Growth Of Sugarcane Plants Research Articles

Bacillus velezensis YC89-mediated recruitment of rhizosphere bacteria improves resistance against sugarcane red rot

BackgroundSugarcane red rot is a soil-borne disease caused by Colletotrichum falcatum. It can reduce the yield of sugarcane and the purity of sugarcane juice, which seriously restricts the development of sucrose industry. Biocontrol bacteria can control diseases by regulating rhizosphere microecology. In this study, the effects of biocontrol bacteria on sugarcane rhizosphere microecology were studied by metagenomics and metabolomics, and the control effects of biocontrol bacteria and rhizosphere dominant bacteria on sugarcane red rot were further explored by pot experiment.ResultsThe results of metagenomic sequencing showed that inoculation with B. velezensis YC89 and pathogens could significantly change the microbial diversity of the sugarcane rhizosphere. The relative abundance of beneficial strains such as Streptomyces, Burkholderia, Sphingomonas, and Rhizobium increased significantly in the rhizosphere of sugarcane in the YC treatment group. Pseudomonas was significantly enriched in the rhizosphere of sugarcane in the C treatment group. The results of metabolome sequencing showed that the content of amino acids in sugarcane root exudates increased after inoculation with B. velezensis YC89, and the contents of phenolic acids and flavonoids decreased. Spearman correlation analysis showed that there was a significant correlation between differential metabolites and rhizosphere microorganisms. The results of pot experiment showed that YC89 strain and three rhizosphere microorganisms could significantly reduce the disease index of red rot and promote the growth of sugarcane plants. In addition, these strains can also significantly increase the JA and SA content of sugarcane leaves and induce plant system resistance-related enzyme activities. Among them, the synthetic community treatment group had the best biocontrol effect on red rot, and its relative control effect was 67.50%.ConclusionsTherefore, we conclude that B. velezensis YC89 could recruit beneficial rhizosphere microorganisms to enrich the rhizosphere and change the content of some phenolic acids and flavonoids in the root exudates. In addition, the isolated rhizosphere dominant bacteria and YC89 strain can resist red rot by inducing plant systemic resistance and promote the growth of sugarcane plants. This study provides a theoretical basis for the use of biocontrol bacteria to regulate rhizosphere bacteria to jointly control plant soil-borne diseases.Graphical

Factors affecting the production of sugarcane yield and sucrose accumulation: suggested potential biological solutions.

Environmental stresses are the main constraints on agricultural productivity and food security worldwide. This issue is worsened by abrupt and severe changes in global climate. The formation of sugarcane yield and the accumulation of sucrose are significantly influenced by biotic and abiotic stresses. Understanding the biochemical, physiological, and environmental phenomena associated with these stresses is essential to increase crop production. This review explores the effect of environmental factors on sucrose content and sugarcane yield and highlights the negative effects of insufficient water supply, temperature fluctuations, insect pests, and diseases. This article also explains the mechanism of reactive oxygen species (ROS), the role of different metabolites under environmental stresses, and highlights the function of environmental stress-related resistance genes in sugarcane. This review further discusses sugarcane crop improvement approaches, with a focus on endophytic mechanism and consortium endophyte application in sugarcane plants. Endophytes are vital in plant defense; they produce bioactive molecules that act as biocontrol agents to enhance plant immune systems and modify environmental responses through interaction with plants. This review provides an overview of internal mechanisms to enhance sugarcane plant growth and environmental resistance and offers new ideas for improving sugarcane plant fitness and crop productivity.

Respon Pertumbuhan Bibit Tebu (Saccharum Officinarum L.) Pada Aplikasi Biostimulan Dari Ekstrak Bawang Merah

