Ratoon Cane Research Articles

Growth and Yield Potential of New Sugarcane Varieties during Plant and First Ratoon Crops

Newly released sugarcane varieties need to be adapted to various environments. This research was aimed at examining the growth and yield potential of newly released varieties of sugarcane in the first year as plant cane (PC) and the second year as first ratoon cane (RC1) on dry land. The research was carried out at Wedarijaksa station, Trangkil Sugar Mill area, Pati, Central Java in 2019–2021. Four sugarcane varieties were grown using a double rows system, AAS Agribun, ASA Agribun, AMS Agribun, and CMG Agribun and one commercial variety, PSJK 922. Measurements of crop growth were made periodically: yield components at harvest in PC-RC1, and physiological characteristics 5 months after planting. The results indicate that mean tonnes of cane and sugar per hectare between PC and RC1 decreased by 22.7% and 21.0%, respectively, for AAS Agribun, ASA Agribun, and CMG Agribun due to decreased stem weights. AMS Agribun showed the smallest decrease in tonnes of cane (4%) and increase in tonnes of sugar per hectare (2%) from PC to RC1. The highest number of tonnes of sugar in PC was achieved by ASA Agribun (12.8 t ha−1), slightly above PSJK 922 (12.69 t ha−1). The decline in tonnes of cane and sugar needs to be reduced by the continuously improving cultivation techniques. The mean photosynthetic water use efficiency of tested new varieties was 7.46 µmol CO2 mol H2O−1. These research findings provide information on crop performance and can be used as a basis for selecting varieties to be developed in the region. Further studies will be required to test these new sugarcane varieties in a wide range of agroecological zones in Indonesia.

Sugarcane (Saccharum officinarum L.) under saline stress: Growth, productivity, technological quality, and industrial yield

Water scarcity is one of the main factors that contribute to the reduction of productivity in crops, and irrigation with lower water quality is an option to minimize water stress. The objective of this work was to evaluate the growth, productivity, technological quality, and industrial yield of the plant sugarcane and the first ratoon irrigated with brackish water and leaching conditions and the productivity of the second ratoon under the rainfed regime. The research was carried out at the Federal Rural University of Pernambuco, Recife-PE, in drainage lysimeters using a completely randomized design, in a 5 × 2 factorial scheme: five levels of irrigation water salinity (ECw: 0.5, 2.0, 4.0, 6.0, and 8.0 dS m −1 ) obtained by adding NaCl and CaCl 2 to the local distribution water (0.5 dS m −1 ) and conditions without leaching fraction (LF1 = 0) and with leaching fraction (LF2 = 0.17), corresponding to 100 % and 120 % of the crop evapotranspiration , with four replications. The growth, productivity, and technological quality were measured in the plant and first ratoon cane and the productivity of the second ratoon. The salinity of the irrigation water reduced the growth, productivity, technological quality, and industrial yield in the plant sugarcane and first ratoon; this effect is minimized by the leaching fraction of 0.17. The salinity of irrigation water from plant sugarcane and the first ratoon promoted a residual effect , negatively affecting the agronomic performance of the second ratoon. • Salinity reduces growth, yield, technological quality, and industrial yield in sugarcane plants. • Salinity of 8 dS m −1 promotes an average yield reduction of up to 43 % in the condition without leaching fraction. • The use of the leaching fraction (0.17) promotes a yield greater than 25 % compared to the condition without leaching. • Sugarcane is classified as moderately salinity tolerant when the leaching fraction (0.17) is adopted.

