Publications - Birte Boelt

Efterafgrøders potentielle risiko for at være væsentlige kilder til ukrudtsforurening i efterfølgende afgrøder

Boelt, B., Jensen, P. K. — Mon, 04 Dec 2023 13:49:15 +0100

Olieræddike som potentielt ukrudt og forureningskilde ved dyrkning som efterafgrøde

Boelt, B., Jensen, P. K. — Fri, 01 Dec 2023 13:49:15 +0100

Fagligt belæg for undtagelse af frøafgrøder og forlængelse af omlægningsperioden i GLM 6-kravet om jorddække.

Boelt, B., Jensen, P. K. — Mon, 01 May 2023 13:49:15 +0200

Udsætning af snyltehvepsekokoner i hvidkløver

Topbjerg, H. B., Boelt, B. — Fri, 01 Apr 2022 13:49:15 +0200

Alternative Management Strategy Towards Weevils in White Clover Seed Production

Wed, 01 Feb 2023 13:49:15 +0100

Fond lukker efter mangeårig værdifuld støtte til frøavlen

Boelt, B., Gislum, R. — Fri, 01 Apr 2022 13:49:15 +0200

A chemometric method for the viability analysis of spinach seeds by near infrared spectroscopy with variable selection using successive projections algorithm

Lakshmanan, M. K., Boelt, B., Gislum, R. — Wed, 01 Feb 2023 13:49:15 +0100

This paper proposes a chemometric method for evaluating the viability of spinach seeds using near infrared (NIR) spectroscopy and successive projections algorithms (SPA). An essential step of the procedure is to apply the SPA to optimize the choice of variables for multivariate classification. Variable selection using SPA has been described as an optimization problem in which a cost function is minimized. Selecting the correct variables makes the chemometric models more complete, precise, accurate, and less complex. The NIR spectra were processed using the Savitzky-Golay and multiplicative scatter correction techniques. After that, the best wavelength subset was selected using SPA. Different classification techniques are then applied to the dimension-reduced data to determine the seeds’ viability. The results show that the proposed method is less complex compared to existing canonical variance methods (1.7% miscalculation error in the proposed way) and is also easier to implement.

Opdatering af screening af afgrøder, som Landbrugsstyrelsen skal have fokus på i planlagte kontroller af mulig forekomst af ikke-godkendt GMO i udsæd

Gregersen, P. L., Madsen, C. K., Konnerup, D., Boelt, B. — Sat, 01 Oct 2022 13:49:15 +0200

Kort faglig evaluering af, hvorvidt det af hensyn til plantesundhed er nødvendigt at afbrænde halm fra frøgræs på arealer, hvor frøgræs afgrøden dyrkes igen næste år

Jørgensen, L. N., Boelt, B., Topbjerg, H. B. — Thu, 02 Jun 2022 13:49:15 +0200

Scheimpflug lidar range profiling of bee activity patterns and spatial distributions

Rydhmer, K., Prangsma, J., Brydegaard, M., et al. — Sat, 01 Jan 2022 13:49:15 +0100

Background: Recent declines of honeybees and simplifications of wild bee communities, at least partly attributed to changes of agricultural landscapes, have worried both the public and the scientific community. To understand how wild and managed bees respond to landscape structure it is essential to investigate their spatial use of foraging habitats. However, such studies are challenging since the foraging behaviour of bees differs between species and can be highly dynamic. Consequently, the necessary data collection is laborious using conventional methods and there is a need for novel methods that allow for automated and continuous monitoring of bees. In this work, we deployed an entomological lidar in a homogenous white clover seed crop and profiled the activity of honeybees and other ambient insects in relation to a cluster of beehives. Results: In total, 566,609 insect observations were recorded by the lidar. The total measured range distribution was separated into three groups, out of which two were centered around the beehives and considered to be honeybees, while the remaining group was considered to be wild insects. The validity of this model in separating honeybees from wild insects was verified by the average wing modulation frequency spectra in the dominating range interval for each group. The temporal variation in measured activity of the assumed honeybee observations was well correlated with honeybee activity indirectly estimated using hive scales as well as directly observed using transect counts. Additional insight regarding the three-dimensional distribution of bees close to the hive was provided by alternating the beam between two heights, revealing a “funnel like” distribution around the beehives, widening with height. Conclusions: We demonstrate how lidar can record very high numbers of insects during a short time period. In this work, a spatial model, derived from the detection limit of the lidar and two Gaussian distributions of honeybees centered around their hives was sufficient to reproduce the observations of honeybees and background insects. This methodology can in the future provide valuable new information on how external factors influence pollination services and foraging habitat selection and range of both managed bees and wild pollinators.

