No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Impact of Climate Change on Sucrose Synthesis in Sugarcane Varieties
Abstract
Sugarcane is an economically important crop, and the impact of climate change can be manifested much more in all stages like germination, tillering, grand growth, and maturity phases. Cane yield and sucrose content are the two principal traits determining commercial cane yield of sugarcane genotypes. Sucrose accumulation in sugarcane stalks is known as ripening, which is influenced by ambient air temperature and sheath moisture index of sugarcane genotypes. Early ripening genotypes are photosynthetically efficient and complete the vegetative developmental phase much faster than the mid-late cultivars by their synchronized tillering phase and low ratio of acid and neutral invertases. Prolonged lower air temperature during the maturity phase before harvest favors sucrose synthesis in sugarcane genotypes due to decreased concentration of acid invertase enzymes in stalks. The average daily temperature of 12–14 °C would be more desirable for proper ripening. However, a drastic decline in temperature below 8 °C during ripening alters the activities of sucrose synthesizing and hydrolyzing enzymes resulting in a sharp decline in sugar recovery. The impact of changing temperature regimes on sucrose accumulation emphasizes future research initiatives to develop improved models that can record the crop physiological processes that will simulate crop response to predicted changes in climate. Modeling approaches predicted that increased sucrose yield could be achieved when the decrease in stalk dry mass is not more than 10%. Impact assessment using CANEGRO model to study the effect of various combinations of temperature and CO2 projected an enhance in fresh stalk biomass and a decrease in sucrose mass by nearly 10–70% (rainfed) and 6–37% (irrigated) in 2040–2060 compared to 1971–2000 across the agro-climatic areas in India. Therefore, detailed studies are required in the future to demonstrate the causes of changes in the behavior of commercial varieties and the effect of climatic variables on the enzyme balance that regulates vegetative growth and ripening.
ResearchGate has not been able to resolve any citations for this publication.
Silicon (Si) has never been acknowledged as a vital nutrient though it confers a crucial role in a variety of plants. Si may usually be expressed more clearly in Si-accumulating plants subjected to biotic stress. It safeguards several plant species from disease. It is considered as a common element in the lithosphere of up to 30% of soils, with most minerals and rocks containing silicon, and is classified as a "significant non-essential" element for plants. Plant roots absorb Si, which is subsequently transferred to the aboveground parts through transpiration stream. The soluble Si in cytosol activates metabolic processes that create jasmonic acid and herbivore-induced organic compounds in plants to extend their defense against biotic stressors. The soluble Si in the plant tissues also attracts natural predators and parasitoids during pest infestation to boost biological control, and it acts as a natural insect repellent. However, so far scientists, policymakers, and farmers have paid little attention to its usage as a pesticide. The recent developments in the era of genomics and metabolomics have opened a new window of knowledge in designing molecular strategies integrated with the role of Si in stress mitigation in plants. Accordingly, the present review summarizes the current status of Si-mediated plant defense against insect, fungal, and bacterial attacks. It was noted that the Si-application quenches biotic stress on a long-term basis, which could be beneficial for ecologically integrated strategy instead of using pesticides in the near future for crop improvement and to enhance productivity. Citation: Verma, K.K.; Song, X.-P.; Tian, D.-D.; Guo, D.-J.; Chen, Z.-L.; Zhong, C.-S.; Nikpay, A.; Singh, M.; Rajput, V.D.; Singh, R.K.; et al.
The application of silicon appears potentially significant to
enhance crop productivity linked with agro-industries may be an enormous challenge for near future to feed the people
globally with ecofriendly ecosystem with improve sustainable
agricultural crop efficiency/ carbon transformation into the
precisions food for future under limited water availability in
arid and semi-arid agro-climatic zones worldwide.
Broadening genetic base through backcross breeding is an effective approach to generate diverse genetic stocks for important economic traits coupled with red rot resistance. Three hundred backcross hybrids developed by backcrossing elite F1 clones (derived by utilizing improved clones (S.officinarum, S. robustum and S. barberi) with improved S. officinarum or improved S. robustum or Co canes showed variability for the traits studied. Heritability estimates varied over the different nobilising generations and study indicated that selection of parents for sucrose % during the nobilisation process will be effective. BC1 and BC2 hybrids developed from improved S. robustum x improved S. officinarum showed an improvement of 16.71% and 34.09%: 22.36% and 40.58% for sucrose % at 360 days in comparison with improved S. officinarum and S. robustum parents, respectively. Crosses with PIR 96-285 and PIR 001188 as one of backcross parents generated high quality recombinants. The introgression of new genes provided backcross progenies with redrot resistance. The prebred clones expressed wide variability for various traits like internode colour, cane thickness, leaf colour, canopy, hairiness, cane yield and quality characters. Among the pre bred materials, 26 clones recorded single cane weight > 1.25 kg, 45 clones with brix % above 20% and 41 clones with juice sucrose above 18.5% and most of them were derived from the crosses involving improved S.officinarum x improved S. robustum parents back crossed to improved S. officinarum or Co canes. Elite trait specific BC1 hybrids viz., 13-69, 13-251, 13-103, 13-208, 13-253, 14-57 and 14-60 and BC2 hybrids viz.,14-42, 14-66, 14-161 combining good quality and yield traits coupled with red rot resistance: 13-57, 13-114, 13-147 and 13-251, 14-76, 14-69, 14-163 and 14-174 with thickness and resistance to red rot can be utilized in sugarcane varietal improvement programmes.
