Total Dry Biomass Research Articles

Optimal harvest number and genotypic evaluation of total dry biomass, stability, and adaptability of elephant grass clones for bioenergy purposes

For elephant grass breeding for bioenergy purposes, selection should be based on repeated harvests to maximize the selection efficiency. Selecting genotypes with high total dry biomass, associated with high adaptability and stability, is extremely important. Thus, the objective of this study was to estimate the minimum number of harvests required for total dry biomass to enable an accurate selection of elephant grass clones in multiple environmental trials. Additionally, the relative performance of genetic values (HMRPGV) and centroid methods were used to cluster and rank the best clones on the basis of their total dry biomass, adaptability, and stability. Nineteen clones and two checks were evaluated in six environments. Two or four harvests were performed in each environment. A mixed model methodology (REML/BLUP) was used to estimate the variance components and predict the genotypic values. The repeatability coefficient for total dry biomass was 0.20. The accuracies of performing two and four harvests were 59% and 72%, respectively. The increase in selection efficiency by performing two, four, and seven harvests instead of just one was 29%, 57%, and 76%, respectively. Finally, the clones were clustered into four classes according to their total dry biomass, adaptability, and stability. We conclude that at least seven harvests are required to achieve an accuracy of 80%, and that the HMRPGV and centroid methods are practical, visual, and reliable for simultaneously clustering, ranking, and selection of clones based on their adaptability, stability, and total dry biomass production.

Waterlogging tolerance of the common reedsPhragmites mauritianusandP. australis

AbstractThis study compared the responses ofPhragmites mauritianusandP. australisto waterlogging stress for 5 months. Plants were subjected to a 2 × 4 factorial experiment with two species and four soil moisture regimes: well drained (WD), half flooded (½F), flooded/drained at weekly intervals (F/D) and continuously flooded (F). Soil redox potential (Eh) was high in the WD (+138 to +126 mV) and low in the F treatments (−360 to −401 mV). Flooding increased plant height, number of culms, shoot elongation and total dry biomass accumulation in both species. In the flooded treatments, there was greater biomass allocation to above ground than below ground components, which contributed to increases in above‐ground/below‐ground ratios. In the flooded treatments, specific gravity of culms decreased by 18% inP. australisand by 10% inP. mauritianusindicating greater aerenchyma with waterlogging. In both reeds, flooding induced numerous adventitious roots from the base of the culms. In the F treatments, plant height, number of culms, total dry biomass accumulation and aerenchyma development were greater inP. australisthan inP. mauritianus. These data suggest thatP. australishas a competitive edge overP. mauritianusunder waterlogged conditions.

Genetic architecture of Al3+ toxicity tolerance in rice F2:3 populations determined through QTL mapping.

Aluminum (Al3+) toxicity is one of the factors limiting crop production in acidic soils. Identifying quantitative trait loci (QTLs)/genes for tolerance to Al3+ toxicity at seed germination can aid the development of new tolerant cultivars. The segregating population derived from Pak Basmati (Indica) × Pokkali (Indica) was used for mapping QTLs linked with tolerance to Al3+ toxicity ranging from 0 to 20 mM at pH 4 ± 0.2 at germination. The favorable alleles for all new QTLs were analyzed based on germination traits, i.e., final germination percentage (FG%), germination energy (GE), germination speed (GS), germination index (GI), mean germination time (MGT), germination value (GV), germination velocity (GVe), peak value of germination (GPV), and germination capacity (GC), and growth traits, such as root length (RL), shoot length (SL), total dry biomass (TDB) and germination vigor index (GVI). The phenotypic evolution showed transgressive variations. For genome-wide mapping, 90 polymorphic SSRs with 4 gene-specific markers and Win QTL Cart were used for QTL analysis. In all, 35 QTLs for germination and 11 QTLs for seedling growth were detected in distinct chromosomal regions by composite interval mapping (CIM), and multiple interval mapping (MIM) confirmed the pleiotropy at region RM128 on chromosome 1. Based on our genetic mapping studies, the genes/QTLs underlying tolerance to Al3+ toxicity could differ for both the germination and seedling stages in segregated populations. The QTLs identified in this study could be a source of new alleles for improving tolerance to Al3+ toxicity in rice.