Sugarcane (Saccharum officinarum L.) is a plantation commodity that has an important role in the economy in Indonesia. The demand for sugar increases with the increase in population. Therefore efforts to increase sugar production by increasing the productivity of sugarcane, one of which is through the use of high quality seeds. Sugarcane Bud Chip seeds have the potential to produce sugarcane with high yields, but efforts to stimulate seedling growth really need to be increased. The use of natural Growth Regulatory Substances (PGR) from shallot extract needs to be tested on sugarcane seedlings because shallots contain the hormone auxin and vitamin B1 which are very necessary to increase the growth of sugarcane seedlings. Therefore this study aims to determine the effect of shallot extract concentration on the initial growth of sugarcane plants using the bud chip method and determine the best concentration. This study was conducted for 2.5 months and was designed using a non-factorial randomized block design with 5 concentrations of shallot extract including B0 (control/no extract); B1 (20%); B2 (40%); B3 (60%); B4 (80%). The parameters include the number of tillers, plant height, number of leaves, and root length. The results of this study indicated that the shallot extract gave a significantly different response to the growth of sugar cane seedlings, as seen in the parameters of the number of tillers, the number of leaves and root length. From the data obtained, shallot extract at a concentration of 40% was the best concentration for all parameters.

Evaluasi Pertumbuhan Klon Tanaman Tebu (Saccharum officinarum L.) Ratoon I Di Desa Watesari, Kecamatan Balongbendo, Kabupaten Sidoarjo

In the last five years, sugar cane production in Indonesia has fallen by 4%. Sugar self-sufficiency can be achieved through plant breeding programs to create high-yielding sugarcane varieties. The research objective was to determine the correlation between growth variables, genetic diversity, and sugarcane (Saccharum officinarum L.) growth in test clones. The research was conducted at the Watesari Village, Balongbendo District, Sidoarjo Regency in November 2022 - August 2023. The test materials were clones SB01 UMG NX 22, SB03 UMG NX 22, SB04 UMG NX 22, SB11 UMG NX 22, SB12 UMG NX 22, SB19 UMG NX 22, and SB20 UMG NX 22, BL variety and PS881 variety. The variables observed included stem height, stem diameter, number of stems, number of leaves, and brix. Data analysis used ANOVA, DMRT test, correlation test, genetic diversity, and heritability. The SB12 UMG NX 22 clone had the best growth, including stem height of 293.89 cm (39 MSK); total of 8.22 units (31 MSK), 8.44 units (33 MSK), 8.44 units (35 MSK), 8.78 units (37 MSK), and 9.11 units (39 MSK). There is a correlation between growth variables. There are genetic variations that affect the growth of sugarcane plants including moderate KKG values ​​(stem diameter, number of stems, and brix). Low KKG (stem height and number of leaves). Low GFC (stem height, stem diameter, stem, number of leaves and brix). H2 height (rod height, stem diameter, number of rods, and brix). Moderate H2 (number of leaves).

Respon Pertumbuhan Bibit Dua Varietas Tanaman Tebu (Saccharum Officinarum L.) Pada Beberapa Letak Mata Tunas Asal Bud Set Di Media Pottray

Sugarcane (Saccharum Officiarum L.) is a plant with high economic value, especially in developing countries with tropical climates such as Indonesia, because of the high sugar content in the stems. Preparation of seeds and determination of specific location superior varieties is one of the determining factors for the success of sugarcane cultivation. This research was conducted to determine the effect of bud location from bud set and several varieties on the growth of sugarcane seedlings. The research was conducted from July to December 2022, at the Jember State Polytechnic nursery using a two-factor Randomized Group Design (RAKF). The results showed that good germination growth came from the location of the scion buds. The location of the buds has a significant effect on the parameters of the number of leaves and the number of tillers. Kinds of sugarcane varieties had a significant effect on plant height (cm), number of leaves, number of tillers. The VMC 76-16 variety was the best for the number of leaves and plant height parameters, while the GMP 04 variety was the best for the number of tillers. The interaction of the effect of the location of the bud buds from the bud set and the variety of varieties had a significant effect on height growth (cm) at the age of 28 and 42 days after planting. The results of this study can be concluded that the location of the bud eye and the type of variety have a significant effect on the growth of sugarcane plants and there is a significant interaction on the plant height parameter.

Genome analysis of a halophilic Virgibacillus halodenitrificans ASH15 revealed salt adaptation, plant growth promotion, and isoprenoid biosynthetic machinery.

