Recoverable Sugar Research Articles

Effect of Harvesting Ages on Yield and Yield Components of Sugar Cane Varieties Cultivated at Finchaa Sugar Factory, Oromia, Ethiopia.

This study was initiated with the objective of determining the effect of different harvesting ages (12, 13, 14, 15, and 16 months) on yield and yield components of selected the two sugar cane varieties (B52/298 and NCo 334) grown in Finchaa sugar factory, Oromia, Ethiopia. A field experiment was conducted at Finchaa sugarcane plantation using a randomized complete block design of a factorial arrangement of 2 × 5 with three replications. The data were performed using SAS version 9.3, and a significant difference was considered at p ≤ 0.05. The results showed that B52/298 variety had a higher estimated recoverable sucrose than NCo 334 variety. The results also indicated that as harvesting ages increase yield, yield components of sugar cane quality are increased. The maximum sugar yield of 1.89-ton ha-1 month-1 was obtained at the harvesting age of 15 months. There was a significant difference (p < 0.05) between harvesting age and sugarcane varieties on cane yield, sugar yield, brix percent juice, pol percent, and recoverable sugar. Generally, the findings imply that as harvesting ages in month increase, brix percent juice, estimated recoverable sucrose, and sucrose percentage in both varieties were simultaneously increased. The findings suggested that B52/298 sugar cane variety with harvesting age between 14 and 16 is highly recommended to obtain optimum sugar cane yield and yield components at the tropical areas of Finchaa sugar factory.

Efficient irrigation management in sugarcane cultivation in saline soil

ABSTRACT The objective of this study was to evaluate the influence of leaching fraction on the biometric and production characteristics and technological quality of the juice of sugarcane varieties grown in saline soil in the Brazilian semiarid region. The experimental design was in randomized blocks, with three repetitions, in a 2 × 3 × 3 factorial scheme, corresponding to two sugarcane cultivation cycles: plant cane and ratoon cane; three sugarcane varieties: RB72454, SP943206 and VAT90212; and, three leaching fractions of irrigation water: 0; 9.1; and 16.6%. Number of living leaves, number of internodes, leaf area, stem diameter, plant height, number of tillers, yield, total soluble solids content (°Brix), percentage of industrial fiber, juice purity, juice Pol%, cane Pol% and total recoverable sugar were evaluated. At the end of the two crop cycles, water use efficiency was determined. The varieties SP943206 and VAT90212 showed higher yield under leaching fraction of irrigation water of 9.1% in both cycles, and higher water use efficiency values were observed for the variety VAT90212. Application of leaching fractions to reduce soil salinity does not promote changes in the technological quality of the sugarcane varieties RB72454, SP943206 and VAT90212.

Supplementary Nitrogen Fertilization in Sugarcane

In Brazil, sugarcane (Saccharum spp.) is considered one of the most economically important crops. Nitrogen (N) is one of the most required elements in sugarcane cultivation. Nevertheless, the information about the soil and foliar applications of this nutrient in crops are discrepant. Therefore, the importance of this study is evident. Given the above, this study aimed to evaluate the soil-applied and foliar N fertilization of sugarcane. The experiment was conducted at the Arapor&amp;atilde; Bioenergia S.A. power plant, located at Fazenda Santa Rita, in the municipality of Itumbiara-GO. The 5 &amp;times; 5 factorial design was adopted, with four repetitions, including five doses of soil-applied ammonium nitrate and five doses of foliar Amidic N polymer. The nutrient extraction, the experiment&amp;rsquo;s initial and final total chlorophyll content, the biometric indexes and the industrial quality indexes were analyzed for sugarcane. The ammonium nitrate doses caused differences in fiber, sacarose content, total recoverable sugar, sugar cane Brix, magnesium, and zinc, which was statistically different for the foliar polymer doses. There was no increment of the production variables with the increase of the nitrogen supply in the soil. On the other hand, the levels of zinc and magnesium in the leaves increased 12% and 27%, respectively, reflecting the importance of this fertilization in sugarcane cultivation.