Seed production of red clover (Trifolium pratense L.) under danish field conditions

Jing, S., Boelt, B. — Wed, 01 Dec 2021 13:49:15 +0100

High and stable seed yield is critical for red clover (Trifolium pratense L.) seed production and the commercial exploitation of the crop. A three-year experiment was conducted from 2013 to 2015 under Danish field conditions to explore the influence of precipitation during peak flowering on the seed yield of three red clover cultivars. We investigated the flowering duration and intensity based on a visual scale assessment, seed yield, and thousand seed weight in all three experimental years. In 2014 and 2015 we measured the seed yield components of floret number per flower head, seed number per flower head, and seed set. During the experimental period, high seed yields of more than 1000 kg ha⁻¹ were obtained for the diploid cultivars ‘Rajah’ and ‘Suez’. Although a relatively high seed yield of 500 kg ha⁻¹ was obtained in the tetraploid cultivar ‘Amos’, this was only around half of the seed yield and seed set of the diploid cultivars. Precipitation during peak flowering positively influenced the seed yield and thousand seed weight for the three cultivars. We conclude that observations of flowering phenology are required to determine the impact of environmental conditions on seed yield in red clover cultivars. Further, adequate water supply during peak flowering is important to obtain the high seed yield of red clover.

Opdatering af viden og data der ligger til grund for dyrkningsvejledninger for dyrkning af visse genetisk modificerede afgrøder

Boelt, B., Kudsk, P. — Wed, 10 Nov 2021 13:49:15 +0100

Pollination and Plant Reproductive Success of Two Ploidy Levels in Red Clover (Trifolium pratense L.)

Jing, S., Kryger, P., Markussen, B., Boelt, B. — Sun, 01 Aug 2021 13:49:15 +0200

Plant reproduction in red clover requires cross-fertilization via insect pollination. However, the influences of visitation rate and timing on maximizing ovule utilization are yet to be determined. We aimed to study the influences of visitation rate, flowering stage, and self-incompatibility on reproductive success. We applied hand and honey bee pollination in the study of eight red clover cultivars with two ploidy levels released between 1964 and 2001. In hand pollination, increasing the visitation rates (from 10 to 80 pollinated florets per flower head) increased the seed number per flower head but reduced the seed number per pollinated floret. Different flowering stages (early, middle, and full flowering) did not influence the seed number per pollinated floret significantly. There was a marked difference in reproductive success depending on the ploidy level, with 0.52 seeds per pollinated floret in diploid and 0.16 in tetraploid cultivars. During the cultivar release history, seed number per pollinated floret seemed to decrease in diploid cultivars, whereas it increased in tetraploids. In honey bee pollination, diploid cultivars had more two-seeded florets than tetraploids. Different visitation rates and the stochastic nature of pollen transfer resulted in difficulties when the plant reproductive success between hand and bee pollination was compared. A maximum of 0.27 seeds per pollinated floret were produced in hand pollination compared to the 0.34 in honey bee pollination. In spite of this, hand pollination provided a valuable method for studying the pollination biology and reproduction of red clover. Future studies may employ hand pollination to unravel further aspects of the low reproductive success with the future perspective of improving seed number per pollinated floret in tetraploid red clover.

Assessment of grass lodging using texture and canopy height distribution features derived from UAV visual-band images

Tan, S., Mortensen, A. K., Ma, X., Boelt, B., Gislum, R. — Fri, 01 Oct 2021 13:49:15 +0200

Lodging is a major limiting factor for the yield, quality and harvesting efficiency of selected crops worldwide. This study presents an efficient, robust and non-destructive assessment of lodging severity for four different grasses for seed production, using images collected by an unoccupied aerial vehicle (UAV) in two field plot experiments across five growing seasons. Canopy texture and height related features were extracted from individual plot images and evaluated for estimating lodging severity. Histograms of oriented gradients (HOG) were used as texture features, and three canopy height distributions features (CHV1, CHV2 and CHV3) were proposed. Each canopy height distribution feature divides the plots into subplots and estimates the average height of each subplot. CHV1 concatenates average height of the subplots into its feature, while CHV2 concatenates the difference in average height between all subplots, and CHV3 concatenates the difference in average height between adjacent subplots. The plots were classified using support vector machines into three categories according to the lodging severity. The results showed that the HOG and height distribution features can be used for grading lodging severity in UAV images with high accuracy (71.9% and 79.1%, respectively). However, the HOG features showed a negative relationship to the ground sample distance (GSD), while the CHV1 had a constant accuracy across the GSDs. Combination of the two features did not significantly improve the classification accuracy. The present results have potential to generate lodging severity maps for application in precision farming and thereby to increase grass seed yield and harvest efficiency at farm scale. It should be noted that results and methods from the current study might not be transferred to other crops due to crop specific lodging characteristics and effect of yields.