Globally, due to widespread dispersion, intraspecific diversity, and crucial ecological components of halophilic ecosystems, halophilic bacteria is considered one of the key models for ecological, adaptative, and biotechnological applications research in saline environments. With this aim, the present study was to enlighten the plant growth-promoting features and investigate the systematic genome of a halophilic bacteria, Virgibacillus halodenitrificans ASH15, through single-molecule real-time (SMRT) sequencing technology. Results showed that strain ASH15 could survive in high salinity up to 25% (w/v) NaCl concentration and express plant growth-promoting traits such as nitrogen fixation, plant growth hormones, and hydrolytic enzymes, which sustain salt stress. The results of pot experiment revealed that strain ASH15 significantly enhanced sugarcane plant growth (root shoot length and weight) under salt stress conditions. Moreover, the sequencing analysis of the strain ASH15 genome exhibited that this strain contained a circular chromosome of 3,832,903 bp with an average G+C content of 37.54%: 3721 predicted protein-coding sequences (CDSs), 24 rRNA genes, and 62 tRNA genes. Genome analysis revealed that the genes related to the synthesis and transport of compatible solutes (glycine, betaine, ectoine, hydroxyectoine, and glutamate) confirm salt stress as well as heavy metal resistance. Furthermore, functional annotation showed that the strain ASH15 encodes genes for root colonization, biofilm formation, phytohormone IAA production, nitrogen fixation, phosphate metabolism, and siderophore production, which are beneficial for plant growth promotion. Strain ASH15 also has a gene resistance to antibiotics and pathogens. In addition, analysis also revealed that the genome strain ASH15 has insertion sequences and CRISPRs, which suggest its ability to acquire new genes through horizontal gene transfer and acquire immunity to the attack of viruses. This work provides knowledge of the mechanism through which V. halodenitrificans ASH15 tolerates salt stress. Deep genome analysis, identified MVA pathway involved in biosynthesis of isoprenoids, more precisely "Squalene." Squalene has various applications, such as an antioxidant, anti-cancer agent, anti-aging agent, hemopreventive agent, anti-bacterial agent, adjuvant for vaccines and drug carriers, and detoxifier. Our findings indicated that strain ASH15 has enormous potential in industries such as in agriculture, pharmaceuticals, cosmetics, and food.

Selenium enhances ROS scavenging systems and sugar metabolism increasing growth of sugarcane plants

Selenium (Se) beneficial effect on plants is related to an increase in nitrogen (N) assimilation and its role as an abiotic stress mitigator by reactive oxygen species (ROS) scavenging enhanced by antioxidant metabolism. This study aimed to evaluate sugarcane (Saccharum spp.) growth, photosynthetic and antioxidant responses, and sugar accumulation in response to Se supply. The experimental design was a factorial scheme 2 × 4: two sugarcane varieties (RB96 6928 and RB86 7515) and four Se application rates (0; 5; 10 and 20 μmol L−1) applied as sodium selenate in the nutrient solution. Leaf Se concentration increased under Se application in both varieties. The enzymes SOD (EC 1.15.1.1) and APX (EC 1.11.1.11) showed increase activities under Se application on variety RB96 6928. Nitrate reductase activity increased in both varieties resulting in the conversion of nitrate into higher total amino acids concentration indicating an enhanced N assimilation. This led to an increased concentration of chlorophylls and carotenoids, increased CO2 assimilation rate, stomatal conductance, and internal CO2 concentration. Selenium provided higher starch accumulation and sugar profiles in leaves boosting plant growth. This study shows valuable information regarding the role of Se on growth, photosynthetic process, and sugar accumulation in sugarcane leaves, which could be used for further field experiments. The application rate of 10 μmol Se L−1 was the most adequate for both varieties studied considering the sugar concentration and plant growth.

Complete genome sequence of biocontrol strain Bacillus velezensis YC89 and its biocontrol potential against sugarcane red rot.

