4) greatly increase the zinc concentration in grain cereals. Generally, soil with foliar application increases the zinc concentration in grains many folds. Chelation-based strategies play a key role in zinc uptake and remobilization. So, agronomic strategies with chelation help to increase zinc content many folds in cereal grains.

Combining multi-environmental trials and crop simulation to understand soybean response to early sowings under contrasting water conditions

Anticipating sowing date in spring-sown crops is an agronomic strategy often suggested in Europe to escape water and heat stresses during the most susceptible growth periods occurring in early summer. This strategy was evaluated experimentally in soybean (Glycine max (L.) Merrill) by comparing early and conventional sowing dates for a range of cultivars grown in 18 “site x year” environments from southern France between 2010 and 2018. Conventional sowing often resulted in higher grain yields than early sowing, the latter being more favorable to grain size and protein concentration. STICS crop growth model was used to calculate dynamic abiotic (radiation, water, high and low temperatures, nitrogen) stress factors influencing the main crop physiological processes. Ecoclimatic and STICS-based agrophysiological indicators were used in a PLS (Partial Least Squares) regression as explanatory variables of grain yield (r² = 0.33). The key indicators were radiation interception from emergence to maturity, severe stomatal water stress during all the reproductive phase and high temperature since the beginning of grain filling. STICS crop model was used to characterize the 157 “cultivar x site x year x sowing date x irrigation” environments, according to water, heat and cold stresses importance in different phenophases. Then 5 profiles of abiotic stresses emerged from a clustering analysis in two steps by hierarchical ascending classification and K-means. STICS-based environmental characterization was used to explain the relative success or failure of early sowing dates and early-maturing cultivars.

Effective Categorization of Tolerance to Salt Stress through Clustering Prunus Rootstocks According to Their Physiological Performances

The effects of climate change on traditional stone fruit producing areas, together with the generation of new varieties with lower chilling requirements that allow the cultivation of previously unexplored areas, are setting up a challenging scenario for the establishment of productive orchards that must be more efficient in their capacity to adapt to new edaphoclimatic conditions. In this context, the rootstock breeding programs are a key piece in the agronomic strategy to achieve this adaptation through the development of rootstocks compatible with the new varieties and capable of transferring their tolerance to stress. An effective categorization of phenotypes within the germplasm involved in a plant breeding program is of utmost importance. Through the measurement of physiological parameters in both roots and leaves, tolerance to saline stress (120 mM NaCl) was evaluated in seven Prunus rootstocks whose genetic background included representatives of the subgenera Prunus, Cerasus, and Amygdalus. To group the genotypes according to their physiological performance under salt stress, an agglomerative hierarchical clustering was applied. The genotypes were grouped into three clusters containing rootstocks very sensitive (‘Mazzard F12/1’), moderately tolerant (‘Maxma 60’, ‘Cab6P’ and ‘AGAF 0204-09’), and tolerant (‘Mariana 2624’, ‘Garnem’ and ‘Colt’) to salt stress. ‘Mariana 2624’, a plum-based rootstock, was identified as the most tolerant Prunus rootstock. The information reported is valuable both in the productive context, for the selection of the most appropriate rootstocks to establish an orchard, and in the context of plant breeding programs, when choosing parents with outstanding traits to obtain progenies tolerant to salt stress.

Agronomic Strategies to Improve N Efficiency Indices in Organic Durum Wheat Grown in Mediterranean Area.

Organic farming systems are often constrained by limited soil nitrogen (N) availability. Here we evaluated the effect of foliar organic N and sulphur (S), and selenium (Se) application on durum wheat, considering N uptake, utilization efficiency (NUtE), grain yield, and protein concentration as target variables. Field trials were conducted in 2018 and 2019 on two old (Cappelli and old Saragolla) and two modern (Marco Aurelio and Nadif) Italian durum wheat varieties. Four organic fertilization strategies were evaluated, i.e., the control (CTR, dry blood meal at sowing), the application of foliar N (CTR + N) and S (CTR + S), and their joint use (CTR + NS). Furthermore, a foliar application of sodium selenate was evaluated. Three factors—variety, fertilization strategies and selenium application—were arranged in a split-split-plot design and tested in two growing seasons. The modern variety Marco Aurelio led to the highest NUtE and grain yield in both seasons. S and N applications had a positive synergic effect, especially under drought conditions, on pre-anthesis N uptake, N translocation, NUtE, and grain yield. Se treatment improved post-anthesis N uptake and NUtE, leading to 17% yield increase in the old variety Cappelli, and to 13% and 14% yield increase in Marco Aurelio and Nadif, mainly attributed to NUtE increase. This study demonstrated that the synergistic effect of foliar applications could improve organic durum wheat yields in Mediterranean environments, especially on modern varieties.

