Fat Hen Research Articles

Plant cultivation and diversity at the Early Neolithic settlement in Biskupice in Poland

The emergence of the Linear Pottery Culture (LBK) during the Neolithic period within Polish territory 5400–4900 BC, introduced plant cultivation, yet the definitive list of cultivated species remains debated. This study examines plant assemblages (fruits, seeds, pollen, and spores) from the LBK settlement in Biskupice, southern Poland, aiming to identify cultivated and wild species used during the development of the first stable settlements in the Carpathian Foothills. Due to extensive sampling, Biskupice yielded over 11,000 macroscopic plant specimens, enabling detailed analysis of plant diversity, distribution, and implications for agrarian and dietary practices. The analysis revealed a focus on emmer and einkorn wheat cultivation, with barley playing a minor role, alongside evidence of flax and pulses. Radiocarbon dating supported the settlement’s existence in the 6th millennium BCE, and confirmed the use of barley. However, a younger date excluded bread wheat cultivation at this site. The plant assemblage included a diverse array of herbaceous wild plants like black bindweed, fat hen and brome species, suggesting their economic use. Additionally, the presence of cockspur grass, linked with Southeast Asia, indicates alternative migration routes of weeds in Europe, as supported by radiocarbon dating. Palynological analysis suggests existence of nearby cereal plots or the processing of cereals at the settlement, supporting archaeological evidence.

Olfactory Responses of Asproparthenis punctiventris Germar to Leaf Odours of Amaranthaceae Plants.

Understanding the stimuli used by insect pests to find their food plants can be a first step towards manipulating their behaviour and, thus, controlling them. We investigated the responses of the sugar beet weevil Asproparthenis punctiventris (Coleoptera: Curculionidae) to the volatile leaf odours of its food plants, including Beta vulgaris subsp. vulgaris (Altissima and Cicla groups), Atriplex hortensis, Chenopodium album, and Amaranthus retroflexus, in a four-arm olfactometer. A bioassay procedure was developed, and the frequency of visits and time spent by adult weevils in the quadrant of the olfactometer with leaf volatiles was recorded, as was their first choice of quadrant. Females and males were equally attracted to the leaf odours of young B. vulgaris subsp. vulgaris plants, i.e., sugar beet and chard, as indicated by the overall picture of the behavioural parameters analysed. Males, but not females, responded positively to the leaf odour of the garden orache (A. hortensis), and no response was observed when the weevils were tested with the leaf odours of fat hen (C. album) or common amaranth (A. retroflexus). These results suggest that A. punctiventris uses leaf odours to locate sugar beet and other food plants. Knowledge of the olfactory responses of this pest can provide a basis for improved monitoring or mass trapping strategies.

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FAT HEN INCORPORATED AND RHIZOSPHERE SOIL AFFECTS THE GERMINATION AND SEEDLING GROWTH OF MUNGBEAN AND MAIZE

Fat hen is a dominating weed of wheat and several important crops around the globe. Interference of this weed has not only caused substantial yield reduction in associated crops but also negatively influenced the succeeding crops in rotation pattern. Residual effects of fat hen infested soils were investigated in a bioassay at glass house, Department of Agronomy, Bahauddin Zakariya University, Multan during 2021. Rhizosphere soil along with fat hen incorporated soils were included in experiment while, for comparison sand and clay loam soils were also used as control treatments. Data regarding germination indices like time taken to 50 percent germination, mean emergence time, final emergence percentage, germination index, germination energy and seedling growth parameters like shoot/root length, shoot/root dry weight all indicated that fat hen incorporated soils exhibited a strong negative effect on the test crops (mungbean and maize). Whereas, rhizosphere soil also showed inhibitory effect on both test crops in comparison to sand and clay loam soils. However, the negative effects of incorporated soils are more prominent than the rhizosphere soil of fat hen. Rich allelochemicals profile of fat hen could be the possible reason of these negative influences. Findings of this investigation were used for planning of crop rotation pattern because farmers incorporate the standing fat hen into the soil after harvesting of their crops. So, farmers should avoid incorporation of fat hen in to the soil to avoid the possible negative effect on the succeeding crops.