Sugarcane is one of the most important sugar crops worldwide, however, sugarcane production is seriously limited by sugarcane red rot, a soil-borne disease caused by Colletotrichum falcatum. Bacillus velezensis YC89 was isolated from sugarcane leaves and can significantly inhibited red rot disease caused by C. falcatum. In this study, the genome of YC89 strain was sequenced, its genome structure and function were analyzed using various bioinformatics software, and its genome was compared with those of other homologous strains. In addition, the effectiveness of YC89 against sugarcane red rot and the evaluation of sugarcane plant growth promotion were also investigated by pot experiments. Here, we present the complete genome sequence of YC89, which consists of a 3.95 Mb circular chromosome with an average GC content of 46.62%. The phylogenetic tree indicated that YC89 is closely related to B. velezensis GS-1. Comparative genome analysis of YC89 with other published strains (B. velezensis FZB42, B. velezensis CC09, B. velezensis SQR9, B. velezensis GS-1, and B. amyloliquefaciens DSM7) revealed that the strains had a part common coding sequences (CDS) in whereas 42 coding were unique of strain YC89. Whole-genome sequencing revealed 547 carbohydrate-active enzymes and identified 12 gene clusters encoding secondary metabolites. Additionally, functional analysis of the genome revealed numerous gene/gene clusters involved in plant growth promotion, antibiotic resistance, and resistance inducer synthesis. In vitro pot tests indicated that YC89 strain controlled sugarcane red rot and promoted the growth of sugarcane plants. Additionally, it increased the activity of enzymes involved in plant defense, such as superoxide dismutase, peroxidase, polyphenol oxidase, chitinase, and β-1,3-glucanase. These findings will be helpful for further studies on the mechanisms of plant growth promotion and biocontrol by B. velezensis and provide an effective strategy for controlling red rot in sugarcane plants.

Keragaman Morfologi Pertumbuhan 7 Klon dan 2 Varietas Tanaman Tebu (Saccharum officinarum L.) di PT Perkebunan Nusantara X Ploso Klaten-Kediri

Sugarcane (Saccharum Officinarum L.) is the basic ingredient for making sugar. In Indonesia, in the last 5 years, sugar productivity only reached 5.2 tons/ha, very different from the productivity in 1935-1940, which averaged 17 tons/ha. This is because this Aat variety has not yet reached the desired productivity rate. The purpose of this study was to determine the diversity of growth of sugarcane (Saccharum officinarum L.) in clone SB01, clone SB03, clone SB04, clone SB11, clone SB12, clone SB19, clone SB20, variety PS862 and variety Bululawang. This research was carried out in the Djengkol garden, Ploso Klaten, Kediri. The tools used are sickle, cloth, tape measure, caliper, camera and stationery. The materials used are clone SB01, clone SB03, SB11, SB12, SB19, SB20, PS862 variety, Bululawang variety. Observations included growth variables (stem height, number of stems, number of leaves, stem diameter). Data analysis used ANOVA with a 5% F test. If there is a significant difference, proceed with the 5% DMRT test, correlation test, genetic diversity, heritability, genetic progress. Clone SB12 had an advantage in variable stem height of 395.83 (cm), number of stems 5.67 (stem), number of leaves 9.44 (strands), while clone SB01 had an advantage in stem diameter with the highest value of 31.99 (mm). Correlation relationship on sugarcane plant growth variables. The diversity of 7 clones and 2 varieties is heavily influenced by genetics and slightly influenced by the environment as shown by the KKG values in the medium-high category, the KF values in the low-high category, the Heritability (H2) medium-high category and the genetic progress (KG) category. rather high.

Sugarcane plant growth promoting rhizo bacterial interaction for enhanced salinity tolerance

The present investigation was meted out on two promising sugarcane genotypes CoN-13072 and CoN-13073, were exposed to different NaCl levels to assess rhizobacterial interaction for salinity tolerance. From the shoot apex portion of two sugarcane genotypes tissue culture plantlets were developed. From that regenerated plantlets shifted to polyhouse and exposed to different NaCl levels to assess rhizobacterial interaction for salinity tolerance. Maximum shoot length (25.40 cm) was observed in genotype CoN-13073 under rhizobacterial inoculum at 2.0% NaCl concentration and maximum root length (12.40 cm) was observed at 0.0% and 1.5% NaCl concentration under rhizobacterial inoculum in genotype CoN-13072 and CoN-13073 respectively. Maximum shoot root ratio (2.60) and (2.40) was observed at 0.0% NaCl concentration with rhizobacterial inoculum within the rooting mixture of both the genotypes CoN-13073 and CoN-13072 respectively. High chlorophyll content index (5.48) and leaf area (41.20 cm2/plant) was observed in genotype CoN-13073 at 0.0% NaCl concentration under rhizobacterial inoculum. In genotypes CoN-13073 and CoN-13072, with a rise in NaCl concentration upto 2.0% and 1.5% respectively, increase in shoot length, leaf area and chlorophyll content index was observed as a result of increase in ACC deaminase activity. ACC deaminase activity and ethylene content within the plant body are negatively correlated. Increase in ACC deaminase activity results decrease in ethylene synthesis in plant body to avoid stress. Among the 2 genotypes, CoN-13073 found to be more salt tolerant at higher NaCl levels with the exhibition of low osmotic conductance, maximum leaf area with high chlorophyll content index.