Soybean crop incorporation in irrigated rice cultivation improves nitrogen availability, soil microbial diversity and activity, and growth of ryegrass

Due to the genetic improvement of soybean cultivars more adapted to lowlands and to new drainage technologies, there has been a great insertion of soybean cultivation in rotation with irrigated rice in South America. Soybean has innumerable features beyond the fact that it is a legume, which can directly impact the microbial activity and diversity of the soil and the development of crops established in succession. Therefore, the objective was to evaluate nitrogen (N) dynamics, extracellular enzyme activity, soil microbial community, and the subsequent development of ryegrass in a Gleysol cultivated with irrigated rice and soybean in an area with a long history of irrigated rice cultivation. The experiment was conducted in the crop season 2015/16 at the Rice Research Station, Rio Grande do Sul, Southern Brazil, in an area that had been cultivated for 70 years with irrigated rice. The treatments used are irrigated rice cultivation and soybean in randomized blocks with 4 replicates. Hydrolysis of fluorescein diacetate, acid phosphatase, urease and β-glucosidase were evaluated. Bacterial communities were estimated in soil by extracting DNA and sequencing the V3-V4 region of the 16S rRNA gene. Ryegrass dry biomass was quantified after irrigated rice and soybean. Greater mineral N availability (+ 49%), higher extracellular enzyme activity (+ 51%) and microbial diversity (+ 7%) were observed after soybean cultivation compared to irrigated rice. These changes, after soybean cultivation, had a direct impact on the development of ryegrass plants, which showed higher ryegrass dry biomass production. Thus, the adoption of soybean rotation in areas traditionally cultivated with irrigated rice is an important agronomic strategy to increase the sustainability of agriculture, since it allows the increase of soil quality and availability of nutrients in lowland crop production systems.

Colluvial slope agriculture in context: An extensive agricultural landscape along the slopes of Punalu‘u Valley, O‘ahu Island, Hawai‘i

Archaeological research on traditional Hawaiian agriculture has generally focused on two primary strategies: irrigated pondfield and intensive dryland cultivation. However, other cultivation strategies, such as colluvial slope agriculture, were practiced but have been less intensively studied and remain poorly understood. To begin to remedy this paucity of information, a joint education and research project between International Archaeological Research Institute, Inc., the University of Hawai‘i at Mānoa (UHM) Department of Anthropology, and Kamehameha Schools (KS) was conducted in Punalu‘u Ahupua‘a to examine an integrated slope agricultural, religious, and residential complex. Subsurface investigations and radiometric dating indicate that initial vegetation clearing of the area may have occurred as early as the late thirteenth to early fifteenth centuries AD. As early as the fifteenth century, some stands of economic trees were growing, which may have coincided with initial placement of boundary walls along some portions of the slopes. Major expansion of the surface agricultural infrastructure along the landscape occurred through the sixteenth and eighteenth centuries AD. Religious structures and associated features were built as early as the seventeenth century and later. These results situate colluvial slope agriculture within the broader context of traditional Hawaiian agronomic strategies and political and social processes across the Hawaiian archipelago.

Global impact of trace non-essential heavy metal contaminants in industrial cannabis bioeconomy

The intrinsic signatures of Cannabis species to bioaccumulate non-essential harmful heavy metals (HMs) such as As, Pb, Cr, and Hg are determined by their high tolerance, weedy propensities, phenotypic plasticity attributes, and pedoclimatic stress adaptation in a biota. This unstructured meta-analysis study provides details of cannabis involvement in HMs phytoremediation, new insights into HMs transportation and distribution, homeostasis, and health implications of HMs contaminated product. A blueprint of agronomic strategies to alleviate HMs uptake by cannabis is proposed. We show revamping cannabis global production necessitates a rethinking of agronomic best practices and post-harvest technologies to remove metal contaminants.

Yield, technological quality and water footprints of wheat under Mediterranean climate conditions: A field experiment to evaluate the effects of irrigation and nitrogen fertilization strategies

The evaluation of the role of different agronomic strategies in achieving sustainable wheat yields under variable Mediterranean climate conditions may involve the use of resource-use indicators that combine productivity and environmental impact. A two-seasons field experiment was conducted in South Portugal to study the effect of water regimes and nitrogen fertilization on wheat yield, grain quality and water use evaluated with water productivity and water footprint indicators. The water regime treatments were full irrigation, supplemental irrigation, and rainfed. Nitrogen fertilizer treatments, including conventional and enhanced efficiency fertilizers (EEF) were distinguished by N splitting and timing over the crop cycle. Contrasting meteorological variables in the two years caused distinct wheat productive responses. Although leading to lower grain yields, supplemental irrigation guaranteed a water productivity similar to full irrigation. The use of EEFs in which 50% of the total nitrogen was applied at the booting phase had a positive significant effect on grain protein content and on dough rheologic properties, indicating that late nitrogen applications benefit the technological quality of wheat. The average total water footprints estimated for the two seasons showed no relevant differences but the partition of the green, blue and grey components in irrigated wheat varied, with an increased importance of blue water consumptive use in the second year of the experiment. In fact, the ratio blue water footprint/green water footprint increased from 0.40 to 2.00 due to higher irrigation requirements. High grey water footprint in rainfed wheat was mostly influenced by lower yields in 2018–2019, and by an advantageous rainfall distribution during the 2017–2018 season. No significant reduction in grey water footprint was observed when using EEFs. A multivariate statistical approach through factor analysis (FA) and multivariate linear regression (MLR) was used to examine the data structure and correlation. FA resulted in three-factor models of yield and water use, yield components and wheat quality, in the first season. In the second, drier, season, variables most related with irrigation water use were clustered in one detached factor. The stepwise MLR pointed to a good prediction capability of water footprints from NDVI measured with proximal sensors at booting, anthesis, maturation and/or tillering.