Silicon (Si) is not categorized as a biologically essential element for plants, yet a great number of scientific reports have shown its significant effects in various crop plants and environmental variables. Plant Si plays biologically active role in plant life cycle, and the significant impact depends on its bioaccumulation in plant tissues or parts. In particular, it has been investigated for its involvement in limited irrigation management. Therefore, this experiment was conducted to examine the effect of Si application in eco-physiological, enzymatic and non-enzymatic activities of sugarcane plants against water stress. Four irrigation levels, i.e., normal (100-95% of soil moisture), 80-75, 55-50, and 35-30% of soil moisture were treated for the sugarcane cultivar GT 42 plants supplied with 0, 100, 200, 300, 400 and 500 mg Si l −1 and exposed for 60 days after Si application. Under stress, reduction in plant length (~26-67%), leaf area-expansion (~7-51%), relative water content (~18-57%), leaf greenness (~12-35%), photosynthetic pigments (~12-67%), physiological responses such as photosynthesis (22-63%), stomatal conductance (~25-61%), and transpiration rate (~32-63%), and biomass production were observed in the plants without Si application. The drought condition also inhibited the activities of antioxidant enzymes like catalase (~10-52%), peroxidase (ca. 4-35), superoxide dismutase (10-44%) and enhanced proline (~73-410%), and malondialdehyde content (ca. 15-158%), respectively. However, addition of Si ameliorated drought induced damage in sugarcane plants. The findings suggest that the active involvement of Si in sugarcane responsive to water stress ranges from plant performance and physiological processes, to antioxidant defense systems.
Research on the development of plants grown for energy purposes is important for ensuring the global energy supply and reducing greenhouse gas emissions, and simulation is an important method to study its potential. This paper evaluated the marginal land that could be used to grow sugarcane in the Guangxi Zhuang Autonomous Region. Based on the meteorological data from 2009 to 2017 in this region and field observations from sugarcane plantations, the sensitivity of the APSIM (Agricultural Production Systems sIMulator) model parameters was analyzed by an extended Fourier amplitude sensitivity test, and the APSIM model was validated for sugarcane phenology and yields. During the process of model validation, the value of the determination coefficient R2 of the observed and simulated values was between 0.76 and 0.91, and the consistency index D was between 0.91 and 0.97, indicating a good fit. On this basis, the APSIM sugarcane model was used to simulate the sugarcane production potential of the marginal land on a surface scale, and the distribution pattern of sugarcane production potential in the marginal land was obtained. The simulation results showed that if sugarcane was planted as an energy crop on the marginal land in Guangxi, it would likely yield approximately 42,522.05 × 104 t of cane stalks per year. It was estimated that the sugarcane grown on the marginal land plus 50% of the sugarcane grown on the cropland would be sufficient to produce approximately 3847.37 × 104 t of ethanol fuel. After meeting the demands for vehicle ethanol fuel in Guangxi, 3808.14 × 104 t of ethanol fuel would remain and could be exported to the ASEAN (Association of Southeast Asian Nations).
This study investigated the impact of climate change on yield, harvested area, and production of sugarcane in Thailand using spatial regression together with an instrumental variable approach to address the possible selection bias. The data were comprised of new fine-scale weather outcomes merged together with a provincial-level panel of crops that spanned all provinces in Thailand from 1989–2016. We found that in general climate variables, both mean and variability, statistically determined the yield and harvested area of sugarcane. Increased population density reduced the harvested area for non-agricultural use. Considering simultaneous changes in climate and demand of land for non-agricultural development, we reveal that the future sugarcane yield, harvested area, and production are projected to decrease by 23.95–33.26%, 1.29–2.49%, and 24.94–34.93% during 2046–2055 from the baseline, respectively. Sugarcane production is projected to have the largest drop in the eastern and lower section of the central regions. Given the role of Thailand as a global exporter of sugar and the importance of sugarcane production in Thai agriculture, the projected declines in the production could adversely affect the well-being of one million sugarcane growers and the stability of sugar price in the world market.
The CANEGRO model was calibrated and validated for phenology and yield attributes viz plant height, drymatter accumulation, LAI, cane yield and commercial cane sugar yield of two cultivars of sugarcane (Co 86032 and Co 99004) using experimetal data collected during 2012-13 to 2016-17 at Sugarcane Research Station, Navsari Gujarat. The validation results indicated that the model can be used for identifying research gap, yield forecasting and climate change impact studies.
Climate change is the one of the most emerging problem of today's world. It is the most potent threat to the existence of mankind. These sudden abrupt changes in the climate are affecting all the crops to a great extent. High concentrations of CO₂ are one of the leading reasons contributing to climate change due to the increasing level of greenhouse gases. The elevation in CO₂ level is hampering crop production and productivity of different crops by causing effect on different physiological attributes. Unlike other crops, in sugarcane, several beneficial effects have been detected such as escalation in biomass, photosynthesis, leaf area, stalk juice volume, leaf dry weight and stem dry weight under such condition. Sugarcane crop is known to be one among those crops that is able to cope up with the increasing level of CO₂ due to four natural endowments it possesses. Very low carbon dioxide compensation point and unique property of sequestering carbon in form of phytolith or planstone is some of the important natural endowment with respect to the rising CO₂ concentration in atmosphere. Here, we have discussed the influence of atmospheric rising CO₂ concentration on sugarcane crop.