Genome Characteristics Reveal the Biocontrol Potential of Actinobacteria Isolated From Sugarcane Rhizosphere.

To understand the beneficial interaction of sugarcane rhizosphere actinobacteria in promoting plant growth and managing plant diseases, this study investigated the potential role of sugarcane rhizospheric actinobacteria in promoting plant growth and antagonizing plant pathogens. We isolated 58 actinobacteria from the sugarcane rhizosphere, conducted plant growth-promoting (PGP) characteristics research, and tested the pathogenic fungi in vitro. Results showed that BTU6 (Streptomyces griseorubiginosus), the most representative strain, regulates plant defense enzyme activity and significantly enhances sugarcane smut resistance by regulating stress resistance-related enzyme (substances (POD, PAL, PPO, TP) in sugarcane) activity in sugarcane. The genomic evaluation indicated that BTU6 has the ability to biosynthesize chitinase, β-1,3-glucanase, and various secondary metabolites and plays an essential role in the growth of sugarcane plants under biotic stress. Potential mechanisms of the strain in improving the disease resistance of sugarcane plants and its potential in biodegrading exogenous chemicals were also revealed. This study showed the importance of sugarcane rhizosphere actinobacteria in microbial ecology and plant growth promotion.

Insights into the Bacterial and Nitric Oxide-Induced Salt Tolerance in Sugarcane and Their Growth-Promoting Abilities.

Soil salinity causes severe environmental stress that affects agriculture production and food security throughout the world. Salt-tolerant plant-growth-promoting rhizobacteria (PGPR) and nitric oxide (NO), a distinctive signaling molecule, can synergistically assist in the alleviation of abiotic stresses and plant growth promotion, but the mechanism by which this happens is still not well known. In the present study, in a potential salt-tolerant rhizobacteria strain, ASN-1, growth up to 15% NaCl concentration was achieved with sugarcane rhizosphere soil. Based on 16S-rRNA gene sequencing analysis, the strain ASN-1 was identified as a Bacillus xiamenensis. Strain ASN-1 exhibits multiple plant-growth-promoting attributes, such as the production of indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate deaminase, siderophores, HCN, ammonia, and exopolysaccharides as well as solubilized phosphate solubilization. Biofilm formation showed that NO enhanced the biofilm and root colonization capacity of the PGPR strain ASN-1 with host plants, evidenced by scanning electron microscopy. The greenhouse study showed that, among the different treatments, the combined application of PGPR and sodium nitroprusside (SNP) as an NO donor significantly (p ≤ 0.05) enhanced sugarcane plant growth by maintaining the relative water content, electrolyte leakage, gas exchange parameters, osmolytes, and Na+/K+ ratio. Furthermore, PGPR and SNP fertilization reduced the salinity-induced oxidative stress in plants by modulating the antioxidant enzyme activities and stress-related gene expression. Thus, it is believed that the acquisition of advanced information about the synergistic effect of salt-tolerant PGPR and NO fertilization will reduce the use of harmful chemicals and aid in eco-friendly sustainable agricultural production under salt stress conditions.

Continuous Sugarcane Planting Negatively Impacts Soil Microbial Community Structure, Soil Fertility, and Sugarcane Agronomic Parameters.