Different pollination approaches to compare the seed set of diploid and tetraploid red clover Trifolium pratense L.

Jing, S., Kryger, P., Boelt, B. — Tue, 01 Jun 2021 13:49:15 +0200

In red clover seed production, low seed yield is limiting the commercial exploitation of tetraploid red clover. To explore if pollination is the limiting factor for the seed yield in tetraploid red clover, we investigated pollinator behaviour and plant reproductive success in diploid (2x) cultivar ‘Rajah' and tetraploid (4x) cultivar ‘Amos' using honey bee and hand pollination approaches. We measured the seed set at the flower head level with the increasing visitation rate of honey bees (one bee, two bees and open pollination) and pollen diversity (one and two pollen donors) of hand pollination. We found no difference in honey bee pollination behaviour (visitation rate) between the diploid and tetraploid red clover. Surprisingly, the seed set in two bees was significantly lower than that of one bee in ‘Rajah'. We suggest that honey bees prefer to visit already tripped florets or to visit fewer florets due to scent marks left by the previous honey bees. In open pollination, seed number per flower head in ‘Amos' (on average 11) was half of ‘Rajah' (on average 20). Seed set in ‘Amos' was lower than 50% of ‘Rajah' in honey bee (one bee treatment) and hand pollination (one and two pollen donors treatments). There were no differences in stigma receptivity whereas pollen viability in ‘Amos' was lower than ‘Rajah' after the peak pollen viability was reached (six days after the onset of flowering). We suggest that the fertility problems such as low pollen viability may be the reason for the low seed set in tetraploid red clover. This conclusion should be verified by investigating other fertility traits during the ovary, embryo and seed development with a broader range of diploid and tetraploid cultivars.

The Use of Remote Sensing to Determine Nitrogen Status in Perennial Ryegrass (Lolium perenne L.) for Seed Production

Gislum, R., Thomopoulos, S., Gyldengren, J. G., Mortensen, A. K., Boelt, B. — Tue, 01 Jun 2021 13:49:15 +0200

Sufficient nitrogen (N) supply is decisive to achieve high grass seed yields while overfertilization will lead to negative environmental impact. From the literature, estimation of N rates taking into account the crop’s N status and its yield potential, seems promising for attaining high yields and averting adverse environmental impacts. This study aimed at an evaluation of remote sensing to predict final seed yield, N traits of the grass seed crop and the usability of nitrogen nutrition index (NNI) to measure additional N requirement. It included four years’ data and eight N application rates and strategies. Several reflectance measurements were made and used for the calculation of 18 vegetation indices. The predictions were made using partial least square regression and support vector machine. Three different yield responses to N fertilization were noted; one with linear response, one with optimum economic nitrogen (EON) at ~188 kg N ha−1, and one with EON at ~138 kg N ha−1. We conclude that although it is possible to make in-season predictions of NNI, it does not always portray the differences in yield potential; thus, it is challenging to utilize it to optimize N application.

Diseases in red fescue

Jørgensen, L. N., Madsen, H., Boelt, B. — Mon, 01 Mar 2021 13:49:15 +0100

Review of seed yield components and pollination conditions in red clover (Trifolium pratense L.) seed production

Jing, S., Kryger, P., Boelt, B. — Thu, 01 Apr 2021 13:49:15 +0200

Red clover (Trifolium pratense L.) is an important forage legume grown in many of the temperate regions around the world. In order to evaluate possible causes for the low seed yield in particular in tetraploid red clover, we surveyed 71 studies of red clover seed production published from 1948 to 2019, reviewing seed yield components, pollination and reproductive traits. Seed yield components are recorded to contribute to and improve our understanding of the complex processes leading to the red clover seed yield. However, the measurement approaches varied largely among the studies, depending on whether the seed yield components are directly measured or calculated. Red clover seed production is dependent on insect pollen transfer. However, much uncertainty of pollination and reproductive success remains. Pollination conditions were often neglected: one third of the papers did not mention pollination conditions. The information that connects pollination and seed set are lacking, very few studies measured traits in floral morphology, ovule fertilisation and seed maturation. We suggest that consistent and comprehensive evaluation of pollination and reproductive success are required to improve our understanding of reasons for the low seed yield in red clover and hence the possibilities for future improvement.

