bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of Brassica juncea to chlorocholine chloride and ethrel sprays in association with nitrogen application
Authors: Grewal H. S. , Kolar J. S. 
Published: March 2009

SUMMARYField studies conducted in 1983/84–1985/86 at Ludhiana showed that the response of physiological and yield characters of Brassica juncea to foliar sprays of chlorocholine chloride as cycocel (CCC) at 250 and 500 p.p.m. and ethrel at 500, 1000 and 1500 p.p.m. differed at different doses of N (O, 50 and 100 kg/ha). The crop did not respond to CCC or ethrel in the absence of N, whereas a significant response was obtained with 250 p.p.m. CCC or 500 p.p.m. ethrel at 50 kg N/ha and 500 p.p.m. CCC or 1000 p.p.m. ethrel at 100 kg N/ha. Response to increasing doses of N increased in the presence of CCC or ethrel spray. The highest concentration of ethrel (1500 p.p.m.) proved detrimental at 0 and N/ha. CCC and ethrel reduced the crop canopy, enhanced the chlorophyll content of leaves, interception of photosynthetically active radiation and sink capacity (number of pods per plant and 1000-seed weight) at 50 and 100 kg N/ha. A higher leaf area index was obtained during the pod development phase with CCC and ethrel sprays. The oil content and germination potential of seeds from crops treated with CCC (250 and 500 p.p.m.) and ethrel (500 and 1000 p.p.m.) were as high as in the untreated crop, irrespective of N dose. However, 1500 p.p.m. of ethrel sprayed on a crop raised without N suppressed germination capacity.
Source–sink relations and effects of post-anthesis canopy defoliation in wheat at low latitudes
Authors: Aggarwal P. K. , Fischer R. A. , Liboon S. P. 
Published: March 2009

SUMMARYSource–sink balance was studied by imposing different canopy defoliation treatments on wheat crops grown in Los Banos (Philippines) in 1985/86 and 1986/87, Sonora (Mexico) in 1972/73 and 1974/75 and New Delhi (India) in 1987/88. The crops were grown in replicated trials with optimum cultural management. Six defoliation treatments were imposed at anthesis on all shoots in the canopy in an area ranging between 1·65 and 3·0 m2. Defoliation reduced dry weight in proportion to the reduction in percentage light interception. The number of grains per unit land area was reduced slightly, and in most cases not significantly, except when all leaves were removed. Despite reduction of leaf lamina area index to as low as 0·5, the decrease in grain yield was small. In particular, flag leaf removal led to a remarkably small reduction in grain yield. Grain nitrogen content in defoliated crops decreased much less than expected from the amount of N removed by defoliation. The slope of the relation between reduction in grain yield with defoliation and reduction in post-anthesis dry matter accumulation was 0·56, indicating moderate source limitation for grain filling. The crops at the hottest site, in the Philippines, were less limited by source than the other crops. It is suggested that selection for smaller flag leaves may be worthwhile for high-input wheat crops.
The chemical buffer system in raw and digested animal slurry
Authors: Sommer S. G. , Husted S. 
Published: March 2009

SUMMARYSlurry pH is of great importance for the regulation of ammonia volatilization from livestock slurry, and therefore more knowledge of the buffer system controlling pH is urgently needed for modelling ammonia losses from stored and surface-applied slurry. The composition of 17 different Danish cattle, pig and biogas plant-digested slurries was studied. The results were used to describe the main buffer components in the slurries, and to discover the most important chemical components necessary for modelling slurry pH. The results showed that the pH of slurry was mainly controlled by the species NH4+/NH3, CO2/HCO3-/CO32-and CH3COOH/CH3COO-, and that ion pair formation did not change the ionic balance significantly. There were only trace amounts of Ca2+, Mg2+and inorganic phosphates in solution due to precipitation of CaCO3(calcite) and MgNH4PO4.6H2O (struvite). Measured electrical conductivities were found to be strongly correlated with the calculated ionic strength.
Factors affecting faecal endogenous phosphorus loss in the sheep
Authors: Scott D. , Rajaratne A. A. J. , Buchan W. 
Published: March 2009