Continuous planting has a negative impact on sugarcane plant growth and reduces global sugarcane crop production, including in China. The response of soil bacteria, fungal, and arbuscular mycorrhizae (AM) fungal communities to continuous sugarcane cultivation has not been thoroughly documented. Using MiSeq sequencing technology, we analyzed soil samples from sugarcane fields with 1, 10, and 30 years of continuous cropping to see how monoculture time affected sugarcane yield, its rhizosphere soil characteristics and microbiota. The results showed that continuous sugarcane planting reduced sugarcane quality and yield. Continuous sugarcane planting for 30 years resulted in soil acidification, as well as C/N, alkali hydrolyzable nitrogen, organic matter, and total sulfur content significantly lower than in newly planted fields. Continuous sugarcane planting affected soil bacterial, fungal, and AM fungal communities, according to PCoA and ANOSIM analysis. Redundancy analysis (RDA) results showed that bacterial, fungal, and AM fungal community composition were strongly associated with soil properties and attributes, e.g., soil AN, OM, and TS were critical environmental factors in transforming the bacterial community. The LEfSe analysis revealed bacterial families (e.g., Gaiellaceae, Pseudomonadaceae, Micromonosporaceae, Nitrosomonadaceae, and Methyloligellaceae) were more prevalent in the newly planted field than in continuously cultivated fields (10 and 30 years), whereas Sphingomonadaceae, Coleofasciculaceae, and Oxyphotobacteria were depleted. Concerning fungal families, the newly planted field was more dominated than the continuously planted field (30 years) with Mrakiaceae and Ceratocystidaceae, whereas Piskurozymaceae, Trimorphomycetaceae, Lachnocladiaceae, and Stigmatodisc were significantly enriched in the continuously planted fields (10 and 30 years). Regarding AMF families, Diversisporaceae was considerably depleted in continuously planted fields (10 and 30 years) compared to the newly planted field. These changes in microbial composition may ultimately lead to a decrease in sugarcane yield and quality in the monoculture system, which provides a theoretical basis for the obstruction mechanism of the continuous sugarcane planting system. However, continuous planting obstacles remain uncertain and further need to be coupled with root exudates, soil metabolomics, proteomics, nematodes, and other exploratory methods.

Sugarcane-Legume Intercropping Can Enrich the Soil Microbiome and Plant Growth

Soil microbes have a direct impact on plant metabolism and health. The current study investigates the comparative rhizobiome between sugarcane monoculture and sugarcane–soybean intercropping. A greenhouse experiment was performed with two treatments: (1) sugarcane monoculture and (2) sugarcane–soybean intercropped. We used a high-throughput sequencing (HTS) platform to analyze the microbial community. We used the 16S rRNA gene and internal transcribed spacer region primers to identify the microbial diversity. HTS results revealed that a total of 2,979 and 124 bacterial and fungal operational taxonomic units (OTUs) were observed, respectively. Microbial diversity results concluded that the intercropping system has a beneficial impact on soil microbes. The highest numbers of bacterial and fungal OTUs were found in the intercropping system, and these results also collaborated with quantitative PCR results. Additionally, intercropped sugarcane plants showed a higher weight of above- and below-ground parts than the monoculture. Soil chemical analysis results also complemented that the intercropping system nourished organic carbon, total nitrogen, and soil enzyme activities. Correlation analysis of the diversity index and abundance concluded that soil nutrient content positively influenced the microbial abundance that improves plant growth. The present study frames out the profound insights of microbial community interaction under the sugarcane–soybean intercropping system. This information could help improve or increase the sugarcane crop production without causing any negative impact on sugarcane plant growth and development.

Status of Selected Physicochemical Properties of Soils Under Long Term Sugarcane Cultivation Fields at Wonji-Shoa Sugar Estate

A declining trend in per hectare yield of sugarcane in Wonji-Shoa Sugar Estate is being observed due to altering of soil physicochemical properties resulted from long term sugarcane cultivation. Cognizant of this fact, a study was conducted in 2017at Wonji-Shoa Sugar Estate with the objective of determining the effects of more than 62 years of sugarcane cultivation on the physicochemical properties of soil. In order to achieve this objective disturbed and undisturbed soil samples were collected from 0-30 and 30-60 cm layers of selected cultivated and uncultivated light and heavy soils for laboratory analysis. Results of the study indicated that long term cultivation of sugarcane at the same depth and low soil organic matter content of cultivated fields induced soil compaction and consequently highest bulk density was recorded in subsoil layer of cultivated than uncultivated land. The bulk density and total porosity values were out of ranges recommended for optimum sugarcane cultivation and suggest the existence of some degree of compaction. The finding further showed that the pH of study area soils is out of the normal pH range for sugarcane plant growth. The soil organic carbon, total nitrogen content and available phosphorus concentration of soils under both land uses of all soils was found within low range. Therefore, based on the result of the study it can be concluded that under condition of strong base soil pH of study area the availability of essential nutrients are critically affected. This indicates that the strong pH values at Wonji-Shoa Estate require more attention. Moreover, the low levels of organic carbon, total nitrogen, and available P contents under both cultivated and uncultivated soils indicated that soil fertility is among the constraints for sustainable sugarcane production in the estate. Based on the findings and conclusions of this study one can recommend that to maintain sustainability of sugarcane production in the estate soil management practices that can protect as well as ameliorate soil compaction, increase soil organic carbon, total nitrogen, soil available P and that can decrease soil pH are important. Nevertheless, in order to give conclusive recommendation further research studies are needed for more soil management units in the estate.

