Sugarcane Canopy Research Articles

Within-plant distribution and rapid assessment of sugarcane rust mite population on sugarcane canopy

Sugarcane rust mite (SRM), Abacarus sacchari, has been recognized in Florida since 1983. However, no detection technique had been developed yet, whereas a reliable, effective, and efficient technique is important in a mite management practice. The purposes of this study were to determine the within-plant distribution and to develop a sampling technique for SRM. The study was carried out in sugarcane fields naturally infested with the mite population. The mite distribution was identified with the visual direct counting technique and the imprinting technique. Subsequently, the effectiveness and reliability of both techniques were evaluated. The results showed that the within-plant distribution of mite populations was more concentrated in the middle canopy than in the upper or lower canopies. Furthermore, the mite sampling of the middle portion of the leaf could represent the entire mite population on the plant. More importantly, the imprinting technique was reliable, especially when the third or fourth (+3 or +4) fully expanded leaf was taken as sample, resulting in relative variation (RV) as low as 12.9% and 12.4%, respectively; therefore, the imprinting technique is a promising technique for population monitoring programs.

Sugarcane Water Productivity for Bioethanol, Sugar and Biomass under Deficit Irrigation

Knowledge of how certain crops respond to water stress is one of the prerequisites for choosing the best variety and best management practices to maximize crop water productivity (WPc). The selection of a more efficient protocol for managing irrigation depths throughout the cultivation cycle and in the maturation process at the end of the growth period for each sugarcane variety can maximize bioethanol productivity and WPc for bioethanol, sugar and biomass, in addition to the total energy captured by the sugarcane canopy in the form of dry biomass. This study aimed to evaluate the effect of four irrigation depths and four water deficit intensities on the maturation phase for eight sugarcane varieties under drip irrigation, analyzing the responses related to WPc for bioethanol, sugar and biomass. These experiments were conducted at the University of São Paulo. The plots were positioned in three randomized blocks, and the treatments were distributed in a factorial scheme (4 × 8 × 4). The treatments involved eight commercial varieties of sugarcane and included four water replacement levels and four water deficits of increasing intensity in the final phase of the crop season. It was found that for each variety of sugarcane, there was an optimal combination of irrigation management strategies throughout the cycle and during the maturation process. The RB966928 variety resulted in the best industrial bioethanol yield (68.7 L·Mg−1), WPc for bioethanol (0.97 L·m−3) and WPc for sugar (1.71 kg·m−3). The energy of the aerial parts partitioned as sugar had a direct positive correlation with the availability of water in the soil for all varieties. The RB931011 variety showed the greatest potential for converting water into shoots with an energy of 1.58 GJ·ha−1·mm−1, while the NCo376 variety had the lowest potential at 1.32 GJ·ha−1·mm−1. The productivity of first-generation bioethanol had the highest values per unit of planted area for the greatest water volumes applied and transpired by each variety; this justifies keeping soil moisture at field capacity until harvesting time only for WR100 water replacement level with a maximum ethanol potential of 13.27 m3·ha−1.

Mode of dispersal of the sugarcane rust mite (Abacarus sacchari) in the sugarcane field

ABSTRACT The sugarcane rust mite (SRM), Abacarus sacchari, infests sugarcane in the Everglades Agricultural Area in southern Florida. Reddish-brown symptoms associated with SRM feeding on leaves appear in April and reach their peak in August-September. Mite dispersal plays an important role in habitat colonization. However, SRM dispersal in sugarcane fields has not yet been explored because of its microscopic size. This study aimed to determine the role of aerial dispersal in the colonization of sugarcane fields. Mite dispersal was studied by measuring aerial mites and mite population on the sugarcane canopy with the elimination of possible ambulatory movement among plants. In addition, the potential dispersal using ambulatory movement as well as precipitation was also investigated. The result suggests that aerial dispersal was the most important method for SRM dispersal. Moreover, females predominated airborne mites, comprising approximately 90% of those measured with 60% gravidity. This strong female bias and its high gravidity in airborne mites further demonstrate the potential role of aerial dispersal in the colonization of sugarcane fields.