Evaluation of sugarcane genotypes with respect to sucrose yield across three crop cycles using GGE biplot analysis

SummaryThe experiment was carried out in three crop cycles as plant cane, first ratoon, and second ratoon at five locations on Florida muck soils (histosols) to evaluate the genotypes, test locations, and identify the superior and stable sugarcane genotypes. There were 13 sugarcane genotypes along with three commercial cultivars as checks included in this study. Five locations were considered as environments to analyze genotype-by-environment interaction (GEI) in 13 genotypes in three crop cycles. The sugarcane genotypes were planted in a randomized complete block design with six replications at each location. Performance was measured by the traits of sucrose yield tons per hectare (SY) and commercial recoverable sugar (CRS) in kilograms of sugar per ton of cane. The data were subjected to genotype main effects and genotype × environment interaction (GGE) analyses. The results showed significant effects for genotype (G), locations (E), and G × E (genotype × environment interaction) with respect to both traits. The GGE biplot analysis showed that the sugarcane genotype CP 12-1417 was high yielding and stable in terms of sucrose yield. The most discriminating and non-representative locations were Knight Farm (KN) for both SY and CRS. For sucrose yield only, the most discriminating and non-representative locations were Knight Farm (KN), Duda and Sons, Inc. USSC, Area 5 (A5), and Okeelanta (OK).

Environmental, field and impurity factors to increase the agricultural performance of Brazilian and Australian sugarcane mills.

This study aims to identify explanatory factors to increase the agricultural performance of Brazilian and Australian sugarcane mills. The relevance of Brazil and Australia for the sugar industry motivated the development this study based on the most important factors in both countries responsible for increasing the efficiency in sugarcane production. Thus, this study is designed to assess the hypothesis that there are a few explanatory variables that are deeply responsible for the agricultural efficiency in the sugar-energy sector. As a specific objective, it proposes a DEA (Data Envelopment Analysis) model that seeks to optimize the production of Total Recoverable Sugar (TRS) by planted area, and simultaneously, minimizes mineral and vegetable impurities. The sample consists of 82 observations from 32 sugarcane mills. An agricultural efficiency study was performed using the two-stage DEA, in which the evaluated mills according to the level of efficiency in the proposed model. Then, a Multiple Linear Regression Analysis was performed to identify the variables with the greatest influence on the performance of the mills in terms of efficiency. The results revealed six relevant variables for increasing the agricultural performance in the production of sugarcane: rainfall (mm weekly), chopped cane delivery (%), delivery time (h), borer (%), air humidity (%), and rods in raw wine (× 105/mL). Finally, semi-structured interviews with Brazilian and Australian experts in the sugar-energy sector allowed the identification of five other relevant complementary factors that were unavailable in the database: genetic variety, agricultural cultivation activities, edaphoclimatic factors, renewal of sugarcane fields and irrigation system. The results of this study were grouped into the dimensions of environment, yield, and impurities, providing quantification and better understanding of the identified explanatory factors and the agricultural performance in terms of production efficiency, offering fundamental information that enables managers to make decisions and prioritize the aspects that contribute more significantly to the increase in agricultural productivity of the planted area. Graphic abstract

Recycling of beet sugar byproducts and wastes enhances sugar beet productivity and salt redistribution in saline soils.

Soil salinity adversely affects the growth, yield, and quality parameters of sugar beet, leading to a reduction in root and sugar yields. Improving the physical and chemical properties of salt-affected soils is essential for sustainable cultivation and sugar beet production. A field experiment was conducted at the Delta Sugar Company Research Farm, El-Hamool, Kafr El-Sheikh, Egypt, to evaluate the response of sugar beet to the application of beet sugar filter cake treated with sulfuric and phosphoric acid-treated, phosphogypsum (PG), desaline, humic acid, and molasses under saline soil conditions. The application of treated filter cake enhanced root length, diameter, and leaf area. The application of molasses enhanced root length, diameter, and leaf area as well. Application of molasses increased sugar content and root yield. The application of either treated filter cake or molasses produced the highest recoverable sugar yield. Linear regression analysis revealed that the root yield, quality index, and recoverable sugar yield increased in response to the increased availability of either Ca2+ or K content in the soil which increases in response to the application of soil amendments and molasses. The application of treated beet sugar filter cake and molasses increased the calcium, magnesium, and potassium availability in the soil. Treated filter cake is a promising organic soil amendment that enhanced the yield by 29% and yield-related traits of sugar beet by improving the physical and chemical properties of the soil.