Crithmum maritimum L.: First Results on Phenological Development and Biomass Production in Mediterranean Areas

In Mediterranean cropping systems, it is important to utilise marginal lands for the cultivation of native food crops. Previous research on Crithmum maritimum L., a species native to southern Europe, has focused on its alimentary and chemical parameters. The aim of the present study was to identify the effects of irrigation and fertigation systems on C. maritimum in Mediterranean cropping systems. We planted C. maritimum seeds in an organic farm in Italy, and we carried out three experiments (fertigation, irrigation, and control) with three replications each. We evaluated plant phenological development and biomass production. We found that these treatments significantly influenced plant phenology and biomass parameters. Even with low irrigation and fertigation, this species showed a significant difference in the Bundesanstalt, Bundessortenamt, CHemischeIndustrie (BBCH) phase at harvest: in fact, there were 39 and 35 leaves on the main stem in the irrigation and fertigation treatments, respectively, while there were 29 leaves on the main stem in the rainfed unfertilised control. Biomass production also showed the same significant difference: 1.8 and 2.0 t ha−1 of total dry biomass in the irrigation and fertigation treatments, respectively, and 1.2 t ha−1 of total dry biomass in the rainfed unfertilised control. In conclusion, we recommend the use of C. maritimum for food production in Mediterranean organic cropping systems.

Pilot-scale biorefining of Scenedesmus obliquus for the production of lipids and proteins

The whole process of algae farming and biomass biorefining was evaluated on a pilot scale for the production of protein concentrate for poultry feeding and crude lipids. Scenedesmus obliquus was produced in open raceway ponds, and the cells were disrupted under low-pressure homogenization operating at 150 bar. Lipids were efficiently extracted using a hybrid multistage process based on a wet extraction using hexane and ethyl acetate, followed by dry extractions using hexane. The protein concentrate containing 43.1% of total proteins was recovered at low centrifugation of 400g and submitted to a desolventization process to remove residual hexane. The protein concentrate showed a similar composition of essential amino acids in comparison to soybean which is the main protein source used in feed formulation. Aspartic acid and glutamic acid were the main amino acids observed in the microalgal protein concentrate. As a feed supplement for broilers, the protein concentrate-based feed showed equal ingestion of the control, but the latter showed lower energy efficiency. The processing of 168 kg of wet biomass (14.8 kg on a dry weight basis) resulted in a production of 1.3 kg of crude lipids and 12.6 kg of protein concentrate, which corresponded to 93.7% of the total dry biomass.

Arbuscular mycorrhizal inoculation increases drought tolerance and survival of Cenostigma microphyllum seedlings in a seasonally dry tropical forest

Seasonally dry tropical forests are characterized by several months of drought. Cenostigma microphyllum is a native woody species widely found in a seasonally dry tropical forest. These forests are in need of restoration and C. microphyllum is a species that can be used to this end. We studied, 1) acute water deficiency using plant in pot, and 2) chronic water deficiency in field conditions in areas with different rainfall gradients, always with two group of plants: inoculated and non-inoculated with arbuscular mycorrhizal fungus. Acute water deficit levels in previously inoculated and non-inoculated treatments were similar, however, after rehydration, the inoculated potted plants showed faster recovery of water status and gas exchange. In field conditions, on the 120th day, before the beginning of the dry period, 100% of transplanted seedlings survived, while the total plant dry biomass did not differ between the inoculated and control groups. The same patterns emerged across rainfall gradient. After 365 days of seedling transplantation, the field survival dropped from 100% to 58%. Sixty-eight percent of the inoculated plants survived, whereas more than half of the non-inoculated individuals did not resprout at the beginning of the rainy season. Among the remaining plants, 63% were from the rainiest plots. The average of CO2 assimilation for both treatments was 2.63 and 9.43 μmol m−2 s−1 in the two driest and wettest plots, respectively. Our results suggest that artificial inoculation appears to be associated with better plant recovery or resilience following low water availability, particularly chronic/prolonged drought. Thus, the present work recommends the use of the seedling production technique, with long roots as well as the previous inoculation with selected native mycorrhizal fungi.