Growth, Yield, Quality and Insect-Pests in Sugarcane (Saccharum officinarum) as Affected by Differential Regimes of Irrigation and Potash under Stressed Conditions

Land productivity and quality were negatively impacted by both unbalanced fertilization and water-stressed conditions, which has arisen as an important topic of research. In the semi-arid tropics, sugarcane is the main source of sugar and ethanol; however, no potash (K) dose is recommended for the deficient sites in the region, which are further responsible for lower recovery. As a result, in order to standardize the K dose for deficient sites, present experiments carried out during plant (2019–2020) and ratoon (2020–2021) seasons. The statistical design was a split-plot design with main plot treatments comprised of I1 (irrigated) and I2 (stressed) treatments followed by K1, K2, K3, and K4 plots fertilized with 0, 40, 80, and 120 kg K2O ha−1 in subplots. Germination was reported to be 13.7, 25.0 and 32.3% higher during plant and 6.2, 17.3 and 24.4% higher during ratoon season in K2, K3, and K4 plots, respectively. Tiller’s cane−1 was recorded to be significantly affected by potash levels at 241 days after planting (DAP) and 261 and 326 days after harvesting (DAH). Periodic chlorophyll content of the sugarcane leaves was reported not to be affected by irrigation treatments except at 355 DAP and 324 and 357 DAH, where respected values were reported to be 2.06% in the plant season and 1.55 and 2.54% higher in the ratoon season in I1 plots, respectively. During plant season purity and extraction after the 10th month, respective values were reported to be 1.5% lower and 4.03% higher under I1 plots, while only Brix (%) was reported as significant and 2.42% higher in I1 plots during plant season after the 12th month. The incidence of early shoot borer (Chilo infuscatellus) and stalk borer (Chilo auricilius) was reported to be significantly higher under stressed conditions (30.4 and 21.5% lower in I1 plots) during the plant season, while early shoot borer (Chilo infuscatellus), stalk borer (Chilo auricilius) and top (Scirpophaga excerptalis) incidences were significantly lower in I1 plots to the tune of 19.6, 22 and 9.73% as compared to the I2 plots during the ratoon season. The application of 80 kg K2O ha−1 resulted in significantly higher cane yield and decreased insect-pest occurrence. Even though 120 kg K2O ha−1 promoted different plant and ratoon sugarcane characteristics, they were all statistically equivalent. In I1 plots, benefits increased from K2 to K3 plots by 26.7% during plant and 155% during ratoon seasons but decreased from K3 to K4 plots by 21.0% during plant and 26.1% ratoon seasons. In I2 plots, however, benefits from K2 to K3 plots were reported to be 72.7% during plant and 76.5% during ratoon seasons, which was reduced to 10.5% during plant and 16.7% during ratoon seasons in K4 plots. Results of a two-year study on plant and ratoon canes revealed that 80 kg K2O ha−1 at deficient sites significantly improved the performance of both plant and ratoon canes yields, sugar yields, reduced the insect-pests’ incidence, and finally the benefits of the cane farmers under both irrigation regimes.

UFSM XIKA FW: sugarcane cultivar for southern Brazil

In Brazil, in view of the different soil and climatic conditions of the sugarcane-producing regions, a strategy of creating small breeding programs for the crop is being used. Since 2008, the sugarcane breeding program of the Federal University of Santa Maria (UFSM), has been developing new, better adapted and higher-yielding sugarcane cultivars for the climate conditions of the southern region of Brazil. Cultivar UFSM XIKA FW was developed at the Laboratories of Agroclimatology and Genetic Breeding and Plant Production of the UFSM, Campus Frederico Westphalen. It is the first mutation-induced sugarcane cultivar that was protected by the Ministry of Agriculture, Livestock and Food Supply, Brazil. The genotype used for mutation induction was cultivar IAC 87-3396, due to its good performance characteristics in the southern region. The mutation mechanism was induced in 2011, by immersing individual buds in a solution of the chemical mutagenic agent methyl methane sulfonate. The best genotypes were selected and tested in plant cane in 2013 and 2018 and in ratoon cane trials in 2014 and 2015. The new cultivar has a higher sugar production potential, and the mean yield of four years was 8.2 t ha-1 higher than that of the control, indicating a high yield potential.