Estimation of leaf nitrogen levels in sugarcane using hyperspectral models

ABSTRACT: Sugarcane is a good source of renewable energy and helps reduce the emission of greenhouse gases. Nitrogen has a critical role in plant growth; therefore,estimating nitrogen levels is essential, and remote sensing can improve fertilizer management. This field study selects wavelengths from hyperspectral data on a sugarcane canopy to generate models for estimating leaf nitrogen concentrations. The study was carried out in the municipalities of Piracicaba, Jaú, and Santa Maria da Serra, state of São Paulo, in the 2013/2014 growing season. The experiments were carried out using a completely randomized block design with split plots (three sugarcane varieties per plot [variety SP 81-3250 was common to all plots] and four nitrogen concentrations [0, 50, 100, and 150 kgha-1] per subplot) and four repetitions. The wavelengths that best correlated with leaf nitrogen were selected usingsparse partial least square regression. The wavelength regionswere combinedby stepwise multiple linear regression. Spectral bands in the visible (700-705 nm), red-edge (710-720 nm), near-infrared (725, 925, 955, and 980 nm), and short-wave infrared (1355, 1420, 1595, 1600, 1605, and 1610 nm) regions were identified. The R² and RMSE of the model were 0.50 and 1.67 g.kg-1, respectively. The adjusted R² and RMSE of the models for Piracicaba, Jaú, and Santa Maria were 0.31 (unreliable) and 1.30 g.kg-1, 0.53 and 1.96 g.kg-1, and 0.54 and 1.46 g.kg-1, respectively. Our results showed that canopy hyperspectral reflectance can estimate leaf nitrogen concentrations and manage nitrogen application in sugarcane.

Stemflow generation as influenced by sugarcane canopy development.

Rainfall is generally partitioned into throughfall, stemflow, and interception in ecosystems. Stemflow variability can affect the hydrology, ecology, and soil chemistry patterns. However, the influence of canopy structure and rainfall characteristics on stemflow production in sugarcane plantations which are important for renewable energy production remain poorly understood. By using funnels attached to the sugarcane stems, the present study determined the stemflow amount during the period of sugarcane growth and its relationship with plant development. Approximately, 14% of gross rainfall reached the soil as stemflow, and the funneling ratios was 60. In general, it was observed a positive relationship between stemflow rates with both leaf area index and plant height. This was attributed to an increasing number of acute branching angles of the sugarcane leaves as well as high stem tillering and density. However, at the end of growth cycle, stemflow rate was lower than in previous periods which can be attributed to changes in sugarcane canopy such as stems inclination and lodging, reducing the effectiveness of water conveyance along the stem. Our study showed the need to include stemflow to better understand the hydrology of sugarcane plantations.

Non-destructive Measurement Methods of Sugarcane Canopy using Drone Technology

Destructive methods in the field of leaf area measurement are not effective for predicting plant growth. The development of Unmanned Aerial Vehicle (UAV) and digital camera sensors makes it easier to obtain Small Format Aerial Photography (SFAP) data. Nondestructive sugarcane (Saccharum officinarum) cutting using UAV technology is more effective than destructive methods. This study aims to determine the width of the tree canopy using Small-Format Aerial Photography Near-Infrared (NIR). The research stage includes a preliminary survey of sugarcane plantations and determination of Ground Control Point (GCP), data acquisition and SFAP using a modified Syma X8 Pro UAV drone and a Nikon Coolpix a 100 modified NIR camera, infrared aerial photo processing, measurement of cane area on sugarcane objects using Image Processing and Geographic Information Systems (GIS). The results of this research block sugarcane plantation SFAP in Balecatur Village, Sleman Regency, and a map of the area of sugarcane canopy in Balecatur Village, Sleman Regency. The cane canopy area of the study area is 29.3 m2.

Weeds in Florida Sugarcane as Host Plants for Three Species of Rice Stink Bugs (Hemiptera: Pentatomidae)

Weeds in Florida Sugarcane as Host Plants for Three Species of Rice Stink Bugs (Hemiptera: Pentatomidae)

Effects of Spray Parameters on the Effective Spray Width of Single-Rotor Drone in Sugarcane Plant Protection

