Soft Dough Research Articles

MINERAL ELEMENT DISTRIBUTION AND ACCUMULATION PATTERNS WITHIN TWO BARLEY CULTIVARS

Growth stage effects on distribution of mineral nutrients or beneficial elements phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), chloride (Cl), iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), molybdenum (Mo), sodium (Na), silicon (Si) and nickel (Ni), and the elements bromine (Br), rubidium (Rb), strontium (Sr), barium (Ba), lanthanum (La), cerium (Ce), and uranium (U) in two barley (Hordeum vulgare L.) cultivars and how the distribution of these elements changed were determined during the 2006–2007 growing season in a field experiment. Barley plants were sampled from the field at shooting, heading, soft dough, hard dough and harvest stages, and mineral nutrients and other elements concentrations of spike, flag leaf, old leaf, and stem samples were determined by polarized energy dispersive X-ray fluorescence (PEDXRF). Distribution patterns varied considerably from element to element. At the end of the season much of the Ca, Mg, S, Si, Fe, Mn, Cu, Ni, Sr, Ba, La, Ce, and U were located in the spikes. However, much of the P, K, Zn, Cl, Na, Br, and Rb remained in the old leaves or stem.

Effect of modified celluloses on dough rheology and microstructure

The effect of different modified celluloses on dough microstructure and rheological characteristics was studied. Microcrystalline cellulose (MCC), carboxymethylcellulose (CMC) and two different types of hydroxypropylmethylcellulose (HPMC F4M and HPMC F50) were tested in a range of concentration from 0.25% to 1.5% (flour basis). Doughs were formulated without and with salt (2%w/w flour basis). Farinographic water absorption increased when hydrocolloids were incorporated and the highest values were obtained in mixtures without NaCl and when HPMCs were added. A linear relationship between the percentage increment in water absorption and the hydrocolloid level was observed within the assayed range of concentrations. The development time was markedly increased when CMC was added. CMC and HPMC did affect or not dough stability depending on the presence or absence of salt whereas the stability was not modified by MCC. Texture attributes and the rheometric parameter tan δ were analyzed through Principal Component Analysis (PCA). Two factors described the 88.9% of total variation, one of them composed by hardness, consistency, adhesiveness and tan δ and the other composed by resilience and cohesiveness. Hydrocolloids addition softened the dough, particularly when salt was absent. Samples with salt and with hydrocolloids exhibited more cohesive and less resilient characteristics. Rheological results were in agreement with the characteristics of gluten network studied by SEM since a diminished stability and softer dough could be associated with a more disrupted matrix.

Use of a mechanical roller-crimper as an alternative kill method for cover crops

Cover crops have long been recognized as a beneficial component of many cropping systems; however, their use is still not commonplace. Usage may be increased by identifying more cost-effective and environment-friendly techniques for cover-crop management. This study was conducted to determine the effectiveness of using a mechanical roller-crimper as-an alternative method for killing cover crops. The study location was in east-central Alabama, using a split-split plot experimental design with four replications and 3 site-years during 1999–2000. Rye, wheat and black oat were evaluated in terms of ease of kill and optimum time of kill using a roller-crimper, two herbicides (paraquat and glyphosate) at their labeled rate, and two reduced chemical (half label rate) combinations of the same chemicals with the roller-crimper. Four Feekes' scale growth stages were used to determine optimum time of kill; 8.0 (flag leaf), 10.51 (anthesis), 10.54 (early milk) and 11.2 (soft dough). Plant growth stage was the main determining factor for effectiveness of the roller-crimper for killing the cover crops. At the flag leaf stage, the roller-crimper provided only 19% kill across all covers over the 3 site-years. After plants reached anthesis, the roller-crimper with half-rate herbicide combinations equaled the effectiveness of herbicides alone at their label rate, averaging 94% kill. By the soft dough growth stage, all kill methods were equally effective due to accelerating plant senescence (95% mean kill across kill methods). Use of the roller-crimper alone after anthesis can decrease costs by as much as $26.28 per ha, while providing a kill rate equivalent to that of herbicide treatment alone.