Growth Analysis in Sugarcane Ratoon Crop as Influenced by Potassium Nutrition in Subtropical India

ABSTRACT A field experiment was conducted for two cropping seasons during 2016–19 at the ICAR-Indian Institute of Sugarcane Research, Lucknow, Uttar Pradesh, India, with the objectives to study the effect of i) K nutrition and variable sources of K on growth analysis of sugarcane ratoon crop, ii) the response of K on the photosynthetic rate of crop and iii) contribution of K on yield attributes, sugarcane, and sugar yields. Mean results of two cropping seasons indicated that the application of potassium brought forth a 12.08% improvement in tiller population over no K (107.3 thousand/ha). Potassium application through K2SO4 (SOP) showed the highest net rate of photosynthesis (15.28 µmol/m2/s) which was about 30.71% higher than the control. Among the various sources of K, SOP was found the best in improving sugarcane and sugar yields. Application of SOP resulted in 18.69% ratoon cane yield improvement over the control. Application of 75% K through K2SO4 resulted in a higher sugar yield (12.01 t/ha) which was 25.76% higher than the control (9.55 t/ha). Potassium ammonium sulfate (PAS) and murate of potash could not produce better results as compared to K2SO4. Potassium application through SOP showed the highest net rate of photosynthesis (15.28 µmol/m2/s) during the grand growth phase. Application of 50.4 kg K/ha (75% more than recommended) through K2SO4 increased 18.69% sugarcane (106.7 t/ha) and 25.76% (12.01 t/ha) sugar yields over the control (no K) and was found to the best and could be recommended for improving sugarcane and sugar yields of ratoon in subtropical India.

Tillage systems impact on soil physical attributes, sugarcane yield and root system propagated by pre-sprouted seedlings

Soil compaction caused by intense machine traffic is a challenge in the sugarcane production system, but its implications can be mitigated by the higher content of soil organic matter and plant root growth provided by conservation management practices (i.e., no-tillage). Thus, we aim to study the impacts of tillage systems on the soil physical attributes, root system and yield of sugarcane propagated by pre-sprouted seedlings. Sugarcane was cultivated under four tillage systems: conventional tillage with harrow (CT); conventional tillage with harrow and subsoiling (CTS), minimum tillage with Rip Strip® equipment (MT) and no-tillage on soybean residue (NT). Soil parameters (soil bulk density, porosity and organic carbon contents) in the 0–60 cm layer, root system (root area and root dry biomass) in the 0–100 cm layer and sugarcane yield were evaluated from 2017 to 2019 during the cane-plant and first-ratoon cane cycles. The no-tillage system showed the highest yields of stalks, biomass and root area of sugarcane even with the highest values of soil penetration resistance and soil bulk density between the rows. The system with Rip Strip® presented the lowest yields of sugarcane stalks. No-tillage had the highest organic carbon content in the topsoil compared to the other tillage systems. The sugarcane yield showed a positive linear relationship with root biomass accumulated in 0–100 cm soil layer. Sugarcane cultivation under no-tillage system provided gains of 15 Mg ha−1 in productivity and higher root dry biomass of the cane-plant cycle in the 0–20 cm soil layer. It also preserves the physical attributes of the soil, increases the soil organic carbon content and favours the increase in the yield and root biomass of sugarcane in both cane-plant and first ratoon cane.

Establishment of DRIS Standards and Indices for Ratoon Cane Production in the Southern Region of Goiás, Brazil

Establishment of DRIS Standards and Indices for Ratoon Cane Production in the Southern Region of Goiás, Brazil

Sugarcane fertilization package with double row system to increase yield of first ratoon cane