Image-to-Image Translation-Based Data Augmentation for Improving Crop/Weed Classification Models for Precision Agriculture Applications

Applications of deep-learning models in machine visions for crop/weed identification have remarkably upgraded the authenticity of precise weed management. However, compelling data are required to obtain the desired result from this highly data-driven operation. This study aims to curtail the effort needed to prepare very large image datasets by creating artificial images of maize (Zea mays) and four common weeds (i.e., Charlock, Fat Hen, Shepherd’s Purse, and small-flowered Cranesbill) through conditional Generative Adversarial Networks (cGANs). The fidelity of these synthetic images was tested through t-distributed stochastic neighbor embedding (t-SNE) visualization plots of real and artificial images of each class. The reliability of this method as a data augmentation technique was validated through classification results based on the transfer learning of a pre-defined convolutional neural network (CNN) architecture—the AlexNet; the feature extraction method came from the deepest pooling layer of the same network. Machine learning models based on a support vector machine (SVM) and linear discriminant analysis (LDA) were trained using these feature vectors. The F1 scores of the transfer learning model increased from 0.97 to 0.99, when additionally supported by an artificial dataset. Similarly, in the case of the feature extraction technique, the classification F1-scores increased from 0.93 to 0.96 for SVM and from 0.94 to 0.96 for the LDA model. The results show that image augmentation using generative adversarial networks (GANs) can improve the performance of crop/weed classification models with the added advantage of reduced time and manpower. Furthermore, it has demonstrated that generative networks could be a great tool for deep-learning applications in agriculture.

Determination of Minimum Doses of Imazamox for Controlling Xanthium strumarium L. and Chenopodium album L. in Bean (Phaseolus vulgaris L.)

This study was conducted to investigate the minimum doses of the imazamox active ingredient (ai) that provide satisfactory efficacy (>90%) against fat hen (Chenopodium album L.) and common cocklebur (Xanthium strumarium L.). These two weeds are among the most troublesome weeds of bean fields. The minimum dose studies were carried out separately in the 2–4 and 6–8 true leaf stages of both weeds. The experiments were carried out in pots under greenhouse conditions. The experiments were repeated three times. In the first two experiments, the recommended dose of imazamox (100%) together with 75%, 50% and 25% doses were applied to the weeds during the above-mentioned leaf stages. Some pots were left untreated for control. In the third experiments, 12.50% and 6.25% of the recommended doses were also tested. Plant height and the number of leaves were recorded on the 1st, 3rd, 5th, 7th, 14th, 21st and 28th days following the herbicide application. As a result of the studies, it was determined that nearly half the recommended dose (48.18 g ai/da) provides 90% success in the control of common cocklebur (X. strumarium) when applied at the 2–4 true leaf stages, while a lower dose (36.11 g ai/da) is required for obtaining the same control when applied at the 6–8 true leaf stages. For the fat hen (C. album), only a 17.69 g ai/da application dose was found to provide 90% control at the period of 2–4 true leaves, while 21.21 g ai/da was noted to provide 90% control when applied at the 6–8 true leaf stage. The results suggest that the increase in leaf area reduces the imazamox requirement for the control of X. strumarium.

Possibilities of weed control in sugar beet crop after desmedipham withdrawn and possible non-approval of further use of phenmedipham and chloridazone

The field research were carried out in 2019–2020, in Picobella sugar beet. The aim of the study was to develop an alternative weed control program without phenmedipham, desmedipham and chloridazone. The tested mixtures containing metamitron, ethofumesate, triflusulfuron-methyl, and lenacil used in various combinations together with the Atpolan BIO 80 EC adjuvant effectively controlled Fat hen (Chenopodium album) up to phase 1 of a pair of true leaves (BBCH 12). Excluding ethofumesate from mixtures of metamitron (700 g/ha) and triflusulfuron-methyl (15 g/ha) reduces the effectiveness of weed control. In the absence of ethofumesate, the effectiveness of the action is improved by increasing the dose of metamitron (1050 g/ha) and adding lenacil (100 g/ha) to the composition of the mixture. The conducted research proved that it is possible to effectively protect beet crops against Fat hen (Ch. album) after the desmedipham withdrawn and possible non-approval of phenmedipham and chloridazone.

