Season-specific varietal management as an option to increase rainfed lowland rice production in East African high altitude cropping systems

Due to land expansion and an increase in productivity, rice production in sub-Saharan Africa has been growing at a rate of 6% in the past decade. Rainfed rice production systems have accounted for a large share of this expansion. In these systems, the potential growing period not only depends on the length of the rainy season and thus water availability, but is often, especially in the highlands of East Africa, bordered by the onset of the cool period of the year, when low minimum temperatures compromise rice yields. The objective of this study was to investigate the yield potential of 30 rice varieties contrasting in crop duration and cold tolerance in the highlands of East Africa, with its limited length of growing period. A field trial was conducted in the cropping seasons in 2016 and 2017 at the Fogera rice research station, Ethiopia. As a function of the onset of rains, rice was sown mid-July in 2016 and early July in 2017. Early sowing in 2017 led to an extended crop duration and significantly lower yields of the short-duration varieties, and to a shortened duration and significantly higher yields of the medium- and long-duration varieties, when compared to late sowing in 2016. Late sowing compromised yield of the medium- and long-duration varieties because of low temperatures during booting stage, which led to high spikelet sterility. Early sowing resulted in low yields of the short-duration varieties, probably due to low solar radiation during the cloudy rainy season, which coincided with the vegetative stage. Therefore, choice of variety should be a function of the variable onset of the rainy season and related sowing date. However, crop models precisely calibrated for potential varieties and the respective environmental conditions could fully support the selection of a suitable variety, depending on the date of sowing, for example with the help of online tools or smartphone applications.     

Body condition scoring (BCS) in corn snakes (Pantherophis guttatus) and comparison to pre-existing body condition index (BCI) for snakes

In the veterinary profession, the body condition score (BCS) plays an important role in the assessment of patients. It is a subjective, tactile method of evaluating body fat and muscle mass and is used in numerous species. Recognizing obesity (or the contrary, emaciation) is important for veterinarians treating reptiles and could be facilitated by a BCS. An existing form of body condition assessment already used is the body condition index (BCI), where the residuals from a regression of body mass on body length are calculated. Therefore, the goal of this study was to provide practitioners with a BCS system for corn snakes (Pantherophis guttatus) and to test it against the BCI. A total of 22 corn snakes (Pantherophis guttatus), stationed at the “Auffangstation für Reptilien” in Munich (reptile rescue centre, RRC), were subject of this study. Each had the following measurements taken: body weight (BW), snout–tail tip length (STL), snout–vent length (SVL) and circumference in the middle (C). Manual palpation of spine, area between vertebral spinous and transverse process, ribs and neck of each snake was performed by three veterinarians and assigned to specific scores by each examiner. A BCS (mean of examiners’ scores) was given to each snake according to manual palpation. The BCS system was chosen to be out of 5 in 0.5-point steps with 2.5 considered as ideal BCS. In the studied snakes, the BCS ranged from 1.5 to 3.5, with a median of 2.5. The median BW was 309 g (75–967 g), the median STL was 123 cm (79–153 cm), the median SVL was 104 cm (73–133 cm) and the median C was 7.5 cm (4.3–11 cm). BCS and BCI were positively correlated. A BCS includes a manual palpation of the animal and thus gives the examiner additional information to the objectively measured/calculated index.     

DISPERSAL PATTERN OF INJECTATE FOLLOWING CT‐GUIDED PERINEURAL INFILTRATION IN THE CANINE THORACOLUMBAR SPINE: A CADAVER STUDY

An increasing proportion of canine patients are presented with chronic thoracolumbar back pain and without compressive spinal lesions. In humans, spinal perineural infiltrations have been reported to have a favorable effect on pain control. The purpose of this prospective cadaver study was to describe the dispersal pattern of injectate following CT‐guided spinal perineural infiltration in the canine thoracolumbar region. Seven fresh canine cadavers were first scanned using multislice CT and then CT‐guided spinal perineural infiltration was performed at 42 sites from T13/L1 to L6/L7. The injectate for each site was a mixture of new methylene blue and iodinated contrast medium. Immediately following CT‐guided injection, cadavers were frozen, cut, and dissected macro‐ and mesoscopically (using a magnifying glass) to identify anatomic structures that were infiltrated. In the majority of sites (64.3%), complete epidural and hypaxial staining of spinal nerve components (including the spinal ganglion, trunk, and ventral branch) was successfully achieved. However, no (11.9%) or unpredictable staining (9.5%) of nervous tissue occurred in some sites despite careful CT guidance and the application of relatively large volumes of injectate. Optimal results were achieved when the needle tip was positioned periforaminally ventral to the cranial contour of the cranial articular process. Findings from this ex vivo study indicated that CT‐guided spinal perineural infiltration is feasible for testing in the canine thoracolumbar region and that successful nerve tissue infiltration would likely occur in the majority of sites. Future in vivo studies are needed to determine the safety and efficacy of this technique.     