Sugarcane is the most important sugar crop in the world. The development of sugarcane plant protection by drones is still at the early stage. The evaluation and determination of the effective spray width and droplet distribution in the effective range of aerial spray not only improve the efficiency and quality of the aerial spray operation, but also reduce the pollution of chemical pesticides. To study the influence of the spray parameters of single-rotor drone on the effective spray width and droplet deposition in sugarcane canopy, experiments with two factors (flight height and flight velocity) and three levels were carried out. The results showed that the major factor affecting the effective spray width was drone flying height. For droplet density, the combination of 5.5 m flight height and 2.0 m/s flight velocity was found suitable. Under the condition of 6.0 m of flight height and 2.0 m/s of flight velocity, the effective spray width was the optimal. For droplet deposition uniformity, the combination of 6.0 m flight height and 3.0 m/s flight velocity was suitable. Under the comprehensive consideration, the optimal spraying parameters were chosen as 6.0 m of flight height and 2.5 m/s of flight velocity, which led to the lowest usage of pesticide at 15.38 L/ha. The results of this research can provide guidance for choosing proper parameters of single-rotor drone in sugarcane protection.

Effects of Spray Parameters of Drone on the Droplet Deposition in Sugarcane Canopy

Sugarcane is an important sugar crop in China and the world. Manual sprayer is the main method for pesticide application in sugarcane in China, the spray efficiency of which is low and chemical waste is enormous. Aerial spray by drone has the advantages of high efficiency and flexibility. However, effects of spray parameters of drone on the droplet distribution on sugarcane canopy have not been reported. In the present study, spray experiments were conducted with orthogonal design with three factors (spray volume, flight height, and flight velocity) and three levels by quad-rotor drone. For droplet deposition density, it was found optimal when 15 L/ha of spray volume, 3 m of flight height, and 4 m/s of flight velocity were used for the upper layer. For the mid-layer and lower layers, it was found suitable using 15 L/ha of spray volume, 2 m of flight height, and 4 m/s of flight velocity. For droplet deposition uniformity, it was found optimal for the upper layer when using 15 L/ha of spray volume, 4 m of flight height, and 4 m/s of flight velocity, and that 15 L/ha of spray volume, 3 m of flight height, and 4 m/s of flight velocity for the mid-layer, and 12 L/ha of spray volume, 3 m of flight height, and 5 m/s of flight velocity for the lower layer. For droplet deposition penetration, it was appropriate using 12 L/ha of spray volume, 4 m of flight height, and 4 m/s of flight velocity. Under comprehensive consideration of the density, uniformity, and penetration of droplet deposition, the optimal spraying parameters were 15 L/ha of spray volume, 3 m of flight height, and 4 m/s of flight velocity, which could be used as a reference parameter of drone when applied in sugarcane crop.

Sugarcane canopy detection using high spatial resolution UAS images and digital surface model

The use of an unmanned aerial system (UAS) equipped with multispectral cameras is a potential approach to acquire canopy reflectance to make various correlations with desired crop parameters. However, the acquired reflectance data are mixed with unwanted data, such as reflectance from soil, which significantly affects some commonly used vegetation indices, such as the NDVI. This study compares the performance of three methods for detecting the canopy area of 3-month-old sugarcane crops. These methods extract the canopy areas using 5 NDVI thresholds (0.2, 0.3, 0.4, 0.5, and 0.6), a principal component analysis (PCA) threshold, and a digital surface model (DSM) threshold. The performance assessment will deliberately consider the quality percentage (QP) of each method to correctly detect the canopy area of short sugarcane crops in 10 selected images. The results show that filtration by the PCA threshold method provides the best result with a QP of 65.89-78.72%. The NDVI threshold method at levels of 0.3 and 0.4 follow with QPs of 58.42-68.81% and 40.80-70.81%, respectively, and the lowest accuracy is obtained by the DSM threshold method, which has QPs of 14.80-30.78%.

Sugarcane response and fall panicum (Panicum dichotomiflorum) control with topramezone and triazine herbicides

