Sugar Beet Fields Research Articles

Agricultural robot dataset for plant classification, localization and mapping on sugar beet fields

There is an increasing interest in agricultural robotics and precision farming. In such domains, relevant datasets are often hard to obtain, as dedicated fields need to be maintained and the timing of the data collection is critical. In this paper, we present a large-scale agricultural robot dataset for plant classification as well as localization and mapping that covers the relevant growth stages of plants for robotic intervention and weed control. We used a readily available agricultural field robot to record the dataset on a sugar beet farm near Bonn in Germany over a period of three months in the spring of 2016. On average, we recorded data three times per week, starting at the emergence of the plants and stopping at the state when the field was no longer accessible to the machinery without damaging the crops. The robot carried a four-channel multi-spectral camera and an RGB-D sensor to capture detailed information about the plantation. Multiple lidar and global positioning system sensors as well as wheel encoders provided measurements relevant to localization, navigation, and mapping. All sensors had been calibrated before the data acquisition campaign. In addition to the data recorded by the robot, we provide lidar data of the field recorded using a terrestrial laser scanner. We believe this dataset will help researchers to develop autonomous systems operating in agricultural field environments. The dataset can be downloaded from http://www.ipb.uni-bonn.de/data/sugarbeets2016/.

Area-wide mass trapping by pheromone-based attractants for the control of sugar beet weevil (Bothynoderes punctiventris Germar, Coleoptera: Curculionidae).

Owing to the changing climate, narrow crop rotation, and changes in insecticide application practice, sugar beet weevil (SBW) (Bothynoderes punctiventris Germar) has become the most important economic pest in sugar beet. To develop alternative control methods, an area-wide (AW) control program using aggregation pheromones was implemented over 4 years on an area of 6 and 14.8 km2 in east Croatia. The mass trapping of SBW on the 'old' sugar beet fields reduced the population from 0.73% to 11.59%. Owing to the strong attack, mass trapping was not effective enough to avoid an insecticide application. However, it significantly reduced the number of insecticide applications, the amount of insecticide used, and the damage compared to the fields outside the mass trapping area. This is the first study to implement an AW program for SBW. It may not be possible to state from this study that trapping alone can reduce the SBW population below the economic threshold level. However, the data do suggest that trapping can play an important role in the reduction of insecticide applications and in creating an integrated pest management plan for dealing with SBW under similar circumstances. © 2017 Society of Chemical Industry.

Role of Common Lambsquarter and Chard Weeds in Increasing Beet Fly Pegomyia mixta Larval-Pupal Parasitoid, Opius nitidulator (Nees) in Sugar Beet Fields

Role of Common Lambsquarter and Chard Weeds in Increasing Beet Fly Pegomyia mixta Larval-Pupal Parasitoid, Opius nitidulator (Nees) in Sugar Beet Fields

Within-field variations in sugar beet yield and quality and their correlation with environmental variables in the East of England

Abstract Spatial variability of sugar beet yield and quality within fields and their correlation with environmental variables was investigated in order to explore the potential for more precise agronomy. In three uniformly-managed, commercial sugar beet fields in the east of England spatial variation in the commercial value of the sugar yield ranged from £232 to £3320 per hectare. This variation was not random; there were high and low yielding patches in each field. Sugar beet root yield was positively correlated with the spatial distribution of crop plant population, soil organic matter and soil moisture, but negatively with weed density and canopy temperature. Correlations of sugar beet yield with soil type, elevation and soil available phosphate, potassium and magnesium were, however, inconsistent between the three fields and over two seasons. With respect to sugar beet quality, spatial variation in the amino acid and potassium concentrations in the sugar beet roots was associated with soil type and elevation, whereas sugar percentage varied randomly in two of the fields. Interventions and research that could help to optimize yield on a spatially-variable basis are discussed.

Beet curly top virus Strains Associated with Sugar Beet in Idaho, Oregon, and a Western U.S. Collection.