What was on the menu? Mesolithic cooking and consumption practices in inland central Europe based on analysis of fireplaces

The northern Bohemian sandstone region brings an exceptionally rich record of Mesolithic settlement, particularly in the form of fireplaces as key structures to be studied when addressing cooking and consumption practices. A large number of different fireplace structures – including kettle-shaped pits and surface or sunken fireplaces, some lined with stones – can be interpreted in terms of performing roasting, boiling, steaming or smoking procedures. The organic remains directly associated with them reveal which resources were exploited and almost certainly consumed, although in many cases they seem to have been discarded into the fire after processing. A Mesolithic inland settlement of northern Bohemia was undoubtedly economically based on the exploitation of plant and animal resources occurring in varied local forest and river environments. According to the evidence, hazelnuts were a staple component of the plant diet, probably processed using roasting hearths. Some fireplaces also yielded carbonised remains of other edible plants, such as raspberry (Rubus idaeus, Rubus sp.), elderberry (Sambucus nigra), red elderberry (Sambucus racemosa) and fat hen (Chenopodium album). The faunal vertebrate assemblages suggest a broad-spectrum economy, exploiting terrestrial mammals, birds, amphibians and fish. The molluscan record suggests the exploitation of edible land snails as well as thick-shelled river mussels. Rather than assuming a simple connection between fireplace type and the resources identified, a complex set of biases is considered and discussed.

Protective role of fat hen (Chenopodium album L.) extract and gamma irradiation treatments against fusarium root rot disease in sunflower plants.

One of the most drastic diseases causing economic losses in sunflower crops is fusarium root rot caused by Fusarium solani. Plant extracts and ionizing radiation provide alternative environmentally safe control agents that have a significant role in controlling and overcoming this fungal plant pathogen. In the present study, the effect of different concentrations of aqueous Chenopodium album extract (2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6.0%) and gamma radiation at a dose of 6Gy were examined for their efficacy in inducing resistance of sunflower plants against fusarium root rot caused by F. solani MG-3 by evaluation of some physiological and biochemical parameters of infected and healthy plants under greenhouse conditions. The pre-treatment of sunflower seeds with 6% C. album extract and 6Gy gamma radiation reduced fusarium incidence from 47.49% to 28.25%. Also, nucleic acid content, ascorbic acid, α-tocopherol, anthocyanin, total flavonoids, proline, glycine betaine and lipid components significantly increased in irradiated infected plants treated with C. album extract, while H2 O2 content and lipid peroxidation markedly decreased as compared with healthy control plants. Moreover, treatment with gamma radiation reduced the amount of unsaturated fatty acids through accumulation of saturated fatty acids compared with non-irradiated plants; treatment with C. album extract also enhanced the content of unsaturated fatty acids, with a noticeable decrease in saturated fatty acid content. Hence, C. album extract and gamma radiation can be used to enhance biological control of fusarium root rot of sunflower plants.

Kashi Bathua-2: A bathua variety for higher nutrient and yield

Bathua or leafy chenopod (Chenopodium album L.) is also known as fat hen, lamb’s quarters, goose foot, pigweed, dungweed, melde, etc. Though cultivated in some regions, the plant is also a potentially serious weed in almost all winter-sown crops of the subtropics and tropics. It belongs to family Amaranthaceae, sub-family Chenopodiaceae, genus Chenopodium, and species album that has almost worldwide distribution and comprises of about 250 species (Risi and Galwey 1984).