Sugarcane Plant Growth and Physiological Responses to Soil Salinity during Tillering and Stalk Elongation

A pot study was conducted to investigate influences of salinity on sugarcane (Saccharum spp.) plant growth, leaf photosynthesis, and other physiological traits during tillering and stalk elongation. Treatments included two commercial sugarcane cultivars (Canal Point (CP) 96-1252 and CP 00-1101) and an Erianthus with five different soil salt concentrations (0 [Control], 38, 75, 150, and 300 mM of NaCl added). Growth (tillers, plant height, and nodes) and physiological (leaf net photosynthetic rate [Pn], stomatal conductance [gs], intercellular CO2 concentration, and leaf water soluble sugar concentrations) characters were determined during the experiment. Responses of sugarcane growth, photosynthesis, and photoassimilate translocation to salinity depended on soil salt concentration. Plant height was the most sensitive while the number of nodes was the most tolerant to soil salinity among the three growth traits measured. CP 96-1252 differed from CP 00-1101 significantly in response of shoot:root ratio to high salt concentration. Leaf Pn of plants treated with the 38 mM salt did not differ from that of the control plant, but plants treated with the 75, 150, and 300 mM salt had 12.7, 18.7, and 35.3% lower leaf Pn, respectively, than the control. The low leaf Pn due to salinity was associated with not only the decrease in gs, but also the non-stomatal factors. Results of leaf sugar composition and concentrations revealed that high salt concentration also depressed photoassimilate translocation from leaves to other plant tissues. These findings are important for better understanding of some physiological mechanisms of salinity influence on sugarcane growth and yields.

Efficacy of Copper-Based Texel Fabric in Preventing Root Escape from Pots and Improving Nematode Resistance Screening of Sugarcane Accession Lines in a Glasshouse

Plant-parasitic nematodes are major constraints in the production of sugarcane in Australia. Sugar Research Australia commenced a program to screen sugarcane germplasm accessions and commercial cultivars for nematode resistance in a glasshouse under a subirrigation system. Although the subirrigation system provided reasonable growth of sugarcane plants and significantly reduced the use of irrigation water in the glasshouse, it created a few issues. Sugarcane roots escaped through the bottom of the pots and created networks of roots under the fabrics used in the subirrigation system. This made it difficult to reduce cross contamination among the treatment pots and also facilitated nematodes to migrate outside of the pots. This research was undertaken to determine the effectiveness of two types of Texel fabrics (Tex-R commercial products) in mitigating sugarcane root escape from pots as well as impact on nematode population in the pots. Very few or no roots escaped from the pots placed on both types of Texel fabrics compared with other treatment methods, in which prolific root escape was evident at the bottom of the pots, forming a network of roots on or under the fabrics. Nematode numbers in pots placed on Texel fabrics were significantly higher (approximately 50,000 nematodes per pot) compared with other treatment methods (30,000 to 41,000 nematodes per pot). This research demonstrated that Texel fabrics were effective in stopping sugarcane root escape and preventing nematode migration from pots. This study also indicated that the nematode population inside the pots was not adversely impacted by the use of Texel fabrics.