Sugarcane is one of the main cash crops in India, and around 42 lakh farmers directly or indirectly depend on this crop which occupies 23 lakh hectare areas in Uttar Pradesh. Temperature and humidity plays an important role in sucrose synthesis and accumulation in C4 plant such as sugarcane. In C4 plants, formation of phosphoenolpyruvate carboxykinase is sensitive to low temperatures. During low temperature and high humidity, there is an increase in juice acidity, probably due to the formation of organic acids, which are formed by the conversion of stored sucrose in the stalk. This conversion is reversed when the atmospheric temperature becomes favourable for sucrose accumulation. In subtropical India, sugarcane crop experiences varied weather conditions during its growth and development. The crushing season of sugar mills of Uttar Pradesh (UP), India, starts from November and continues till the April/May. However, due to immaturity of plant crop, sugar industries avoid starting their crushing season in November, but due to pressure of cane quantity as well as sowing time of wheat crop during this time by the farmers, sugar mills are forced to start their crushing season in November. The area of early varieties in UP was about 35% during crushing season 2015–2016, and sugar recovery was 10.62%; however, area of early-maturing high sugared varieties in UP increased up to 53% during crushing season 2016–2017, but sugar recovery was at par, i.e., 10.61%. Seeing the recovery data of different crushing seasons, a study was conducted at UPCSR Shahjahanpur to evaluate the impact of climatic conditions on sugar recovery percentage. Totally, 15 sugar mills were selected for this study from east, central and west zones of UP and their recoveries were observed and correlated with temperature and humidity. The study revealed that in spite of 18% increase in the area of high yielding, high sugared varieties in the state, which could have increased the sugar recovery, the low-temperature and high-humidity conditions during the start of the crushing season 2016–2017, affected the sugar accumulation in sugarcane, resulting into the average recovery which was at par as the previous year.
China's sugar production and consumption continues to increase. This process is already ongoing for over 15 years and over 90% of the sugar production comes from sugarcane (Saccharum officinarum). Most of the sugarcane is planted in the south (e.g. the Chinese provinces of Yunnan, Guangxi, Guangdong and Hainan) and it represents there a major economic crop in these landscapes. As found virtually worldwide, climate change is generally expected to influence such suitable planting areas. Here we started a first empirical assessment how climate change would influence the spatial distribution of those current and future suitable planting areas of this strategic crop in China. We employed an ensemble machine learning algorithm (Random Forest; bagging) and increasingly used and robust species distribution models (SDMs). These are based on our compiled and best publicly available crop data sampled from the Chinese sugarcane industry map. They were linked with bioclimate variables from the Worldclim database. This powerful concept allowed us to project sugarcane's current and future (2070) suitable distributions. Our results were extrapolated to three Global Circulation Models (GCMs; BCC-CSM1-1, CNRM-CM5 and MIROC-ESM) under three representative concentration pathways (RCPs of 2.6, 4.5 and 8.5). The evaluations of these models indicated that our results had a powerful performance (AUC=0.97, TSS=0.96) for robust inference. Bioclimatic variables related to temperature were the most important predictors for sugarcane planting. All models showed similar increasing spatial trends in suitable distribution area and just a few original suitable areas would be lost. Our finding puts emphasize on new growing areas, their soil and management. It is the first to provide the necessary background to safely cultivate sugarcane in climate-suitable areas and to obtain more sugar production for farmers and the industry; it is of large and strategic importance for food security and national autonomy of this central commodity.
The DSSAT CANEGRO model was calibrated and validated using field experimental data (1997- 2013) from four locations of north Indian region. The genetic coefficients for 10 cultivars of sugarcane were estimated.R² obtained between measured and simulated stalk yield was 0.69 with the nRMSE (7.50%) and D-index (0.91) and R² between measured and simulated sucrose mass was 0.57 with the nRMSE (11.75%) and D-index (0.85). The model underestimated both the stalk fresh mass as well as sucrose mass by 2 and 6 per cent only, respectively. Hence,the CANEGRO model can be used to simulate the phenology and yield attributes of sugarcane cultivars of north India particularly of Uttar Pradesh region. The model can also be used to evaluate and improve the present practices of sugarcane crop management to obtain increased cane production and sugar recovery.
Sugarcane ripening is a process controlled by cultivar characteristics and the interaction of genotypes with local climate. The objective of this study was to characterise the temporal variation of sugarcane ripening by assessing the multivariate structure contained in sugarcane quality data, and by correlating the results with local climatic conditions. Eight sugarcane cultivars were evaluated from March to October in Piracicaba, São Paulo State, Brazil. Characteristics related to the quality of raw sugarcane juice were submitted to statistical analysis by ANOVA, hierarchical and non-hierarchical (k-means) clustering methods, and principal components, in order to classify the cultivars into groups for each month of sampling. The ANOVA showed a clear difference (P < 0.001) among harvesting months for all sugarcane quality variables, which was reinforced by the cluster analysis for the whole dataset that selected groups according to the month of harvest. By analysing the quality variables by months,
The sugarcane flowering is a complex physiological process that consists of several stages of development, each stage has its physiological and environmental requisition. The external factors related to flowering are: photoperiod, temperature, humidity, solar radiation in addition to soil fertility. Already the internal factors involved are: phytochrome, hormones, florigene, nucleic acids, among others. The intensity of the flowering and the consequences on the quality of sugarcane vary with the variety and the climate. The reduction of the sugarcane juice is the main factor which affected by the flowering, resulting from due to the increased fiber content. As other Poaceae, the sugarcane flowers, fruit and dies, ensuring the perpetuation of the species. Thus, the man tries to interfere in nature, trying to prevent the flowering sugarcane, either through breeding or through plant growth regulators. In areas of sugarcane commercial production, where there are ideal conditions for the flowering culture, it is recommended the se of variety with lower potential of flowering. And when this varietal management is more difficult, the use of inhibitors of flowering is the best alternative to avoid more losses of sucrose content.