Curly top of sugar beet is a serious, yield-limiting disease in semiarid production areas caused by Beet curly top virus (BCTV) and transmitted by the beet leafhopper. One of the primary means of control for BCTV in sugar beet is host resistance but effectiveness of resistance can vary among BCTV strains. Strain prevalence among BCTV populations was last investigated in Idaho and Oregon during a 2006-to-2007 collection but changes in disease severity suggested a need for reevaluation. Therefore, 406 leaf samples symptomatic for curly top were collected from sugar beet plants in commercial sugar beet fields in Idaho and Oregon from 2012 to 2015. DNA was isolated and BCTV strain composition was investigated based on polymerase chain reaction assays with strain-specific primers for the Severe (Svr) and California/Logan (CA/Logan) strains and primers that amplified a group of Worland (Wor)-like strains. The BCTV strain distribution averaged 2% Svr, 30% CA/Logan, and 87% Wor-like (16% had mixed infections), which differed from the previously published 2006-to-2007 collection (87% Svr, 7% CA/Logan, and 60% Wor-like; 59% mixed infections) based on a contingency test (P < 0.0001). Whole-genome sequencing (GenBank accessions KT276895 to KT276920 and KX867015 to KX867057) with overlapping primers found that the Wor-like strains included Wor, Colorado and a previously undescribed strain designated Kimberly1. Results confirm a shift from Svr being one of the dominant BCTV strains in commercial sugar beet fields in 2006 to 2007 to becoming undetectable at times during recent years.

Molecular and experimental evidence of multi-resistance of Cercospora beticola field populations to MBC, DMI and QoI fungicides

Cercospora leaf spot (CLS) caused by Cercospora beticola occurs annually in Serbia causing severe yield losses of sugar beet, which requires intensive use of fungicides. In recent years we have observed unsatisfactory control of CLS originating from northwestern Serbia. Frequency of C. beticola populations resistant to Quinone outside inhibitors (QoI) was 81% (51/63 isolates), 98% (62/63) to sterol-demethylation inbibitors (DMI) and 54% (34/63) to methyl-2-benzimidazole carbamate fungicides (MBC). The genetic basis underlying the resistance was tested by characterizing the cob, CYP51 and s-tubulin genes, associated with resistance to QoI, DMI and MBC fungicides, respectively. Isolates that were resistant to QoI fungicides had the G143A mutation in the cob gene. Characterization of the CYP51 gene revealed seven diverse haplotypes; however, no correlation with sensitivity or resistance to DMI fungicides could be identified. Resistance to MBC fungicides was associated with the presence of the E198A mutation in the s-tubulin gene of all resistant isolates. From a total of 63 isolates originating from sugar beet fields of northwestern Serbia, 62 isolates showed resistance to multiple modes of action. Three multi-resistant phenotypes were identified: MR1 (N = 29) - resistant to QoI and DMI fungicides (QoI-R and DMI-R) but sensitive to MBC fungicides (MBC-S); MR2 (N = 11, QoI-S, DMI-R and MBC-R); and MR3 (N = 22), resistant to all three groups of fungicides (QoI-R, DMI-R and MBC-R). This is the first report of C. beticola resistance to QoI fungicides in Serbia. This study revealed development of multi-resistance of C. beticola isolates to MBC, DMI and QoI fungicides, which represents the first record of this phenomenon in C. beticola populations.

Sugar beet yield loss predicted by relative weed cover, weed biomass and weed density

Sugar beet yield loss was predicted from early observations of weed density, relative weed cover, and weed biomass using non-linear regression models. Six field experiments were conducted in Germany and in the Russian Federation in 2012, 2013 and 2014. Average weed densities varied from 20 to 131 with typical weed species compositions for sugar beet fields at both locations. Sugar beet yielded higher in Germany and relative yield losses were lower than in Russia. Data of weed density, relative weed cover, weed biomass and relative yield loss fitted well to the non-linear regression models. Competitive weed species such as Chenopodium album and Amaranthus retroflexus caused more than 80% yield loss. Relative weed cover regression models provided more accurate predictions of sugar beet yield losses than weed biomass and weed density.

Aggregation Behavior and a Putative Aggregation Pheromone in Sugar Beet Root Maggot Flies (Diptera: Ulidiidae).