Продуктивность сорго зернового в зависимости от применения гербицидов

Abstract. The purpose of the work is to establish the effectiveness of weed in control in crops of grain sorghum with herbicides of soil and leaf action. Scientific novelty. For the first time in sorghum crops for weed control, effective combinations of soil and leaf herbicides have been identified. Methods. Experiments were carried out on the black soils of steppe zone Ukraine. Research methods are generally accepted. The control options were herbicide-free and weed-free. Results. At tillering stage the number of weeds in sorghum crops reached 141 pieces/m2 and their air-dry weight was 218 g/m2. Green amaranth (Amaranthus retroflexus), fat hen (Chenopodium album), field mustard (Sinapis arvensis), ragweed ragweed (Ambrosia artemisiifolia), barnyard grass (Echinochloa crus-galli), bristlegrass (Setaria viridis) were dominant in the crops. The use of foliar-applied herbicides such as Agritox (1 l/ha), Ballerina (0.4 l/ha), Dialen Super (0.7 l/ha) in the stage of three-five leaves and a pre sowing soil-applied herbicide Primextra Gold (3 l/ha) ensured the maximum reduction of weed infestation of grain sorghum crops. The number of weeds with the use of these herbicides decreased by 10.4–19.7 times, and their weight decreased by 4.1–4.8 times in comparison with the options without the use of weed control measures. The conditions for plant growth and development were improved due to the reduction of weed infestation of grain sorghum crops. The growing period of the crop reduced from 125 to 114 days, the height of plants increased by 19–21 cm and their weight increased by 2.7–2.8 times. The sorghum grain yield reached 6.32–6.34 t/ha, which was higher than with the options without the use of weed control measures by 4.01–4.30 t/ha or 3.0–3.1 times. The same results were obtained in production conditions.

Coeval basin formation, plutonism and metamorphism in the Northern Tasmanides: extensional Cambro-Ordovician tectonism of the Charters Towers Province

The Charters Towers Province, of the northern Thomson Orogen, records conversion from a Neoproterozoic passive margin to a Cambrian active margin, as characteristic of the Tasmanides. The passive margin succession includes a thick metasedimentary unit derived from Mesoproterozoic rocks. The Cambrian active margin is represented by upper Cambrian–Lower Ordovician (500–460 Ma) basinal development (Seventy Mile Range Group), plutonism and metamorphism resulting from an enduring episode of arc–backarc crustal extension. Detrital zircon age spectra indicate that parts of the metamorphic basement of the Charters Towers Province (elements of the Argentine Metamorphics and Charters Towers Metamorphics) overlap in protolith age with the basal part of the Seventy Mile Range Group and thus were associated with extensional basin development. Detrital zircon age data from the extensional basin succession indicate it was derived from a far-field (Pacific-Gondwana) primary source. However, a young cluster (<510 Ma) is interpreted as reflecting a local igneous source related to active margin tectonism. Relict zircon in a tonalite phase of the Fat Hen Creek Complex suggests that active margin plutonism may have extended back to ca 530 Ma. Syntectonic plutonism in the western Charters Towers Province is dated at ca 485–480 Ma, close to timing of metamorphism (477–467 Ma) and plutonism more generally (508–455 Ma). The dominant structures in the metamorphic basement formed with gentle to subhorizontal dips and are inferred to have formed by extensional ductile deformation, while normal faulting developed at shallower depths, associated with heat advection by plutonism. Lower Silurian (Benambran) shortening, which affected metamorphic basement and extensional basin units, resulted in the dominant east–west-structural trends of the province. We consider that these trends reflect localised north–south shortening rather than rotation of the province as is consistent with the north–south paleogeographic alignment of extensional basin successions.KEY POINTSNorthern Tasmanide transition from passive to active margin tectonic mode had occurred by ca 510 Ma, perhaps as early as ca 530 Ma.Cambro-Ordovician active margin tectonism of the Charters Towers Province (northern Thomson Orogen) was characterised by crustal extension.Crustal extension resulted in the development of coeval (500–460 Ma) basin fill, granitic plutonism and metamorphism with rock assemblages as exposed across the Charters Towers Province developed at a wide range of crustal levels and expressing heterogeneous exhumation.Protoliths of metasedimentary assemblages of the Charters Towers Province include both Proterozoic passive margin successions and those emplaced as Cambrian extensional basin fill.