Growth of yacon under artificial shading

ABSTRACT Yacon is a tuberous root cultivated in mild climate regions with high altitudes, but the crop shows the capacity to develop at low altitudes. The objective of this study was to evaluate growth rates and the partition of photoassimilates in yacon plants under different levels of artificial shading. The experiment was conducted in four shading levels (0%, 30%, 50% and 70%), and seven monthly harvests in a completely randomized design. We evaluated the accumulation of total dry mass on the whole plant and its parts; leaf area; leaf area ratio; leaf mass fraction; stem mass fraction; rhizophores mass fraction; tuberous roots mass fraction; estimates of relative growth rate, absolute growth, and net assimilation. The lower accumulation of total dry biomass and the lowest growth rates indicate that conditions of noticeable light restriction (70% shading) restrict the growth of yacon. Yacon plants grown under moderate shading levels (30 to 50%) showed greater capacity of accumulation of total biomass, directing part of this biomass to the tuberous roots, which directly reflects gains in the agronomic productivity of this crop, indicating that yacon has the potential to be associated with other crops, which promote a moderate shading.

Effects of topsoil removal on nitrogen uptake, biomass accumulation, and yield formation in puddled-transplanted rice

• Topsoil removal reduced total N uptake, total dry biomass, and grain yield of rice. • Topsoil had the largest contribution to plant N uptake from midtillering to panicle initiation. • Topsoil removal had the largest effect on panicles m −2 among yield components. • Total dry biomass rather than harvest index was affected by topsoil removal. Rice nitrogen (N) uptake and yield formation depend on both applied N fertilizer and soil-derived N. In this study, we determined the effects of topsoil removal on the N uptake and yield formation of rice crop. Four rice varieties were grown in farmers’ fields in Wuxue County, Hubei Province, China in 2016–2018 under the treatments of topsoil removal (TR) and control (CK). The TR treatment was established by desurfacing soil at about half of the topsoil depth (11−15 cm). Experiments were conducted in three adjacent fields in the three years and 100 kg N ha −1 was applied in all plots except for zero-N treatment in 2018. Averaged across years, N treatments, and varieties, topsoil removal reduced total N uptake by 27.8 %. The period from midtillering to panicle initiation had the highest daily N uptake from topsoil compared with other growing periods. During this growing period, the percentage of N uptake from topsoil to plant N uptake ranged from 54.2 to 62.4 % with an average value of 56.4 % across both zero-N and N-applied treatments. On average, topsoil removal reduced grain yield by 16.7 % and total dry biomass by 17.6 %. Among yield components, panicles m −2 was mainly responsible for the yield reduction in TR. Furthermore, total dry biomass rather than harvest index explained the yield reduction in TR compared with CK. Our results suggest that topsoil provided substantial N to rice crop especially during the period from midtillering to panicle initiation for achieving higher grain yield through increased panicles m −2 and biomass production.