Male-biased aggregations of sugar beet root maggot, Tetanops myopaeformis (Röder) (Diptera: Ulidiidae), flies were observed on utility poles near sugar beet (Beta vulgaris L. [Chenopodiaceae]) fields in southern Idaho; this contrasts with the approximately equal sex ratio typically observed within fields. Peak observation of mating pairs coincided with peak diurnal abundance of flies. Volatiles released by individual male and female flies were sampled from 08:00 to 24:00 hours in the laboratory using solid-phase microextraction and analyzed using gas chromatography/mass spectrometry (GC/MS). Eleven compounds were uniquely detected from males. Three of these compounds (2-undecanol, 2-decanol, and sec-nonyl acetate) were detected in greater quantities during 12:00–24:00 hours than during 08:00–12:00 hours. The remaining eight compounds uniquely detected from males did not exhibit temporal trends in release. Both sexes produced 2-nonanol, but males produced substantially higher (ca. 80-fold) concentrations of this compound than females, again peaking after 12:00 hours. The temporal synchrony among male aggregation behavior, peak mating rates, and release of certain volatile compounds by males suggest that T. myopaeformis flies exhibit lekking behavior and produce an associated pheromone. Field assays using synthetic blends of the putative aggregation pheromone showed evidence of attraction in both females and males.

EPSPS Gene Copy Number and Whole-Plant Glyphosate Resistance Level in Kochia scoparia.

Glyphosate-resistant (GR) Kochia scoparia has evolved in dryland chemical fallow systems throughout North America and the mechanism of resistance involves 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene duplication. Agricultural fields in four states were surveyed for K. scoparia in 2013 and tested for glyphosate-resistance level and EPSPS gene copy number. Glyphosate resistance was confirmed in K. scoparia populations collected from sugarbeet fields in Colorado, Wyoming, and Nebraska, and Montana. Glyphosate resistance was also confirmed in K. scoparia accessions collected from wheat-fallow fields in Montana. All GR samples had increased EPSPS gene copy number, with median population values up to 11 from sugarbeet fields and up to 13 in Montana wheat-fallow fields. The results indicate that glyphosate susceptibility can be accurately diagnosed using EPSPS gene copy number.

Efficacy and safety of generic azoxystrobin at controlling Rhizoctonia solani in sugar beet

Rhizoctonia solani Kühn is a major soil-borne pathogen limiting sugar beet (Beta vulgaris L.) production in the United States and other countries worldwide. There is no commercial cultivar which is immune from infection by R. solani and highly resistant cultivars typically have a yield penalty. Growers use cultivars with some levels of resistance and rely on the timely application of fungicides to control R. solani. Azoxystrobin (Quadris®) has been the most widely used fungicide for control of R. solani on sugar beet since its registration in the United States in 1997. In 2015, growers wanted to know whether generic azoxystrobin, which became available on the market and at a lower price than Quadris®, would provide effective control of R. solani. The objectives of this greenhouse study were to evaluate the efficacy and safety of generic azoxystrobins at controlling R. solani on sugar beet compared to the industry's standard Quadris. Three generic azoxystrobins – Satori®, Aframe™ and Equation™ - and two application methods - in-furrow at planting and band applications to 4-leaf stage sugar beet - were evaluated. Inoculation with R. solani AG 2-2IIIB was done after fungicide applications. To check for phytotoxicity, fungicides were applied but with mock inoculation. Plant survivors, plant height, root weight and disease severity were evaluated. Results indicated that the generic azoxystrobins were safe to use on sugar beet seeds and plants and provided similar disease control of R. solani as the industry's standard Quadris treatment. This study demonstrated under greenhouse conditions that Satori®, Aframe™ and Equation™ have the potential to be used by growers for disease management in sugar beet fields with a history of R. solani.