SUMMARYSheep fitted with a ruminal and a duodenal cannula were used to study the effect of dry matter intake and the physical form of the diet on salivary P secretion and faecal endogenous P loss. At constant low P intake, changing the form of the diet had no effect on either parameter and while increasing dry matter intake did produce small changes in the partitioning of P excretion between urine and faeces it had no effect on overall endogenous P loss (faecal endogenous P + urine P) which was largely determined by P intake.
Effects of strategic feed supplementation during pregnancy on birthweight and perinatal survival of West African Dwarf kids
Authors: Osuagwuh A. I. A. 
Published: March 2009

SummaryVaried quantities of concentrate supplement were fed to three groups of pregnant West African Dwarf (WAD) goats at different gestational periods, while forage was provided ad libitum throughout pregnancy. One group (A) was fed on concentrate at the rate of 50 g/kg metabolic weight (W0·75) per day throughout pregnancy, a second group (B) was offered concentrate from Days 61 to 120, and 121 to term at the rate of 50 g and 25 g/kg metabolic weight per day, respectively, and a third group (C) was provided with concentrate from Days 61 to 120 and 121 to term at the rate of 25 g and 50 g/kg metabolic weight per day, respectively.Results showed that there were no abortions, although two animals from group A had dystocia (difficult birth). There was no significant difference between the mean birthweight and neonatal growth rates of kids from groups A and B. The mean birthweight and neonatal growth rates of the kids from group C were significantly (P < 0·01) lower than those of groups A and B. There was no significant (P >0·05) difference between the mean udder circumference of animals in group C and those in groups A and B. All the neonatal deaths were recorded among the kids in group C. It is concluded that for economic animal production although it may not be necessary to feed pregnant WAD goats on high concentrate rations throughout the gestational period, they should not be underfed between Days 61 and 120 of pregnancy.
Effect of soil water stress on water economy and oil composition in sunflower (Helianthus annuus L.)
Authors: Talha M. , Osman F. 
Published: March 2009

SUMMARYIn a field experiment sunflower plants were subjected to soil water stress (SWS) at — 15 bar during stages of slow elongation, rapid elongation, flowering and ripening.Significant decreases in yield, 100-seed weight and oil content were found as a result of SWS. The treatment resulted too in less evapotranspiration and a better water economy for production of seeds and oil.The iodine value but not the acid or saponification values of the oil was affected by SWS. No qualitative differences in oil composition occurred at different treatments. However, percentage of oleic acid was higher than that of linoleic acid; SWS resulted in a clear tendency for an increase in the ratio of oleic/linoleic acids especially for plants subjected to SWS during elongation stage.Sunflower plants were more sensitive to SWS during the elongation and flowering stages than during ripening stage
Changes in the biochemical composition of herbage upon freezing and thawing
Authors: Macrae J. C. , Campbell D. R. , Eadie J. 
Published: March 2009

SUMMARYSix herbage samples (ranging from poor quality hill herbages to high quality ryegrass and clover) were analysed for soluble carbohydrate, total and soluble nitrogen (N), cell-wall carbohydrates andin vitrodigestibility. Changes during freezing and thawing processes were measured. Invertase activity occurred in all frozen and thawed samples. Although the total N content of all samples remained constant throughout, the soluble-N contents of the four better quality herbages were considerably reduced on freezing and thawing. Cell-wall carbohydrates andin vitrodigestibility measurements were unaffected by freezing and thawing.
Diurnal patterns of heat production and heart rate under thermoneutral conditions in Holstein Friesian cows differing in milk production
Authors: Purwanto B. P. , Abo Y. , Sakamoto R. , Furumoto F. , Yamamoto S. 
Published: March 2009

SUMMARYTen dairy cows were allocated into three groups according to milk productivity (four high, four intermediate and two dry cows, respectively). Heat production and heart rate, but not rectal temperature, were significantly different (P < 0·05) between groups. Heat production increased during feeding in the morning and in the afternoon and reached a peak 3 h later. Minimum heat production was observed in the early morning before feeding. The diurnal pattern for heart rate reflected that of heat production. These results suggest that cooling dairy cows during hot summer days is most effective at feeding time and 3 h afterwards.
Heritability of frost tolerance in white clover (Trifolium repens)
Authors: Caradus J. R. , Mackay A. C. , Bosch J. Van Den , Wewala S. , Greer D. H. 
Published: March 2009