Evaluation of Minimum Preparation Sampling Strategies for Sugarcane Quality Prediction by vis-NIR Spectroscopy.

Proximal sensing for assessing sugarcane quality information during harvest can be affected by various factors, including the type of sample preparation. The objective of this study was to determine the best sugarcane sample type and analyze the spectral response for the prediction of quality parameters of sugarcane from visible and near-infrared (vis-NIR) spectroscopy. The sampling and spectral data acquisition were performed during the analysis of samples by conventional methods in a sugar mill laboratory. Samples of billets were collected and four modes of scanning and sample preparation were evaluated: outer-surface (‘skin’) (SS), cross-sectional scanning (CSS), defibrated cane (DF), and raw juice (RJ) to analyze the parameters soluble solids content (Brix), saccharose (Pol), fibre, pol of cane and total recoverable sugars (TRS). Predictive models based on Partial Least Square Regression (PLSR) were built with the vis-NIR spectral measurements. There was no significant difference (p-value > 0.05) between the accuracy SS and CSS samples compared to DF and RJ samples for all prediction models. However, DF samples presented the best predictive performance values for the main sugarcane quality parameters, and required only minimal sample preparation. The results contribute to advancing the development of on-board quality monitoring in sugarcane, indicating better sampling strategies.

Cultivation Practices of Sugarcane: An Analysis of the Competitiveness of Sugarcane Suppliers in Brazil

To ensure the competitiveness of sugarcane production chains, it is necessary to invest in new technologies and management practices at all stages of production, especially in cultivation practices. The question arises as to which production system presents the best competitiveness index (CI) for the sugarcane crop in Brazil. Thus, scientific studies are required for management and provide inputs for the maximization of productivity; total recoverable sugar; sugarcane cutting medium; and the minimization of average total costs cultivation practices of sugarcane. The aim of this study is to analyze the cultivation practices of sugarcane through competitiveness indexes. In this study, 55 suppliers from the Central-South region in Brazil provided data for the 2019/2020 season. The questionnaire was validated through an initial application and approved in the first round using the Delphi technique. A CI was raised to determine the best production system and for descriptive analysis and to evaluate the Spearman’s correlation profile of systems used by suppliers. The results revealed that in cultivation practice, the use of variable rate decreased the cost of production, whereas fixed rate increased profit maximization. The suppliers produced 88 tons/ha, which was greater than the average production in Brazil.

Application of beet sugar byproducts improves sugar beet biofortification in saline soils and reduces sugar losses in beet sugar processing.

Improving the chemical and physical properties of saline soils is crucial for the sustainable production of sugar beet and efficient processing of beet sugar. Here, the impacts of the application of treated filter cake on sugar beet biofortification under saline soil and sugar losses into molasses during beet sugar processing were evaluated for the first time. The application of treated filter cake significantly reduced K%, Na%, and α-amino-N while enhanced sucrose content and quality index of beet root juice. Consequently, sugar loss percentage, sugar loss yield, and relative sugar loss yield were reduced, whereas recoverable sugar yield was enhanced. Linear regression analysis revealed that quality index and sugar loss yield were increased, whereas sugar loss percentage and relative sugar loss yield were reduced in response to the reduction of soil Na+ content accompanied with increasing Ca2+ content in the soil increased. The results provide treated filter cake as a promising amendment for saline soil remediation for improving biofortification of sugar beet and reducing sugar losses during beet sugar processing.

