Sorghum Plants Research Articles

Integrated management of yellow aphid (Melanaphis sacchari Zehntner) in sorghum (Sorghum bicolor L.) Moench in Guerrero, Mexico

Sorghum is cultivated in tropical and subtropical regions of the world and is an important cereal for Mexico. However, it is affected by different pests, especially the yellow aphid. The objective of the research was to evaluate the effectiveness of biological, botanical and chemical insecticides in reducing Melanaphis sacchari populations in sorghum plants under greenhouse conditions. Planting was conducted in a greenhouse, using the sorghum hybrid 945-M. Pests, diseases and weeds management were implemented. The incidence of the yellow aphid was induced artificially. A total of 13 treatments were applied. The following variables were assessed: the number of aphids per leaf, the biological effectiveness of the treatments, plant height, diameter of the plant stem, number of leaves, and the weight of fresh and dry plants. An analysis of variance was conducted for each variable under study, as along with a comparison of means using the Tukey method (α=0.05) and correlation analysis using the SAS® 9.4 software. The chemical, biological and organic insecticide that exhibited the greatest control of the yellow aphid (more than 95%) were: Toretto® (sulfoxaflor), PHC® Meta Tron® (M. anisopliae), Bio-Die® (Argemonin, Berberine, Ricinin and a-Terthienyl). Adequate management strategies are needed to avoid health problems in people, environmental contamination and resistance or multiple resistance.

Effect of Drought Stress on Morpho Phenological and Yield Parameters in Sorghum Genotypes

Drought stress is a major challenge for sorghum production, particularly during the reproductive stage. This study investigated the effects of drought stress on sorghum genotypes, focusing on their morpho-phenological characteristics and yield parameters. A field experiment was conducted over two rabi seasons (2021-22 and 2022-23) at the University of Agricultural Science, Dharwad, India. Twenty sorghum genotypes were evaluated under both irrigated and rainfed conditions using a split-plot design with two replications. Water stress reduced sorghum plant height, with a mean height of 190.41 cm under irrigated conditions and 176.50 cm under rainfed conditions at 90 days after sowing. Water stress advanced the physiological maturity by 10 days compared to irrigated condition. Yield parameters revealed significant differences, the mean grain yield was 70.23 g/plant for irrigated conditions and 54.54 g/plant for rainfed conditions. Water stress also had an impact on harvest index, with irrigated conditions having a mean harvest index of 30.91% and rainfed conditions having a mean harvest index of 28.13%. Genotypes by overall performance Phule Anuradha, BJV 44, and M-35-1 tolerated water stress, by minimizing yield reduction by drought.

Effect of Productive Tillers on Seed Yield and Seed Quality of Sorghum (<i>Sorghum bicolor L</i>.) Varieties in Assosa District, Western Ethiopia

Poor management of sorghum tillers is a significant problem in the Benishangul-Gumuz region of Ethiopia, affecting seed yield and quality. An experiment was conducted to determine the impact of sorghum productive tillers on seed yield and quality. The study involved two Sorghum varieties (Assosa-1 and Adukara) and three plant types per spot. The treatments were aligned as RCBD and CRD in factorial combination, replicated three and four times for field and laboratory experiments respectively. Varieties influenced TSW (P < 0.0001), Number of tiller influenced by number plants head matured for seed production (P ≤ 0.0001), plants height (P ≤ 0.0004), The interaction effects of varieties and number of tillers per plant influenced yields, Panicle length (P < 0.0001). For laboratory experiments varieties influenced Speed of germination (P < 0.0001), number of Dead seeds (P < 0.0001). Number of tiller influenced Speed of germination (P < 0.0001), number of Dead seeds, shoot length (P < 0.004), Vigor index one and Vigor index two (P≤0.05). The interaction effects of varieties and number of tillers per plant influenced Standard germination (P < 0.001). The main shoot plants had the highest number of fertile sorghum heads (86.5), followed by primary tillers (27.08). Secondary tillers had the highest plant height (96.52 cm). The main shoot plant yielded more seeds than primary and secondary tillers, with the shoot exceeding these yields by 302.96% and 1333%, respectively. Primary and secondary tillers had higher percentages of dead seeds than the main shoot plant, 53.5% and 45.2%, respectively. The primary and secondary tillers experienced a decline in seedling vigour index one over different periods, while the main sorghum plant varieties, Adukara and Assosa-1, showed an upward trend. The germination percentages of the primary and secondary tillers were less than the 85% Ethiopian seed standard requirement. Because sorghum tillers lower seed quality, they should be eliminated for seed production. If sorghum is grown for grain production, secondary tillers have the benefit of raising overall yield production.