The objective of this research was to evaluate the activity of acid and neutral invertases in controling the storage of sucrose in sugarcane variety SP80-3280 due to plant regulators application in the middle of the cropping season in Igaraçu do Tietê (SP), Brazil. The experiment was carried out in ratoon cane (crop 2004 and 2005) in a randomized block design with five replications. The treatments consisted of four plant regulators application of the class of growth retainers (Ethephon, Ethyl.trinexapac, Potassium nitrate and Potassium nitrate + Boron) and a control (natural ripening), whose commercial products (c.p.) were Ethrel, Moddus, Krista Kana and Krista Kana Plus, with dosage of 2L c.p. ha-1, 0.8L c.p. ha-1, 3kg c.p. ha-1 and 3c.p. kg ha-1, respectively, without adjuvants application. The growth regulators provide alterations of different and significant intensity in soluble acid invertase and neutral invertase levels enzymes. The agricultural efficiency of maturators was affected significatively by the weather and time of application. The treatments with maturators, were affected most in 2004, when wheater conditions were unfavourable to natural ripening, were favour the ripening sugarcane process implicating in improvement technological quality of stems.
Reliable predictions of sugarcane response to climate change are necessary to plan adaptation strategies. The objective of this study was to assess the use of global climate models (GCMs) and a crop simulation model for predicting climate change impacts on sugarcane production. The Canegro model was used to simulate growth and development of sugarcane crops under typical management conditions at three sites (irrigated crops at Ayr, Australia; rainfed crops at Piracicaba, Brazil and La Mercy, South Africa) for current and three future climate scenarios. The baseline scenario consisted of a 30-year time series of historical weather records and atmospheric CO2 concentration ([CO2]) set at 360 ppm. Future climate scenarios were derived from three GCMs and [CO2] set at 734 ppm. Future cane yields are expected to increase at all three sites, ranging from +4 % for Ayr, to +9 and +20 % for Piracicaba and La Mercy. Canopy development was accelerated at all three sites by increased temperature, which led to increased interception of radiation, increased transpiration, and slight increases in drought stress at rainfed sites. For the high potential sites (Ayr and Piracicaba), yield increases were limited by large increases in maintenance respiration which consumed most of the daily assimilate when high biomass was achieved. A weakness of the climate data used was the assumption of no change in rainfall distribution, solar radiation and relative humidity. Crop model aspects that need refinement include improved simulation of (1) elevated [CO2] effects on crop photosynthesis and transpiration, and (2) high temperature effects on crop development, photosynthesis and respiration.
This study evaluated the effects of climate change on sugarcane yield, water use efficiency, and irrigation needs in southern Brazil, based on downscaled outputs of two general circulation models (PRECIS and CSIRO) and a sugarcane growth model. For three harvest cycles every year, the DSSAT/CANEGRO model was used to simulate the baseline and four future climate scenarios for stalk yield for the 2050s. The model was calibrated for the main cultivar currently grown in Brazil based on five field experiments under several soil and climate conditions. The sensitivity of simulated stalk fresh mass (SFM) to air temperature, CO2 concentration [CO2] and rainfall was also analyzed. Simulated SFM responses to [CO2], air temperature and rainfall variations were consistent with the literature. There were increases in simulated SFM and water usage efficiency (WUE) for all scenarios. On average, for the current sugarcane area in the State of São Paulo, SFM would increase 24 % and WUE 34 % for rainfed sugarcane. The WUE rise is relevant because of the current concern about water supply in southern Brazil. Considering the current technological improvement rate, projected yields for 2050 ranged from 96 to 129 t ha−1, which are respectively 15 and 59 % higher than the current state average yield.
Esta pesquisa foi realizada na Fazenda Capim da Destilaria Miriri, situada no município de Capim na Paraíba, com o objetivo de se identificar o comportamento da cultura da cana-de-açúcar, primeira soca (segunda folha), diante de diferentes lâminas de irrigação e níveis de adubação de cobertura. Com este propósito, conduziu-se um experimento utilizando-se a variedade SP79-1011, em blocos casualizados num arranjo fatorial de 4 x 2 (quatro lâminas de irrigação e dois níveis de adubação de cobertura), com três repetições. O total de água aplicada nos respectivos tratamentos foi 807, 986, 1164 e 1343 mm e os níveis de adubação de cobertura utilizados foram 85 e 305 kg ha-1 da mistura, contendo N e K2O na proporção 1 para 0,94, respectivamente. Analisaram-se parâmetros de crescimento, qualidade e rendimento da cana-de-açúcar. As irrigações influenciaram na fase inicial de crescimento e no início do máximo desenvolvimento da primeira soca. A dose de adubação influenciou mais nos parâmetros analisados que a lâmina de irrigação. A lâmina de irrigação influenciou significativamente, segundo um comportamento linear positivo, os parâmetros de crescimento, enquanto a sacarose (POL) da cana apresentou comportamento quadrático.