Zinc seed priming improves spinach germination at low temperature

Imran, M., Mahmood, A., Neumann, G., Boelt, B. — Mon, 01 Mar 2021 13:49:15 +0100

Low temperature during germination hinders germination speed and early seedling development. Zn seed priming is a useful and cost-effective tool to improve germination rate and resistance to low temperature stress during germination and early seedling development. Spinach was tested to improve germination and seedling development with Zn seed priming under low temperature stress conditions. Zn priming increased seed Zn concentration up to 48 times. The multispectral imaging technique with VideometerLab was used as a non-destructive method to differentiate unprimed, water-and Zn-primed spinach seeds successfully. Localization of Zn in the seeds was studied using the 1,5-diphenyl thiocarbazone (DTZ) dying technique. Active translocation of primed Zn in the roots of young seedlings was detected with laser confocal microscopy. Zn priming of spinach seeds at 6 mM Zn showed a significant increase in germination rate and total germination under low temperature at 8^◦C.

The Use of Multispectral Imaging and Single Seed and Bulk Near-Infrared Spectroscopy to Characterize Seed Covering Structures:

Mortensen, A. K., Gislum, R., Jørgensen, J. R., Boelt, B. — Thu, 01 Apr 2021 13:49:15 +0200

The objective of seed testing is to provide high-quality seeds in terms of high varietal identity and purity, germination capacity, and seed health. Across the seed industry, it is widely acknowledged that quality assessment needs an upgrade and improvement by inclusion of faster and more cost-effective techniques. Consequently, there is a need to develop and apply new techniques alongside the classical testing methods, to increase efficiency, reduce analysis time, and meet the needs of stakeholders in seed testing. Multispectral imaging (MSI) and near-infrared spectroscopy (NIRS) are both quick and non-destructive methods that attract attention in seed research and in the seed industry. This review addresses the potential benefits and challenges of using MSI and NIRS for seed testing with a comprehensive focus on applications in physical and physiological seed quality as well as seed health.

Blomsterstriber for bier og biodiversitet

Nielsen, M. B., Dupont, Y. L., Boelt, B. — Mon, 01 Feb 2021 13:49:15 +0100

Bidrag til verificering af forekomst af GM-pampasgræs og vurdering af mulige miljømæssige risici ved en sådan forekomst

Boelt, B., Gregersen, P. L., Brinch-Pedersen, H., Strandberg, M. T. — Fri, 01 Jan 2021 13:49:15 +0100

Multispectral and X-ray images for characterization of Jatropha curcas L. seed quality

Bianchini, V. d. J. M., Mascarin, G. M., Silva, L. C. A. S., et al. — Fri, 01 Jan 2021 13:49:15 +0100

Background: The use of non-destructive methods with less human interference is of great interest in agricultural industry and crop breeding. Modern imaging technologies enable the automatic visualization of multi-parameter for characterization of biological samples, reducing subjectivity and optimizing the analysis process. Furthermore, the combination of two or more imaging techniques has contributed to discovering new physicochemical tools and interpreting datasets in real time. Results: We present a new method for automatic characterization of seed quality based on the combination of multispectral and X-ray imaging technologies. We proposed an approach using X-ray images to investigate internal tissues because seed surface profile can be negatively affected, but without reaching important internal regions of seeds. An oilseed plant (Jatropha curcas) was used as a model species, which also serves as a multi-purposed crop of economic importance worldwide. Our studies included the application of a normalized canonical discriminant analyses (nCDA) algorithm as a supervised transformation building method to obtain spatial and spectral patterns on different seedlots. We developed classification models using reflectance data and X-ray classes based on linear discriminant analysis (LDA). The classification models, individually or combined, showed high accuracy (> 0.96) using reflectance at 940 nm and X-ray data to predict quality traits such as normal seedlings, abnormal seedlings and dead seeds. Conclusions: Multispectral and X-ray imaging have a strong relationship with seed physiological performance. Reflectance at 940 nm and X-ray data can efficiently predict seed quality attributes. These techniques can be alternative methods for rapid, efficient, sustainable and non-destructive characterization of seed quality in the future, overcoming the intrinsic subjectivity of the conventional seed quality analysis.

Vurdering af blomsterstribers værdi for bier

Nielsen, M. B., Dupont, Y. L., Boelt, B. — Mon, 01 Feb 2021 13:49:15 +0100

Blomsterstriber er blevet populære langs vejene og i markkanter. De er ofte en fryd for øjet og giver variation i det dyrkede land for vildt og insekter. Men har bierne præferencer mellem blomsterstriberne og hvilke blandingerne skaber mest værdi for insekterne?

Skader det at vækstregulere, når det er tørt?

Topbjerg, H. B., Boelt, B. — Wed, 01 Apr 2020 13:49:15 +0200

Vækstregulering: AU Flakkebjerg har for hundegræs og strandsvingel undersøgt, hvad det betyder for effekten af en vækstregulering, at det sker under tørre vejrforhold.