Cadmium Phytoremediation Effect of Sweet Sorghum Assisted with Citric Acid on Typical Parent Soil in Southern China

Sweet sorghum has a large biomass and strong cadmium (Cd) absorption capacity, which has the potential for phytoremediation of Cd-contaminated soil. In order to study the Cd phytoremediation effect of sweet sorghum assisted with citric acid on the typical parent materials in southern China, a field experiment was carried out in two typical parent material farmland areas (neutral purple mud field and jute sand mud field) with Cd pollution in Hunan Province. The results showed that:① Citric acid had no inhibitory effect on the growth of sweet sorghum. After the application of citric acid, the aboveground biomass of sweet sorghum at the maturity stage increased by 10.1%-24.7%. ② Both sweet sorghum planting and citric acid application reduced the soil pH value, and the application of citric acid further reduced the soil pH value at each growth stage of sweet sorghum; this decrease was greater in the neutral purple mud field, which decreased by 0.24-0.72 units. ③ Both sweet sorghum planting and citric acid application reduced the total amount of soil Cd, and the decreases in the neutral purple mud field and jute sand mud field were 23.8%-52.2% and 17.1%-31.8%, respectively. The acid-extractable percentage of soil Cd in both places increased by 38.6%-147.7% and 4.8%-22.7%, respectively. ④ The application of citric acid could significantly increase the Cd content in various tissues of sweet sorghum. The Cd content in the aboveground part of the plant in the neutral purple mud field was higher than that in the jute sand mud field, and the Cd content in stems and leaves was 0.25-1.90 mg·kg-1 and 0.21-0.64 mg·kg-1, respectively. ⑤ After applying citric acid, the Cd extraction amount of sweet sorghum in neutral purple mud soil in the mature stage reached 47.56 g·hm-2. In summary, citric acid could enhance the efficiency of sweet sorghum in the phytoremediation of Cd-contaminated soil, and the effect was better in neutral purple mud fields. This technology has the potential for remediation coupled with agro-production for heavy metal-contaminated farmland.

Post-synthetic modification of nano-chitosan using gibberellic acid: Foliar application on sorghum under salt stress conditions and estimation of biochemical parameters

The challenge of desert farming with a high salt level has become an ecological task due to salt stress negatively affecting plant growth and reproduction. The current study deals with the cultivation of sorghum under salt stress conditions to counteract the effect of chitosan and gibberellic acid (GA3). Here, the effects of chitosan, GA3 and nano-composite (GA3@chitosan) on biochemical contents, growth and seed yield of sorghum under salinity stress conditions were studied. The results showed that spraying with GA3@chitosan increased sorghum grain yield by 2.07, 1.81 and 1.64 fold higher than salinity stressed plants, chitosan treatment and GA3 treatment, respectively. Additionally, compared to the control of the same variety, the GA3@chitosan spraying treatment improved the concentration of microelements in the grains of the Shandweel-1 and Dorado by 24.51% and 18.39%, respectively for each variety. Furthermore, spraying GA3@chitosan on sorghum varieties increased the accumulation of the macroelements N, P, and K by 34.03%, 47.61%, and 8.67% higher than salt-stressed plants, respectively. On the other hand, the proline and glycinebetaine content in sorghum leaves sprayed with nano-composite were drop by 51.04% and 11.98% less than stressed plants, respectively. The results showed that, in Ras Sudr, the Shandweel-1 variety produced more grain per feddan than the Dorado variety. These findings suggest that GA3@chitosan improves the chemical and biochemical components leading to a decrease in the negative effect of salt stress on the plant which reflects in the high-yield production of cultivated sorghum plants in salt conditions.