Weeding: a love poem

Weeding:a love poem Brendan Ryan (bio) Couch grass, bindweed, dock and dandelion.Each weed takes me back to earthto the bending, the pulling, the constant work. To weed is to love drifting offto the smell of capeweedin a winter paddock long wavering heads of spear grasson the river flats in summer,tussocks that cut our fingers Scotch thistles I hacked from the dirtscrubby ferns I couldn't get enough ofstretches of blackberry where we hid dead calves. Pigweed, fat hen, oxalis and nettle.Kneeling before buttercups I think aboutthings I shouldn't think about. The very plants I want to yank outI'm finding ways back to lovesour sob, lantana, nut grass. I pull out weeds to see where the dayhas gone, a type of reverie like listeningto the radio outdoors, of doing one job while attending to another, of returningto milk thistle where the thinking gets done,to weed is to love the plants nobody wants. [End Page 147] Brendan Ryan Brendan Ryan grew up on a dairy farm at Panmure in Western Victoria. His poetry, reviews, and essays have been published in literary journals and newspapers, including Island, Westerly, Antipodes, the Age, the Weekend Australian, The Best Australian Poems series (Black Inc), and Contemporary Australian Poetry (Puncher and Wattman). He is the author of six collections of poetry, and Travelling through the Family (Hunter Publishers) was short-listed for the 2014 Victorian Premier's Awards. His latest collection of poetry, The Lowlands of Moyne, was published by Walleah Press in 2019. Copyright © 2020 Wayne State University Press

&lt;p&gt;&lt;strong&gt;&lt;em&gt;Potamosiphon australiensis&lt;/em&gt; &lt;em&gt;gen. nov.&lt;/em&gt;, &lt;em&gt;sp nov.&lt;/em&gt; (Oscillatoriales), a new filamentous cyanobacterium from subtropical north-eastern Australia&lt;/strong&gt;&lt;/p&gt;

A new filamentous cyanobacterium, Potamosiphon australiensis gen. et sp. nov., was isolated from a small coastal stream in subtropical north-eastern Australia, and characterised using combined morphological and phylogenetic attributes. It was found growing on the benthos of Fat Hen Creek amongst cobbles, gravel and large woody debris, mostly as single straight or variously flexuous filaments amongst other algae, but occasionally formed loose aggregations amongst littoral vegetation. Morphologically, Potamosiphon is most similar to members of the genus Lyngbya. Filaments were isopolar, cylindrical, not or slightly constricted at the cross walls. Vegetative cells were discoid, broader than long with finely granular contents, aerotopes were not present. Apical cells were rounded, without calyptra or a thickened outer cell wall. Reproduction occurred via motile hormogonia, which formed often in series, after the occurrence of necridic cells. Trichome fragmentation also occurred following a diagonal division. Following this division trichomes often continued to grow past each other within a common sheath. Thylakoids were irregularly arranged throughout the whole cell volume. Phylogenetic analyses using partial 16S rRNA sequences obtained from three strains of P. australiensis showed that it formed a well supported monophyletic clade, sharing less than 94% nucleotide similarity with other cyanobacterial sequences, including putatively related taxa within the Oscillatoriaceae. It also formed a novel clade in the nifH phylogeny, which was associated with the genus Microseira G.B. McGregor &amp; Sendall.

Oxalate Contents of Raw, Boiled, Wok-Fried and Pesto and Juice Made from Fat Hen (Chenopodium album) Leaves.

The total, soluble, and insoluble oxalate contents of fresh and wok-fried fat hen (Chenopodium album) leaves were extracted and measured using High pressure liquid chromatography. The total oxalate content of the raw leaves was 1112.4 mg/100 g dry matter (DM), and the levels were significantly reduced by boiling (682.8 mg/100 g DM) or cooking the leaves in a wok (883.6 mg/100 g DM). The percentages of soluble oxalate contents in the total oxalates of the raw and boiled leaves were similar (mean 75%), while the proportion of soluble oxalate content in the wok-fried leaves was reduced to 53.4% of the total, giving a significant increase in the insoluble oxalate content of the wok-fried leaves. The percentage of insoluble calcium in the total calcium was significantly reduced (p < 0.05) when the leaves were boiled, but the insoluble oxalate content significantly increased (67.2%) in the wok-fried leaves when compared to the content of the original raw leaves. Processing the cooked leaves into pesto or extracting the juice gave final products that contained significantly reduced total and soluble oxalate contents. The addition of calcium chloride to the juice caused a very small reduction in the soluble oxalate content in the juice.