Agricultural land use affects abundance and dispersal tendency of predatory arthropods

Predatory arthropods contribute to biological control, but to become an integral part of agricultural management, it is essential to identify drivers of their spatio-temporal distribution at the landscape scale. This study focuses on how agricultural land use affects the community composition, emergence and dispersal tendency of predatory arthropods. The arthropods were collected in emergence traps during the growing season (14 weeks) in a gradient of agricultural land uses from intensively managed sugar beet fields, over winter wheat fields, to less intensively managed grasslands. The emergence traps were equipped with one pitfall trap and a collecting bottle at the top. The distribution of the arthropods between these two collecting methods was assumed to represent their tendency to move out of the habitat. The grasslands had the highest numbers of spiders, while the winter wheat fields had the highest numbers of omnivorous rove beetles and macropterous predaceous ground beetles. The phenology of emergence differed between the land-use types, resulting in seasonal differences in community composition. The overall dispersal tendency of predatory arthropods was higher in crop fields than in grasslands. This study suggests that only a diverse mix of agricultural land uses will provide high levels of predators from different functional groups, throughout the growing season.

Pathogenicity, vegetative compatibility and genetic diversity of Verticillium dahliae isolates from sugar beet

Verticillium wilt of sugar beet is a disease that has received very little attention, but which has been reported to reduce sugar quality. A survey of sugar beet fields with wilt symptoms was conducted in 2007 (5 roots from each of 40 fields) and 2008 (5 roots from each of 45 fields) in Idaho. Verticillium dahliae was isolated from all root samples. From a collection of 106 V. dahliae sugar beet isolates, all were of the MAT1-2 mating type. The vegetative compatibility grouping (VCG) was evaluated for 93 of these isolates and 95, 3, 1 and 1% were VCG 4A, VCG 2B, VCG 4B and non-compatible, respectively. All the VCG 4A isolates had the same mitochondrial haplotype based on sequencing of cox3 to nad6 and cox1 to rnl loci, while the VCG 2B isolates had two haplotypes. Pathogenicity tests on sugar beet cultivar ‘Monohikari’ revealed that the VCG 4A isolates produced more foliar symptoms (P < 0.0001) than VCG 1, 1A, 2A, 2B, 3 and 4B isolates, but none of the VCGs consistently reduced root and foliage weight. Since V. dahliae VCG 4A isolates have also been reported as a pathogen of potato in North America, rotating sugar beet fields with potato could be a concern.

Effective Vision‐based Classification for Separating Sugar Beets and Weeds for Precision Farming

The use of robots in precision farming has the potential to reduce the reliance on herbicides and pesticides through selectively spraying individual plants or through manual weed removal. A prerequisite for that is the ability of the robot to separate and identify the value crops and the weeds in the field. Based on the output of the robot's perception system, it can trigger the actuators for spraying or removal. In this paper, we address the problem of detecting sugar beet plants as well as weeds using a camera installed on a mobile field robot. We propose a system that performs vegetation detection, local as well as object‐based feature extraction, random forest classification, and smoothing through a Markov random field to obtain an accurate estimate of crops and weeds. We implemented and thoroughly evaluated our system using a real farm robot in different sugar beet fields, and we illustrate that our approach allows for accurately identifying weeds in a field.

A cost-effective canopy temperature measurement system for precision agriculture: a case study on sugar beet

Increasing agricultural efficiency in a sustainable manner will contribute to feed a growing population under limited land, nutrient and water resources. Water scarcity and the increasing social concern for this resource are already requiring more sophisticated irrigation and decision-support systems. To address the heterogeneity in crop water status in a commercial field, precision irrigation requires accurate information about crops (e.g., crop water status), soil (e.g., moisture content) and weather (e.g., wind speed and vapor pressure deficit). Numerous studies have shown that plant canopy temperature can be used to derive reliable plant water stress indicators, thus making it a promising tool for irrigation water management. However, efficient and cost-effective measurement techniques are still lacking. This paper assesses the potential of infrared thermometry and thermal imaging for monitoring plant water stress in a commercial sugar beet field by comparing canopy temperature data acquired from a conventional thermal camera with an inexpensive infrared sensor, both mounted on a rotary-wing unmanned aerial vehicle (UAV). Measurements were taken at various phenological stages of the sugar beet growing season. Laboratory tests were performed to determine the key features for accurate temperature measurements and flight altitude. Experiments were conducted in 2014 and 2015 in experimental and commercial sugar beet fields in Southwestern Spain to (i) develop an affordable infrared temperature system suitable for mounting on a UAV to obtain thermal information, (ii) compare sugar beet canopy temperature measurements collected with the low-cost platform with those obtained from a conventional thermal camera, both mounted on a rotary-wing UAV, (iii) identify the factors that will limit the use of the low-cost system to derive temperature-based water stress indices. To accomplish these objectives, well-watered and deficit irrigated plots were established. Results indicated that the lightweight canopy temperature system was robust and reliable, although there were some constraints related to weather conditions and delimitation of the area covered by the infrared sensor.