Presence of the neurotoxin β-N-methylamino-L-alanine in irrigation water and accumulation in cereal grains with human exposure risk.

The present study demonstrates the presence of the neurotoxin β-N-methylamino-L-alanine and its cyanobacterial producers in irrigation water and grains of some cereal plants from farmlands irrigated with Nile River water in Egypt. BMAA detected by LC-MS/MS in phytoplankton samples was found at higher concentrations of free form (0.84-11.4μg L-1) than of protein-bound form (0.16-1.6μg L-1), in association with the dominance of cyanobacteria in irrigation water canals. Dominant cyanobacterial species isolated from these irrigation waters including Aphanocapsa planctonica, Chroococcus minutus, Dolichospermum lemmermanni, Nostoc commune, and Oscillatoria tenuis were found to produce different concentrations of free (4.8-71.1µgg-1 dry weight) and protein-bound (0.1-11.4µgg-1 dry weight) BMAA. In the meantime, BMAA was also detected in a protein-bound form only in grains of corn (3.87-4.51µgg-1 fresh weight) and sorghum (5.1-7.1µgg-1 fresh weight) plants, but not in wheat grains. The amounts of BMAA accumulated in these grains correlated with BMAA concentrations detected in relevant irrigation water canals. The presence of BMAA in cereal grains would constitute a risk to human and animal health upon consumption of contaminated grains. The study, therefore, suggests continuous monitoring of BMAA and other cyanotoxins in irrigation waters and edible plants to protect the public against exposure to such potent toxins.

Influence of cover crop residue and residual herbicide on emergence dynamics of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in grain sorghum

Abstract A field study was conducted from 2020 to 2023 at Kansas State University Agricultural Research Center near Hays, KS, to understand the emergence dynamics and periodicity of glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Watson) as influenced by cover crop (CC) residue and residual herbicide in grain sorghum [Sorghum bicolor (L.) Moench]. The study site was under a wheat (Triticum aestivum L.)–sorghum–fallow rotation with a natural seedbank of GR A. palmeri. Treatments included (1) fall-planted CC mixture [winter triticale (×Triticosecale Wittm. ex A. Camus [Secale × Triticum])/winter peas (Pisum sativum L.)/rapeseed (Brassica napus L.)/radish (Raphanus sativus L.)] after wheat harvest and terminated at triticale heading stage (next spring before sorghum planting) with glyphosate alone or (2) glyphosate plus acetochlor/atrazine, (3) chemical fallow (no CC but treated with acetochlor/atrazine and dicamba before sorghum planting), and (4) nontreated control (no CC and no herbicide). Results indicated that CC terminated with glyphosate plus acetochlor/atrazine had a delayed and reduced cumulative emergence of GR A. palmeri as compared with chemical fallow and CC terminated with glyphosate alone across all 3 yr. Compared with chemical fallow, the CC terminated with glyphosate alone and glyphosate plus acetochlor/atrazine required 66 to 643 and 105 to 1,257 more cumulative growing degree days, respectively, to achieve 90% cumulative emergence of GR A. palmeri across all 3 yr. The combined effect of CC residue with glyphosate plus acetochlor/atrazine reduced the total emergence counts of GR A. palmeri by 42% to 56% and 82% to 94% as compared with chemical fallow and nontreated control, respectively. These results suggest that fall-planted CC combined with a residual herbicide at termination can be utilized for GR A. palmeri suppression in grain sorghum.