AbstractField studies were conducted on organic soils in Belle Glade, FL, in 2016 to 2017 to evaluate sugarcane tolerance and fall panicum control with topramezone applied alone or in combination with triazine herbicides (atrazine, metribuzin, ametryn). Treatments included topramezone (25 and 50 g ai ha−1) applied alone or in combination with atrazine (2,240 g ai ha−1), metribuzin (2,240 g ai ha−1), and ametryn (440 g ha−1) on four plant cane varieties to evaluate tolerance, and on second ratoon fields to determine efficacy on fall panicum control. Topramezone applied alone had no effect on sugarcane chlorophyll fluorescence (i.e., the ratio of variable fluorescence to maximum fluorescence), total chlorophyll, and carotenoid 7 to 28 d after treatment (DAT), suggesting sugarcane tolerance. Significant reduction of these parameters occured 7 to 14 DAT when topramezone (50 g ai ha−1) was applied with ametryn or metribuzin; however, reductions were not detected thereafter, indicating recovery. Sugarcane yield was not affected by topramezone applied alone or in combination with the triazine herbicides. Topramezone (50 g ai ha−1) plus metribuzin resulted in acceptable control of fall panicum (84%) with limited to no regrowth of meristematic tissue at sugarcane canopy closure, equivalent to 56 to 70 DAT. These results indicate that when sequential applications of topramezone, applied alone or in combination with these triazine herbicides, are required for efficacious weed control, topramezone applications alone can be made after 7 d, whereas the combinations can be made after 14 or 21 d, depending on sugarcane sensitivity.

Sugar cane Canopy Spraying: A Perspective Solution with Ergonomics and Mechatronics Approach

Chemicals application is very significant for control of disease and insect infestation in sugar cane crop. The problem observed with existing practice is inefficient spraying due to inconvenience of operation as workers are prone to injuries and working above shoulder height results in postural stresses as sugar cane being a tall crop. To overcome these issues, a novel approach to develop canopy sprayer for sugar cane crop based on the application of mechatronics and ergonomics is worked out that consists of self-propelled e-powered unit, sensor-based foldable spraying system, operable conditioned system with control monitor unit. It will be equipped with variable height platform for safety and comfort of operator along with effective spraying at desired height.

Effects of Mixed Planting of Horizontal- and Erect-Leafed Varieties on Canopy Light Use and Growth in Sugarcane

Improving sugarcane canopy structure using varietal mixtures, by exploiting the diversity of plant types available, is effective for improving biomass production and cane yield. A single variety cannot meet the demands for optimal canopy structure at each growth stage and for adaptability to changing within- and above-canopy light environments. The present study performed mixed planting of two varieties with different plant types to demonstrate the effects of such a mixture on canopy growth and its light use in simulated canopy conditions at the early growth stage. The varietal mixture induced plasticity of plant size, leaf allocation, and nitrogen accumulation, and altered the growth habit of each variety compared with that when each was grown as a monocrop. Mixed-variety planting increased the plant size of the erect-leafed variety while decreasing that of the horizontal-leafed variety; however, the total canopy biomass of the mixture was greater than the one predicted on the basis of the two-component monocropped ones. Leaves of the erect-leafed variety were distributed at a higher canopy layer, whereas those of the horizontal-leafed variety were distributed at a lower canopy layer under mixed planting than under the monocrops. Through such habitat segregation, lower light extinction coefficients were obtained with the moderate leaf area index of the mixture.

Estimations of Nitrogen Concentration in Sugarcane Using Hyperspectral Imagery

This study aims to estimate the spatial variation of sugarcane Canopy Nitrogen Concentration (CNC) using spectral data, which were measured from a spaceborne hyperspectral image. Stepwise Multiple Linear Regression (SMLR) and Support Vector Regression (SVR) were applied to calibrate and validate the CNC estimation models. The raw spectral reflectance was transformed into a First-Derivative Spectrum (FDS) and absorption features to remove the spectral noise and finally used as input variables. The results indicate that the estimation models developed by non-linear SVR based Radial Basis Function (RBF) kernel yield the higher correlation coefficient with CNC compared with the models computed by SMLR. The best model shows the coefficient of determination value of 0.78 and Root Mean Square Error (RMSE) value of 0.035% nitrogen. The narrow sensitive spectral wavelengths for quantifying nitrogen content in the combined cultivar environments existed mainly in the electromagnetic spectrum of the visible-red, longer portion of red edge, shortwave infrared regions and far-near infrared. The most important conclusion from this experiment is that spectral signals from the space hyperspectral data contain the meaningful information for quantifying sugarcane CNC across larger geographic areas. The nutrient deficient areas could be corrected by applying suitable farm management.