Estimation of sugar beet biomass and yield comparing NDVI measurements and physical soil parameters

This study was conducted to estimate the relationship of soil sample analysis and satellite imagery with sugar beet yield (BY). The red NDVI obtained monthly from Landsat OLI satellite images during the 2017 and 2018 sugar beet growing seasons were used to establish relationships between imagery and georeferenced soil sample analyses and sugar beet harvest sites. The study was carried out in the field of Sugar Institute Ilgın Experiment Station, Turkey, in 2017 and 2018. Soil samples were obtained in a 0.4 ha grid, and sugar beet yield and recoverable sugar yield (RSY) were obtained from the same sampling areas. The results showed that there were relationships between some soil analysis factors and BY and beet quality. The overall results showed that the amount of clay, electric conductivity (EC), and organic matter in the field might be indicators of BY and beet quality. A statistically significant moderate positive correlation was also obtained between NDVI (Normalized Difference Vegetation Index) images and BY and RSY values in all images obtained by satellite near the harvest date.

Influence of Harvester and Rotation of the Primary Extractor Speed in the Agroindustrial Performance of Sugarcane

This study aimed to evaluate the amount of vegetable and mineral impurities, and the industrial quality standards of the sugarcane, under different harvester speeds and rotations of the primary extractor, in the first cut from a sugarcane field in a terrain with 7% declivity. The experiment took place in the city of Pacaembu, in the western region of the State of Sao Paulo, Brazil. The space between plant rows was 1.4 m, and the field had an estimated productivity of 75 t ha−1 and low weed incidence. The sugarcane variety planted was RB96-5902, and the treatments were the combination of two harvester speeds (3 and 6 km h−1) and two primary extractor rotation speeds (700 and 1200 rpm). Besides, the standard speed of 5 km h−1 and 950 rpm, commonly used by the industry, was used as control treatment, which made a total of 5 different treatments analyzed. The response variables studied were vegetable impurities (IV, %), mineral impurities (IM, %), total impurities (IT, %), fiber (%), brix, pol (%), corrected sugarcane pol (PCC, %), apparent juice purity (PZA, %), reducing sugars (AR, %) and total recoverable sugars. According to the results obtained, the factor, which presented major influence over the level of impurities and the technological characteristics of the raw matter, was the rotation speed of the primary extractor. In this scenario, the highest rotations decreased the impurity levels and improved the industrial qualities. Considering the treatments applied, the most efficient rotation speed was at 1200 rpm.

Modelling of genotype by environment interaction to improve the recommendation of sugarcane cultivars for the state of Goiás, Brazil

Abstract The objective of this work was to identify environmental factors with significant effects on the genotype by environment interaction (GEI) of sugarcane, and to generate thematic maps yield adaptability of genotypes for the state of Goiás, Brazil, through the integrated use of factorial regression models and the geographic information system (GIS). The study was based on the yield of recoverable sugar (YRS) from cultivar field trials carried out in nine locations. Fourteen environmental factors were used, out of which 11 were divided into 10 crop growth phases, totaling 113 environmental covariates (ECs). The selection of ECs was done by successive simple linear regressions, and the respective genotypic sensitivity coefficients were used to generate adaptability maps. Approximately 57% of the GEI effects were related to the covariates longitude, average temperature at crop germination phase, and maximum temperature at the beginning of the phase of greatest growth. For YRS, the RB034128 and RB034021 clones show specific yield adaptations, and the RB034045 cultivar can share the growing area with the RB867515 check cultivar.