SUMMARYWhite clover genotypes selected for frost tolerance and susceptibility were pair-crossed in various combinations with unselected genotypes of Grasslands Huia. Progeny lines and parent genotypes were artificially frosted at −8°C and scored for percentage of leaves damaged. Progeny from crosses between frost-tolerant genotypes were less damaged by frost than progeny from crosses involving either susceptible genotypes or unselected Grasslands Huia genotypes. Heritability estimates for frost tolerance or susceptibility were high, ranging from 0·75 to 0·93, depending on method of calculation. Removal of leaf-size effects from scores of frost damage reduced heritability estimates to 0·54–0·73. It was concluded that, because heritability for frost tolerance was high, selection for this character and incorporation of frost tolerance into agronomically suitable but frost-sensitive cultivars by breeding would be successful.
Analysis of artificial mixtures of pure chemicals by near-infrared reflectance
Authors: Wetherill G. Z. , Murray I. , Glasbey C. A. 
Published: March 2009

SUMMARYCompositional analysis of feeds and other materials by near-infrared reflectance (NIR) has been proposed as a cheap and rapid alternative to traditional wet chemical methods. A theoretical basis for NIR measurements is needed and may be obtained from the study of artificial mixtures of pure chemicals.Mixtures of lactose, casein and sodium oleate, in widely differing concentrations, were analysed by NIR. Principal component analysis was used to study the variations between spectra, and multiple linear regressions gave predictors of sample compositions from the spectra. Optical densities at most combinations of wavelengths gave good predictions of sample compositions because there was much less unexplained variation between NIR spectra than would occur between natural samples.
Response to sowing time of three contrasting Australian cultivars of oilseed rape (Brassica napus)
Authors: Mendham N. J. , Russell J. , Jarosz N. K. 
Published: March 2009

SUMMARYSerial sowings of three cultivars of oilseed rape were made from autumn (May) to spring (October) at two sites, one in the north and one in the south of Tasmania, in 1981. The highest seed yields at both sites exceeded 5 t/ha from early sowing, ranging down to c. 2 t/ha from late sowing at a site where irrigation was adequate and to < 1 t/ha where late-sown crops suffered from water stress. The midseason cultivar Marnoo gave the highest yields at both sites, resulting from a combination of substantial (800 g/m2) top growth before flowering, excellent seed survival, a long period for grain filling and high oil content. The early-flowering line RU1 made much less growth before flowering; while this was partly made up for in later growth, nearly as many seeds per pod being retained as in Marnoo, oil content was low. The later-flowering cultivar Wesbell made more growth before flowering than the other cultivars, but when sown early it tended to grow tall, lodge and lose many pods in the dense, tangled canopy. This, combined with generally fewer seeds per pod, resulted in a much less efficient crop in allocation of dry matter to seeds and oil. Wesbell failed to flower uniformly from the late sowings, indicating segregation for vernalization response. The many immature seeds at harvest gave a low overall oil content. All three cultivars responded to vernalization and longer photoperiod in a pot experiment. While photoperiod appeared to be the main factor controlling the development rate to flowering in the field, there were interactions with vernalization response andtemperature.
Effect of the developmental stage of potato seedlings on recovery after transplanting to the field and on tuber yield
Authors: Engels C. , Schwenkel J. , Bedewy R. El , Sattelmacher B. 
Published: March 2009

