Simulation analysis of relative yield advantage of barley and wheat in an eastern Mediterranean climate

Barley (Hordeum vulgare) and wheat (Triticum aestivum) are similar crops that can be grown in the arid regions of southwestern Asia. Generally, barley is favored over wheat in drier areas. However, the quantitative basis for the relative advantage of each crop under differing growing conditions has not been resolved. This study was undertaken to compare the two crops using the same model structure. A wheat model developed for southwestern Asia was readily adapted to simulate barley. Simulations of barley crops proved to be robust over a range of environments. Comparison of simulated yields in a number of environments showed that the critical difference between species was the cumulative effect of plant development traits that allowed barley to mature much earlier than wheat. Consequently, early maturity of barley in contrast to wheat often allowed barley to complete its growing cycle before water-deficit conditions developed in the spring. There was, however, little or no yield advantage for barley in seasons of high rainfall. Also, rare seasons with significant rainfall after barley matured allowed wheat to actually produce the greater yield. These simulation results indicated that development traits are crucial in the interaction between crop yield and exposure to water deficits at the end of the growing season.     

Retention of canopy lichens after partial-cut harvesting in wet-belt interior cedar–hemlock forests,British Columbia,Canada

Old-growth cedar–hemlock forests of the interior wet-belt of British Columbia are rich in abundance and diversity of canopy lichens, but are subject to forest harvesting. If these distinctive canopy lichen communities are to be conserved, it is important to learn how they are affected by forestry practices, including partial-cutting techniques designed to retain old-growth attributes. The retention of canopy lichens after 30 and 70% partial-cut harvesting (immediate post-harvest and 2-year post-harvest measurements) was examined using direct canopy access methods (tree climbing) in two old-growth interior cedar–hemlock forest stands of the upper Fraser River valley. Mean lichen loading was generally lower in all treatment areas, including control sites, 2 years after harvesting. However, three of four lichen-sampling groups (cyanolichen, foliose, and Bryoria group lichens) did not show significant treatment effects (total lichen loading) by harvesting type (30, 70 or 100% retention), when data sets were standardized against initial post-harvest lichen loading. Only in Alectoria group lichens were treatment effects observed. Although cyanolichen loading was not significantly different in retained trees in most harvest blocks, many thalli, especially those near south-facing edges, were discolored, suggesting that future cyanolichen loading may be lower within partial-cut harvest blocks. Litterfall in general was greater during 2001/2002 than 2002/2003, even in the control units, suggesting weather-related differences between years. For Alectoria, there appeared to be a treatment-related pulse of litterfall that was more pronounced in the 70% removal than the 30% removal treatment unit. Deposition patterns of litterfall components in relation to edges of openings indicated a heightened level of Alectoria litterfall along edges. Treatment-related differences were absent or weak in other groups, and cyanolichen litterfall did not differ between years in any study area/treatment unit combination. These findings suggest that lichen retention in the residual stand of both partial-cut treatments was adequate to meet management goals, but also point to the necessity of future monitoring, as other edge effects (e.g. microclimate changes) influence future lichen growth and mortality.     

Dyserythropoeisis, sideroblasts/siderocytes and hemoglobin crystallization in a dog

Dyserythropoiesis characterized by enhanced intramedullary destruction, pathologic sideroblasts and siderocytes, and hemoglobin crystallization was detected in a female Cocker Spaniel presented for poor exercise tolerance. Examination of peripheral blood revealed intraerythrocytic crystals, granulation of erythrocytes, nucleated erythroid cells, reticulocytosis and marked variation in erythrocyte morphology in the absence of anemia. Bone marrow examination revealed sideroblasts, a low M:E ratio and evidence of enhanced intramedullary destruction of erythroid cells. Electron microscopy of peripheral blood and bone marrow confirmed pathologic mitochondrial iron accumulation in erythroid cells and the presence of intraerythrocytic hemoglobin crystals. A cause for the hematologic changes was not identified. After the animal became clinically normal, siderocytes disappeared from peripheral blood but intraerythrocytic crystals and reticulocytosis persisted.     