Irrigation -yield response factor of winter wheat for different growth phases

The yield response factor of semi-dwarf winter wheat was determined from field experimental data conducted during three consecutive years (2002-03 to 2004-05). The yield response factor (ky) varies depending on growth phases and also among seasons. On an average, the ky for early, vegetative, booting-heading, and flowering-soft dough stages were 0.27, 0.21, 0.25, and 0.17, respectively. According to the value of yield response factor, the most sensitive growth stages were in the order: CRI> booting-heading>maximum tillering> flowering-soft dough. For the alternate deficit strategies (deficit at tillering + flowering –soft dough; deficit at CRI + booting-heading stages), the ky values were 0.77 and 0.61, respectively. For the whole growing period, the ky values were 1.58, 0.43, 2.29, and 0.61 for deficit at early, vegetative, booting-heading, and flowering-soft dough stages, respectively. The sensitivity index (lembda i, of Jensen model) for early, vegetative, booting-heading, and flowering-soft dough phases were 0.35, 0.22, 0.31, and 0.14, respectively. A more sensitive growth stage has a higher value of lambda i, and therefore water supply is more important at early and booting-heading phases.

Thermal time models for estimating wheat phenological development and weather-based relationships to wheat quality

Accurate prediction of crop phenology is a key requirement for crop development models. The prediction of spring wheat yield and quality from meteorological data can be improved by quantifying heat and moisture conditions during specified phenological phases; therefore, accurate prediction of phenological development is important for estimating weather impacts on wheat quality. The objective of this study was to test the accuracy of biometeorological time (BMT), growing degree days (GDD), and physiological days (Pdays) for prediction of wheat phenological stages and impacts of growing season weather during those stages on wheat bread-making quality. Observed crop phenological stages and detailed weather data across 17 site-years in western Canada for six hard spring wheat varieties were collected to assess BMT, GDD and Pdays. Biometeorological time was most consistent for predicting the length of the seeding to jointing and seeding to anthesis growth stages and second most consistent behind GDD for predicting seeding to soft dough and seeding to maturity. The ability of the BMT and GDD models to predict calendar days to anthesis and maturity were further tested using field data from 166 farms across western Canada. Both GDD and BMT models were effective for predicting time from seeding to anthesis (R2 = 0.84 and 0.90, respectively) and seeding to maturity (R2 = 0.62 and 0.66, respectively). BMT- and GDD-predicted wheat growth phases were used to calculate modeled crop water use by growth period for producer fields. Crop water use is significantly correlated to key bread-making quality parameters of flour protein, farinograph dough development time and farinograph stability. Biometeorological time predicted water use was more highly correlated to these quality parameters than GDD predictions. Accordingly, the BMT scale is recommended for estimation of wheat phenological development especially for modeling weather impacts on wheat end-use quality.Key words: Spring wheat, phenological development, biometeorological time, growing degree day, physiological day, wheat quality

Effect of stage of growth on the chemical composition, nutritive value and ensilability of whole-crop barley