Utilization of sugar factory wastes as an ameliorant on sugarcane seedling media with bud chips technique

Filter mud and boiler ash are sugar factory wastes that have benefits as a soil amendment. The huge quantities of unutilized filter mud and boiler ash was a fuel of this study. The aim of this research is to analyze the effect of sugarcane wastes to planting media for bud chips sugarcane nurseries. This experiment was used randomized group design with three different planting media, consisting of filter mud and soils (P1), boiler ash and soils (P2), and soils only (P3). The sugarcane seeds used were bud chips sugarcane with Bululawang varieties. The results showed that the application of sugar factory wastes in planting media was able to enhance the sugarcane plant growth, including the amount of leaves, the diameter of stem, wet and dry weight of plants in 8 weeks after planting. Sugarcane wastes did not significantly improve the height of plants dan plant roots. Combinations of filter mud and soils has the highest value of vegetative growth compared to other media.

The Impact of Silicon on Photosynthetic and Biochemical Responses of Sugarcane under Different Soil Moisture Levels

Increasing drought stress is one of the most limiting factors for agricultural crop productivity across the world. Silicon (Si) has been known to augment plant protection against drought stress. In this experiment, the responses of sugarcane with silicon application to drought stress for photosynthetic and biochemical activities were investigated. Three water regimes [75 ± 5, 50 ± 5 and 25 ± 5% of soil water content capacity (SWCC) from 70 to 115 days after transplanting] and six silicon levels such as 0, 20, 40, 60, 80 and 100 g CaO.SiO2 pot−1 equivalent to 0, 194, 387, 581, 774 and 968 mg Si kg−1 soil, respectively, were applied. This experiment was arranged in a completely randomized block design. It was found that water stressed plants with silicon application showed increasing trends in photosynthetic CO2 assimilation (~2–106%), stomatal conductance (~8–113%), transpiration (~13–274%) and chlorophyll fluorescence yield (~0.3–10%) of 75 ± 5, 50 ± 5 and 25 ± 5% of SWCC as compared to the controls without Si application. The silicon application improved the plant growth under water stress, accompanied with the up-regulation in leaf relative water content (~2–8%), photosynthetic pigments (~2–35%), activities of catalase (ca. 12–91%), peroxidase (ca. 7–30%) and superoxide dismutase (ca. 3–96%) enzymes. These results indicate that Si fertilizer plays an important role in mitigating the negative effects of drought stress on sugarcane plant growth by improving water status, photosynthetic parameters and activating the antioxidant machinery. Findings demonstrated the silicon application an efficient strategy to improve sugarcane tolerance to drought stress.

Biology, natural enemies and damage of the sugarcane whitefly (Neomaskellia andropogonis) (Homoptera: Aleyrodidae) in Iran

AbstractAn outbreak of the sugarcane whitefly (Neomaskellia andropogonis Corbett) recently occurred in sugarcane fields in Khuzestan Province of Iran. This pest sucks plant sap producing large amounts of honeydew. In Khuzestan Province, populations of all developmental stages increase from early August until late November. At this time, when sugarcane is at the ripening stage, nymphs suck the sap, and in cases of severe infestation, retard the growth of sugarcane plants. In this study, we investigated the biology of the pest on different cultivars of sugarcane and under different temperatures. Also, we conducted experiments to determine the damage caused by the pest in the field. Mean pre-adult developmental times were 24.09, 28.06, 27.27 and 26.64 days on CP69-1062, CP57-1062, CP48-103 and NCO-310 cultivars, respectively, and only female progeny were produced. Mean longevity of females on the four cultivars was 6, 8.49, 4.15 and 4.60 days, respectively. Adult females laid an average of 61.80, 58.80, 41.10 and 39.38 eggs on the four cultivars, respectively. Results show that the optimum temperature for development of different stages of N. andropogonis is 30±1°C during the day and 25±1°C at night, and at this temperature, egg and nymphal duration (including first, second, third instars and pupae) and adult longevity were 6.2, 17.0 and 7.6 days, respectively. Females of cultivar CP69-1062 laid an average of 50.09 eggs. Analysis of data on the quality of damage (including Brix, pol and refined sugar factors) shows that damage was inversely and significantly correlated with the number of infested leaves. Whitefly damage differed among cultivars; and, based on the quality of damage, early maturing cultivars were more susceptible to whitefly damage. We collected two parasitoid wasps from nymphs—Encarsia inaron (Walker) (Hym.: Aphelinidae) and Eretmocerus delhiensis Mani (Hym.: Aphelinidae). To the best of our knowledge, this is the first study to assess the biology, damage and natural enemies of N. andropogonis on sugarcane in Iran.