Combining Sun-Induced Chlorophyll Fluorescence and Photochemical Reflectance Index Improves Diurnal Modeling of Gross Primary Productivity

Sun-induced chlorophyll fluorescence (F) is a novel remote sensing parameter providing an estimate of actual photosynthetic rates. A combination of this new observable and Monteith’s light use efficiency (LUE) concept was suggested for an advanced modeling of gross primary productivity (GPP). In this demonstration study, we evaluate the potential of both F and the more commonly used photochemical reflectance index (PRI) to approximate the LUE term in Monteith’s equation and eventually improve the forward modeling of GPP diurnals. Both F and the PRI were derived from ground and airborne based spectrometer measurements over two different crops. We demonstrate that approximating dynamic changes of LUE using F and PRI significantly improves the forward modeling of GPP diurnals. Especially in sugar beet, a changing photosynthetic efficiency during the day was traceable with F and incorporating F in the forward modeling significantly improved the estimation of GPP. Airborne data were projected to produce F and PRI maps for winter wheat and sugar beet fields over the course of one day. We detected a significant variability of both, F and the PRI within one field and particularly between fields. The variability of F and PRI was higher in sugar beet, which also showed a physiological down-regulation of leaf photosynthesis. Our results underline the potential of F to serve as a superior indicator for the actual efficiency of the photosynthetic machinery, which is linked to physiological responses of vegetation.

Identification of strain types of some Beet necrotic yellow vein virus isolates determined in Northern and Central Parts of Turkey

Beet necrotic yellow vein virus (BNYVV), the agent of rhizomania disease, causes severe economic losses in sugar beet fields in all over the world. The virus is transmitted by a plasmodiophorid vector, Polymyxa betae Keskin. Twenty soil samples, collected from sugar beet fields in northern and central parts of Turkey during surveys in 2004 and 2005 and known to be infested with viruliferous cultures of P. betae carrying BNYVV, were selected and used in this study. Sample selection was made according to symptom expression of beet seedlings in preliminary bait plant tests and locations of the soil samples that accurately represent the region from which they were taken. Total RNAs were extracted from sugar beet plants grown in these soils and used to amplify RNA-2 (nt. 19-1088) and RNA-3 (nt. 50-1268) of BNYVV by reverse transcription polymerase chain reaction (RT-PCR) method. Restriction fragment length polymorphism (RFLP) analysis of PCR-amplified products showed that most of BNYVV isolates studied were A-type strain, however, two isolates did not exactly match the band profile of A-type strain. Additionally, the presence of BNYVV RNA-5 component was investigated by RT-PCR using the primers specific for P26 coding region. Four samples belonging to three provinces were found to be involving RNA-5 segment (20%).

Characterization of carbofuran bound residues and the effect of ageing on their distribution and bioavailability in the soil of a sugar beet field in north-western Morocco