Chemical composition, nutritive value and ensilability of whole-crop barley as a supplementary feed for dairy cows was investigated using a range of maturities of barley (seed coat ripe—GS 69, early dough stage—GS 82, soft dough—GS 87 and grain ripe—GS 90) in small scale silos. The ensiling experiment was based on a complete randomised design with three replicate silos per harvest date. Twelve 0.225 m 3 plastic silo (were used in the experiment and silo were sampled on opening for chemical composition and nutritive value. The fermentation process reduced the concentrations of water-soluble carbohydrate in the ensiled forage compared to the fresh forage. The proportion of residual WSC in silage did however increase with increasing crop maturity (0.051, 0.077, 0.167 and 0.560 of WSC retained in the silage after the process of fermentation from forages cut at GS 69, 82, 87 and 90 respectively). Silages that were made from forage cut at the most mature stage of growth had a substantially lower production (P<0.001) of total fermentation acids (38.9 g/kg DM for GS 90) compared to those made from the least mature forage (203.4 g/kg DM for GS 69). The pH and concentrations of the various fermentation acids for silages made with the least mature forage (GS 69) were typical of acetic acid dominated fermentation. These silages contained little or no butyric acid and had a pH of 4.5 and contained high concentrations of ammonia-N (186 g/kg total N). Silages produced from forages cut at growth stage 82 were similar to those conserved from immature forages, having acetic acid dominated fermentation (lactic acid to acetic acid ratio of 1:1.22), relatively high pH (4.85) and high concentrations of ammonia-N (141 g/kg total N). These silages differed from those made from the most immature forage insofar that they contained high concentrations of butyric acid (50.5 g/kg DM). The processes of fermentation were affected by the stage of growth of the forage at ensiling and hence the economics of silage production. If the forage was too immature at ensiling, the yield of crop would be compromised but the silage produced may have moderate to high nutritive value and reasonable aerobic stability during the feed out phase. If the whole-crop forage was grown as a crop to secure high levels of supplementary feed from an alternative forage source (other than grass), the trade-off between yield, nutritive value and losses of feed immediately after silo opening would suggest the crop should be harvested between 350 and 450 g DM/kg dry matter.

LOSSES IN GRAIN YIELD OF SOME RICE CULTIVARS DUE TO BLAST INFECTION AT DIFFERENT GROWTH STAGES

Two Experiments were carried out in 1999 season. The first was at the experimental farm of Rice Research and Training Center (RRTC),Sakha, whereas the second was at the experimental farm of Gemmiza Research Station. The study aimed to investigate the effect of rice blast disease on yield losses at different growth stages of cvs. Giza 171, Reiho and Giza 176. The cultivars were evaluated in split- plot design as a main plots, wheras the treatments (protection by Beam at the rate of 100g/ fed) at both tillering and heading stages, artificial inoculation with spore suspension of Pyricularia grisea (5×104 spores/m2( at tillering and or heading stage (milking, soft dough) and natural infection were allocated as Sub-plots. The highest severity and area under disease progress curve (AUDPC) for leaf blast infection were obtained from artificial inoculation at tillering stage. Also, the highest severity and AUDPC of panicle blast infection were recorded from artificial inoculation at milking stage. Giza 171 was the highest susceptible cultivar during vegetative stage, while Giza 176 was the most susceptible cultivar during heading stage. Maximum actual loss due to blast infection in grain yield and 1000- grain weight was obtained from artificial inoculation at milking stage. Panicle blast infection had stronger influence than leaf blast infection. Whereas yield losses due to panicle infection of Giza 171 were two folds compared to those due to leaf infection. These losses were three and four folds in case of Reiho and Giza 176.

The three classes of wheat xylanase-inhibiting proteins accumulate in an analogous way during wheat ear development and germination

Wheat contains high levels of the three classes of xylanase inhibitors (XIs), Triticum aestivum xylanase inhibitor (TAXI), xylanase-inhibiting protein (XIP) and thaumatin-like xylanase inhibitor (TLXI). These proteins have been linked to plant defense. In this study, expression of XIs during wheat ear development and germination was examined using immunoblotting. The three types of XIs accumulated at high levels between the milky and the soft dough stages of ear development, and reached the highest levels at the hard kernel stage. From the hard kernel stage to harvest ripeness, a slight drop in inhibitor levels was observed, which was more marked for TAXI and TLXI than for XIP. During germination, the levels of the three types of XIs initially decreased, but XIs accumulated again after 1-2d, reaching maximum levels between 5 and 9d after imbibition. The levels of TAXI, XIP and TLXI in the seedlings then gradually and continuously declined as a function of time. 1D- and 2D-immunoblotting indicated that the three types of XIs occur in a wide variety of forms. This polymorphism is maintained throughout ear development and germination, although the proportions of the different (iso)forms vary with time. A differential temporal profile was observed for the unprocessed and processed forms of TAXI-type proteins. Finally, the occurrence of TAXI and XIP, but not TLXI, in roots and shoots of young seedlings was demonstrated. No XIs were detected in roots, leaves or stems at later stages of ear development. Overall, the three classes of XIs show remarkable similarities in their temporal distribution, indicating a related function within the wheat plant.