Early-Generation Evaluation of Marker-Assisted Transfer of bmr6 and bmr12 Alleles into Sweet and High-biomass Sorghum

The effects of transferring brown midrib (bmr) alleles in sweet and high biomass sorghums (SS/HBM) are not fully understood, and available works produced mixed results depending upon the genetic background of the recurrent parent used. Early-generation testing of the effects of the two mutations in the background of the recurrent parents can help predict the final products and make appropriate early go/no-go breeding decisions, yet, this information is missing. The present study was therefore carried out to reduce these gaps. Marker-assisted transfer of the bmr6 and bmr12 was performed using four (SSV84, ICSB474, ICSV18003, ICSV100324) SS and one (ICSV15024) HBM wild type (WT) lines as recurrent parents, and one bmr6 (N609) and two bmr12 (ICSV101039 and N600) lines as donor parents. Crossing and backcrossing techniques were used to transfer the bmr alleles to develop BC2F2 and F3 populations. Kompetitive allele-specific PCR (KASP) marker genotyping assays were performed and implemented for the indirect selection of the bmr transfer in F1 and BC_F1 populations. While the bmr6 markers were polymorphic, the bmr12 markers were monomorphic. The successful bmr6 transfer was therefore confirmed by markers in F1 and BC_F1, while for bmr12 the transfer was confirmed after segregation assessment in F2 and BC_F2 populations. The transfer of bmr12 improved the cellulose content relative to WT genotypes, and bmr12 populations were shorter-statured relative to bmr6 individuals, meaning that bmr12 gene can be considered in sorghum breeding to boost 2G bioethanol bioconversion and to control lodging, and hence favouring mechanical harvesting and limiting yield losses. The observed earliness in the bmr lines is an attractive trait conferring adaptation in the drylands, particularly in the world’s semi-arid tropics characterized by terminal drought stress. Both bmr alleles did not show any negative trade-offs relative to the must-have sorghum plant characteristics, implying that they can safely be deployed in sorghum breeding for bioenergy production purposes. The observed superior bmr lines with farmer-preferred phenotypic acceptance are candidates not only for advancement in breeding pipelines but also for subsequent pyramiding bmr6 and bmr12 in the same genetic background, further improving the bmr-conferred benefits. The successfully used molecular markers will be uploaded in the public domain and can help breed sorghum products other than SS/HBM such as high-quality forage sorghums.

Genome-wide association study of plant color in Sorghum bicolor.

Sorghum plant color is the leaf sheath/leaf color and is associated with seed color, tannin and phenol content, head blight disease incidence, and phytoalexin production. In this study, we evaluated plant color of the sorghum mini core collection by scoring leaf sheath/leaf color at maturity as tan, red, or purple across three testing environments and performed genome-wide association mapping (GWAS) with 6,094,317 SNPs markers. Eight loci, one each on chromosomes 1, 2, 4, and 6 and two on chromosomes 5 and 9, were mapped. All loci contained one to three candidate genes. In qPC5-1, Sobic.005G165632 and Sobic.005G165700 were located in the same linkage disequilibrium (LD) block. In qPC6, Sobic.006G149650 and Sobic.006G149700 were located in the different LD block. The single peak in qPC6 covered one gene, Sobic.006G149700, which was a senescence regulator. We found a loose correlation between the degree of linkage and tissue/organ expression of the underlying genes possibly related to the plant color phenotype. Allele analysis indicated that none of the linked SNPs can differentiate between red and purple accessions whereas all linked SNPs can differentiate tan from red/purple accessions. The candidate genes and SNP markers may facilitate the elucidation of plant color development as well as molecular plant breeding.

Mass Production of Arbuscular Mycorrhizal Fungi on the Sorghum Plants Inoculated with Burkholderia arboris Using Soybean Mill Waste and Vermicompost-Amended Soil-Sand Substrate.