VINASSE APPLICATION MANAGEMENT ON TWO SUGARCANE VARIETIES IN THE CERRADO GOIANO

ABSTRACT Sugarcane is considered as one of the prominent agricultural crops in Brazil, with Goiás being the second largest national producer. During the processing of sugarcane, waste is generated, and one of these is vinasse. The objective of this study was to evaluate the biometric and technological performances of two varieties of sugarcane for different depths and vinasse parceling. Experiments were conducted at Fazenda Boa Sorte, located in the municipality of Carmo do Rio Verde-GO. A randomized block design was used with a subdivided plot containing two varieties of sugarcane (RB 86-7515 and SP 80-1816) and each subplot having three management types for the application of vinasse (M1 20-20 mm, M2 40-0 mm, and M3 30-30 mm) and four repetitions. The applications were performed in the months of May and June (dry period). The variables analyzed were the plant height, number of photosynthetically active green leaves, stem diameter, leaf area, stalk productivity, soluble solids content, broth pol, apparent sucrose content, fiber content, total reducing sugars, and reducing sugars. Analysis of variance was performed on the results obtained using the F test; subsequently, for the significant data, the test of means was performed. The SP 80-1816 variety showed superiority for both the biometric and technological variables. The ethanol yield and total recoverable sugar content were higher for the SP 80-1816 variety, with no difference between the vinasse application management. The vinasse application installment did not show viability.

Impact of N-fixing bacterium Nitrospirillum amazonense on quality and quantitative parameters of sugarcane under field condition

Sugarcane is the world’s largest crop by production quantity. In Brazil, the sugarcane cultivation requires 30-70% less nitrogen than in other countries, due to the biological nitrogen fixation. Nitrospirillum amazonense is an N-fixing bacterium that has proven to increase plant growth and yields of sugarcane in greenhouse experiments. However, studies on field conditions are very scarce. For these reasons, this study aimed to assess the impact of different doses of a pre-commercial product, Aprinza®, containing N. amazonense on quality and quantitative parameters of the cultivar RB867515 in field conditions. The plant height, number of internodes, stem yield and sugar yield were measured. The leaf nutrient content was analyzed 60, 90 and 180 days after planting and the plant nutrient content was analyzed after harvest. The inoculation of N. amazonense did not affect the leaf and the stem nutrient content positively. The stem yield was increased 27.5 tons ha-1 (20%) and the total recoverable sugar yield increased 4.6 tons ha-1 (25%), compared to the control, by using 1 liter of Aprinza® per hectare. Therefore, N. amazonense can increase sugarcane stem and sugar yields in sandy soils with low nitrogen application, reducing the environmental impacts of the sugarcane cultivation system.

Glucose Required for Tissue Formation and Its Effects on Cane Yield, Recoverable Sugar, and Sugar Yield

Glucose in sugarcane affected cane yield, recoverable sugar, and sugar yield. Glucose is available since the formation of the stems and stored until sugarcane is ready to be harvested. Information regarding the need for glucose to form sugarcane plant tissue is still not widely available. So, research was conducted to determine the quantity of glucose to form sugarcane plant tissue and its relation to cane yield, recoverable sugar, and sugar yield obtained. The research was carried out at the Karangploso Research Station and Laboratory of Plant Chemistry, Indonesian Sweeteners and Fiber Crops Research Institute, in July 2016–September 2017. A split plot design with two factors and three replications was utilized. The main factor was the growth phases, namely, the vegetative phase and maturity phase, while the other factor was sugarcane varieties, namely, PS-881 (early mature), JR-01 (early-middle mature), Kenthung (early-middle mature), and Bululawang (middle-late mature). The measurements of nitrogen, carbon, and the ash content of the leaves and stems were at 5 months (representing the growth period) and 9 months (representing the ripening period). The results showed that quantities of 1.962–2.160 kg and 2.066–2.113 kg glucose were required to form each kg of leaf and stem tissue depending on the growth phase and variety. Glucose requirements in the maturing phase affected the cane yield, recoverable sugar, and sugar yield as much as by 51.48%, 57.60%, and 58.26%, respectively.