Effect of stage of growth and silage additives on whole crop cereal silage nutritive and fermentation characteristics

The efficient production and subsequent utilisation of home-grown forage is seen as the cornerstone of profitability of the dairy industry as it leads to lower unit costs of milk production compared with purchased forage or grain supplements. Cereals such as wheat (Triticum aestivum L.), oats (Avena sativa L.) and triticale (Triticum × Triticosecale) all have the potential to produce high forage dry matter (DM) yields. These forages are not widely grown within dryland Australian dairy systems and there is a paucity of information on both the agronomic requirements and subsequent ensiling and feed-out management under these conditions. The experiment reported in this paper examines the DM yield, nutritive and ensiling characteristics of three small-grain cereals (triticale, wheat and oats) cut at various stages of development and ensiled with or without silage additives. We hypothesised that: (1) delaying harvesting until later stages of growth would result in higher DM yields, but negatively impact on both nutritive and fermentation characteristics of subsequent silages; (2) ensiling wilted material at earlier harvests would improve fermentation characteristics compared with direct ensiled material; and (3) the use of silage additives at all harvests would improve fermentation characteristics of resultant silages compared with untreated silages. Apart from winter oats, the estimated metabolisable energy of forages was highest at the boot stage of growth, declined during anthesis and then rose again during milk and soft-dough stage of growth. The crude protein content of forages declined with maturity, with final values at soft dough below 90 g/kg DM. Neutral detergent fibre content was highest at anthesis and then declined, with lowest values observed at soft dough (497–555 g/kg DM). In the majority of cases silages were well preserved, with direct ensiled material having pH values generally below 4.5 and wilted material below 5.0, with limited proteolysis as assessed by ammonia-N contents in the range of 5–15% of total-N. The production of volatile fatty acids and lactic acid was influenced by wilting and the use of additives. Generally, wilted silages fermented less than the corresponding direct ensiled forages, whereas the use of Sil-All 4 × 4 additive resulted in a lactic acid-dominant fermentation compared with LaSil additive, which resulted in a greater proportion of acetic acid as an end product of fermentation. The findings of the present study highlight the potential of forage cereals to produce high DM yields for whole crop cereal silage. The timing of harvest directly influences nutritive characteristics of forages for ensiling. The use of silage additives can assist in controlling fermentation pathways during ensilage, ensuring the production of silages with fermentation attributes more likely to lead to higher intakes when fed to animals.

Effect of different grazing strategies on dry matter yields and nutritive characteristics of whole crop cereals

Forage cereals offer the potential to increase the amount of forage grown and consumed on dairy farms in southern Australia. The effect of single or multiple grazing of winter cereal forages by lactating dairy cattle on dry matter (DM) yield and nutritive value at grazing and on subsequent silage production harvested at the soft-dough stage of growth was determined in three studies in south-western Victoria. In the first two studies, a range of forage cereals and an annual ryegrass were grazed either once (G1) during tillering (GS 21–29), followed by locking up for silage, grazed twice (G2) (GS 21–29 and GS 32–34), followed by locking up for silage, or not grazed (NG) and harvested for silage only. In the third study, two forage cereals were either ungrazed (NG) or grazed at either GS 21, GS 24, GS 30 or GS 32 and subsequently locked up and harvested for silage. All silage harvests occurred at GS 84 (soft dough). In all studies, grazing at early tillering resulted in DM yield of less than 1.4 t DM/ha, although crude protein (CP) (30–37% DM) and estimated metabolisable energy (ME) (12.2–14 MJ/kg DM) were high. Deferring grazing until the start of stem elongation resulted in higher DM yields (1.8–4.3 t DM/ha). Silage DM yields were higher (P &lt; 0.05) for G1 and NG treatments than for G2 in all cases apart from McKellar wheat in study 1. At silage harvest, CP and estimated ME contents of cereals were lower than for annual ryegrass. In general, total DM yields across the growing season were higher for the G1 and NG treatments compared with forages that were grazed twice before silage harvest. Deferment of a single grazing from early tillering to stem elongation did not adversely affect total DM production. However, delaying grazing until stem elongation resulted in significant declines in CP concentration and estimated ME. These studies highlight the potential of cereal forages to contribute to DM production on dairy farms in southern Australia. They can provide additional flexibility into forage systems through the provision of forage for a single grazing in early winter and in the production of high DM yield silage harvests. Cereals grazed in early winter have a high estimated ME and CP content, whereas the nutritive characteristics when harvested for silage at soft dough are of only moderate feed value. Consideration is required as to how best to incorporate these into diets of lactating dairy cattle.