This study was undertaken to investigate distribution, fractionation, bioavailability and remobilization characteristics of bound soil-aged carbofuran and the effect of ageing in clay soil in a typical field of sugar beet at Loukkos in northwest Morocco. Results indicate that initially there were high levels of bound residues (BR) in the humin fraction, which decreased with incubation time and ageing of the BR. While in the fulvic and humic acid fractions, the amount of BR increased with the ageing of the BR and occurred predominantly (60%) in the fulvic acid fraction. The possibility of the mineralization and release of BR with ageing was studied using fresh soil and an incubation period of 90 days. The results indicate that the ageing of the residues have a great influence on the remobilization and mineralization rates of carbofuran BR; 9.45 to 14.90% of the total BR was released as extractable residues, and 1.95 to 4.15% was mineralized depending on the age of the residues in soil and the soil-aged carbofuran BR. The incorporation of the residues in the humin fraction is considered to be a threat to the environment. On the other hand, the clear prevalence of residues in the fulvic and humic acid fractions, may have an important effect on their bioavailability and movement in soil. Moreover, the re-extractability of BR could pose a potential environmental risk. Consequently, the BR remobilized must be taken into account when assessing for registration processes the environmental risk of pesticides persisting in soils.

From South Texas to the Nation: The Exploitation of Mexican Labor in the Twentieth Century. By John Weber

From South Texas to the Nation: The Exploitation of Mexican Labor in the Twentieth Century . David J. Weber Series in the New Borderlands History. By John Weber. (Chapel Hill: University of North Carolina Press, 2015. xiii + 320 pp. Illustrations, maps, notes, bibliography, index. $34.95.) “Get me more Mexicans!,” South Texas cotton growers, undoubtedly, commanded labor agents since the 1920s, when migrant families absconded northward to work in the sugar beet fields of Colorado. This developed as revolutions emerged on both sides of the U.S.-Mexico border in South Texas in the early twentieth century. Consequently, John Weber contends niftily that South Texas growers perfected a model of labor relations ultimately emulated by the nation. This entailed a gross surplus of Mexican workers (both U.S. citizens and nationals of Mexico) stripped of civil and … Frank.barajas{at}csuci.edu

Evaluation of sugar beet lines for resistance to beet curly top viruses

Curly top disease caused by beet curly top viruses (BCTVs) has been a problem in sugar beet fields for a long time. In recent years, climate change has increased the spread of virus vectors and disease damage in infected regions. To find a natural resistance source to curly top viruses in Iran (Beet curly top virus-C, BCTV-C and Beet curly top Iran virus, BCTIV), the reaction of 50 sugar beet lines to the above-mentioned viruses was evaluated in a completely randomized design experiment in 2014. Sugar beet lines were agroinoculated at the 4–6 leaf stage by virus infectious clones under greenhouse condition and then the symptom severity and virus presence was monitored by enzyme-linked immunosorbent assay and polymerase chain reaction methods 8 weeks after inoculation. Five out of 50 lines were found to be resistant to both viruses. Given that both viruses were detected in most sugar beet cultivation areas in Iran, these lines could be suggested for cultivation in Iran. In addition, some lines displayed completely different reactions to the viruses indicating different effects of the viruses on sugar beet lines.

Susceptibility of Five Sugar Beet Cultivars to the Black Bean Aphid, Aphis fabae Scopoli (Hemiptera: Aphididae).

The black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), is one of the important pests of sugar beet. The relative impact of resistance, including antibiosis and antixenosis of five sugar beet cultivars (Doroti, Perimer, Pershia, Rozier and 006) on A. fabae was studied under laboratory conditions using clip cages. The antibiosis test was based on life table parameters. Significant differences on developmental time, mean number of nymphs/aphid/day, fecundity, and adult longevity of A. fabae were found across tested sugar beet cultivars. In addition, there were significant differences among the sugar beet cultivars for population growth parameters such as the intrinsic rate of natural increase (r m ), net reproductive rate (R 0), finite rate of increase (λ), doubling time (DT), and mean generation time (T) of A. fabae. The highest and lowest (r m ) values were observed on Pershia (0.449 nymphs/female/day) and Perimer (0.358 nymphs/female/day), respectively. No significant differences were found for the preference of the black bean aphid, and antixenosis had no effect on resistance against this aphid. As a result, our findings showed that the Pershia cultivar was a relatively susceptible host plant. Two cultivars (Perimer and Rozier) were relatively resistant to A. fabae, which could prove useful in the development of IPM programs for this aphid in sugar beet fields.