Water stress may become one of the most inevitable factors in years to come regulating crop growth, development, and productivity globally. The application of eco-friendly stress mitigator may sustain physiological fitness of the plants as uptake and accumulation of silicon (Si) found to alleviate stress with plant performance. Our study focused on the mitigative effects of Si using calcium metasilicate (wollastonite powder, CaO·SiO 2) in sugarcane (Saccharum officinarum L.) prior to the exposure of water stress created by the retention of 50−45% soil moisture capacity. Si (0, 50, 100, and 500 ppm L −1) was supplied through soil irrigation in S. officinarum L. grown at about half of the soil moisture capacity for a period of 90 days. Water stress impaired plant growth, biomass, leaf relative water content, SPAD value, photosynthetic pigments capacity, and photochemical efficiency (F v /F m) of photosystem II. The levels of antioxidative defense-induced enzymes, viz., catalase, ascorbate peroxidase, and superoxide dismutase, enhanced. Silicon-treated plants expressed positive correlation with their performance index. A quadratic nonlinear relation observed between loss and gain (%) in physiological and biochemical parameters during water stress upon Si application. Si was found to be effective in restoring the water stress injuries integrated to facilitate the operation of antioxidant defense machinery in S. officinarum L. with improved plant performance index and photosynthetic carbon assimilation.
Plant cell and water relationship regulates morphological, physiological and biochemical characteristics to optimize carboxylation for enhanced biomass yield in sugarcane. Insufficient water irrigation is one of the serious problems to impair potential yield of agriculturally important sugarcane cash crop by loss in plant performance. Our study aims to reveal consequences of foliar spray of silicon (Si) using calcium metasilicate powder (Wollastonite, CaO.SiO2) to alleviate the adverse effects of limited water irrigation in sugarcane. Silicon (0, 50, 100 and 500 ppm) was applied as foliar spray on normally grown 45 days old sugarcane plants. Further, these plants were raised at half field capacity (50%) using water irrigation precisely up to 90 days under open environmental variables. Consequently, restricted irrigation impaired plant growth-development, leaf relative water content (%), photosynthetic pigments, SPAD unit, photosynthetic performance, chlorophyll fluorescence variable yield (Fv/Fm) and biomass yield. Notably, it has enhanced values of proline, hydrogen peroxide (H2O2), malondialdehyde (MDA), antioxidative defense enzyme molecules viz., catalase (CAT), ascorbate peroxidase (APx) and superoxide dismutase (SOD). The foliar spray of Si defended sugarcane plants from limited water irrigation stress as Si quenched harmful effect of water-deficit and also enhanced the operation of antioxidant defense machinery for improved sugarcane plant performance suitably favored stomatal dynamics for photosynthesis and plant productivity.
CANEGRO-Sugarcane model was used to assess the impact of climate change on sugarcane in different combinations of elevated temperature and CO2 concentration. Additionally, we used dynamically downscaled bias-corrected regional climate model (RCM) data using RegCM4 under RCP4.5 scenarios (2040–2060) to project the future change in sugarcane stalk fresh mass (SFM) and sucrose mass (SM). The results showed an increase in temperature, rainfall and solar radiation in the future projections at the study site. The SFM and SM were found to be vulnerable (3–25% decrease) by increasing temperature (1–4 _C); however, a higher concentration (2–14% increase) was observed for both SFM and SM under elevated CO2 levels (450–850 ppm). The combined effect of increased temperature and elevated CO2 had a beneficial effect on SFM but negative on SM (more for rainfed crop). Overall, SFM was projected to increase by 3–39% (rainfed) and 7–47% (irrigated) in 2040–2060 relative to 1971–2000 in diverse agro-climatic zones of the region. Similarly, SM was projected to decrease by 9–69% (rainfed) and 6–37% (irrigated). In general, water stress conditions combined with the projected increase in temperature adversely affected the sugarcane. The findings suggest the development of a water use efficiency, heat-tolerant cane variety and improved farm management strategies in the near future to assist the sugar industry and to adapt to the changing climate in northern India. This is required in the greater perspective of decrease in sucrose mass in spite of double-fold increase in CO2.
Keywords Stalk fresh mass _ Sucrose mass _ RegCM4, RCP4.5 _ CANEGRO-Sugarcane
The sustainability and production capacity of sugarcane (Saccharum officinarum (L.)) in Southern China is essential
to ensure sugar security in China, yet potential crop yield and yield gap (the difference between actual
and potential crop yield) of sugarcane is poorly known. In this study, the sugarcane growth and development
model, QCANE, was validated for sugarcane phenology, stalk height, and yields, then used to simulate potential
yields and yield gaps of sugarcane in Southern Chine (SC) between 1970 and 2014. Simulated potential yields
decreased as longitude and latitude increased, driven by spatial variation in solar radiation and maximum
temperature. The gap between potential and water-limited yields was noticeably larger in Yunnan province
because of the prevalence of seasonal water deficiency. However, nitrogen stress was the dominant driver of the
yield gap, given the abundant precipitation in SC. Across SC, large variation in the yield gap between water-andnitrogen
limited yields and on-farm yields was observed for different counties, a difference that was usually
larger than the local yield gap. Averaged across SC, on-farm sugarcane yields were only 27% of potential yields,
31% of water-limited yields, and 52% of nitrogen-limited yields. This result highlights considerable potential to
significantly increase sugarcane production by improving varieties, government support, effective management
measures such as fertilization, irrigation, and mechanization.