The purpose of this study was to obtain a package of compound fertilization on a double row system on growth, cane yield, sugar content, and sugar yield on first ratoon cane (RC1) in dry land. The research was conducted from January to October 2016 at Asembagus Research Station, Situbondo, East Java. Six treatments of fertilizer packages were arranged in a Randomized Block Design with four replications, consisting of standard fertilizer packages for a single row (6 quintal compound fertilizer NPK (15-15-15) + 5 quintals ZA) per ha, 1.2, 1.4, 1.6, 1.8, and 2.0 times the standard fertilizer package. The results showed that the highest RC1 sugarcane yield (138.57 t/ha) was achieved by fertilizing 8.4 compound fertilizer + 7 ZA (quintal/ha) or 1.4 times the standard dose, resulting in a 25.52% increase in sugarcane yield compared to standard fertilizer (110.40 t/ha). The sugar content did not differ among the treatments ranging from 9.2 to 10%. The highest sugar yield was 12.97 t/ha in line with sugarcane yield. This finding suggested the recommendation of a fertilizer package for a double row system in sugarcane.

Evaluation of the health and sugarcane seed production from the first ratoon cane at various harvest ages

Increasing the productivity of sugarcane can be done by using healthy and pure seeds. This study aimed to evaluate the health and production of sugarcane seed from ratoon sugarcane derived from tissue culture. The study was conducted in 2017 using a split-plot design, as the main plots were varieties BL and PSJK922; as subplots, the age of seed cane harvest was 5, 6, 7, and 8 months, repeated three times. Bud set from each variety was planted in 5 rows with a length of 8 m. Varieties did not significantly affect all variables of plant growth and seed germination. Seed harvesting age at plant cane (PC) and first ratoon (RC1) affected sugarcane growth except for the number of productive tillers at plant cane. The longer the harvesting age of sugarcane seeds, the higher the attack of the shoot and stem borer. In addition, in plants with seeds originating from the first ratoon, no Ratoon Stunting Disease (RSD) was found. Therefore, the first ratoon cane can be used as a source of healthy sugarcane seeds and produce high seed quality following Indonesian national standards for sugarcane seed production if supported by good management.

The phytonematodes species on sugarcane plants (Saccharum officinarum L.) at Subang Sugar Factory PT PG Rajawali II, West Java

Phytonematodes are an important plant pest in sugarcane. The presence of phytonematodes can cause root damage and eventually reduce plant productivity. This study aimed to identify and calculated the abundance of sugarcane phytonematodes species in the Subang Sugar Factory of PT PG Rajawali II, West Java. The symptoms of sugarcane plants infected by phytonematodes include stunting plants and slender stems, and necrotic roots with blackish purple spots that spread unevenly on young roots. The diagnostic samples, consisted of roots and soil, were taken from the second ratoon cane. The stages of the research included nematode extraction from soil sample by centrifugation flotation method and extraction nematode from the root using the mist chamber method, nematode staining inside root tissue, and nematode identification. The nematode species were identified based on the morphological characters. Eight phytonematodes species, namely Pratylenchus zeae, Xiphinema setariae, Hoplolaimus indicus, Rotylenchulus reniformis, Criconemoides morgenensis, Coslenchus paramaritus, Helicotylenchus sp., Coslenchus paramaritus and Tylenchus sp. were identified. Based on the highest absolute population in sugarcane roots was Pratylenchus zeae.

Optimal Minimum Number of Samples to Determine the Water Retention Curve in an Oxisol with Ratoon Caneoptimal Minimum Number of Samples to Determine the Water Retention Curve in an Oxisol with Ratoon Cane

Optimal Minimum Number of Samples to Determine the Water Retention Curve in an Oxisol with Ratoon Caneoptimal Minimum Number of Samples to Determine the Water Retention Curve in an Oxisol with Ratoon Cane