Arbuscular mycorrhizal (AM) fungi are being used as a new generation of biofertilizers to increase plant growth by improving plant nutrition and bio-protection. However, because of the obligatory nature of the plant host, large-scale multiplication of AM propagules is challenging, which limits its applicability. This study evaluates the ability of Burkholderia arboris to increase AM production in soybean mill waste and vermicompost amended by soil-sand mixture planted with sorghum as a host plant. The experiment was conducted in a nursery using a completely randomized design with four inoculation treatments (B. arboris, AM fungi, B. arboris + AM fungi, and control) under sterilized and unsterilized conditions. AM production was investigated microscopically (spore density and root colonization), and biochemically (AM-specific lipid biomarker, 16:1ω5cis derived from neutral lipid fatty acid (NLFA), and phospholipid fatty acid (PLFA) fractions from both soil and roots). Integrating B. arboris with AM fungi in organically amended pots was found to increase AM fungal production by 62.16 spores g-1 soil and root colonization by 80.85%. Biochemical parameters also increased with B. arboris inoculation: 5.49nmol PLFA g-1 soil and 692.68nmol PLFA g-1 root and 36.72nmol NLFA g-1 soil and 3147.57nmol NLFA g-1 root. Co-inoculation also increased glomalin-related soil protein and root biomass. Principal component analysis (PCA) further supported the higher contribution of B. arboris to AM fungi production under unsterilized conditions. In conclusion, inoculation of AM plant host seeds with B. arboris prior to sowing into organic potting mix could be a promising and cost-effective approach for increasing AM inoculum density for commercial production. Furthermore, efforts need to be made for up-scaling the AM production with different plant hosts and soil-substrate types.

Combining silicon, organic matter, and Trichoderma harzianum to mitigate salt stress in forage sorghum

Salt stress is a major abiotic factor limiting plant growth worldwide, particularly in arid and semiarid regions where excessive groundwater use in irrigation leads to high salt concentrations. To address this issue, this study investigated the efficacy of silicon, either alone or in combination with Trichoderma harzianum and organic matter, in mitigating salt stress in forage sorghum. The experiment took place in a saline Fluvisol in Parnamirim, a semiarid region of Pernambuco, Brazil, and followed a randomized block design with five treatments and four replicates: sorghum (control); sorghum + Si; sorghum + Si + OM (organic matter); sorghum + Si + T (T. harzianum); and sorghum + Si + T + OM. Sorghum plants were assessed over three cycles (initial cut and two regrowths) from June 2021 to April 2022. The combined treatments of Si + OM, Si + T, and Si + T + OM increased plant growth by 42.17, 35.49, and 27.51%, respectively, compared to the control. Similarly, these treatments led to biomass accumulation gains of 39.42, 40.44, and 31.77% in sorghum plants relative to the control. Silicon alone did not yield significant growth or biomass accumulation improvements. The application of silicon in conjunction with T. harzianum and/or organic matter shows promise in enhancing forage sorghum growth under saline stress conditions in semiarid regions.

Condicionamento de sementes com peróxido de hidrogênio atenua os danos causados pelo estresse salino em sorgo

ABSTRACT Salinity affects physiological processes, such as photosynthesis, in various agricultural crops, such as sorghum, around the world. Thus, mitigating techniques such as priming seeds with hydrogen peroxide (H2O2) can increase plant tolerance to salt stress. Thus, the objective of present study was to evaluate the priming of seeds with hydrogen peroxide on gas exchange and shoot phytomass of sorghum grown under salt stress. The treatments were distributed in a randomized block design, in a 4 × 4 factorial arrangement, with four levels of electrical conductivity of irrigation water - (ECw- 0.3, 1.5, 3.5, and 5.5 dS m-1) and four concentrations of H2O2 (0, 6, 12, and 18 μM L-1), with three replications. The salinity of the water reduced gas exchange, shoot fresh and dry mass, in addition to shoot moisture content in sorghum plants. However, priming the seeds with H2O2 improved gas exchange and the accumulation of plant dry mass. Seed priming with H2O2 at dose of 8.2 µM increases the acclimatization of sorghum plants under salt stress.

Effects of mycorrhizal symbiosis and Ulva lactuca seaweed extract on growth, carbon/nitrogen metabolism, and antioxidant response in cadmium-stressed sorghum plant.