The sugarcane production system is very complex, involving a large number of variables, namely genotype, environmental conditions and crop management, which define yield level. Thus, estimation of sugarcane yield is also complex, nevertheless, highly important for planning and decision-making in the sugarcane industry. Crop simulation models calibrated to local conditions can be useful to estimate yield, since they can capture the effect of the crop management. On the other hand, recent studies have shown that the use of at least three simulation models in an ensemble can reduce simulation uncertainties, resulting in more reliable estimates than using a single model. Thus, the aims of this study were: i) to evaluate the performance of three sugarcane simulation models (FAO‐AZM, DSSAT/CANEGRO and APSIM‐Sugarcane), separately and in a multi-model approach, for commercially managed fields in Brazil; and ii) to propose a management factor (kdec) associated with the yield decline along successive crop cycles to improve performance of these models. Sugarcane yield and meteorological data were obtained for seven Brazilian states. The FAO‐AZM model was calibrated by changing the crop water deficit sensitivity coefficient values. For the DSSAT/CANEGRO and APSIM‐Sugarcane models, small adjustments were made to coefficients previously calibrated for Brazilian cultivars to improve their performances. The three models presented a weak performance, with high mean absolute error (MAE > 29 t/ha) and low precision (R2 < 0.54), which were caused by the lack of coefficients accounting for crop management. The introduction of kdec, which reflects the crop management level, improved yield estimates for all models. When kdec was applied, the mean absolute error decreased to ≤ 12.9 t/ha for the calibration phase, and between 13.0 and 14.9 t/ha for the validation with independent data. Precision was improved, with R2 ranging between 0.70 and 0.72 for calibration phase and between 0.58 and 0.64 for validation. The multi‐model approach also allowed an improvement in modelling performance, in both phases, reducing errors (MAE between 11.7 and 12.9 t/ha) and increasing precision and accuracy. The use of kdec associated with the multi-model approach improved the performance of sugarcane yield estimates, representing more effectively the distinct commercial field conditions of sugarcane cultivated under different cropping systems and Brazilian regions.
Reliable predictions of climate change impacts on water use, irrigation requirements and yields of irrigated sugarcane in South Africa (a water-scarce country) are necessary to plan adaptation strategies. Although previous work has been done in this regard, methodologies and results vary considerably. The objectives were (1) to estimate likely impacts of climate change on sugarcane yields, water use and irrigation demand at three irrigated sugarcane production sites in South Africa (Malelane, Pongola and La Mercy) for current (1980–2010) and future (2070–2100) climate scenarios, using an approach based on the Agricultural Model Intercomparison and Improvement Project (AgMIP) protocols; and (2) to assess the suitability of this methodology for investigating climate change impacts on sugarcane production.
Cultivation of sugarcane is limited by moderate chilling temperatures of 15° in subtropical areas of the world, whereas high temperatures seem to pose less problems. To obtain an overview of the physiological parameters affected, sugarcane plants were grown at 15, 27, and 45° for up to 10 months and photosynthetic parameters of the leaves were determined, namely chlorophyll content, Hill reaction, chlorophyll fluorescence parameters concerning photosystem II and electron transport activity, and critical temperature of chloroplast membrane organization. In all cases plants grown at 27° were superior to those grown at 15 or 45°. The photosynthetic performance of plants grown at 45° was superior to those grown at 15° in all parameters, when the plants were young (3 months old). With age some adaptation to the unfavourable temperatures proceeded, indicated by a change of photosynthetic properties in the direction of plants grown at optimal temperature (27°). The adaptation was especially strong for the plants grown at 15°, so that after 9 months their performance was better than that of 45° plants. The conclusions for breeding of more temperature adapted sugarcane plants are discussed.
Sugarcane plants were grown for 10 months in the greenhouse at 27°, considered the optimal temperature, and at low temperature (15°) and high temperature (45°). The growth pattern, biomass production, sugar levels in leaves and stem, and activity of the enzymes involved in sucrose metabolism were determined on plants grown at each temperature. Plants maintained at 15°were very slow growing, with few and short internodes and few leaves. At 45°the plants had nearly as many internodes and leaves as control plants (27°), but the internodes were smaller and shorter and the leaves became dry earlier; side shoot formation (tillering) was increased. The shoot/root ratio was approximately constant over time and the same for all three growth temperatures. The leaf area per plant increased over time and was highest at 27°. The leaf area per shoot biomass was constant over time, but twice as high at 15°as at 45°and 2.5 higher than at 27°. Total biomass production was half to one third at 45°and one tenth at 15°. The carbohydrate level in the leaves, especially sucrose and starch, were highest in plants grown at 15°and lowest in plants grown at 45°. This result together with the growth data was interpreted as indication that sucrose translocation by the phloem is especially strongly inhibited at 15°whereas at 45°the elevated leaf respiration, which is highest at 45°reduces the amount of available sugar for translocation. The sucrose concentration in the stalk was the same in internodes for plants grown at 15°and 27°and lower in internodes of plants grown at 45°. The hexose concentration in the young internodes was higher at 27°than at the other temperatures, indicating the higher growth rate. All four enzymes of sucrose metabolism (acid and neutral invertase, sucrose synthase and sucrose phosphate synthase) were highest in the stalk at 27°and lowest at 15°the development of activity during internode ripening was the same for all three temperatures. There was a strong correlation, valid for all three growth temperatures, between the sucrose concentration in the stalk internodes and the difference between sucrose phosphate synthase and acid invertase, not however for neutral invertase, although the latter may be higher in activity in some cases. The results are taken as evidence for a decisive role of acid invertase in regulation of sugar storage in sugarcane.
A model of sugarcane (Saccharum officinarum) was made to predict the potential yield under climate change scenarios to analyze the sustainability of new expanded cultivation areas in Brazil and Australia due to increased of the ethanol production. The potential yield in terms of dry matter of sugarcane was adjusted to estimate the carbon dioxide absorption (CO 2), as C4 photosynthesis plant, in relation with air temperature and solar radiation to calculate monthly production of dry mass (DM), during the crop cycle. The sugarcane DM model takes in account a gross photosynthetic rate subtracting losses by maintenance respiration, senescence of leafs and tillers during the crop cycle. The projected increase in mean temperature up to 1.3 to 2.7 °C would increase the suitability for sugarcane production. Our results indicate that the sugarcane increased its productivity under double CO 2. The simulated and observed productivity were 192 vs. 168 t/ha (sugarcane-plant) and 170 vs. 137 t/ha (ratoon). Sugarcane productivity under year 2070 scenarios will increase up to 13% both in São Paulo (Brazil) and Queensland (Australia).