Impact of Rye Rolling Direction and Different No-Till Row Cleaners on Cotton Emergence and Yield

Cover crops have been recognized as a vital component of conservation agriculture. However, cover crops must produce substantial biomass to be effective. Because of the large amount of residue produced by many cover crops, they must be managed appropriately to avoid planting problems. Roller-crimpers have been used to manage cover crops by flattening them and creating a thick mat over the soil surface. A study was conducted to determine the effect of different rolling directions (parallel, diagonal, and perpendicular to cotton planting direction) using a roller/crimper, three different commercial row cleaners (Dawn, Dawn without coulter, and Yetter), and no row cleaner on cotton (Gossypium hirsutum L.) stand, emergence rate, yield, and net returns. The study was conducted at two Alabama locations with a replicated strip plot design. Presented results illustrate two growing and harvest seasons (2004 and 2005). Rye (Secale cereale L.) was chosen as the cover crop due to its potential to produce large amounts of biomass and its popularity with Alabama producers. Rye was rolled at the soft dough growth stage and terminated using Roundup (glyphosate). Data showed that parallel rolling with respect to the planting direction for cotton produced the highest cotton stand and yield in both years. In 2004, the Yetter row cleaner resulted in higher cotton stand and yield for both locations when compared with the Dawn row cleaner. However, in 2005, the Dawn row cleaner resulted in a greater cotton yield than the Yetter. Based on the emergence rate index (ERI), the most rapid emergence was observed with parallel rolling and both row cleaners. The slowest emergence rate was observed with perpendicular and diagonal rolling and no row cleaners. Parallel rolling minimized accumulated rye residue on the row cleaners and minimized the cleaning time for the row cleaners. General findings from this research are: for tall rye producing large biomass, parallel rolling and Dawn or Yetter row cleaners are recommended. For shorter rye producing low biomass, no row cleaners were required for rolled rye with the parallel rolling direction, or cotton could be planted into standing rye using Dawn or Yetter row cleaners. Regardless of the height and amount of rye residue and the row cleaner type, the perpendicular and diagonal rolling directions are not recommended.

EFFECT OF REPLACEMENT OF SUGAR WITH SUCRALOSE AND MALTODEXTRIN ON RHEOLOGICAL CHARACTERISTICS OF WHEAT FLOUR DOUGH AND QUALITY OF SOFT DOUGH BISCUITS

