Glyphosate injury on Cyperus esculent us leaves and basal bulbs: histological study

The effect of glyphosate on leaves and basal bulbs of yellow nutsedge (Cyperus esculentus L.) plants was studied. Treatment with glyphosate did not affect leaf anatomy, although light necrotic spots were seen on the veins. In contrast, basal bulb organization was greatly affected with large necrotic zones and disorganization in the vascular cylinder due to herbicide accumulation. Depletion or disappearance of vacuolar phenols was observed in bulbs of plants treated with the highest doses of glyphosate. The most remarkable effect of glyphosate was the appearance of one layer of sclerenchymatic cells between root and rhizome primordia and the cortical tissues which could play an important role in the inhibition of rhizome and root emergence by the herbicide.     

Screening potato varieties for short dormancy

Summary Autumn grown potatoes harvested in December cannot be used for planting in February–March, as they are still dormant at that time. The lengthy dormant period ofUp-to-Date, the main variety cultivated in Israel, was found to be the bottleneck of the problem of supply of locally grown seed tubers. In order to find varieties with a shorter dormant period, 52 varieties from different sources were introduced. The seed material was propagated twice before it was used for the first screening test in spring 1956. The first test has shown that varieties with a short dormant period gave the best results and those with a long one the worst. The second screening in spring 1957, in which a limited number of the most promising varieties were tested, has shown that length of growing period is at least as important as length of dormant period, and that early and medium-early varieties are best. In spite of the results obtained we consider that it will be necessary to breed new varieties more adapted to the specific requirements of growing two crops a year.

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Zusammenfassung Im Herbst ausgepflanzte und im Dezember geerntete Kartoffeln k?nnen nicht zum Auspflanzen im Februar verwendet werden, da sie sich dann noch in der Keimruhe befinden. Die ziemlich lange Keimruhe vonUp-to-Date, der in Israel am meisten angebauten Sorte, erwies sich als die gr?sste Schwierigkeit bei der L?sung des Problems der Versorgung mit einheimischem Saatgut. Um Sorten mit kürzerer Keimruhe zu finden, wurden 52 Sorten verschiedener Herkunft eingeführt. Das Saatgut wurde zweimal fortgezüchtet, bevor es für den ersten Auslesetest im Frühjahr 1956 verwendet wurde. Der erste Versuch zeigte, dass Sorten mit kurzer Keimruhe die besten und Sorten mit langer Keimruhe die schlechtesten Resultate ergaben. Die zweite Auslese im Frühjahr 1957, wobei eine kleinere Anzahl der aussichtsreichsten Sorten geprüft wurde, zeigte, dass die Dauer der Wachstumsperiode mindestens ebenso wichtig ist wie die L?nge der Keimruhe und dass frühe und mittelfrühe Sorten die besten sind. Ungeachtet dieser Ergebnisse halten wir es für angezeigt, neue Sorten zu züchten, die den besonderen Ansprüchen einer zweimaligen Ernte im Jahr besser genügen.

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Résumé Les pommes de terre d'automne récoltées en décembre ne peuvent servir de semence en févriermars, puisqu'elles se trouvent encore à l'état latent à cette époque. La période de latence assez prolongée de l'Up-to-date, la principale variété cultivée en Israel, constitue le majeur obstacle à l'approvisionnement en semences locales. Afin de trouver des variétés à courte période de latence, nous avons introduit 52 variétés de différentes provenances. Celles-ci ont d? être multipliées deux fois avant que nous ayons pu entreprendre le premier essai au printemps 1956. Ce premier essai a permis de constater que les variétés à courte période de latence étaient les meilleures, celles à période de latence prolongée donnant les résultats les moins bons. La seconde sélection fut effectuée au printemps 1957. A cette occasion, un plus petit nombre de variétés particulièrement prometteuses furent étudiées. Il fut constaté que la durée de végétation a une importance au moins égale à celle de la durée de latence. Les variétés précoces et moyennes étaient les meilleures. Malgré les résultats de cette étude, nous en sommes arrivés à cette conclusion qu'il nous faudra sélectionner, des variétés nouvelles, mieux adaptées aux exigences particulières de la culture de la pomme de terre effectuée à deux reprises dans la même année.

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Publication of the National and University Institute of Agriculture, Rehovot, 1960. Series No. 354-E.     