Water use efficiency of sugarcane clones under rainfed condition

Crop water use study is necessary for crop management. The purpose of the research was to determine water use efficiency (WUE) of sugarcane clones under rainfed conditions. A field trial was carried out in rainfed at Kediri, East Java, from August 2018 to June 2020 in two seasons of plant cane (PC) and first ratoon cane (RC1). A Split-Plot Design was used for the field trial with three replications. Three planting arrangements were allocated to the main plot. Sub-plots consisted of five clones and one check variety. The WUE is the ratio of sugarcane yield to total crop evapotranspiration. Crop evapotranspiration was the reference evapotranspiration multiply by crop coefficients. Reference evapotranspiration needs meteorological data and relied on the FAO Penman-Monteith method. The average sugarcane crop evapotranspiration for two seasons was 1260.9 mm/year in PC and RC1, with effective rainfall of 817.6 mm and 797 mm, respectively. Average water use efficiency to produce sugarcane were 11.47 and 10.85 t/100 mm and sugar 1.085 and 0.884 t/100 mm, respectively, in PC and RC1. The WUE benefit as criteria for crop selection and to calculate the potential yield given the available water.

Potassium and Water-Deficient Conditions Influence the Growth, Yield and Quality of Ratoon Sugarcane (Saccharum officinarum L.) in a Semi-Arid Agroecosystem

Groundwater and soil potassium deficiencies are present in northern India. Sugarcane is a vital crop in the Indian Punjab; it is grown on approximately 91,000 hectares with an average yield of 80 tonnes ha−1 and a sugar recovery rate of 9.59%. The role of potassium (K) fertilizer under both sufficient and deficient irrigation in ratoon sugarcane crops is not well documented. We conducted a split-plot ratoon cane experiment during 2020–2021 at the Gurdaspur Regional Research Station of Punjab Agricultural University, India, on K-deficient soils. Main treatments were fully irrigated (I1) and water stressed (I0) conditions, with sub-treatments reflecting K fertilizer application rates of 0 (M1), 67 (M2), 133 (M3), and 200 (M4) kg K ha−1. The ratoon sugarcane performance was assessed in terms of growth, productivity, sugar quality and incidence of key insect pests. At harvest, trends in the growth and yield parameters in I1 were improved over the I0 treatment, with cane height (+12.2%), diameter (+3.3%), number of internodes (+5.4%), biomass yield (+7.6%) and cane yield (+5.9%) all higher, although little significant difference was observed between treatments. Ratoon cane yield under irrigation was 57.1 tonnes ha−1; in water-stressed conditions, it was 54.7 tonnes ha−1. In terms of sugarcane quality parameters, measured 12 months after harvesting the initial seed crop, values of Brix (+3.6%), pol (+3.9%), commercial cane sugar percentage (+4.0%) and extractable sugar percentage (+2.8%) were all higher in the irrigated treatments than the water-stressed plot. Irrigated treatments also had a significantly lower incidence of two key insect pests: top borer (Scirpophaga excerptalis) was reduced by 18.5% and stalk borer (Chilo auricilius) by 21.7%. The M3 and M4 treatments resulted in the highest cane yield and lowest incidence of insect pests compared to other K-fertilizer treatments. Economic return on K-fertilizer application increased with increasing fertilizer dosage. Under the potassium-deficient water-stressed conditions of the region of north India, a fertilizer application rate of 133 kg K ha−1 is recommended to improve ratoon sugarcane growth, yield, and quality parameters and economic returns for sugarcane farmers.

Water deficit modifies C:N:P stoichiometry affecting sugarcane and energy cane yield and its relationships with silicon supply

Climate change has increased the occurrence of water deficit in regions where sugarcane and energy cane are cultivated, jeopardizing dry matter production of stems. It was hypothesized that the reasons behind this fact relate to C:N:P stoichiometric modifications in these species that impair the conversion rates of accumulated nutrients in the stems, which could be attenuated by supplying silicon (Si) to the crops. Thus, the aims of this study were to evaluate the effects of water deficit in sugarcane and energy cane ratoons in the presence and absence of Si, in the C:N:P stoichiometry of stems, in the use efficiency of these nutrients and in the accumulation of dry matter in stems. Two experiments were carried out, using sugarcane (Saccharum officinarum) and energy cane (S. spontaneum), cultivated in pots filled with a Typic Quartzipisamment. The treatments for both experiments were arranged in a factorial scheme 2 × 2, without (70% of the soil’s water retention capacity) and with (30% of the capacity) water deficit, without and with the application of Si via fertirrigation, associated with foliar pulverization, both at a concentration of 2.5 mmol L−1, arranged in randomized blocks. The reduction in dry matter production of stems in both species caused by water deficit was due to modifications of the C, N and P stoichiometric homeostasis, but the benefit of Si in these plants when increasing dry matter production was not a reflection of the change in homeostasis, thus it may be involved in other mechanisms that remain unknown and should be further studied.