Seed germination and seedling growth parameters in nine tall fescue varieties under salinity stress

Shiade, S. R. G., Boelt, B. — Sat, 01 Aug 2020 13:49:15 +0200

To assess seed germination parameters and identifying tolerant varieties, seeds of nine tall fescue varieties (Festuca arundinacea Schreb.) were germinated under various salinity levels for 14 days. Tall fescue is considered ‘moderately tolerant’ to salinity stress, but our study revealed a remarkable diversity among the tested varieties. Armani, Essential, Fatcat, and Starlett were found to reach the same final germination (>90%), irrespective of NaCl concentration up to 15 ds m⁻¹ NaCl; Asterix and Meandre expressed lower germination under the highest salinity level (>75%); and final germination decreased in Eyecandy, Rhizing star, and Thomahawk gradually with increasing salinity (>55%). The main effect of increasing salinity was a delay in germination, and our study suggests that the recording of final germination, which is performed on day-14 in a standard germination test, should be postponed in order to understand the full effect of salinity on germination potential. Nonetheless, a delay in germination will affect turf quality negatively and hence there is good reason to test for salinity tolerance when choosing a variety for sowing on saline soil. Further, our findings indicate a future perspective for breeding for improved salinity tolerance in tall fescue by the identification of salinity-tolerant breeding lines or varieties.

Virkemidler til reduktion af kvælstofbelastningen af vandmiljøet

Eriksen, J., Thomsen, I. K., Hoffmann, C. C., et al. — Wed, 08 Jul 2020 13:49:15 +0200

Linket i højre side henviser til DCA rapporten. Dokumentet over linket er selve leveringen til ministeriet med følgebrev.

I DCA-rapporten er der foretaget mindre sproglige og redaktionelle rettelser i forhold til versionen, som blev leveriet til ministeriet den 8. juli 2020. Derudover er der i kapitlet Afgasning af husdyrgødning kombineret med højere udnyttelseskrav for afgasset gødning sket en justering af beregningsgrundlaget af hensyn til overensstemmelse med seneste rådgivningsnotat på området. Ændringen påvirker ikke den kvalitative vurdering af klimaeffekten i kataloget. I Bilag 3, Klimagasser, er der desuden tilføjet et forklarende afsnit vedr. den indirekte N2O-emissionsfaktor relateret til nitratudvaskning.

Fungicide application improves seed yield of perennial ryegrass upon infection with stem and crown rust fungi

Rodriguez-Algaba, J., Boelt, B., Matzen, N., Jørgensen, L. N. — Wed, 01 Jan 2020 13:49:15 +0100

Rust epidemics may have detrimental effects on seed yield in perennial ryegrass (Lolium perenne L.). Field trials comprising two cultivars of perennial ryegrass were established to evaluate the impact of stem rust (Puccinia graminis subsp. graminicola) and crown rust (Puccinia coronata f.sp. lolii) on seed yields. Two or three applications of a mixture of fungicides (epoxiconazole plus boscalid mixed with pyraclostrobin) provided effective control of both stem rust and crown rust and positive seed yield responses, although differences were observed between cultivars. For stem rust, two fungicide applications led to variable levels of disease control (from 86% to 100% for cv. Esquire and from 15% to 98% for cv. Calibra), whereas three applications resulted in 100% disease control in both cultivars. Two fungicide applications were sufficient for an appropriate control of crown rust on both cultivars (approx. 98–100% disease control). Generally, two fungicide applications resulted in an increase in seed yield for both cultivars. On average, an increment of 4% and 15% was observed in Esquire and Calibra equivalent to 86 kg/ha and 352 kg/ha, respectively. Three fungicide applications provided an increase of 2% and 17% in Esquire and Calibra equivalent to 45 kg/ha and 434 kg/ha, respectively. Significant differences were only observed in Calibra after two or three fungicide applications. Additionally, results from semi-open field trials testing for preventive and curative effects showed that tebuconazole, pyraclostrobin, picoxystrobin, azoxystrobin, and a mixture of epoxiconazole, pyraclostrobin, and boscalid fungicides resulted in high efficacy in reducing stem rust occurrence, the latter resulted in the largest preventive and curative effect. Experiences from field and semi-open field trials indicated that fungicide mixtures with contrasting modes of actions, e.g., triazoles, strobilurins, and SDHIs, and applied close to the time of inoculation provided an effective control of rust fungi and increased seed yield in perennial ryegrass.