Field attraction of Cerambyx welensii to fermentation odors and host monoterpenes

Cerambyx welensii Küster is one of the greatest threats to Quercus suber L. and Quercus ilex L. in Spain. Efficient control methods for this species are currently being tested, and the use of traps baited with food-related products for their monitoring and control has been proposed. Cerambyx welensii adults prefer to colonize old or decayed trees, in which cortical exudates frequently release fermentation odors. Fermentation-related compounds, such as ethanol, have been cited as attractants to various hardwood woodborers (as Cerambyx cerdo L.), used either alone or sometimes in combination with other host odors. In this work, we conducted field experiments to ascertain whether chemical blends mimicking fermentation odors were attractive for C. welensii. To this end, we used three types of traps (multiple funnel, cross-vane and single-funnel) baited with six synthetic blends including one or more fermentation-related chemicals (ethanol, ethyl acetate, 3-methyl-1-butanol, acetaldehyde, 2-methyl-1-propanol and 2-methyl-1-butanol), various food-related products (beer, melon and red wine mixed with peach juice) and host monoterpenes (α-pinene, β-pinene, limonene, α-phellandrene and camphene). At high release rates (5–11 g/day), various synthetic blends proved attractive irrespective of trap type. Our results contribute to understand the impact of volatile organic compounds in host selection by woodborers infesting deciduous trees. The results hold promise for optimizing trapping strategies to control C. welensii within an integrated pest management framework.     

Effect of Breeding Activity on the Microflora of the External Genitalia and in the Semen of Stallions,and the Relationship Between Micro‐organisms on the Skin and on the External Genitalia

A possible role of breeding activities in the composition of the microbial population in stallions' external genitalia (EG) and the relationship between micro‐organisms colonizing the skin of the abdomen and the ones colonizing the EG have not been studied. In experiment 1, EG microbiological samples were collected from 41 stallions used for both natural cover and semen collection (BST) and from 18 non‐breeding stallions (NBST). A higher (p < 0.05) frequency of isolation of potentially pathogenic species was found for BST. Age did not influence number of micro‐organism species isolated both in BST and NBST. In experiment 2, the microbial content of the EG and semen was compared in 23 BST. Most micro‐organisms isolated from the EG were present in semen, albeit with a numerically lower prevalence. In 7 stallions, six microbial species isolated from semen were absent from the EG cultures, suggesting contamination by the operator. In experiment 3, a numerically higher number of micro‐organism species was isolated from the EG of 31 stallions, than from their skin of the ventral abdomen in contact with the penis or from the skin of the thorax. With the sole exception of Escherichia coli, potentially pathogenic bacteria were only isolated from the EG but not from the skin. Results suggest that breeding activity increased the number of species colonizing the EG; most species isolated from the EG were also found in semen even if with a lower frequency, and additional semen contamination seemed to occur during its manipulation. Many micro‐organism species of the skin were also isolated from the penis, but independently of being or not in contact with the penis, skin did not seem to provide an adequate environment for the growth of potentially pathogenic bacteria that were isolated from EG, with the sole exception for E. coli.     

Changes in productivity and profitability of wool-growing farms that follow recommendations from agricultural and veterinary studies

Objective To estimate the changes in productivity and profitability in a group of wool-growing farms as they adopted major recommendations from agricultural and veterinary studies.
Farms Four wool-growing farms in south western Victoria were selected from the clients of the Mackinnon Project, a farm consultancy service run from the University of Melbourne. Each farm had closely followed recommended procedures, kept comprehensive financial and physical records and had been clients for at least 5 years. The comparison group was the South Western Victoria Monitor Farm Project (SWVMFP), about 45 farms in the same region as the study farms that were monitored annually by Agriculture Victoria.
Procedure For a 7-year period, the financial and physical performance of both groups of farms was estimated. Stocking rate, wool production, gross farm income, farm operating costs, net farm income and return on assets were compared.
Results Mean gross farm income of the four study farms steadily rose from 86% of the average SWVMFP farm before the adoption of recommendations to an average of 155%. During the same period, net farm income rose from 70% to 207% of the average of the SWVMFP. Return on asset of the four farms rose irregularly from 26% to 145% of the average of the SWVMFP. Farm operating costs on the four farms were higher than for the SWVMFP group, but the ratio of costs remained relatively constant.
Conclusion The adoption of proven research results was associated with large increases in net farm income. An increase in gross income, rather than a reduction in costs was the main reason for this. Research results offer a way to increase the financial viability of wool-growing farmers, many of whom are currently unable to maintain their lifestyle, resources and infrastructure.     