Extraction, isolation and identification of flavonoid from Chenopodium album aerial parts

Chenopodium album L., (C. album) (family: Chenopodiaceae) is an annual shrub widely grown in Asia, Africa, Europe and North America. It is commonly known as Bathua (in Hindi), pigweed, fat hen or lamb-quarters. The leaves of C. album are applied as a poultice to bug bites, sunstroke, rheumatic joints and as mild laxative. The flavonoids contained in C. album aerial parts were extracted, identified and characterized. Sequential soxhlet extraction was subjected to preliminary phytochemical screening and flavonoid quantification. The results showed that maximum yield of the flavonoid (7.335 mg/g) were obtained from acetone extract. This acetone extract was subjected to flash chromatography for isolation of flavonoid. Characterization of isolated flavonoid was done by UV, IR, 1H & 13C NMR and MS. On the basis of chemical and spectral analysis structure was elucidated as 2-(3, 4-dihydroxyphenyl)-3, 5, 7-trihydroxy-4H-chromen-4-one, a flavonoid.

Spray retention on whole plants: modelling, simulations and experiments

Retention of sprays on plants is a critical component influencing the effectiveness of agrichemical applications. Previous simulations of spray retention by plants gave poor agreement for hard-to-wet species when compared with actual measured retention. A new model is developed here that accounts for: species wettability, impaction angle, droplet bounce, partial retention on shatter, a variable time to shatter, and the number of daughter droplets produced. The aim of this study was to compare predictions from the new model with data obtained by spraying five mixtures via five nozzles onto easy-to-wet cotton (Gossypium hirsutum L.), and hard-to-wet wheat (Triticum aestivum L.) and fat hen (Chenopodium album L.). The new model correctly predicts retention to be highest on cotton and lowest on wheat. The trend in both measured data and the model predictions is for retention to decrease with increasing droplet size, on all three plant species. Formulation is correctly predicted to have little influence on retention by easy-to-wet cotton plants and to enhance retention by the harder-to-wet wheat and fat hen plants. The parameters that describe partial retention on shatter and variable time to shatter have a substantial influence on retention, as they affect primary or secondary droplet capture. A better understanding of the kinetic energy effects and the interactions between the formulation and the leaf surface are needed to refine their input values.

Weed spectrum in different wheat-based cropping systems under conservation and conventional tillage practices in Punjab, Pakistan

Excessive tillage in conventional agriculture has led to soil and environmental degradation. Conservation agriculture (CA) has evolved as an alternate and sustainable crop production system. However, weed control is a serious issue in CA; nonetheless, allelopathy offers a viable option for weed management. This study was conducted to evaluate the shift in weed spectra in different wheat-based cropping systems under different tillage practices in Punjab, Pakistan. Wheat was planted in fallow-wheat, rice-wheat, cotton-wheat, mungbean-wheat and sorghum-wheat cropping systems with zero tillage (ZT), conventional tillage (CT), deep tillage (DT) and CT with beds sowing (BS; 60/30 and 90/45). The most important weeds identified were fat hen, common goosefoot, horseweed, garden spurge, broad-leaved dock, yellow sweet clover, false daisy, salt marsh, rabbit foot grass, bermuda grass, red sprangletop, corn spurry and littleseed canarygrass. Maximum diversity of weeds (number of weed species) was recorded in cotton-wheat under ZT; whereas the sorghum-wheat system had minimum diversity of weeds under DT. Fallow-wheat and mungbean-wheat systems had more grassy and broad leaf weeds, respectively, while sorghum-wheat had less density of these weeds. Likewise, ZT had higher while DT and BS had less density of grassy and broad leaf weeds. However, CT favored some broad leaf weeds like fat hen and common goose foot; DT stimulated only common goose foot; whereas ZT supported some broad leaf and all grassy weeds. Sorghum-wheat system suppressed most of the weeds, grasses in particular, and three grassy weeds (salt marsh, bermuda grass and red sprangletop) were absent owing to its strong allelopathic potential; however, this system favored littleseed canarygrass under ZT. In conclusion, divergent wheat-based cropping systems had different weeds spectra under different tillage practices; and choice of cropping sequence may help suppressing weeds. Inclusion of allelopathic crops, like sorghum, in the wheat-based cropping system may help managing weeds under conventional and conservation tillage practices.