Sugarcane is one of the main extensive crops in Southern Brazil, covering around 8 million ha. The crop is mainly produced under rainfed conditions, which makes the sugarcane sector very susceptible to climate variability and change. The study of the agro-environmental vulnerability of the sugarcane crop is an essential aspect to determine the yield potential, the climatic risks and to conduct the crop planning at medium and long terms. Based on the economic and social importance of sugarcane crop for Southern Brazil and the expected future scenarios of climate change for this region, reported by the IPCC and the First Brazilian Report on Climate Change, the present study had as objectives to assess the impacts of different climate changes scenarios on the water balance and on the potential and actual yields for the main sugarcane production regions of the state of São Paulo, Brazil. For that, twelve climate change scenarios, with increasing temperatures and CO2 concentrations in the atmosphere, and varying changes in rainfall were generated for the years of 2030, 2060 and 2090. The results indicated that, even with the huge impact of climate change on the water balance of all locations, the potential and actual yields may increase substantially as a function of the combination of higher air temperatures, higher CO2 concentration and also better management practices in the future scenarios. By 2090, even with a higher water deficit, the sugarcane actual yield may increase by 82, 71, 51 and 59 %, respectively for Araçatuba, Assis, Jaboticabal and Piracicaba, which indicates an improvement on the water use efficiency. Based on that, sugarcane stands up as a very important crop to face climate change in Brazil and around the world.
The acid invertase content of t.issue slices from immature internodes of sugar· cane decreases rapidly when glucose is supplied in the bat.hing medium, maximum effectiveness occurring at about O· 03r-I.
To prevent negative impacts on food production, energy crops will have to be grown on marginal lands that in some cases may be prone to flooding. Two high fiber/low sugar energycane clones, L 79-1002 and Ho 01-12, and two low fiber/high sugar sugarcane clones, HoCP 96-540 and L 99-226, were grown under periodic flooded and adequately drained conditions to determine if energycane is better suited for cultivation than sugarcane under these stressed field conditions. Periodic flooding consisted of a 7 d duration flood applied every month from February to August. Energycane tolerated the flooded conditions better than sugarcane when biomass and sucrose yields were compared between treatments. Tolerance to flooding was demonstrated in the plant cane and ratoon crops of L 79-1002, and in the ratoon crops of Ho 01-12. Flooding reduced sucrose yields of the two sugarcanes by 23 and 24% in plant and ratoon crops, respectively. Based on total yield loss divided by the number of flooded days, each day of flooding reduced sucrose yields for HoCP 96-540 and L 99-226 by 50 kg ha−1 in plant cane and 30 kg ha−1 for the average of the first and second ratoons. An extensive screening of sugarcane clones is needed to determine if flood tolerance exists within this germplasm. Otherwise exotic sugarcane clones or wild relatives may need to be utilized to develop flood-tolerant sugarcane. If sucrose cannot be produced economically under periodic flooding, energycane for production of cellulosic biomass may be a viable alternative because existing energycane clones are tolerant to periodic flooding.
Rising level of atmospheric CO2 and consequent global warming is evident. Global surface temperature have already increased by 0.8 °C over the 20th century and is projected to increase by 1.4–5.8 °C during the twenty-first century. The global warming will continue till atmospheric concentrations of the major greenhouse gases are stabilized. Among them, CO2 is mainly responsible and is expected to account for about 60% of the warming over the next century. This study reviews advances on causes and consequences of global climate change and its impact on nature and society. Renewable biomass has tremendous potential to mitigate the global warming. Renewable biomass is expected to play a multifunctional role including food production, source of energy and fodder, biodiversity conservation, yield of goods and services to the society as well as mitigation of the impact of climate change. The review highlights the different management and research strategies in forestry, agriculture, agroforestry and grasslands to mitigate the global warming.
Poor yields of sucrose from sugarcane are often associated with low sucrose:cane ratios, particularly when climatic conditions tend to favor stem elongation rather than sucrose accumulation. Plant growth regulators may be used to modify environmental effects on the growth of sugarcane and thus alter the balance between utilization and storage of sucrose. The objectives of this study were to investigate the influence of temperature, soil moisture, and the coadministration of plant growth retardants on the response of sugarcane to treatment with gibberellic acid.
Single foliar applications of GA (gibberellic acid) commercial sugarcane varieties (interspecific hybrids of Saccharum) stimulated stem elongation for from 2 to 6 weeks, but this response was not reflected in higher cane yields unless the plants were harvested within 6 weeks of treatment. A second application of GA at 4 weeks prolonged the growth response. In the field low temperatures were associated with the more prolonged growth responses, which were of smaller amplitude. Moisture stress had no apparent effect on GA response. No correlations were evident between environmental conditions or application rates and the duration of growth responses in greenhouse trials, but the amplitude increased with application rate within the range of 25 to 200 ppm. Three to five immature or semimatttre internodes were affected.