ABSTRACT The effect of replacement of 30% sugar with 0.05% sucralose and of different levels of maltodextrin (MD) on dough rheology and quality of biscuits was studied. The results showed that replacement of sugar with increasing amount of MD from 10 to 40% along with 0.05% sucralose influenced dough rheology. The farinograph water absorption increased up to 20% addition of MD and thereafter decreased. Objective evaluation of biscuits showed that the spread ratio of biscuits with 10% MD was 7.1, 20% MD was 7.8, 30% MD was 9.4 and 40% MD was 10.5, in comparison to control biscuits (9.9) with 30% sugar. The best overall quality score was reported for the control biscuits with 30% sugar, 69 out of the maximum score of 80, followed by 30% MD (65), 40% MD (60.5), 20% MD (54) and 10% MD (49.5). The results showed the possibility of replacing sugar in biscuit with sucralose and MD. PRACTICAL APPLICATIONSThis article discusses the changes as a result of replacement of sugar with sucralose and maltodextrin (MD) in the rheological characteristics of wheat flour dough. The level of sucralose and MD required to replace sugar from control recipe in order to produce rheological characteristics of wheat flour dough comparable with that of the control has been highlighted in the article. This information will have a practical application in the production of sugar‐free soft dough biscuits.

Multivariate analysis of water-related agroclimatic factors limiting spring wheat yields on the Canadian prairies

Water use by spring wheat and soil water contents at meteorological stations on the Canadian prairies were simulated with the Versatile Soil Moisture Budget model for different crop growth stages. Six water-related agroclimatic indices at five growth stages (seeding–emergence, emergence–jointing, jointing–heading, heading–soft dough and soft dough–harvest) and previous non-growing season were correlated to spring wheat yields in the three prairies provinces and in the entire prairie region for the years 1976–2006. Principal component analysis was applied to explore major modes of joint variability in the regional water-related agroclimatic indices. Canonical correlation analysis was employed to further identify joint variability patterns of the water-related indices associated with regional spring wheat yields. Results showed some common features of the effects of the water-related factors at different growth stages: lower-than-normal moisture stress at the jointing–heading stage favoured spring wheat yields in all three provinces. Regional differences were also seen, for example, a slight moisture stress at the heading–soft dough stage could be beneficial to spring wheat yields in Manitoba because of its relatively wetter climate compared to the other two provinces. The results can be used for a better understanding of the effects of water-related agroclimatic conditions at different growth stages on final spring wheat yields on the Canadian prairies, leading to the improvement of crop management. The results can also be used in regional yield forecasting and in the projection of climate change impacts on crop production. This study provided an example of how to quantify crop–climate relationships by the use of statistical multivariate analysis tools.

Response of two-row malting spring barley to water cutoff under sprinkler irrigation

Agricultural production in irrigated areas is becoming more water-constrained. Scheduling the timing of the last irrigation on cereals is one effective method of reducing seasonal water use while maintaining crop yield and quality. The last irrigation application time and its impact on two-row malting barley ( Hordeum distichum cv. Moravian 37) yield, quality, and economic benefits were studied in the 2000, 2001, and 2002 cropping seasons. Irrigation was stopped for the season at Milk, pre-Soft Dough, Soft Dough, and post-Soft Dough grain formation stages. The Soft Dough water cutoff treatment produced the highest grain yield of two-row spring malting barley. Water cutoff before or after Soft Dough stage reduced the grain yield significantly at P < 0.05, but the quality of grain for malt production was not significantly different when water was cut off at pre-Soft Dough or post-Soft Dough stages. Irrigation cutoff at Milk stage produced the lowest grain yield with the lowest quality. Decreases in grain yield and quality with the last irrigation at post-Soft Dough reduced grain value by $174 ha −1 relative to Soft Dough, while irrigation costs were higher (Fig. 6). The economic benefit due to labor and power cost reduction from earlier irrigation cutoff does not offset the resulting loss of grain value/ha for any treatment except post-SD under current southern Idaho energy and labor cost conditions.