Multisite response of sugarcane to nitrogen rates and split application under Brazilian field conditions

AbstractBrazil is the world's largest sugarcane (Saccharum spp.) producer, with 8.5 million ha and 643 million t of stalks produced annually. Sugarcane production has a significant impact in the Brazilian economy due to the large production of sugar, ethanol, and energy. The low N use efficiency is a challenge for sugarcane production and may be due to a lack of synchrony between fertilizer application and maximum N demand. This study tested the hypothesis that split N application can improve sugarcane yield by matching fertilizer application and crop demand. We conducted 25 green sugarcane field trials in south‐central Brazil (15 in the first ratoon stage [Year 1] and 10 in the second ratoon stage [Year 2]) divided into three harvest periods: autumn, winter, and spring. We adopted a factorial design at the autumn and winter sites, evaluating N rates and methods of application (total or split), and a complete block design in spring, evaluating N rates. Measurements included stalk yield, total recoverable sugars, and sugar yield. Nitrogen responsiveness was higher in sugarcane harvested in autumn compared with winter or spring. Split N application (i.e., applying half of the N soon after harvest and half at the beginning of the rainy season) showed the potential to increase yields by 3–7 Mg ha−1 in autumn but not in winter. Among the seven responsive sites, the yield gain was 9–10.5 Mg ha−1, and the average yield at 0.8 kg N Mg−1 was statistically similar to those at 1.0, 1.2, and 1.4 kg N Mg−1.

A Multivariate Approach to Determine the Economic Profitability of Sugarcane Production Under Diverse Climatic Conditions in Brazil

The prominent position of sugarcane as a source of renewable and sustainable energy resulted in the expansion of its production into regions under limiting climatic conditions, thus affecting patterns related to growth, ripening, and profitability. This study provides an assessment of the factors that compose the economic return of sugarcane production using a multivariate approach. Monthly data, including total recoverable sugars, price, productivity (for an average of five mechanized harvesting), and rainfall during seven harvest seasons (2011/2012–2017/2018), were used to perform the multivariate statistical analyses considering the climatic conditions of four regions in the state of Sao Paulo, southeastern Brazil (Aracatuba, Assis, Ribeirao Preto, and Piracicaba). The chosen techniques were hierarchical and non-hierarchical (k-means) cluster analysis and principal component analysis. The data indicated the existence of three groups of months that exhibited different performances: Groups I, II, and III with intermediate, high, and low gross economic returns, respectively. Although group organization presented regional variations, July, August, September, and eventually October (Group II) generally exhibited the best gross economic returns (R$5065.1 ha−1). December and November (Group III) exhibited the lowest economic returns (R$4731.5 ha−1), and April, May, and June (Group I) exhibited intermediate returns that were close to the annual average (R$4829.6 ha−1). Given the territorial extent of Brazil and the significant variations in environmental conditions, the adaptation of sugarcane cultivation and harvesting strategies to the characteristics of each producing region is fundamental for the rational and sustainable exploitation of the crop in the country.

Multivariate Behavior of Irrigated Sugarcane with Phosphate Fertilizer and Filter Cake Management: Nutritional State, Biometry, and Agroindustrial Performance

Increases in production and final quality of the sugarcane crop require the search for new management and evaluation techniques within the production system, which can range from water and nutritional management, such as the application of water saving irrigation associated with sources (conventional and alternative) and phosphorus doses combined with the use of a sophisticated mathematical method, such as multivariate analysis. It can explain the variations caused by the application of irrigation and the sources and doses of phosphorus throughout the crop cycle. Due to the complex relationships and interactions of the soil-water-plant-atmosphere system, the use of multivariate analysis is able to indicate the best management options to be used. The experiment was carried out in a dystrophic Red Yellow Latosol, medium texture. The experiment consisted of randomized blocks and three replications in a 3 × 4 × 2 factorial design comprising three sources of phosphorus (triple superphosphate, Bayovar natural reactive phosphate, and Araxa natural phosphate) and different doses (0, 90, 180, and 360 kg of P2O5 ha−1) in the presence and absence of filter cake (7.5 Mg ha−1, dry basis). Irrigation with rescue equipment was applied in a single blade of 80 mm. Biometrics, nutritional status, and agroindustrial performance of sugarcane were evaluated. The principal component analysis evidenced that the phosphate fertilization associated with filter cake is responsible for increases in sugarcane biometrics, specially tillers at 6 months (0.589) and final tillering (0.577); nutritional status of iron (0.349), manganese (0.348), boron (0.347), sulfur (0.332), and phosphorus (0.331); and agroindustrial performance of sucrose (0.476), stalk yield (0.470), and total recoverable sugar (0.439). The water saving irrigation potentiated the use of phosphate fertilizer associated with filter cake, increasing the nutritional status of the plants. However, the correlation was irrelevant and or negative for levels of potassium and calcium. In addition, it favored biometrics and agroindustrial performance by expressing a direct and positive correlation with stalk yield, sucrose, and total recoverable sugar, but an inverse correlation between final tillering and plant height, tons of pol per hectare, and total recoverable sugar.