In field trials under warm conditions a period of growth retardation followed the initial GA-induced growth stimulation. This did not occur in greenhouse trials. Stem-sugar concentrations fell during the growthstimulation phase, but recovered as growth rates reduced. Attempts were made to accentuate this recovery, and so to increase the accumulation of sugars, by coadministration of growth retardants with GA. Dalapon had a delayed effect on cane growth, slightly curtailing the duration of the GA response, and suppressing growth thereafter. The phase of growth suppression was accompanied by increased stem sugar concentration in greenhouse-, but not in field-trials. Sodium silicate (at up to 200 ppm) had no significant effect on growth or sugar accumulation and did not modify the response to GA. Treatment with azauracil (at up to 400 ppm) strongly inhibited cane growth and increased stem-sugar concentrations, but showed no significant interaction with GA.
Please view the pdf by using the Full Text (PDF) link under 'View' to the left. Copyright © . .
Previous experiments in the Australian tropics have observed a 'slowdown' in biomass accumulation in mature sugarcane crops. By installing scaffolding to prevent lodging, we eliminated the growth 'slowdown' in 3 experiments to confirm that lodging and stalk death are part of the explanation. In both the wet and dry (irrigated) tropics, lodging of sugarcane significantly decreased both fresh cane yield and commercial cane sugar content (CCS). Prevention of lodging increased cane yield by 11–15%, CCS by 3–12%, and sugar yield by 15–35% at the final harvest in August–September. The rate of increase in CCS in lodged cane was reduced following lodging, although CCS had partially recovered by harvest.A possible component of the lodging effect is a slowdown in the growth due to the ageing of the crop. However, a younger crop (late crop treatment) grew no faster than the scaffolded treatment and so discounted this. In the dry tropics, where cane is irrigated and grows under high radiation, sugar yield was 40 t/ha with scaffolding installed. The increased yield (compared with 35 t/ha in lodged cane) was due to both the survival of an extra 0.8 stalks/m2 and increased accumulation of sugar in live stalks. In 2 years in the wet tropics where sugar yield with scaffolding was 16 t/ha, the same factors, with the addition of increased biomass accumulation in live stalks, were responsible for the increase.
A review of the agronomic and physiological concepts of three sugarcane simulation models was conducted with the view of highlighting their published strengths and limitations with respect to the simulation of sucrose yield. A brief history and description of each model is presented with an examination of their performance and a suggested way forward to improve their accuracy and utility. The models examined were the Australian APSIM-Sugarcane model, the South African CANEGRO model and another Australian model; QCANE. Despite limited published performance data, all the models have performed reasonably well, but the prediction of sucrose yields were not the same. Mean errors of prediction (root mean square of residuals) for sucrose yield for APSIM-Sugarcane were 4.12Mgha−1, for CANEGRO 6.07Mgha−1 and for QCANE 2.51Mgha−1. Improvements for each of the models lie in better understanding (1) the effects of stress (water, nitrogen and temperature) on the partitioning of photosynthate to stored sucrose, (2) the response of different cultivars to stress, and (3) the differences between plant and ratoon crops in respect of radiation-use efficiency and transpiration efficiency. A new approach employing a source–sink concept is suggested, but includes the volume of stalks as a state variable to define the sink size. A central feature is to include a new state variable; reducing sugars to allow the hydrolysis and re-synthesis of sucrose for the construction of the structural stalk carbon (fibre) and to supply stalk maintenance carbon (CO2). Such an approach should offer more mechanistic and explanatory investigations into the growth and management of sugarcane with respect to its sucrose yield and purity, particularly in respect of various ripening strategies.
In irrigated sugarcane production, water is usually withheld prior to harvest to dry the field and to raise the sucrose content of the cane. Past research has provided conflicting results on the optimum length of drying-off. An analysis was conducted of pooled data from 37 experiments on drying-off in Southern Africa to: (1) determine the range of responses in sucrose yield and cane sucrose concentration that have been attained under various drying-off regimes; (2) quantify the trade-off between the loss in cane yield under drying-off and any possible gain in sucrose yield and cane sucrose fresh weight (FW) concentration; and (3) identify which components of sucrose yield and sucrose concentration are most sensitive to late-season water deficit, as a means of developing functions for crop simulation models. In only 22% and 61% of the drying-off treatments was there a significant increase in sucrose yield or sucrose FW concentration, respectively. For both sucrose yield and sucrose FW concentration, the average increase attained by drying-off was 8% and the maximum increase was about 15%. Increase in sucrose yield occurred when the decrease in stalk dry mass was no greater than about 10%. This relationship could form the basis for determining the trade-off between reduction in stalk mass and sucrose yield under varying drying-off regimes, and developing economic optima for drying-off severity. Increase in sucrose FW concentration occurred due to an increase in soluble solids and dehydration. Small reductions in fresh yield of cane under drying-off (up to 10%) can be attributed equally to dehydration and reduction in stalk dry mass.
Temperatures can fluctuate rapidly during the sugarcane harvest season, but the effect of short-term temperature changes on sugar metabolism in sugarcane internodes is unknown. This experiment was designed to test the hypothesis that a transient temperature change alters the activity of one or more sucrose cleavage enzymes in sugarcane internodes. In a growth chamber, sugarcane was subjected to a 24-h treatment at 10oC before returning the chamber to a 10-h, 28oC day, 14-h, 18oC night regime. The transient temperature decrease slightly increased sucrose concentration in the most immature internodes sampled for the first two days after initiation of chilling. However, there was no significant change in activities of the sucrose metabolism enzymes soluble acid invertase, neutral invertase, sucrose synthase, sucrose-phosphate synthase, and cell wall acid invertase in vitro. The slight increase in sucrose concentration was likely due to low-temperature suppression of sucrose cleavage enzymes in planta. Thus, the hypothesis that short-term exposure to cold temperatures alters sucrose metabolism in sugarcane was not supported.