In our study on the effect of cadmium (Cd) toxicity (200µM) on the growth of Sorghum bicolor (L.) Moench plants, cultivated with arbuscular mycorrhizal fungi (AMF) (Glomus intraradices) and/or under seaweed treatment (3% Ulva lactuca extract) (U. lactuca), we found that AMF increased the tolerance of sorghum to cadmium stress, either alone or in combination with the seaweed treatment. Morphological parameters were higher in these two culture conditions, with increased chlorophyll content. AMF reduced Cd accumulation in roots and inhibited its translocation to the aerial part, while seaweed treatment alone significantly increased Cd accumulation in leaves and roots without affecting plant growth compared to stressed witnesses. Treatment with AMF and/or U. lactuca attenuated oxidative stress, measured by activation of superoxide dismutase, and resulted in a significant decrease in malondialdehyde and superoxide ions (O2-) in treated plants. Furthermore, it induced significant alterations in carbon and nitrogen metabolic pathways, with a significant increase in the activity of enzymes such as glutamine synthetase, glutamate synthase (GOGAT), glutamate dehydrogenase, phosphoenolpyruvate carboxylase, aspartate aminotransferase and isocitrate dehydrogenase in the leaves of each treated plant. These results confirm that AMF, U. lactuca algae extract and their combination can improve the biochemical parameters of sorghum under Cd stress, through modification of the antioxidant response on one hand, and improved nitrogen absorption and assimilation efficiency on the other.

A nanomaterial for the delivery of dsRNA as a strategy to alleviate viral infections in maize

The current methods for pest managements in cereal crops rely mainly on the applications of conventional chemicals, which are known to have low pest control efficiencies and are less environmentally friendly. The primary aim of this research endeavor was to devise a specific, efficient and eco-friendly biological agent capable of mitigating maize lethal necrosis (MLN), a viral disease that affected maize productivity and mainly caused by coinfection of maize chlorotic mottle virus (MCMV) and sugarcane mosaic virus (SCMV). Through this study, we have found that silencing Ferredoxin 3 (ZmFd3) expression in maize can significantly reduce the damages caused by MCMV and/or SCMV infections. Based on this finding, we have developed a liposome nanoparticles (LNPs)-mediated nanotechnology to suppress MCMV and/or SCMV infections. Using this nanotechnology, we have confirmed that the cationic/anionic liposomes (CLPs and ALPs) can be used to package and promote ZmFd3-dsRNA spread in maize plants. Through leaf spray, we have determined that the anti-MCMV and anti-SCMV activities of ZmFd3@CLPs and ZmFd3@ALPs nanoparticles can reach 52.46 ∼ 79.83 % at 6 days post virus inoculation (dpi). Because ZmFd3 is involved in hypersensitive response (HR), and can interact with MCMV p7b and SCMV HC-Pro, we designed an FHP-dsRNA to target ZmFd3, MCMV p7b, and SCMV HC-Pro transcripts for silencing in plants simultaneously. The result showed that both FHP@CLPs and FHP@ALPs nanoparticles can provide excellent, although short, protection to maize and sorghum plants to MCMV and SCMV infections. Overall, this study has developed a novel nanotechnology that can be used to mitigate virus infection in cereal crops through RNA interference (RNAi).

Using soil amendments and mycorrhiza to improve chemical properties of degraded calcareous soil and yield of sorghum in dryland

Optimized use of calcareous soil in dryland areas needs to begin with rehabilitation efforts using soil amendments, including organic fertilizer and biochar. This study sought to determine whether kinds of soil amendments and mycorrhizal biofertilizers may enhance the chemical quality of calcareous soils and increase the yield of sorghum on dry land. The study was conducted at the experimental garden of the Agricultural Extension Center located in Oelnasi Village from April to August of 2023. Two criteria included in the study were the kind of soil amendment and mycorrhizal biological fertilizer, both of which were arranged in a randomized block design. The parameters observed were soil chemical properties, plant N and P nutrient uptake, and sorghum yield. The research results showed that the application of three types of soil amendments (P1 = cow dung, P2 = rice straw compost, and P3 = corncob biochar) improved the chemical quality of calcareous soil. This application of corncob biochar could significantly reduce soil pH from 7.85 (slightly alkaline) to 7.19 (neutral) and increase soil organic C to 2.55% C, followed by treatment with cow dung and rice straw compost. Other soil chemical properties, i.e., N, P, K, and soil CEC, also improved, which differed from the control treatment. The mycorrhizal biofertilizer provided could also improve the chemical properties of calcareous soil. Providing mycorrhizal biofertilizer could increase the N and P nutrient uptake of sorghum plants by 3.79% dry weight-1 and 2.18% dry weight-1, respectively, as well as increased sorghum yields, respectively by 4.04 t ha-1, 3.97 t ha-1 and 3.87 t ha-1 dry beans, higher than the control which only achieved 2.32 t ha-1 dry beans.