A case of primary choroidal malignant melanoma in a cat

This report describes the clinical presentation, diagnosis, histological lesions, and prognosis of a primary choroidal malignant melanoma in a 15‐year‐old cat. The animal was presented for unilateral blindness. On ocular examination, a raised pigmented mass protruding from the posterior pole into the vitreous body was observed by diffuse transillumination and indirect ophthalmoscopy. Ocular ultrasound and computer tomography (CT) scan confirmed localization of the tumor to the posterior segment. The diagnosis of primary choroidal melanoma was confirmed by histopathology after enucleation. To our knowledge, this is the first reported case of a feline malignant melanoma with a primary choroidal localization without iris involvement.     

Influence of ketamine or xylazine supplementation on isoflurane anaesthetized horses‐ a controlled clinical trial

ObjectivesTo determine the influence of ketamine or xylazine constant rate infusions on isoflurane requirements, cardiovascular parameters and quality of anaesthesia in horses undergoing elective surgery.Study designProspective, matched paired clinical trial.AnimalsFifty four adult Warmblood horses.MethodsAfter premedication with acepromazine, xylazine and butorphanol, anaesthesia was induced with ketamine-midazolam and maintained with isoflurane alone (I), isoflurane with either 1 mg kg⁻¹ hour⁻¹ ketamine (IK) or same dose of xylazine (IX). End tidal concentration of isoflurane (Fe’Iso) was adjusted by the same anaesthetist in all horses according to a scoring system. Dobutamine was infused to maintain mean arterial pressure (MAP) =70 mmHg. Arterial blood gases, heart rate (HR), respiratory rate, MAP and cardiac output (lithium dilution) were measured. Groups I and IK received xylazine before recovery. Recovery quality was scored.ResultsMean ± SD averaged Fe’Iso (volume%) was significantly lower in IX (0.95 ± 0.07) and IK (0.97 ± 0.08) than in I (1.16 ± 0.13). In group IX, HR was significantly lower and averaged MAP (90 ± 13 mmHg) significantly higher than in groups I (71 ± 7 mmHg) and IK (76 ± 7 mm Hg). Differences in other cardiopulmonary variables did not reach statistical significance. All horses recovered well with best score in group IX.ConclusionsBoth CRIs of xylazine and of ketamine resulted in pronounced reduction of isoflurane requirements and blood pressure support based on routinely monitored parameters. Cardiac output appeared well maintained in all three protocols, but lithium dilution induced errors mean the results are untrustworthy. The work requires repetition with another mode of measurement of cardiac output.Clinical relevanceAll three protocols provided good clinical anaesthesia with clinically acceptable cardiovascular effects.     

Agreement of high definition oscillometry with direct arterial blood pressure measurement at different blood pressure ranges in horses under general anaesthesia

ObjectiveTo determine the agreement of high definition oscillometry (HDO) with direct arterial blood pressure measurements in normotensive, hypotensive and hypertensive horses during general anaesthesia.Study designExperimental study.AnimalsSeven healthy warmblood horses, aged 3–11 years, weighing 470–565 kg.MethodsMeasurements from a HDO device with the cuff placed around the base of the tail were compared with pressures measured invasively from the facial artery. High blood pressures were induced by intravenous (IV) administration of dobutamine (5 μg kg⁻¹ minute⁻¹) over ten minutes followed by norepinephrine (0.1 mg kg⁻¹ IV) and low pressures by increasing the inspired fraction of isoflurane and administration of nitroglycerine (0.05 mg kg⁻¹ IV). For analysis three pressure levels were determined: high (MAP>110 mmHg), normal (60 mmHgResultsA total of 245 paired measurements of systolic (SAP), mean (MAP) and diastolic (DAP) pressures were obtained. The HDO device underestimated blood pressure at hypertensive and normotensive levels and overestimated blood pressure at hypotensive levels. Best agreement was obtained for SAP and MAP within normotensive limits. At normotension, bias ± standard deviation for SAP, MAP and DAP were 0.1 ± 19.4 mmHg, 0.5 ± 14.0, 4.7 ± 15.6, respectively. At high pressure levels bias and SD were 26.1 ± 37.3 (SAP), 4.2 ± 19.4 (MAP), 1.5 ± 16.8 (DAP) and at low pressures -20.0 ± 20.9 (SAP), -11.4 ± 19.6 (MAP), -4.7 ± 20.1 (DAP), with HDO measurements at a MAP <50 mmHg often failing.Conclusion and clinical relevanceGood agreement with invasive arterial blood pressures was obtained with HDO at normotensive levels in horses. At high and low pressure ranges HDO was unreliable. Therefore, if haemodynamic instability is expected, invasive measurement remains preferable.     