A satellite based crop water stress index for irrigation scheduling in sugarcane fields

In this study, the capability of crop water stress index (CWSI) based on satellite thermal infrared data for estimating water stress and irrigation scheduling in sugarcane fields was evaluated. For this purpose, eight Landsat 8 satellite images were acquired during the sugarcane growing season (May–September 2015). Simultaneous with the satellite overpass times, in-situ measurements of canopy temperature and vegetation water content (VWC) were conducted in forty points located in eight sugarcane fields per image (in total 320 observation points in 32 fields). These fields were selected with different ages (Plant, Ratoon 1, Ratoon 2, and Ratoon 3) and irrigation schedule. Then, the CWSI was calculated in three different ways including: 1) based on the Idso method and using the handheld infrared thermometer, 2) based on the Idso method and thermal infrared data of Landsat 8 satellite imagery, 3) using a new proposed procedure for retrieving CWSI from the satellite imagery with using the hot and cold pixels. Results show a good relationship between the calculated CWSI based on field measurement and new CWSI based on satellite data with the coefficient of determination of 0.49–0.85 and the root mean square error (RMSE) of 0.12–0.29 for different images. Further, a negative relationship between VWC and CWSI, with R2 values of 0.42–0.78, was observed. This relationship increases with developing sugarcane canopy, and decreases with an increasing plant age. Comparing recorded irrigation events in the fields, estimated CWSI and VWC shows that water stress can be classified into three critical classes including high water stress (0.70<VWC≤0.75), medium water stress (0.75<VWC≤0.8), and low stress (0.8<VWC≤0.85). This classification can be used as a part of an operational procedure for appropriate irrigation scheduling. All of the aforementioned results indicate that the CWSI based on the proposed approach in this study can be used effectively for monitoring water stress and irrigation scheduling in sugarcane fields using satellite imagery without any need for ground ancillary data.

Development of a Three-Dimensional Ray-Tracing Model of Sugarcane Canopy Photosynthesis and Its Application in Assessing Impacts of Varied Row Spacing

Sugarcane has emerged as the second largest source of biofuel, primarily as ethanol produced in Brazil. Dual row planting using asymmetric spacing of rows can decrease damage to plants and soil structure from harvest equipment though potentially can cause some loss of productivity due to increased shading. Can we assess this loss, without experimental testing of the thousands of potential permutations of planting design and cultivar canopy form? Here we develop a computational framework which couples 3D canopy architectural information, a ray-tracing algorithm, and a steady-state C4 photosynthesis model to study this question. We demonstrate the utility of the model by comparing evenly spaced rows at 100 cm to alternating row spacing of 45 and 155 cm. Asymmetric planting caused a 9% decrease in predicted net canopy carbon uptake over the growing season for a major current cultivar. The loss was greater at lower leaf area indices, when leaves were more vertical and when rows were oriented east-west, suggesting agronomic approaches to minimize loss. This study demonstrates the utility of this computational framework, which could also be used to aid breeding by identifying ideotypes for different environments and objectives, and to assess impacts of environmental change.

Assessment of Sugarcane Yield Potential across Large Numbers of Genotypes using Canopy Reflectance Measurements

Canopy reflectance indices have been used to monitor plant growth and estimate yields in many field crops. Little is known if canopy reflectance of sugarcane (a complex hybrid of Saccharum spp.) can be used to estimate growth and yield potential across large numbers of genotypes (clones) in the early stages of a breeding program. The objectives of this study were to identify clonal variation in sugarcane canopy reflectance and yield components and to determine if there were any putative relationships between canopy reflectance or reflectance indices and yield variables. In Stage II of the Canal Point sugarcane breeding and cultivar development program (CP program), canopy reflectance data were collected five to six times from each of 156 to 164 randomly selected clones during the growing seasons in 2011 through 2013 using a multispectral radiometer. Normalized difference vegetation index (NDVI) and other reflectance indices were calculated using the reflectance values. Yield traits, including stalk population, mean stalk weight, cane yield, commercial recoverable sucrose (CRS), and sucrose yield, were determined on mature plants in late October. Stalk population and cane yield were most highly correlated with reflectance at the wavebands centered at 800 and 980 nm and NDVI (r = 0.50–0.68; P &lt; 0.0001), while CRS was not related to canopy reflectance. The best time to measure canopy reflectance for yield estimation across clones was from March to April (tillering stage). Canopy reflectance measurements at the early growth stage can be used as a screening tool to estimate yield potential for large numbers of clones in sugarcane breeding programs.