Sugarcane Ratooning Ability: Research Status, Shortcomings, and Prospects.

Simple SummarySugarcane ratooning ability is directly related to sugarcane production costs and planting benefits. There are several questions within the field that we have explored in this review and that remain to be answered. What is the genetic basis of ratooning ability? How do these traits form and evolve? How does the environment affect the ratooning ability? Where should the research focus of sugarcane ratooning ability be placed in the future? How can technical methods be optimized for breeding sugarcane with strong ratooning ability? In this paper, we reviewed previous studies in terms of the definition, phenotypic traits, major influencing factors, genetic basis, and the physiology associated with sugarcane ratooning ability. We also highlighted the shortcomings of existing research on ratooning ability and suggested the focuses of future studies.Sugarcane is an important sugar crop and it can be subjected to ratooning for several years. The advantages of ratooning include quality improvement, efficiency enhancement, and reduced costs and energy use. The genotype, environment, cultivation management, and harvesting technology affect the productivity and longevity of ratoon cane, with the genetic basis being the most critical factor. However, the majority of research has been focused on only limited genotypes, and a few studies have evaluated up to 100 sugarcane germplasm resources. They mainly focus on the comparison among different genotypes or among plant cane, different selection strategies for the first and second ratoon crops, together with screening indicators for the selection of stronger ratooning ability. In this paper, previous studies are reviewed in order to analyze the importance of sugarcane ratooning, the indicative traits used to evaluate ratooning ability, the major factors influencing the productivity and longevity of ratooning, the genetic basis of variation in ratooning ability, and the underlying mechanisms. Furthermore, the shortcomings of the existing research on sugarcane ratooning are highlighted. We then discuss the focus of future ratoon sugarcane research and the technical methods that will shorten the selection cycle and increase the genetic gain of ratooning ability, particularly the development of linked markers. This review is expected to provide a reference for understanding the mechanisms underlying the formation of ratooning ability and for breeding sugarcane varieties with a strong ratooning ability.

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.

Genetic Variation and Heritability for Juice Quality and Yield Traits in Selection of Sugarcane Genotypes under Irrigation at Early Stage in Ferké 2 Sugar Estate of Northern Ivory Coast

Genetic relationships between important attributes in studying sugarcane populations through breeding and direct selection, are crucialto understand how changes made by selecting one character may cause changes in others. The study aimed to determine the best yielding sugarcane genotypes tested at early selection stage under sprinkler irrigation, in comparison with a check variety (R579). The experiment was designed following a randomized complete block (RCB), with 30 cane genotypes in three replications. Each plot consisted of five dual rows of ten meters, with 0.5 and 1.90 m of inter-row spacing, i.e. 95 m² per plot and nearly 6,000 m² for the whole experiment. It was carried out on a commercial sugarcane plantation of Ferké 2, in northern Ivory Coast, over two seasons (plant cane and first ratoon) as an early-season crop from, November 29, 2018 to October 26, 2020. In each micro-plot, different agro-morphological traits were collected at harvest from three central dual rows.