Variation of seed oil content, oil yield, and fatty acids profile in Iranian Nigella sativa L. landraces

Kiani, M., Alahdadi, I., Soltani, E., Boelt, B., Benakashani, F. — Wed, 01 Jan 2020 13:49:15 +0100

Since there are several diverse landraces across Iran, screening the landraces with high production may lead to finding superior genotype(s) for the future conventional breeding programs. Thus, the aims of this study was to investigate the variation of oil content, yield, and profile of fatty acids in Iranian landraces of Nigella sativa L. Seed yield, oil content and oil yield significantly differed among landraces. The highest seed and oil yields were obtained from Semirom (1250 and 332 kg ha⁻¹). Twelve different fatty acids were detected. Linoleic acid (18:2) had the highest concentration in oil of N. sativa landraces with a range of 48–55 %. After linoleic acid, oleic (18:2) and palmitic (16:0) acids, with an average of 22 and 13 %, accounted for the highest percentage of seed oil compared with the other fatty acids. Saturated fatty acids (∑SFA) was significantly different among the landraces and included 19–22 % and 21–24 % of total fatty acids. Double bond index (DBI) was significantly different among landraces and ranged between 136.5–145.3 in 2018 and 127.5–134.5 in 2019. The Gardmiran landrace had the highest Iodine value (IV) (111.7, an average of two years) and Khaf landrace had the lowest IV (105.7, in average of two years) compared with the other landraces. Cluster analysis indicated that the landraces can be divided into three groups; (1) high yield (>1000 kg ha^-1 seeds and >250 kg ha⁻¹ oil), (2) medium yield (700–1000 kg ha⁻¹ seeds and 190–250 kg ha⁻¹ oil), and low yield (<700 kg ha⁻¹ seeds and <190 kg ha⁻¹ oil) landraces. Iranian landraces were similar in fatty acid compositions and conventional breeding methods may not be a good choice to improve a special fatty acid. However, a large variations existed in seed and oil yield among the landraces for the future conventional breeding programs.

Kommentering af OECD’s udkast til konsensusdokument om miljømæssige overvejelser til risiko- /sikkerhedsvurdering ved udsætning af transgene planter

Boelt, B., Damgaard, C. — Mon, 17 Feb 2020 13:49:15 +0100

En fælles front for vilde bier og honningbier

Dupont, Y. L., Bang Madsen, H., Rasmussen, C., et al. — Thu, 29 Aug 2019 13:49:15 +0200

En fælles front for vilde bier og honningbier

Dupont, Y. L., Bang Madsen, H., Rasmussen, C., et al. — Thu, 29 Aug 2019 13:49:15 +0200

En fælles front for vilde bier og honningbier

Dupont, Y. L., Bang Madsen, H., Rasmussen, C., et al. — Sun, 01 Sep 2019 13:49:15 +0200

Red bierne – mens tid er

Dupont, Y. L., Bang Madsen, H., Rasmussen, C., et al. — Tue, 01 Jan 2019 13:49:15 +0100

22 forskere: Danmark har brug for en national strategi for bestøvere

Dupont, Y. L., Bang Madsen, H., Rasmussen, C., et al. — Mon, 14 Oct 2019 13:49:15 +0200

Produktion af biopolymerer

Jørgensen, J. R., Boelt, B., Kristensen, E. F. — Wed, 01 Jan 2020 13:49:15 +0100

Linket til højre henviser til rapporten i trykt format til download
Dokumentet over linket er selve leveringen til ministeriet med følgebrev
Rapporten er udarbejdet på bestilling af Miljø- og Fødevareministeriet og giver en redegørelse for hvilke specifikke afgrøder, der kan produceres på danske landbrugsarealer er velegnede til anvendelse som biopolymer inden for produktområder som f.eks. tekstil, emballage og byggeri. Rapporten indeholder opdateret viden om produktion af hør og hamp i Danmark og Europa, deres dyrkningssystemer samt en kort gennemgang af tekniske karakteristika for fibertyper af hør og hamp i sammenligning med andre plantefibre. Forventet udbytte og de dyrkningsmæssige udfordringer og muligheder for dyrkning af spindhør og hamp gennemgås. Endvidere beskrives miljø- og klimamæssige perspektiver, der relaterer sig til dyrkning af spindhør og hamp.

En fælles front for alle bier

Dupont, Y. L., Bang Madsen, H., Rasmussen, C., et al. — Tue, 01 Jan 2019 13:49:15 +0100

Vi må redde bierne - mens tid er

Dupont, Y. L., Bang Madsen, H., Rasmussen, C., et al. — Sat, 24 Aug 2019 13:49:15 +0200