Sugar cane nutrient requirements and the role of atmospheric deposition supplying supplementary fertilization in a Venezuelan sugar cane plantation

As a consequence of high industrial and agricultural activities, acidic rains loaded with pollutants—including nutrients—are characteristic of northern central Venezuela, a region dominated by sugar cane plantations. Canopies of forest and agricultural crops can modify the chemistry of rainfall through uptake, leaching and outwash of deposited ions. This paper describes the change in the chemistry of acid rains after passing through a sugar cane canopy. Four plots of 300m2 within a 4.5 ha experimental area, planted with Saccharum officinarum had rain and throughfall collectors installed. The study corresponds to the analysis of the growing season of the third ratoon. The pH of the rain in the agroecosy stem increased after passing through the canopy. The magnitudes of the changes were important and partially related to the significant amount of cations leached from the leaves or washed out from dry deposition to the leaves. N inputs for wet and dry deposition in the agroecosystem were high (25.25kg ha−1 yr−1) as a consequence of the agricultural activity in the area, the local burning of sugar cane before cropping, and the location of the experimental area close to petrochemical and fertilizer industries. Rainfall constitutes an important source of nutrient inputs to the sugar cane system. In the case of macronutrients (N, P and K) the inputs were high and supply an important fraction of plant nutrient needs, as occurs for zinc and copper.

Estimating Canopy Nitrogen Concentration in Sugarcane Using Field Imaging Spectroscopy

The retrieval of nutrient concentration in sugarcane through hyperspectral remote sensing is widely known to be affected by canopy architecture. The goal of this research was to develop an estimation model that could explain the nitrogen variations in sugarcane with combined cultivars. Reflectance spectra were measured over the sugarcane canopy using a field spectroradiometer. The models were calibrated by a vegetation index and multiple linear regression. The original reflectance was transformed into a First-Derivative Spectrum (FDS) and two absorption features. The results indicated that the sensitive spectral wavelengths for quantifying nitrogen content existed mainly in the visible, red edge and far near-infrared regions of the electromagnetic spectrum. Normalized Differential Index (NDI) based on FDS(750/700) and Ratio Spectral Index (RVI) based on FDS(724/700) are best suited for characterizing the nitrogen concentration. The modified estimation model, generated by the Stepwise Multiple Linear Regression (SMLR) technique from FDS centered at 410, 426, 720, 754, and 1,216 nm, yielded the highest correlation coefficient value of 0.86 and Root Mean Square Error of the Estimate (RMSE) value of 0.033%N (n = 90) with nitrogen concentration in sugarcane. The results of this research demonstrated that the estimation model developed by SMLR yielded a higher correlation coefficient with nitrogen content than the model computed by narrow vegetation indices. The strong correlation between measured and estimated nitrogen concentration indicated that the methods proposed in this study could be used for the reliable diagnosis of nitrogen quantity in sugarcane. Finally, the success of the field spectroscopy used for estimating the nutrient quality of sugarcane allowed an additional experiment using the polar orbiting hyperspectral data for the timely determination of crop nutrient status in rangelands without any requirement of prior cultivar information.

Growth and Radiation Use Efficiency of Sugarcane Under Irrigated and Rain-fed Conditions in Sri Lanka

A field experiment was conducted to evaluate sugarcane varieties based on their radiation use efficiencies (RUE) at the Sugarcane Research Institute, Uda Walawe, Sri Lanka. Sugarcane was grown under irrigated (soil water potential >−0.05 MPa) and rain-fed conditions in a split-plot design. Biomass accumulation, canopy development, leaf angle and radiation intercepted by the sugarcane canopy were measured. Seasonal and fractional incoming radiation intercepted, light extinction coefficient (k) and RUE were estimated. Rain-fed crop reduced RUE by 53 % compared to the irrigated crop. RUE varied from 1.63 to 2.09 g MJ−1 and 0.71 to 1.03 g MJ−1 under irrigated and rain-fed conditions respectively. The variety SL 83 06 showed the highest RUE under both water regimes with higher canopy development and lower k values consistently throughout the growing period. The canopy in erect leaves increases biomass production and RUE. As the erect orientation of leaves is genetically governed trait, it could be used for the hybridisation programme of sugarcane to produce highly efficient solar energy-utilising hybrids of sugarcane.