Soil contamination with phenanthrene induces maize mycorrhiza growth suppression

Soil pollution with polycyclic aromatic hydrocarbons (PAH) such as phenanthrene is extremely detrimental to the environment and to all living organisms, which is why appropriate remediation techniques are required. Here we tested single and combination effects of the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis BEG 87 and a soil amendment that results from the fermentation of organic matter through the activity of efficient microorganisms (Bokashi) on maize (Zea mays L.) growth performance, when exposed to phenanthrene. Main results showed that phenanthrene reduced total maize dry biomass, though only in mycorrhizal plants. The AMF root colonization respectively increased and decreased with Bokashi and phenanthrene. Growth suppressions in maize with AMF are common, but to our knowledge this has not been shown in combination with PAH. Possible mechanisms involved in this growth suppression could be related with increased phenanthrene uptake and hence increased plant toxicity or that phenanthrene impaired possible benefits from AMF in terms of nutrient acquisition, which could have resulted in the imbalance of the cost-benefit of the mycorrhizal association leading to growth suppression. However, the underlying mechanisms for this observed negative mycorrhiza growth response in maize when exposed to phenanthrene remains to be identified.

Influence of Rhizobium Inoculation and Phosphate Rock Fertilizer Application on Growth and Yield Components of Green gram (Vigna radiata) in Tharaka-Nithi County, Kenya

Green gram is an important drought tolerant grain legume crop in Kenya. In Tharaka Nithi County green gram is as a major source of food security. Hence, there is need for a cheap and sustainable system of agricultural production is needed to increase its production. The legume/Rhizobium symbiosis in combination with phosphate rock offers a natural system for improving green gram nitrogen fixation. Therefore, this study was aimed at determining the effect of Rhizobium and phosphate rock fertilizer application on growth and yield attributes of N26 and KS20 varieties. The study was carried out at Chuka University Horticultural Research Farm for two seasons, November 2019 to January 2020 and February to April 2020. Factorial experiment of 2x2x2 was laid out in a Randomized Complete Block Design (RCBD). There were three factors, variety (N26 and KS20), phosphate rock (0 and 30 kg P ha-1) and Rhizobium MEA 716 (0 and 100 g ha-1). The experiment contained eight treatments which were replicated three times. The data was collected fortnightly on four randomly selected plants on parameters such as plant height, number of leaves, branches, pods, total dry biomass, shoot and root dry weight and grain yield. These data was analysed using Statistical Analysis Software (SAS). Significant means are separated using Least Significant Difference (LSD) at probability level of 5%. Results for both seasons indicated that combined application of Rhizobium MEA 716 Rhizobium 100 g ha-1 and phosphate rock 30 Kg ha-1 phosphate under variety in treatment (R1P1V2) showed significantly (P<0.05) higher plant height (76.07 cm), number of branches (14.08 plant-1), shoot dry biomass (52.01 g plant-1), root dry biomass (7.60 g plant-1), total dry biomass (146.4 g plant-1), number of pods (84 plant-1) and yield (2158 kg ha-1) compared to variety N26 in treatment (R1P1V1). Therefore, combination of Rhizobium MEA 716 100 g ha-1 and phosphate rock 30 Kg ha-1 under variety KS20 led to improved growth attributes equally yield components of KS20 variety over N26. From these findings, application of Rhizobium MEA716 at 100 g ha-1, and 30 Kg ha -1 phosphate rock under variety KS20 was recommended for improved and a sustainable green gram production in the study area.