From emergence to flowering

Salimi, Z., Boelt, B. — Sun, 01 Dec 2019 13:49:15 +0100

Beta vulgaris comprise various variety groups that are cultivated for vegetative or reproductive production. As a biennial crop, beets have a photothermal induction requirement for the transition from the vegetative to the reproductive stage. Bolting and flowering are not desirable when beets are cultivated for vegetative production and are suppressed during breeding programs, though these structures are important in seed production. Therefore, the potential of seed hydro priming as an enhancement technique to partially induce vernalization in seeds was evaluated. Following hydro priming, seeds were sown in October 2018 and evaluated during three selected phenological stages. Treating seeds with hydro priming significantly improved the emergence rate in all four tested cultivars. Moreover, treatments significantly lowered the required growing degree days (GDD) for transition to the reproductive stage in all four tested cultivars. Regardless of the treatment effect on an individual developmental stage, the treatment efficiency should be evaluated on the whole production process, depending on the purpose of production. The focus of this study was mainly on improvement of seed production performance. The outcome showed the potential of priming to influence the reproductive stages of the plant life cycle rather than just the germination.

Optimization of Germination Inhibitors Elimination from Sugar Beet (Beta vulgaris L.) Seeds of Different Maturity Classes

Salimi, Z., Boelt, B. — Fri, 01 Nov 2019 13:49:15 +0100

Endogenous inhibitors have a crucial effect on the success of sugar beet (Beta vulgaris) seed germination. The strength of this effect changes during seed maturation, and washing away these inhibitors can facilitate germination. Investigation of various washing factors such as water-to-seed ratio, stirring time, and speed of stirring on a mixed-maturity lot of sugar beet seeds revealed the significant effect of the interaction of all factors. Seeds with different maturity classes, from the same lot, were washed using procedures determined from the first experiment. Statistical analysis of the germination data of the washed seeds showed a significant difference in mean germination time depending on maturity class. Washing seeds of different maturity classes with 40 mL of water per gram of seed improved the germination performance of maturity classes 2 and 5, compared with 20 mL water per gram of seed. The UV absorbance of inhibitors washed from seeds differed between maturity classes. The change in seed moisture content during the washing process is another factor altered by the extent of seed development, and this variation in water uptake may reflect the pericarp structure of seed in different maturity classes. The findings in this manuscript highlight the importance of optimizing the pre-treatment procedures in accordance with the individual seed lot. View Full-Text
Keywords: washing; phenol; pericarp; seed enhancement; spectrophotometry; multispectral imaging; moisture content; seed weight; maturity classification; dry fruit

Sådan kan frøavleren hjælpe bier og andre bestøvere

Dupont, Y. L., Boelt, B., Bang Madsen, H. — Tue, 01 Jan 2019 13:49:15 +0100

Ingen sikker effekt af vækstregulering med nye midler

Boelt, B. — Tue, 01 Jan 2019 13:49:15 +0100

SpectraSeed - digital analyse kan forudsige spireevne

Boelt, B., Pedersen, D. V. — Thu, 01 Mar 2018 13:49:15 +0100

Is red clover seed set potential influenced by pollen quality?

Jing, S., Kryger, P., Boelt, B. — Tue, 01 Jan 2019 13:49:15 +0100

The commercial use of high-forage-yielding tetraploid red clover (Trifolium pratense L.) is limited due to its low seed yield, but, surprisingly, the seed set potential of individual florets of diploid and tetraploid red clover cultivars is rarely studied. Hand pollination experiments were conducted in two diploid and one tetraploid red clover cultivars to investigate (1) the correlation between seed set and the number of pollinated florets per flower head, and (2) how seed set is influenced by the different sources and amounts of pollen deposited on the stigmas. The results demonstrate that an increase in the number of pollinated florets (from 0 to 80 florets) increased the number of harvested seeds. However, the seed set rate increased only up to approximately 20 pollinated florets. No significant difference in seed set was found between the florets pollinated with a low (on average 43 pollen grains) or high (on average 84 pollen grains) number of pollen grains, except for the red clover cultivar, which has the highest pollen viability. We suggest that the amount of viable pollen deposited on the stigma influences seed set in red clover. Furthermore, results showed that pollen from cultivars with different ploidy levels might disturb seed set. In conclusion, results indicate the importance of pollen quality (pollen viability and pollen source) to seed set of diploid and tetraploid red clover. We found hand pollination an excellent method/tool for investigating the underlying causes of low seed set in red clover, provided that at least 20 florets per flower head are pollinated.