Effect of ensiled hop (Humulus lupulus L.) residues on plasma acetate turnover rate in sheep

An isotope dilution method using [1‐¹³C]sodium acetate was applied to determine the effect of feeding ensiled hop (Humulus lupulus L.) residues on plasma acetate turnover rate in six adult crossbred sheep. The sheep were fed 63 g/kg body weight (BW)^0.75/day of either mixed hay of orchardgrass (Dactylis glomerata L.) and reed canarygrass (Phalaris arundinacea L.) and round bale silage at 3:1 ratio (Hay‐diet), or another where round bale silage was replaced by ensiled hop residues (Hop‐diet) with a crossover design each of a 3‐week period. The isotope dilution method was performed on day 21 of each dietary treatment. Dry matter digestibility was similar between diets, and nitrogen (N) digestibility was lower (P = 0.001) for Hop‐diet than Hay‐diet. However, N retention did not differ between diets. Plasma acetate concentration was lower (P = 0.04) for Hop‐diet than Hay‐diet, and the turnover rate of plasma acetate did not differ between diets. Plasma concentration of lactate and non‐esterified fatty acids were similar between diets. Hop‐diet was found almost comparable to Hay‐diet on plasma acetate turnover rate in the present experimental conditions. Therefore, it could be concluded that hop residues partially could be used as an alternative to traditionally used round bale silage for rearing sheep.     

Combining sub-lethal heating and on-farm wastes: effects on <Emphasis Type="BoldItalic">Fusarium oxysporum</Emphasis> f.sp. <Emphasis Type="BoldItalic">cumini</Emphasis> causing wilt of cumin

In a 2-year field study, the effects of four heating regimes established by varying temperature or duration of heating on efficiency of on-farm wastes as soil amendments in controlling Fusarium oxysporum f.sp. cumini (Foc) causing wilt on cumin (Cuminum cyminum L.), were ascertained. Significant improvement in reduction of Foc propagules was achieved with the increase in duration and amount of heat. In 2000, mild heating under shade (heat level 4), 31.8–65.9% reduction in Foc propagules was estimated in all the amendments at 0–30 cm soil depth, which improved by 75.7–86.5% in the treatment where Foc-infested soil brought from the laboratory was exposed to direct heat (heat level 3) and amendments and irrigation were applied. Foc propagules were reduced by 76.6–88.3% when infested soil was exposed continuously to dry heat for 56 days (heat level 2), improving efficiency of amendments by 0.9–13.5% compared with heat level 3. After 56 days of exposure to dry heat, elevating the temperature by mulching amended soil with a transparent polyethylene film (50 μm thick) for 20 days (heat level 1) augmented reduction by 80.2–95.5%. In the second season, combining 0.04% of onion, Verbisina encelioides or mustard oil-cake with mustard residues (0.18%) improved the reduction in Foc propagules at all heat levels even at the lower soil depth. Maximum reduction (94.9–100%) in Foc propagules at heat levels 1 to 3 was achieved when residues of Verbisina were supplemented with those of mustard. These results suggest a new approach to improve the control of Foc by combining prolonged heating with on-farm wastes such as Verbisina residues and one summer irrigation.     

The dispersal of Culicoides brevitarsis in eastern New South Wales and associations with the occurrences of arbovirus infections in cattle

Distributions of the vector Culicoides brevitarsis Kieffer (Diptera: Ceratopogonidae) (determined from light trap data) and 2 arboviruses (determined from seroconversions in sentinel cattle) were studied in eastern New South Wales in 1993–94. C brevitarsis was recorded progressively from endemic areas on the north coast, to Nowra on the south coast, and westward to Scone, in the Hunter Valley. C brevitarsis also survived through winter at Paterson, in the Hunter Valley. Its apparently focal reappearance in this marginal area had no obvious effect on the broad pattern of its progression or the dispersal of Akabane and bluetongue viruses. These viruses were first recorded from foci near Coffs Harbour, on the mid-north coast. Their first occurrences at different locations were associated with those of C brevitarsis, but not with each other. The viruses were found only within the recorded limits of the vector's distribution. Delays between the initial occurrence of C brevitarsis and first evidence of virus transmissions at locations ranged from 2 to 7 months. The delays decreased away from the points of focus and were negatively associated with the time of initial occurrence of the vector. Seroconversions to the viruses were related to the presence of C brevitarsis. However, the densities of C brevitarsis had no apparent effect on the initial numbers of cattle seroconverting to either virus. The results support the conclusion that the progressions of C brevitarsis and Akabane and bluetongue viruses were the result of gradual movements by the vector.