Development of one row installation machine for drip lines subsurface irrigation

This study was conducted to develop a manual steering one row locally fabricated drip lines installation machine, and evaluate its performance rate, efficiency and operating costs compared with manual installing. Also, the effect of deficit irrigation regime (DIR) under burial depth on tomato plant growth performance “plant height, root length, total dry biomass, and total marketable yield”; water use efficiency “WUE & TYWUE”; yield response factor “Ky” and yield depression were investigated. Treatments consisted of three levels of DIR (85; 70 and 55 % ETc) represented by (RI); (RII) and (RIII) respectively, throughout the whole growing season, and three burial depths of subsurface drip T-tape at (5; 15 and 25 cm) represented by (DI); (DII) and (DIII) respectively; compared with the common tomato growing practice by using GR-drip tuber 16 mm installed at the soil surface (D0) with 100 % ETc (R0). The applied treatments were: T1 “control” (R0D T2 (RID T3 (RID T4 (RID T5 (RII & D1); T6 (RIID T7 (RIID T8 (RIIID T9 (RIII D (3.84 Mg/fed) and (32.88 Mg/fed) respectively recorded with treatment T1(100% ETc & at the soil surface) while the highest value of root length was (11.4 cm) recorded with treatment T7 (70% ETc & burial depth 25 cm ). The water use efficiency “WUE” on the total dry biomass basis ranged between 2.11 and 1.494 Kg/m3 recorded with treatment T6 (70 % ETc & burial depth 15 cm) and T1 respectively, while the corresponding value for water use efficiency “TYWUE” on total yield basis were 17.85 and 12.16 Kg/m3 recorded with treatment T6 and T10 (55% ETc & burial depth 25 cm). The values of “Ky” ranged between (1.0 and 0.11) recorded with treatments T10 and T6. The yield depression ranged between 47.7 and 0.82 % recorded with treatment T10 and T3 (85 % ETc & burial depth 15 cm) respectively. It is recommended to use the proposed machine for installing drip lines to save time, effort and costs, and to ensure its safety and depth regularity. It is also recommended in tomato cultivation to apply treatment T6 “ DIR 70 % ET & burial depth 15 cm”, in which the irrigation rate can be reduced by 30% while obtaining the highest water use efficiency and the least relative yield depression (2.34%).

Implications of global climate change for the development and ecological interactions between two key Amazonian aquatic macrophytes

ABSTRACT Amazon wetlands are among the most vulnerable ecosystem to be impacted by climate change, which may increase the frequency of extreme droughts and floods. We used Eichhornia crassipes and Pistia stratiotes, two abundant aquatic plants in the Amazon floodplains, to evaluate the effects of combined temperature and [CO2] increase on growth, physiology and ecological interactions. Individual and paired plants were deposited for three weeks in a microcosm under four IPCC scenarios: control (current temperature/CO2), mild (control + 1.5 oC, 200 ppm CO2), intermediate (control + 2.5 oC, 450 ppm CO2) and extreme (control + 3.5 oC, 850 ppm CO2). P. stratiotes died after three weeks in the intermediate and extreme treatments; E. crassipes experienced no mortality or change in any of the measured variables during the same period. P. stratiotes reduced root length in the mild treatment and reduced total dry biomass in intermediate and extreme treatments, revealing less tolerance to climate change. Ecological interactions between the two species changed with increasing [CO2] and temperature neutral interaction changed to facilitation for E. crassipes, while competitive interaction changed to neutral for P. stratiotes. Global climate change may alter the composition, biomass and ecological interactions of Amazonian aquatic plant species.

Growth Performance of Sweet Corn (Zea mays) on the Mineral Soil Amended with Sago Waste Biochar

Sago wastes are viable and utiliable resources for conversion into value-added products. Sago fronds and barks have high potential to be used as biochar feedstocks due to the availability and significant content of starchy-lignocellulosic compounds. However, only few studies were conducted regarding sago wastes conversion into biochar. Thus, this study evaluates the viability of converting sago wastes into biochar and as soil amendment on mineral soil planted with sweet corn (Zea mays) plants. The study was located at the Farm Unit, UiTM Samarahan, Sarawak. Five treatments combination of sago bark (SB) biochar and sago frond (SF) biochar were used in a randomised complete block design (RCBD) with eighty plants per treatment and replicated three times. Parameters measured at harvest 85 days after treatment (DAT) including total dry biomass, cob weight, cob number and cob grade. All the recorded data were statistically analysed by the analysis of variance (ANOVA) using SAS 9.4 (2013). Different treatments showed significant effects on all the parameters studied. The highest value for total dry biomass, cob yield was obtained using SB biochar 100%. The results of this study reveal the potential of SB biochar as an alternative soil amendment to increase sweet corn biomass and yield.