Altered functional loading causes differential effects in the subchondral bone and condylar cartilage in the temporomandibular joint from young mice

Altered loading is an important etiological factor for temporomandibular joint (TMJ) disorders. Studies examining altered loading of the TMJ have been done in rats but the response of the TMJ to altered loading in mice is largely unknown. Therefore, due to the potential usefulness of genetically engineered mice, the goal of this study was to develop a mouse TMJ altered functional loading model. One hundred and thirty four, 21-day-old CD-1 female mice were divided into two groups: (1) normal loading (hard pellet diet) for 2-6 weeks and (2) altered functional loading (incisor trimming every other day and soft dough diet) for 2-6 weeks. The mandibular condylar cartilage was evaluated by histology, the subchondral bone was evaluated by microcomputed tomography (micro-CT) analysis and gene expression was evaluated by real time polymerase chain reaction (PCR) analysis. Altered functional loading for 2-6 weeks caused significant reduction in the thickness of the condylar cartilage whereas, only at 4 weeks was there a significant decrease in the bone volume fraction and trabecular thickness of the subchondral bone. Gene expression analysis showed that altered functional loading for 4 weeks caused a significant reduction in the expression of SRY-box containing gene 9 (Sox9), Collagen type X (Col X), Indian hedgehog (Ihh), Collagen type II (Col II) and Vascular endothelial growth factor (Vegf) and altered loading for 6 weeks caused a significant decrease in the expression of Sox9, Col II, Vegf and Receptor activator of NF-kappaB ligand (Rankl) compared to the normal loading group. Altered functional TMJ loading in mice for 2-6 weeks leads to a loss of the condylar cartilage and a transient loss in the density of the mandibular condylar subchondral bone.

Attractiveness of Stages of Rice Panicle Development to &lt;I&gt;Oebalus pugnax&lt;/I&gt; (Hemiptera: Pentatomidae)

Greenhouse experiments were conducted during 2004 and 2005 with male and female Oebalus pugnax (F.) (Hemiptera: Pentatomidae) caged on rice plants at different stages of panicle development with the objective of determining the most attractive stage to O. pugnax. Field-collected insects were released inside cages containing potted plants and observed during morning and afternoon hours for 5 d. Results showed that attractiveness of male and female O. pugnax to plants with panicles at milk and soft dough stages was greater than plants at preheading and heading stages. Preheading plants were the least attractive to the insects, confirming field observations. Results imply that insecticide applications during the preheading stage are likely ineffective and that monitoring efforts during the milk and soft dough stages of panicle development should be intensified.

The transcription factor Nfixis essential for normal brain development

BackgroundThe Nuclear Factor I (NFI) multi-gene family encodes site-specific transcription factors essential for the development of a number of organ systems. We showed previously that Nfia-deficient mice exhibit agenesis of the corpus callosum and other forebrain defects; Nfib-deficient mice have defects in lung maturation and show callosal agenesis and forebrain defects resembling those seen in Nfia-deficient animals, while Nfic-deficient mice have defects in tooth root formation. Recently the Nfix gene has been disrupted and these studies indicated that there were largely uncharacterized defects in brain and skeletal development in Nfix-deficient mice.ResultsHere we show that disruption of Nfix by Cre-recombinase mediated excision of the 2nd exon results in defects in brain development that differ from those seen in Nfia and Nfib KO mice. In particular, complete callosal agenesis is not seen in Nfix-/- mice but rather there appears to be an overabundance of aberrant Pax6- and doublecortin-positive cells in the lateral ventricles of Nfix-/- mice, increased brain weight, expansion of the cingulate cortex and entire brain along the dorsal ventral axis, and aberrant formation of the hippocampus. On standard lab chow Nfix-/- animals show a decreased growth rate from ~P8 to P14, lose weight from ~P14 to P22 and die at ~P22. If their food is supplemented with a soft dough chow from P10, Nfix-/- animals show a lag in weight gain from P8 to P20 but then increase their growth rate. A fraction of the animals survive to adulthood and are fertile. The weight loss correlates with delayed eye and ear canal opening and suggests a delay in the development of several epithelial structures in Nfix-/- animals.ConclusionThese data show that Nfix is essential for normal brain development and may be required for neural stem cell homeostasis. The delays seen in eye and ear opening and the brain morphology defects appear independent of the nutritional deprivation, as rescue of perinatal lethality with soft dough does not eliminate these defects.