Agronomic Biofortification of Zinc in Chickpea Varieties in Calcareous Soil

Background: Pulses are wonderful gift of the nature to agriculture. They provide nutrition to human beings and animals as food and feed respectively. Among the pulses, chickpea is an important rabi season crop with high acceptability and wider use in nutritional food basket. A field experiment was carried out on medium black calcareous soil at Junagadh Agricultural University, Junagadh, Gujarat during rabi season 2017-18 under saurastra condition to evaluate agronomic biofortification of zinc in chickpea (Cicer arietinum L.) varieties through seed, soil and foliar application. Methods: The experiment was laid out in factorial randomized block design with three replications. The treatment combinations comprised two varieties viz., GG 1 (V1) and GJG 3 (V2) and six zinc fortification treatments viz., control, seed treatment ZnSO4 @ 3 g kg-1 seed, 0.5% ZnSO4 foliar spray, seed treatment ZnSO4 @ 3g kg-1 seed + 0.5% ZnSO4 foliar spray, soil application ZnSO4 @ 25 kg ha-1 and soil application ZnSO4 @ 25 kg ha-1 + 0.5% ZnSO4 foliar spray. The chickpea was grown with standard package of practices. Result: The results revealed that a significant improvement in 100-seed weight, seed yield, stover yield and biological yield were observed with chickpea variety GJG 3 over GG 1. Significantly higher numbers of pods per plant (45.83) was recorded with variety GG 1. Significantly, chickpea variety GJG 3 was found superior in zinc content and uptake in seed and stover. Under agronomic strategy, zinc fortification through soil application ZnSO4 @ 25 kg ha-1 + 0.5% ZnSO4 foliar spray at flowering and pod filling stages significantly improved yield attribute and yield viz., pods per plant (55.17), seed yield (2288 kg ha-1) and stover yield (3553 kg ha-1) and quality parameters viz., protein content in seed (22.89%) and protein yield (523 kg ha-1), zinc content and uptake in seed and stover (45.98 and 37.51 ppm and 104.87 and 133.35 g ha-1, respectively) over all other zinc biofortification treatments.

Biologically active toxin from macroalgae Chaetomorpha antennina Bory, against the lepidopteran Spodoptera litura Fab. and evaluation of toxicity to earthworm, Eudrilus eugeniae Kinb

BackgroundSeaweeds harbour a wide array of bioactive compounds shown to be effective in support of sustainable agricultural practices. The green seaweed Chaetomorpha antennina found in abundance in coastal areas of India has been reported with various bioactivities. Owing to the requirement of alternative and economical natural pest control method to be applied in sustainable agronomic strategies, the current study attempts to evaluate the efficacy of chemical toxins from C. antennina, as insecticidal agents, by inspecting their effects on the physiology, biochemistry, immune system, and histology of one of the most important insect pests of agricultural crops in the Asian tropics, the polyphagous lepidopteran Spodoptera litura.ResultsThe active fraction 5 isolated from C. antennina using methanol extraction produced significant mortality rates of S. litura among all the other fractions obtained. GC–MS analysis revealed the presence of various pesticide compounds. The toxin compounds (active fraction 5) were found to negatively influence the pest’s immune system performance at sub-lethal concentrations (LC50 38.73and LC90 53.60 ppm), affecting insect development, reducing the haemocyte count (69.24%) and reduced the activity of major defence enzyme phenoloxidase decreased post-treatments. Digestive phosphatase enzymes, acid phosphatase, ACP, alkaline phosphatase, ALP, and ATPase were demodulated by 37.5, 39, and 23.9% compared with untreated. Increase in detoxification enzymes coupled with mid-gut collapse are indicative of the toxicity of the compounds. Earthworms exposed to seaweed compounds displayed no debarring effects.ConclusionExtracted seaweed compounds produced significant lethal effect on the insect larvae, affecting the immune as well as digestive systems of the pest. However, no such toxicity was observed in earthworms treated with the seaweed fraction supporting their environmentally benign nature. Since the insect immune system is responsible for the development of resurgence against pesticides, suppression of immunological activities by seaweed toxins indicate the long-term applicability of these compounds as prospective pesticides. The results support the potential of chemicals from C. antennina for biopesticide development to manage economically important agricultural pests.