SUMMARYUnder the short-day conditions and cool temperatures prevailing from January to March in the Nile delta, Egypt, potato (Solatium tuberosum) seedlings grown from true potato seed formed tubers in the nursery when the plants were less than 5 cm in height. In order to examine the hypothesis that slow field establishment after transplanting and low tuber yields of these seedlings were caused by premature tuberization, different treatments to delay tuberization were applied in the nursery before transplanting.Increasing the air and soil temperature in the nursery accelerated both the development of the above-ground and below-ground shoot organs, but did not improve field establishment of the seedlings after transplanting. Extension of the photoperiod with incandescent dim light, exogenous application of gibberellic acid (GA), and removal of the shoot apex to encourage the growth of lateral branches from the leaf buds increased biomass allocation to the above-ground shoot organs, decreased tuberization in the nursery and accelerated field establishment of transplanted seedlings. Extension of the photoperiod was the most effective treatment to delay tuberization, and doubled the final tuber yield from transplanted seedlings.The results are in agreement with the hypothesis that poor field establishment and low final tuber yields from potato transplants may be caused by the presence of strong tuber sinks at transplanting, which reduce assimilate partitioning towards the roots and above-ground shoots.
Relationships between body weight and scrotal characteristics, and between environmental effects and fertility in Ethiopian Horro rams
Authors: Gojjam Yohannes , Gizaw Solomon , Abegaz Solomon , Thwaites C. J. 
Published: March 2009

SUMMARYThe relationships between body weight, scrotal characteristics and environmental effects (year, birth type and age) and fertility were studied in a total of 254 Horro rams. Fertility varied between years (P < 0·01), but not with body weight at mating within the range (30–55 kg) observed, nor with type of birth (both P > 0·05).Testicular diameter and circumference were strongly correlated to body weight (r = 0·95 and 0·89 respectively; both P < 0·001), but weight of testes only weakly so (r = 0–28; NS). Scrotal circumference was more highly correlated to body weight in ram lambs (r = 0–85; P < 0–001) than in adults (r = 0·51; p = 0·06).It is concluded that adequate levels of fertility (82 ± 1·3%) are expressed by 30 kg Horro rams, and that when feed supplies are limited there are no benefits to be gained from maintaining rams of this breed at higher weights.
Effects of nitrogen and the plant growth regulator chlormequat on grain size, nitrogen content and amino acid composition of triticale
Authors: Naylor R. E. L. , Stephen N. H. 
Published: March 2009

SUMMARYField experiments were conducted in Scotland between 1985 and 1987 to examine the responses of mean grain weight and nitrogen content of triticale cultivars to levels of applied nitrogen from 0 to 180 kg N/ha and the plant growth regulator chlormequat. Cultivar differences were seen for both these characters. Mean grain weight generally declined as yield increased, whether with nitrogen or with chlormequat. Nitrogen content of the grain decreased as grain size increased. Nitrogen recovery (g/m2) generally increased with applied nitrogen and was unaffected by chlormequat application. Within a grain sample from an individual treatment, however, grain size was not related to nitrogen content.The response of nitrogen content is interpreted as differential dilution of nitrogen in the grain by different amounts of carbohydrate. This is probably related to the frequent occurrence of shrivelled grain in triticale.
Heat stress during mid-pregnancy in sheep and the consequences for placental and fetal growth
Authors: McCrabb G. J. , McDonald B. J. , Hennoste L. M. 
Published: March 2009

SUMMARYAn experiment was conducted at Toorak Research Station, Julia Creek, in semi-arid northern Australia (141° E, 21° S) during 1990 to determine the relationship between placental and fetal weight in sheep after placental growth had been restricted by chronic heat stress during mid-pregnancy. Placental and fetal weight were measured in single bearing ewes housed either in a thermoneutral environment throughout pregnancy, or in a heated room between the 30th and 80th days of pregnancy followed by a thermoneutral environment until the 140th day of pregnancy. The placental weight of the heat-treated ewes was lower than that of the control ewes at the 80th (P< 0·05) and 140th (P< 0·01) days of pregnancy. Fetal weight and dimensions did not differ significantly between control and heat-treated ewes at the 80th day of pregnancy, although fetal weight (P< 0·01) and fetal dimensions (P< 0·05) for the previously heat-treated ewes were lower than those for the control ewes at the 140th day of pregnancy. Placental and fetal weight at the 140th day of pregnancy were correlated (P< 0·05) with the rectal temperature of ewes measured at 08.00 and 16.30 h during the period of heat-treatment, but not with the change in rectal temperature between 08.00 and 16.30 h. It was concluded that restricted placental growth in heat-treated ewes retarded fetal growth during late pregnancy even in the absence of heat treatment, and it is suggested that selection of ewes which can maintain normal rectal temperatures during periods of heat stress would produce lambs of normal birthweight in a hot climate.
The thermal response of sheep to a hot environment in different years
Authors: McCrabb G. J. , Bortolussi G. , Hennoste L. M. , McDonald B. J. 
Published: March 2009