Responses of different varieties of sugarcane to irrigation levels in the Cerrado

The Cerrado is under full expansion of sugarcane cultivation. However, the climate of this biome limits the production of sugarcane due to a marked water deficit. Therefore, the objective of this study is to evaluate different varieties of sugarcane in two cultivation cycles in response to irrigation levels in the Cerrado. The experiment was conducted in Goiânia-GO, Brazil, from March 2016 to March 2018, during the cycles of plant-cane and ratoon cane in pots. The experiment was completely randomized in a 5 x 6 factorial design. The treatments were five varieties of sugarcane (RB867515, CTC11, SP860042, IAC873396, and IAC911099) and six levels of supplementary irrigation (100, 80, 60, 40, 20 and 0% of the ETc determined by weighing lysimeter), and four replications. Eight biometric analyses were performed 45 days apart. At the end of each cycle, the quality of the raw material was determined through technological analysis. At the initial development phase (between March and August), when growth is low, we found that it is better to use an irrigation level that provides at least 40% of ETc, since the Cerrado environment does not increase sugarcane height. At the growth phase (between September and March), there is active growth corresponding to 74% of the cane's height. Therefore, the ideal irrigation is that at least 80% of the ETc be provided at the growth stage to support the sugarcane to reach a maximum growth and consequently favorable technological indexes. The supplementary irrigation level of 60% of ETc accelearted the process of maturation of sugarcane for a 12-month cycle. We conclude that the level of supplementary irrigation using greater technical viability for the cultivation of sugarcane in the Cerrado is 60% of the ETc. The varieties most adapted to this production environment are RB867515 and IAC873396

Energy conversion efficiency in sugarcane cultivars as a function of production environments in Brazil

Energy production needs to increase in order to meet population and industrial growth in the coming decades, and clean energy that promotes the reduction of polluting gases in the atmosphere is required. Sugarcane is a crop with great potential for bioenergy production due to its high potential for converting solar energy into biomass. In this context, the questions arise: What is the real efficiency of conversion solar energy into biomass by sugarcane? How can the production environment and genetic diversity influence this process? In this sense, the objective of this work was to evaluate the efficiency of the conversion of solar energy into biomass, as well the available energy per hectare, and the productivity of stalks as a function of the production environment in different cultivars. The experiments were carried out in two production environments in Brazil, Prado Ferreira, Paraná State (Production Environment A) and Presidente Bernardes, São Paulo State (Production Environment C) and with three sugarcane cultivars SP80-3280, RB855156 and RB867515 in two cultivation cycles. This study showed: a) the production environment × genotype interaction causes 75.80% variation in stalk productivity; b) biomass productivity is less affected by water deficit than stalk productivity; c) the energy conversion efficiency (ECE) ranged from 2.80 to 4.54% in plant cane and 2.10–3.87% in ratoon cane cycles. The variation of ECE in the production environments was due to four main factors: greater water availability, soil fertility, air temperature and solar radiation.

Prediction of Ratoon Sugarcane Family Yield and Selection Using Remote Imagery

Remote sensing techniques and the use of Unmanned Aerial Systems (UAS) have simplified the estimation of yield and plant health in many crops. Family selection in sugarcane breeding programs relies on weighed plots at harvest, which is a labor-intensive process. In this study, we utilized UAS-based remote sensing imagery of plant-cane and first ratoon crops to estimate family yields for a second ratoon crop. Multiple families from the commercial breeding program were planted in a randomized complete block design by family. Standard red, green, and blue imagery was acquired with a commercially available UAS equipped with a Red–Green–Blue (RGB) camera. Color indices using the CIELab color space model were estimated from the imagery for each plot. The cane was mechanically harvested with a sugarcane combine harvester and plot weights were obtained (kg) with a field wagon equipped with load cells. Stepwise regression, correlations, and variance inflation factors were used to identify the best multiple linear regression model to estimate the second ratoon cane yield (kg). A multiple regression model, which included family, and five different color indices produced a significant R2 of 0.88. This indicates that it is possible to make family selection predictions of cane weight without collecting plot weights. The adoption of this technology has the potential to decrease labor requirements and increase breeding efficiency.