Synergistic effect of ACC deaminase producing Pseudomonas sp. TR15a and siderophore producing Bacillus aerophilus TR15c for enhanced growth and copper accumulation in Helianthus annuus L

Copper (Cu) is an essential element, however it’s excess into the environment causes detrimental effect on plant and risks for public health. Four Cu and drought tolerant 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing rhizobacteria were isolated from the roots of Trifolium repens L. growing on Cu smelter contaminated soils, characterized and identified based on 16S rRNA gene sequencing. A consortium of high ACC deaminase (53.74 μM α-ketobutyrate mg−1 protein h−1) producing bacteria Pseudomonas sp. strain TR15a + siderophore producing Bacillus aerophilus strain TR15c significantly (p < 0.05) produced better results for multiple-metal tolerance including Cu (1750 mg kg−1), antibiotic resistance (ampicillin, kanamycin, chloramphenicol, penicillin, tetracycline, and streptomycin) and plant growth promoting attributes (phosphate solubilization: 315 mg L−1, indole-3-acetic acid (IAA) production: 8 mg L−1, ammonia and hydrogen cyanide production) as compared to individual isolates. Pot scale experiment (enriched with 100 mg Cu kg−1) showed inoculation of Helianthus annuus seeds with consortium of TR15a + TR15c had significantly (p < 0.05) improved seed germination by 32%, total dry biomass by 64%, root Cu by 47% and shoot Cu by 75% as compared to uninoculated control whereas 0.2−7 fold higher results were observed for above stated parameters as compared to four individual isolates studied. The result suggests consortium of ACC deaminase producing Pseudomonas sp. TR15a and siderophore producing B. aerophilus TR15c could play a vital role in enhanced Cu uptake and improvement of biomass and may provide a better alternative for decontamination of Cu contaminated natural ecosystem than individual isolates.

Surface reflectance calculation and predictive models of biophysical parameters of maize crop from RG-NIR sensor on board a UAV

Unmanned aerial vehicles (UAVs) present themselves as an alternative to overcome the limitations of satellite sensors in monitoring agricultural crops, motivating many studies with UAVs. They can carry sensors, which need studies for better understanding. The present study aimed to vicariously calibrate a Red-Green-Near infrared (RG-NIR) low-cost sensor on board a UAV, and to develop predictive models of biophysical parameters for a maize crop. To achieve this purpose, 15 sets of images were captured over 61 days after emergence (DAE) of the maize crop plantation. Each set of images was mosaicked and had their digital numbers (DN) converted to reflectance. After calibration, normalized difference vegetation index (NDVI) and cumulative NDVI (cNDVI) were calculated to serve as an independent variable in the models for estimating crop parameters. In the field, 54 plants were collected and evaluated for height, leaf area and dry biomass. It was observed that the NIR band had an influence on the red band, but this influence was attenuated with the empirical line calibration. NDVI was able to detect seasonal and spatial variations in maize. The NDVI model obtained on the collection day to estimate the total dry above ground biomass had better results, generating RMSE of 68.68 g m−2 and R2 of 0.81, in comparison with cNDVI. For productivity, the result was satisfactory with cNDVI, showing RMSE of 134.00 g m−2 and R2 of 0.63. Calibration of the sensor was shown to be important to attenuate influence between bands.

Comparison of Growth Responses in Sorghum Genotypes and Corn Grown in Arid Regions Under Different Levels of Water and Nitrogen Supplies