Clay and organic compost as quality conditioners of a sandy soil in the brazilian semiarid

Due to natural and anthropic pressures of semiarid regions, like sandy texture, organic matter (OM) deficiency, water scarcity and inadequate management, we carried out an experiment under greenhouse conditions, to evaluate the effects of clay and OM addition on the quality of a sandy soil of the Brazilian semiarid. The experiment lasted 75 days, testing four clay contents (10 and 31% natural soils, 15% by clay addition to a sandy soil and 26% by mixing clay subsoil to a sandy topsoil) in the absence and presence of organic compost (7.5g.kg-1). For biological parameters, sorghum plants were used for biometric and mineral composition analysis, in addition to assessing microbial activity (BSR, MBC, and qCO2). The results showed significant differences in soil microporosity and total porosity; the field capacity and permanent wilting point correlated linearly with clay content and OM addition; potencial and exchangeable soil acidity decreased significantly in the presence of compost. Sorghum plants showed higher values of biometric attributes and lower levels of nutrients in the presence of compost. The microbial activity did not show significant differences in terms of clay content or compost addition. The cluster analysis correlated the mixed soils (26%) to the lowest clay content soil (10%), and the clay addition (15%) to the highest clay content soil (31%), showing potential as soil conditioner in association with compost, as it might promote changes in the soil quality properties of semiarid regions.

Pantoea ananatis, a plant growth stimulating bacterium, and its metabolites isolated from Hydrocotyle umbellata (dollarweed)

ABSTRACT A bacterium growing on infected leaves of Hydrocotyle umbellata, commonly known as dollarweed, was isolated and identified as Pantoea ananatis. An ethyl acetate extract of tryptic soy broth (TSB) liquid culture filtrate of the bacterium was subjected to silica gel chromatography to isolate bioactive molecules. Indole was isolated as the major compound that gave a distinct, foul odor to the extract, together with phenethyl alcohol, phenol, tryptophol, N-acyl-homoserine lactone, 3-(methylthio)-1-propanol, cyclo(L-pro-L-tyr), and cyclo(dehydroAla-L-Leu). This is the first report of the isolation of cyclo(dehydroAla-L-Leu) from a Pantoea species. Even though tryptophol is an intermediate in the indoleacetic acid (IAA) pathway, we were unable to detect or isolate IAA. We investigated the effect of P. ananatis inoculum on the growth of plants. Treatment of Lemna paucicostata Hegelm plants with 4 × 109 colony forming units of P. ananatis stimulated their growth by ca. five-fold after 13 days. After 13 days of treatment, some control plants were browning, but treated plants were greener and no plants were browning. The growth of both Cucumis sativus (cucumber) and Sorghum bicolor (sorghum) plants was increased by ca. 20 to 40%, depending on the growth parameter and species, when the rhizosphere was treated with the bacterium after germination at the same concentration. Plant growth promotion by Pantoea ananatis could be due to the provision of the IAA precursor indole.

Synergistic advantages of volcanic ash weathering in saline soils: CO2 sequestration and enhancement of plant growth