SUMMARYThe aim of this experiment was to determine whether the thermal responses ofsheep exposed to a hot environment were similar in different years. Rectal temperaturesofsheep were measured during the hot months (between November and March) of three consecutive years (1990/91, 1991/92, 1992/93) in a flock of Merino sheep (n = 151) in the semi–arid tropics of northern Australia. Mean daily maximum temperatures in these months were 36±0·4, 39±0·3 and 37±0·3°C in Years 1, 2 and 3, respectively. In Year 1, rectal temperatures were measured on 3 consecutive days;the repeatability was 0·47 at 08·00 h and 0·64 at 16·00 h. In Year 1, two sub-groups were identified according to measurements of rectal temperature, low body temperature(LBT; n = 35) sheep, whose rectal temperature was ≤ 39·8°C at 16·00 h on each of the 3 consecutive measurement days, and high body temperature (HBT; n = 32) sheep, whose rectal temperature was ≥ 39·9°C. The rectal temperatures of LBT and HBT sheep were then measured during the subsequent 2 years. Rectal temperatures of HBT sheep were significantly higher than those of LBT sheep at both 08·00 and 16·00 h, in both Year 2 and Year 3. Rectal temperatures at 16·00 h in Year 1 were correlated (P < 0.001) with rectal temperatures at 16·00 h in both Year 2 (r = 0·79) and Year 3 (r = 0.82), respectively. It was concluded that measurement of rectal temperature in sheep exposed to a hot environment in any oneyear is an accurate index of their rectal temperatures during subsequent years.
Dehydrogenase and phosphatase activities in soil as influenced by the growth of arid-land crops
Authors: Rao A. V. , Bala K. , Tarafdar J. C. 
Published: March 2009

SUMMARYThe distribution of dehydrogenase activity (DHA) and the activities of phosphatases were studied in the rhizosphere of four varieties each of clusterbean (Cyamopsis tetragonoloba(L.) Taub.), mung bean (Vigna radiata(L.) Wilczek), moth bean (Vigna aconitifolia(Jacq.) Marechal) and pearl millet (Pennisetum americanum(L.) Leeke) grown in pots containing soil low in available P. Activities of dehydrogenase and phosphatases were greatest 25 days after sowing and remained constant from 50 days after sowing until crop maturity. Rhizosphere soils showed higher activities than other soils: 26–158% for acid phosphatase, 66–264% for alkaline phosphatase and up to 292% for DHA. Dehydrogenase and alkaline phosphatase activities were significantly higher in the rhizospheres of legumes than in those ofP. americanum.In general, the rhizospheres ofC. tetragonoloba‘HFG314’,V. radiata‘PDM62’,V. aconitifolia‘IPCMO344’ andP. americanum‘RCB2’ had higher activities than those of other varieties of the same species. Acid phosphatase activity was lower than alkaline phosphatase activity and differences between species and varieties were small and nonsignificant. The results suggest that the higher phosphatase activities in the rhizospheres of some crops may increase P availability and utilization from arid soils.
Activity of cytoplasmic acetyl-CoA hydrolase in sheep liver and its potential role in heat production
Authors: Jessop N. S. , Scollan N. D. , Souter M. J. , Crabtree B. 
Published: March 2009

SUMMARYAcetyl-CoA hydrolase which is stimulated by adenosine-5′-triphosphate is present in the cytoplasm of ovine liver and, unlike in certain others species, is not inactivated by cold. It is suggested that this enzyme is involved in a substrate cycle between acetate and acetyl-CoA. The heat produced as a result of such cycling may be as much as 2·5% of basal heat production and may be partly responsible for the increased heat increment that often follows the ingestion of diets that provide large quantities of acetate.