Improving the productivity of cropping systems in terms of irrigation water use and nitrogen (N) fertilizer and exploring the associated effective physiological traits are priorities mostly in water-limited areas. Therefore, this field experiment was conducted on a clay loam soil (thermic family of Typic Haplargids) in central Iran with the three planting dates of 2016 (June 30), early 2017 (June 10), and late 2017 (July 11). Three forage sorghum genotypes including SF002, SF001, and Pegah, three grain sorghum genotypes of MGS5, GS24, GS28, and one common corn hybrid were grown under two irrigation regimes (55% and 85% of the maximum allowable depletion – MAD) as well as two N levels (0 and 112.5 kg N ha−1 in the form of urea, 46% N). The results showed considerable genetic variation among the sorghum genotypes in terms of yield. Due to water-limited conditions, the grain and biomass yields of the corn hybrid were decreased more those of sorghum genotypes. However, higher potential sorghum genotypes recorded total dry biomass (shoot biomass and grain yield) values similar to those of corn under both normal and deficit irrigation regimes. On the other hand, the grain share of the total biomass in the corn hybrid was higher in the two irrigation regimes. Under deficit irrigation, the use efficiency values of irrigation water (IWUEb) and N fertilizer (NUEb) for the biomass yield in Pegah and GS24 were higher than those in the corn hybrid. However, IWUEg and NUEg in corn were significantly higher under both irrigation regimes compared to those recorded for even the high-yield potential genotypes of the grain and forage sorghum. The positive effects of N application on the plants declined under water-limited stress, but the negative effects of water deficit stress were reduced with N application, while dry matter and grain yield increased as a consequence of the increase in the maximum leaf area index, chlorophyll &lt;em&gt;a&lt;/em&gt;, chlorophyll &lt;em&gt;b&lt;/em&gt;, and carotenoid contents, as well as the enhanced antioxidant activities of catalase, ascorbate peroxidase, and peroxidase enzymes. It can be concluded that the corn-based planting system is superior to sorghum even under low irrigation conditions, and N supply could moderate the negative effects of water shortage stress on plant growth.

Leaf Nutrient Concentrations and Dry Biomass of Fig Plants as Modified by the Application of NPK: A Preliminary Study

Aims: The effect of a complete NPK matrix on leaf nutrient concentrations and dry biomass of ‘Black Mission’ fig plant organs was tested under an intensive culture system and protected environment.&#x0D; Study Design: A randomized complete block design with four blocks was employed.&#x0D; Place and Duration of Study: The experiment was conducted from April to November 2016 at the Campo Experimental La Laguna, located in Matamoros, Coahuila, Mexico. This research station belongs to the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP) of Mexico. The experiment was set up under a macro tunnel equipped with a shade mesh with 50% sunlight attenuation.&#x0D; Methodology: Two-year-old fig plants (cv. ‘Black Mission’) previously propagated from stem cuttings were used. There were three application rates each for N (0, 80, and 160 kg ha-1), P (0, 40 and 80 kg ha-1), and K (0, 80, and 160 kg ha-1) arranged in a balanced factorial matrix of 27 treatments. After harvest, leaf samples were collected to determine nutrient concentrations and they were split into roots, shoots, leaves, and fruit&#x0D; Results: The greatest total dry biomass was produced by the interaction of 80 kg ha-1 N and 40 kg ha-1 P and yielded the following leaf nutrient concentrations (mean ± SD): N 2.9 ± 0.3%, P 0.11 ± 0.01%, K 2.1 ± 0.4%, Ca 1.4 ± 0.7%, Mg 0.34 ± 0.03%, Fe 166.4 ± 49.5 mg kg-1, Cu 6.3 ± 1.7 mg kg-1, Mn 83.3 ± 20.9 mg kg-1, and Zn 22. 6 ± 3.8 mg kg-1. Application of 80 kg ha-1 N and 40 kg ha-1 P could be suggested for commercial fig production.&#x0D; Conclusion: Application of 80 kg ha-1 N and 40 kg ha-1 P could be tested under similar commercial production systems; however, the addition of supplemental K deserves further study.

Effects of sewage sludge and other wastes application on the growth and element uptake of Jatropha curcas in abandoned rare-earth mine soil.