Potassium Fertilization in Sugarcane Ratoon Yield Grown in a Tropical Region

ABSTRACTPotassium (K) is closely associated to the improvement of sugarcane quality, acting in the conversion of reducing sugar (RS) to recoverable sugars (TRS). The present study aimed to evaluate the effect of different levels of K-fertilization on the yield and technological quality of sugarcane ratoons grown under edaphoclimatic conditions in the Brazilian central region. The experiment was carried out using the sugarcane variety CTC-4, in a Distrofic Latosols, medium texture (270 g clay kg−1). The study was arranged in a randomized complete block design, with five treatments (0; 50; 100; 150 and 200 kg K2O ha−1), and five replicates. Potassium content in soil and plant, biometric variables, stalk yield and the technological quality at harvest were evaluated. The 200 kg ha−1 dose increased the K content in 160, 156, 56 and 3% in 0–0.20 and 0.20–0.40 m layers at 180 and 360 days after budding (DAB), respectively, promoting greater absorption of the nutrient by plants (X ̅ = 15.22 g kg−1). The higher potassium absorption reflected in yield gains, with an increasing of 7.9%, compared to the control treatment, yielding 100.37 t ha−1. However, soil K fertilization did not affect the technological quality of the sugarcane ratoon.Abbreviations: K: potassium; RS: reducing sugars; TRS: recoverable sugars; DAB: days after budding; SB: Sum of Bases; CEC: Cation Exchange Capacity; V: Saturation Base; Kcl: potassium chloride; AWC: Available water capacity; PC: Pol percent in sugarcane; Brix: total soluble solids; dRYL: Dystrophic Red Yellow Latosol; eRYA: Eutrophic Red Yellow Argisol.

Determining optimum period of withholding irrigation for inducing maturity of sugarcane (Saccharum spp. hybrid) in Southern Ethiopia

Withholding irrigation before harvesting is important for inducing maturity in sugarcane. The study was carried out to determine the optimum period of withholding irrigation for inducing maturity in sugarcane in southern Ethiopia. Field experiments were conducted on two sugarcane varieties, N Co 334 and B 52 298 by five treatments of withholding irrigation periods for 20, 30, 40 50 and 60 days in randomized complete block design at the crop age of 11.3 months during 2014-15. The data on soil moisture content, top to bottom ratio of Brix in cane juice by hand refractometer, Brix, pol, purity and reducing sugars percent juice, and recoverable sugar percent cane, estimated sugar yield were recorded. Error variances for all characters except top to bottom ratio of Brix and reducing sugars in canes in experiments of both varieties were homogeneous and thus the data were also analyzed in split-plot design with varieties as the main plot and withholding irrigation period (WIP) treatments as subplots. The soil moisture percent differed at different WIPs with lowest at WIP for 60 days. Quality characters, top to bottom ratio of Brix in juice, Brix, pol or sucrose, purity, and sugar recovery percent cane increased significantly with the increase in WIPs, being highest at 50 and 60 days. Reducing sugars percent juice declined significantly with lowest at WIPs for 60 days. Estimated sugar yield increased significantly with the maximum at WIP for 50 and 60 days. The optimum period for withholding irrigation was 50 to 60 days for inducing maturity in sugarcane if not offset by rains. It was, therefore, suggestive that the irrigation could be withheld to sugarcane crop of about 12 months for 50 to 60 days but the quality of sugarcane should be determined before harvesting for obtaining maximum sugar yield in southern Ethiopia