Unsaturated vitamin b(12) binding capacity in human and ruminant blood serum - a comparison of techniques including a new technique by high performance liquid chromatography

A new technique by High Performance Liquid Chromatography (HPLC-gel permeation) shows promise as a tool to separate and quantitate the Unsaturated Vitamin B(12) Binding Capacity (UBSC) of the individual Vitamin B(12) binders in blood serum. This method, although not as rapid as protein-coated charcoal or cellulose separation techniques, is more applicable for use with large numbers of samples than gel filtration. The use of a radioactivity detector to monitor the eluant from the column permitted automation of the method. Comparable results for UBBC and for the UBBC of individual binders were obtained when samples were analyzed by gel filtration and HPLC. The HPLC method proved suitably precise and the recovery of added cyanocobalamin was acceptable. It is proposed that HPLC be the method of choice for measurement of the USBC of binders of Vitamin B(12) in blood serum.     

Relationship between equivalent salt solution series of different soils

Equivalent salt solution series have been previously defined as solutions with combinations of sodium absorption ratio (SAR) and electrolyte concentration (E_c) producing the same extent of clay swelling in a given soil. The present study shows that there is a high (r²>0.96) positive correlation between log E_c and log SAR of equivalent salt solutions series, in the equation: where a₁ and b₁ are constants for each equivalent salt solution series for a given soil. Log a₁ could also be represented as a linear function of b₁ resulting in the equation: where a₂ and b₂ are constants for a given soil. Solving this equation using any given value of b₁ yields the combinations of SAR and E_c which make up each equivalent salt solution series for a given soil. The relationship between log a₁ and b₂ for three soils from western United States, namely Waukena, Pachappa and Grangeville, was similar, with their combined data having a r² value of 0.96. This indicated that a single set of equivalent salt solution series values could be used for these three soils which have different clay contents and clay mineralogy. Prediction of hydraulic conductivity decreases with E_c reduction at given values of SAR in red-brown and alluvial soils from southern Tasmania, using the equivalent salt solution series values for Waukena soil, showed similar patterns to measured values and also to those predicted using the equivalent salt solution values applicable to the respective Tasmanian soils. Thus, available data indicate that the same set of equivalent salt series could be applied to the five soils studied. If further testing shows that a single set of equivalent salt solutions values could be applied to all or large groups of soils, this would facilitate the application of the equivalent salt solution concept to predict salt solution flow in the field.     

Observations on the use of feeding space in a commercial broiler chicken house

1. Observations were made on the use of food pans and food trays by commercially grown broiler chickens.

2. Birds fed by going inside the feeders on top of the food or from standing around the outside of the feeders. The feeding times of birds inside feeders were significantly longer than those of birds outside. Different reasons to account for this are proposed for the 2 types of feeder.

3. The total number of birds able to feed together from a tray or pan changed as the birds grew. With trays this change in the number of birds was a steady decline. With pans the change was non‐linear and reflected a changing ratio of birds eating in to birds eating out. This ratio was influenced by pan design features and by competition for feeding space.

4. The data suggest that a linear measure of feeding space, as used in research trials and Codes of Practice for Welfare, does not adequately describe birds’ access to and use of feeding space. Implications for both research and the commercial industry are discussed.     

Immunization against polyandroalbumin leads to increases in lambing and tailing percentages

A series of 10 farm trials was conducted in which the lambing performance of ewes immunised against polyandroalbumin was compared with that of untreated ewes in the same flock. The trials show that polyandroalbumin treatment is a reliable method of increasing lambing and tailing percentages in New Zealand flocks. An average of 39 extra lambs born per 100 ewes tupped was achieved on farms where ewes were given two treatments about four weeks apart and rams were introduced 18-26 days after the second dose. On farms where rams were introduced less than 12 days after this booster injection an average of 19 extra lambs born per 100 ewes tupped resulted. On farms where rams were introduced at 18-26 days post booster injection an average of 35 extra lambs were tailed for every 100 ewes tupped. The response for immunization increased in direct relation to the liveweight of the ewes at tupping.