The wastes such as sewage sludge (SS) can be used to amend soil of abandoned rare-earth mine land (ARL). The energy plant Jatropha curcas could be used as a pioneer tree species in the ARL. In a pot experiment to address the responses of growth and element uptake of J. curcas, three treatments were established: adding SS to the soil of ARL (T1), adding SS and bagasse to the soil of ARL (T2), adding SS, bagasse and passivator to the soil of ARL (T3), with the untreated soil of the ARL as the control (CK). The results showed that compared with CK, T1 only significantly increased the plant height of J. curcas, T2 and T3 significantly increased the plant height, ground diameter and dry biomass of J. curcas, of which the total dry biomass increased by more than 184.7%. All the three treatments significantly increased the contents of N, P, K and Cu in J. curcas. T1 and T2 significantly increased the proportion of exchangeable Zn, Cd and Ni in the substrates, while T3 showed the opposite effects. T3 significantly decreased the migration factor (M) and mobility factor (MF) of Zn, Cd, Ni in the substrates, and significantly reduced the contents of Zn, Pb, Cd, Ni in J. curcas, with an inhibition rate of over 36.1%. The comprehensive evaluation of the membership function showed that the order of growth promotion effects on J. curcas was T2>T3>T1>CK, while the order of capacity of inhibiting J. curcas to accumulate Cu, Zn, Pb, Cd, Ni was T3>CK>T2>T1. The combined application of SS and bagasse significantly promoted the growth and element accumulation of J. curcas, and the addition of passivator significantly reduced heavy metals uptake without affecting the growth of J. curcas.

Assessments in early growth of corn seedlings after hausmanite (Mn3O4) nanoscale seed priming

Nanofertilizer application is becoming a sustainable alternative for plants micronutrients supply. Seed nutrient priming before seeding reduces non-target dispersion; although, applying nanofertilizer in correct concentration must be narrowly chosen to prevent germination and development issues. Here, we evaluated corn seedlings development and germination after seed priming with Mn3O4 nanoparticle (NP), Mn3O4 bulk and MnCl2. Sterile seeds were soaked for 8 hours in priming solutions of 0, 20, 40, 80 and 160 mg L−1 for each Mn sources. The seeds vigor and germination were evaluated after 7 days on germination paper. Root, shoot and total lengths were measured as well as root, shoot and total dry biomass. Compared to the control, the Mn3O4 NP and Mn3O4 bulk promoted beneficial effects. Mn3O4 NP seed-priming exhibited a concentration dependent profile in improving seedling growth, with greatest benefit around 20 mg L−1, providing higher germination, vigor, dry biomass and length than control and the other source tested. Particle size plays an important role in the reactivity of Mn3O4 NP. On the other hand, seeds primed with soluble source did not differ from the control. These findings support NP-seed priming as an alternative to delivery micronutrients.

Conservational Tillage and Weed Management Practices Enhance Farmers Income and System Productivity of Rice–Wheat Cropping System in Central India

An increasing cost of production, declining factor productivity and sustainability in rice–wheat cropping system are forcing the Indian farmers to shift from conventional tillage (CT) practice to conservational tillage (CA) practice for crop cultivation. With all the numerous advantage of CA practice, weed is a major concern restricting the farm productivity and profitability. To evaluate various tillage and weed management practices in rice–wheat cropping system of Central India, a study was carried out at farmers field. An integrated approach of weed management with Sesbania co-culture with rice followed by tank-mix application of bispyribac-Na + 2,4-d effectively reduced the total weed density and dry biomass accumulation and simultaneously increased the rice grain yield and farmers income, whereas, in case of wheat, as compared to CT practice, CA gave ~ 11% higher grain yield by restricting the growth of weeds. The weed density and dry weight were effectively diminished with pre-mix application of mesosulfuron + idosulfuron in wheat, and this pre-mix combination has also significantly increased the wheat grain yield over farmers practice. As compared to sole application, tank-mix or pre-mix application of different herbicides with varied target group of weeds controlled various weed species in a single application. The total system yield of rice–wheat cropping system with CA practice (6.27 t/ha) was higher as compared to CT practice (5.97 t/ha). The sustainable yield index, farmers profit and B:C ratio of the rice–wheat cropping system were in upper side by adopting the CA practice as compared to existing farmers (CT) practice.