Transpiration of grapevines and co-habitating cover crop and weed species in a vineyard. A “snapshot” at diurnal trends

The objective of this study was to quantify transpiration rates of two cover crops, Festuca rubra subsp. rubra (red fescue) and Medicago lupulina (black medick) and 4 weeds, Chenopodium album (fat hen), Cirsium arvense (creeping thistle), Malva neglecta (common mallow) and Taraxacum officinale (dandelion) occurring in a mixed stand in a commercial steep-slope, North-South oriented vineyard as compared to vines, cv. Riesling near Johannisberg (Rheingau), Germany. Leaf transpiration (E) was measured directly on the cover crop and weed species with a portable gas exchange measurement system. Grapevine transpiration was measured concomitantly using custommade Granier-type xylem sap flow gauges. Measurements were conducted on two days in August (15 th and 22 nd ) in 2001 under hot and sunny conditions. All herbaceous species presented a similar diurnal pattern of E, with low values in the morning and afternoon and peak values between 12 and 15 h. In contrast E of grapevines peaked mid-morning (between 8 and 10 h) remained relatively stable until mid-afternoon (16 h) before decreasing continuously until darkness. Significant differences in E between the herbaceous species were observed throughout the day. In general transpiration rates were highest for M. neglecta and lowest for C. arvense, T. officinale and F. rubra subsp. rubra . We estimated the projected leaf area indices (leaf area per surface area covered) for each species and calculated possible transpiration rates for pure stands assuming that all leaves were well exposed. Potential transpiration rates ranged from about 1 mm d -1 (one l m -2 of soil surface) for F. rubra subsp. rubra to = 5 mm d-1 for M. neglecta as compared to only 0.9 mm d -1 for grapevine. These results underline the importance of appropriate cover crop species and the control of some weed species with respect to water use.

Stemphylium sp., the cause of yellow leaf spot disease in sugar beet (Beta vulgaris L.) in the Netherlands

During the summer of 2007, a distinctive type of yellow leaf spot was observed for the first time in sugar beet (Beta vulgaris L.) in the Netherlands. In the following years a rapid spread over all regions of the Netherlands was reported. The infestation appears in June-August on the leaves of sugar beet and starts with small, irregular, yellow spots. Subsequently the yellow spots become necrotic from the centre of the lesion outward, with the tissue becoming brown (or brownish). The spots spread over the leaves and infest all the leaves of the plant. Due to the loss of leaves the size of the canopy declines and yield loss occurs. Research was conducted to identify the causal agent. Climate room trials with isolates obtained from infested sugar beet leaves showed that Stemphylium sp. was able to infest leaves of healthy growing sugar beet plants with brown spots, similar to the necrotic spots seen in the field. From the leaf spots in the climate room trials, Stemphylium sp. was re-isolated, according to Koch’s postulates. Thus, it was confirmed that this Stemphylium sp. is a primary pathogen for sugar beet. In field trials of fungicide efficacy a sugar yield loss of up to 42 % (a financial yield loss of 51 %) was found. Field trials show that it is hard to control this Stemphylium sp. with the fungicides registered for sugar beet in the Netherlands and efficacy of control of Stemphylium sp. differs between fungicides with active ingredients belonging to the same chemical class. In addition to sugar beet, potato (Solanum tuberosum L.), white mustard (Sinapsis alba L.), red beet (Beta vulgaris L.), spinach (Spinacia oleracea L.) and fat hen (Chenopodium album L.) were identified as hosts in an assay of plants grown and inoculated in climate rooms.