Carbon dioxide (CO2) is a primary greenhouse gas that has experienced a surge in atmospheric concentration due to human activities and lifestyles. It is imperative to curtail atmospheric CO2 levels promptly to alleviate the multifaceted impacts of climate warming. The soil serves as a natural reservoir for CO2 sequestration. The scientific premise of this study is that CO2 sequestration in agriculturally relevant, organically-deficient saline soil can be achieved by incorporating alkaline earth silicates. Volcanic ash (VA) was used as a soil amendment for CO2 removal from saline soil by leveraging enhanced silicate rock weathering (ERW). The study pursued two primary objectives: first, we aimed to evaluate the impact of various doses of VA, employed as an amendment for organically-deficient soil, on the growth performance of key cultivated crops (sorghum and mung bean) in inland saline-alkaline agricultural regions of northeastern China. Second, we aimed to assess alterations in the physical properties of the amended soil through mineralogical examinations, utilizing X-ray diffraction (XRD) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) analyses, quantifying the increase in inorganic carbon content within the soil. In the potting tests, mung bean plant height exhibited a noteworthy increase of approximately 41 % with the addition of 10 % VA. Sorghum plant height and aboveground and belowground biomass dry weights increased with VA application across all tested doses. At the optimal VA application rate (20 %), the sorghum achieved a CO2 sequestration rate of 0.14 kg CO2·m−2·month−1. XRD and SEM-EDS analyses confirmed that the augmented inorganic carbon in the VA-amended soils stemmed primarily from calcite accumulation. These findings contribute to elucidating the mechanism underlying VA as an amendment for organically-deficient soils and provide an effective approach for enhancing the carbon sink capacity of saline soils.

Nickel sources affect soil biological properties but do not affect sorghum growth

Nickel (Ni) is an essential element, but it can be phytotoxic in high concentration, which may be caused by high availability in soil solution. The objective of this study was to evaluate the effect of sources and doses of Ni applied to a dystrophic Red Latosol cultivated with sorghum on i) the availability of the metal in the soil; ii) the impact on biological and biochemical properties of the soil; iii) the absorption and distribution in sorghum plants; and iv) crop productivity. The experiment was carried out within a completely randomized design with two nickel sources [nickel(II) nitrate, Ni(NO3)2 and nickel(III) oxide, Ni2O3], three doses (35, 70, and 140 mg Ni kg−1 soil), plus controls without Ni, with 3 replications. The concentrations of Ni in the soil, soil microbial biomass (SMB), basal soil respiration (BSR), metabolic quotient (qCO2), fluorescein diacetate (FDA) hydrolysis, and urease activity were determined. The concentrations of Ni in the leaf diagnostic and in the plant (shoot, root, and grains) were also measured. In the soil, the concentrations of available Ni remained between 0.21 and 54.01 mg Ni kg−1. Ni2O3 contributed very little to the increase in available Ni. SMB and the FDA hydrolysis were not affected by the Ni source or Ni dose, but BSR and qCO2 had significant increase with Ni application rates, suggesting the soil microorganisms faced stress. Soil urease activity was affected by Ni dose but not by Ni source. The dose of Ni as Ni(NO3)2 decreased the metal concentration in the plant, while that of Ni2O3 increased it. Nickel source did not affect dry mass production of the plants, but grain yield was affected in a dose-dependent manner when Ni2O3 was the source of Ni.

Onset of Rainfall and Cumulative Analysis for Sorghum Cultivation in Baringo County

Sorghum is an essential food security crop in the majority of the ASALs regions, such as Baringo County. This study investigated the critical relationship between rainfall levels and the initiation of sorghum planting, with the aim of identifying the threshold at which rainfall is considered sufficient for germination and optimal growth. This study used historical meteorological data from 1990 to 2022, field experiments, statistical analysis, and sorghum growth patterns to discern the trigger points for planting, which are essential for ensuring successful cultivation. This study uncovered alterations in rainfall onset and seasonal rainfall accumulation. The planting window in Baringo County varied significantly, with some dates falling above and below the average onset values of April 4<sup>th</sup> for the long rainfall season and September 24<sup>th</sup> for the short rainfall season. A short rainy season is not ideal for sorghum planting, as it typically receives less than 300 mm of rainfall, which is insufficient for sorghum production. The optimal planting time for sorghum is usually late March and early April. The study found that 36.4% of the long rainy season years had high production, 42.4% had normal production, and only 21% had low or no productivity. The years 2000 and 2018 experienced minimum and maximum rainfall amounts of 198.45 mm and 941.9 mm, respectively.