Resin canal traits relevant for constitutive resistance of Norway spruce against bark beetles: environmental and genetic variability

The influence of genetic determination and environment on the variability of secondary resin canal traits was investigated on 15–19-year-old Norway spruce (Picea abies (L.) Karst.) clones grown in Lower Austria (Pressbaum and Ulmerfeld) and southern Sweden (Knutstorp and Hermanstorp). Eleven and 20 clones were present on the two Austrian and the two Swedish sites, respectively. The sites differed in their water availability, as indicated by different annual precipitation and soil type. Resin canal traits measured were the number of epithelial cells per canal, the number of resin canals per unit tangential wood surface area, the mean resin canal area and the total resin canal area per unit tangential wood surface area. The latter three traits are known to be related to the constitutive resin flow of Norway spruce.

Environment had an influence on the variability of resin canal traits but the most important factor for the variability was the tree’s genetic disposition. Within countries, clones from the drier sites (Pressbaum and Hermanstorp) showed significantly smaller resin canals. Trees from Pressbaum also had smaller total resin canal areas than trees from Ulmerfeld. The number of epithelial cells and the number of canals did not differ between sites.

Resin canal traits had wide genetic variation and high broad sense heritabilities (H²), with values between 0.28 and 0.82. Highest heritability values were reached for the number of epithelial cells and the number of canals (H² > 0.8). Genotypic correlations across trials were high for the resin canal traits and approached 1 in both the Austrian and the Swedish trials, indicating that there was little genotype by environment interaction for these traits and thus the ranking of clones was very similar in the different environments.

The number of epithelial cells, the mean area and the total resin canal area showed either moderately significant positive genotypic correlations with tree growth traits or none at all.

In a breeding context, our results are encouraging and indicate that high constitutive defence potential against bark beetles, such as Ips typographus, is not aligned with low volume growth. But it should be taken into consideration that environment and forestry practices can also have an impact on the resin reservoir provided by the radial resin canals.     

Effects of oil of cloves and citronellol, two commercially available repellents, against the webbing clothes mothTineola bisselliella Hum. (Lepidoptera: Tineidae)

Tineola bisselliella is a common pest on natural fabrics of economic importance. Two commercially available repellents for use against adult webbing clothes moths were tested for their efficacy in dual- and no-choice bioassays. Oil of cloves and citral in combination, as well as citronellol scented with oil of lavender showed promising repellent effects for 4 weeks when applied in small compartments of a wardrobe. Although the repellent efficacy was not 100% under the conditions tested, the usage of essential oils in combination with other infestation prevention techniques is discussed.

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Zusammenfassung Die KleidermotteTineola bisselliella Hum. ist einer der wirtschaftlich bedeutenden tierischen Wollzerstörer. Auch Pelze, Felle, Polsterhaare und Federn werden von dem weit verbreiteten Kleinschmetterling aus der Familie der Tineidae befallen. In der Praxis gilt es vor allem Kleidungsstücke, die z. B. saisonbedingt für längere Zeit ungenutzt in einem Kleiderschrank aufbewahrt werden, vor dem Befall durch die Kleidermotte zu schützen. Hierfür stehen dem Verbraucher neben den konventionellen Bekämpfungsmitteln mit den Wirkstoffen Kampfer, Naphthalin und Paradichlorbenzol sowie pyrethrum- und pyrethroidhaltige Mittel auch Präparate zur Verfügung, die auf die repellierende Wirkung von ätherischen Ölen zurückgreifen. Die abstoßende Wirkung von Nelkenöl in Kombination mit Citral und von Citronellol parfümiert mit Lavendelöl auf die Falter der Kleidermotte wurde auf vergleichbare Eigenschaften untersucht. In Wahlversuchen wurden deutliche Repellent-Wirkungen der Mottenschutz-Präparate sichtbar. Die Präparate zeigten gute Wirkungen, wenn sie zum Schutz gegen den Zuflug von Kleidermotten an wollhaltigen Stoffen in kleinen Kompartimenten eines Kleiderschrankes ausgelegt waren. Auch in Zwangsversuchen hatte dieser Befund zum Teil Bestand. Bei längeren Versuchszeiten wurden allerdings verstärkt Fraßschäden durch Larven an den Wollstoffen festgestellt. Dies ist darauf zurückzuführen, daß Mottenweibchen nicht mehr in dem Maße repelliert wurden und ihre Eier an den Stoffen ablegten.

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This article reports the results of research only. Mention of a proprietary product or pesticide does not constitute an endorsement or a recommendation for its use by the Federal Biological Research Centre for Agriculture and Forestry or by the USDA-ARS.