Organic herbage seed production

Boelt, B., Topbjerg, H. B., Jing, S., Gislum, R. — Tue, 01 Jan 2019 13:49:15 +0100

Organic farmers are supposed to use organically produced seed. For more than 20 years, organic cool season grass and clover seed has been produced in Denmark. For the past 10 years, the average total production area has been approximately 3,000 ha, with the major species in production being perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.). Organic seed crops are undersown in a spring barley cover crop using different establishment techniques. Perennial ryegrass seed is sometimes mixed with and sown with the spring barley and can also be established after a mechanical weeding of the spring barley. Obtaining a solid and uniform establishment of the seed crop is considered a very important weed control strategy, which in organic grass seed production also consists of a relatively high nitrogen application. In the seed production year, various new techniques for mechanical weeding are being tested in experiments at Aarhus University and in grower fields. One of the major challenges in organic white clover seed production is insect pests (Apion spp. and Hypera spp.). Earlier experiments have shown seed yield decreases of 40% in untreated control plots. In years with high incidence of insect pests, the seed grower might choose a late defoliation of the white clover seed crop to reduce the damaging effects of the insects. However, a recent study has shown that biological control using a parasitoid might be promising as a longterm pest management strategy. Over the past two decades, organic seed production practices have been established and, interestingly, are now being tested and adapted in conventional herbage seed production.

Digitalization in herbage grass seed production and research: Opportunities and challenges

Gislum, R., Gyldengren, J. G., Boelt, B. — Sun, 12 May 2019 13:49:15 +0200

Digital herbage seed production and research offer new possibilities but also new challenges. Technological, software, and algorithm development proceeds extremely rapidly, while the development of decision support systems and related agronomic and biological interpretation lags. These challenges must not prevent us from exploring new technology and methods in herbage seed production and research. We must recognize, however, that increasing the utilization of applied and available nutrients through the use of sensors, local weather data, and predictions, in combination with application algorithms, may not necessarily increase farmer revenue or reduce negative environmental impacts. Advanced field phenotyping holds great potential and is receiving a great deal of attention, based on publication frequency, and breeders will gain new knowledge from these technologies and methods. The use of advanced phenotyping in combination with crop models is an interesting area that undoubtedly will increase our basic knowledge of plant development and performance, which is necessary in order to better understand the interactions between nutrient utilization, optimal application timing for plant growth regulation, weed control, and other field operations. The conclusion is that digital herbage seed production and research are still in the early development stage.

Classification of Processing Damage in Sugar Beet (Beta vulgaris) Seeds by Multispectral Image Analysis

Salimi, Z., Boelt, B. — Wed, 22 May 2019 13:49:15 +0200

The pericarp of monogerm sugar beet seed is rubbed off during processing in order to produce uniformly sized seeds ready for pelleting. This process can lead to mechanical damage, which may cause quality deterioration of the processed seeds. Identification of the mechanical damage and classification of the severity of the injury is important and currently time consuming, as visual inspections by trained analysts are used. This study aimed to find alternative seed quality assessment methods by evaluating a machine vision technique for the classification of five damage types in monogerm sugar beet seeds. Multispectral imaging (MSI) was employed using the VideometerLab3 instrument and instrument software. Statistical analysis of MSI-derived data produced a model, which had an average of 82% accuracy in classification of 200 seeds in the five damage classes. The first class contained seeds with the potential to produce good seedlings and the model was designed to put more limitations on seeds to be classified in this group. The classification accuracy of class one to five was 59, 100, 77, 77 and 89%, respectively. Based on the results we conclude that MSI-based classification of mechanical damage in sugar beet seeds is a potential tool for future seed quality assessment.

Biavlere foretrækker bigårde med 8-15 familier

Boelt, B., Kryger, P. — Mon, 01 Apr 2019 13:49:15 +0200

Importance of seed quality for the fresh cut chain

Deleuran, L. C., Olesen, M. H., Shetty, N., Gislum, R., Boelt, B. — Thu, 30 Aug 2018 13:49:15 +0200

Seed is the most fundamental input in vegetable production on which the effectiveness of other inputs and outputs depends. If the seed is of poor quality, the use of other inputs is less successful and will occasionally be irrelevant. A definition of seed quality will depend upon the use for which the seed is intended. Viability, vigor, uniformity, purity and health of the seeds are quality parameters important for all production systems. The ideal situation for both fresh produce and fresh cut would be seeds that germinate uniformly at a high percentage and subsequently grow relatively fast to the desired size, thus, resulting in leaves of improved quality. It is likely that such leaves will be more able to withstand the rigorous processing that includes harvest, transportation, washing, sanitization, de-watering and packaging. This ideal situation would both be determined by the mentioned properties of the seeds and to a large extend the cultivar of the seeds. The quality of a vegetable product is defined by the interaction of these factors, including environmental factors as well as by management and technology. Novel, fast and non-destructive technologies for seed testing allow for new sorting possibilities of a seed lot. At present, new initiatives using multispectral imaging and single seed NIR spectroscopy is being developed at AU for description of seed lots. Preliminary results on investigations of pak choi seeds are presented.

Fastlæggelse af dyrkningsperiode for landbrugsafgrøder under danske forhold

Thu, 28 Mar 2019 13:49:15 +0100