Rainfall and Temperature Distinguish Between Karnal Bunt Positive and Negative Years in Wheat Fields in Texas

Karnal bunt of wheat, caused by the fungus Tilletia indica, is an internationally regulated disease. Since its first detection in central Texas in 1997, regions in which the disease was detected have been under strict federal quarantine regulations resulting in significant economic losses. A study was conducted to determine the effect of weather factors on incidence of the disease since its first detection in Texas. Weather variables (temperature and rainfall amount and frequency) were collected and used as predictors in discriminant analysis for classifying bunt-positive and -negative fields using incidence data for 1997 and 2000 to 2003 in San Saba County. Rainfall amount and frequency were obtained from radar (Doppler radar) measurements. The three weather variables correctly classified 100% of the cases into bunt-positive or -negative fields during the specific period overlapping the stage of wheat susceptibility (boot to soft dough) in the region. A linear discriminant-function model then was developed for use in classification of new weather variables into the bunt occurrence groups (+ or -). The model was evaluated using weather data for 2004 to 2006 for San Saba area (central Texas), and data for 2001 and 2002 for Olney area (north-central Texas). The model correctly predicted bunt occurrence in all cases except for the year 2004. The model was also evaluated for site-specific prediction of the disease using radar rainfall data and in most cases provided similar results as the regional level evaluation. The humid thermal index (HTI) model (widely used for assessing risk of Karnal bunt) agreed with our model in all cases in the regional level evaluation, including the year 2004 for the San Saba area, except for the Olney area where it incorrectly predicted weather conditions in 2001 as unfavorable. The current model has a potential to be used in a spray advisory program in regulated wheat fields.

Effect of Sorghum (Sorghum bicolor (L.) Moench Variety on the Severity of Head Bug (Eurystylus oldi Pop.) Damage

Six sorghum(Sorghum bicolor (L.) Moench) varieties including a resistant and a susceptible check, were evaluated (or damage by the head bug (Eurystylus oldi Pop.) adults under natural and cage conditions using 15 and 20 pairs of E. oldi per panicle at Samaru and Minjibir during 2003 and 2004 rainy seasons. The resistant check, Malisor 86-0.41, did not differ significantly (P&lt;0.05) from SF 85-31-1-,·1-2, 87W81O and 911W 113-2-1 in number of bugs/I 0 panicles at the soft dough, while at hard dough stage Chokwe had the highest bugs per panicle which differed significantly from S34. Similarly, Malisor 86-30-41 had the least bug population and grain damage under cage conditions; comparable values for 87W810 and 911WI1J-2 were numerically higher. The highest percentage yield loss (43,8%) was recorded on the susceptible cultivar, S34, of which 41.4% was due to E. oldi. Malisor 86-30-41 had 21% yield loss of which 185% was attributed to the bug. Loss in monetary term was highest in S34 at both locations and infestation levels W20,132.80 and N18,398.40 loss/ha, respectively, for 15 and 20 pairs per panicle. On Malisor 86-30-41, the monetary losses were N7,899.00 and N4, 158.40/ha, respectively.

Relative Susceptibility of Stages of Rice Panicle Development to Male and Female Oebalus pugnax1

In field experiments conducted in 2005 and 2006, panicles of rice, Oryza sativa L., were infested for 48 h with one male or female rice stink bug, Oebalus pugnax (F.), at heading, milk, soft and hard dough stages of development. Number of grains, number and weight of filled grains, number and weight of empty grains, and percentage whole kernels per panicle were not significantly affected by infestation at any stage of panicle development, nor were any significant differences found in percentage peck caused by male or female O. pugnax. In 2005, percentage peck was significantly lower in uninfested panicles and panicles infested during hard dough than in panicles infested during heading, milk or soft dough. No differences were found in percentage peck caused by O. pugnax during heading, milk or soft dough. In 2006, no significant differences were found in percentage peck produced by O. pugnax in panicles infested during heading, milk, soft dough or hard dough. Higher percentage peck in hard dough may have been the result of late drainage of the field.