Differences In Total Production Research Articles

Inclusion of near‐threatened micronutrient‐rich small indigenous species (SIS) dhela (Osteobrama cotio) in pond aquaculture

AbstractDue to their high content of micronutrients, small indigenous species (SISs) of fish play a vital role in the diets of people. Dhela (Osteobrama cotio) is one of the most important micronutrient‐rich SISs and was once abundant but is currently disappearing from inland waters. This study investigated the culture suitability of dhela with carp species in polycultures in a pond aquaculture system. The stocking density of the carp species was the same in all the treatments, with Labeo catla, Labeo rohita and Cirrhinus cirrhosus at 10,800/ha. Dhela were cultivated at a density of 10,000/ha in treatment 2 (Dhela‐10K) and 15,000/ha in treatment 3 (Dhela‐15K), and no dhela were cultivated in treatment 1 (Dhela‐0). After 7 months of culture, there were no significant differences in total production among the treatments, with yields of 3393.27 ± 120.70, 3534.52 ± 57.03 and 3687.34 ± 244.41 kg/ha in Dhela‐0, Dhela‐10K and Dhela‐15K, respectively. Notably, a significantly greater (p < 0.05) net profit and benefit‒cost ratio were found in Dhela‐10K and Dhela‐15K than in Dhela‐0, but no significant difference was found between Dhela‐10K and Dhela‐15K. The inclusion of dhela in pond polycultures with carp species demonstrates the potential benefits of diversifying aquaculture systems. Farmers could consider incorporating SISs into their existing aquaculture practices to increase overall production and improve economic returns.

ANALYSIS OF FARMERS' INCOME AFFECTED ATTACKS OF PLANT DISTURB ORGANISMS IN SUSOH DISTRICT SOUTHWEST ACEH DISTRICT

Paddy field in Susoh District, Southwest Aceh Regency are very vulnerable to the impacts of climate change such as drought and floods which have caused the intensity of attacks by Paddy field Pest Organisms (OPT) decreased as it had in the previous growing season. Some farmers make mitigation efforts by spraying pesticides according to the recommendations of the local Plant Pest Organism Observer (POPT), but some other farmers do not carry out mitigation due to considerations of production costs that are quite large and ultimately affect the total revenue and income of farmers. This study aims to look at the differences in total production and average income between farmers who mitigate and farmers who do not mitigate pest attacks. The sample was divided into two categories, each category was taken by 28 farmer respondents randomly. The results of the independent test sample t-test on production obtained t-count (4.056) greater than t-table () while for income obtained t-count (4.056) greater than t-table (2.46) indicating there is a difference in production and average income between mitigating and non-mitigating farmers. Total GKP production obtained by mitigating farmers was an average of 2.608 tons and farmers who did not mitigate an average of 2.011 tons. The average income of farmers who mitigate pest attacks is IDR 4,821,834.79 per 0.4 hectare or IDR 12,054,600 per hectare, while farmers who do not mitigate pest attacks are IDR 2,888,103.86 per 0.4 hectare or IDR 7,220,260 per hectare per planting season.

Semidwarf winter wheat roots contain fewer organic acids than wild‐type varieties under phosphorus stress

AbstractOrganic acids are exuded by plant roots into the rhizosphere for a variety of reasons, including nutrient acquisition. The most frequently reported organic acids are those involved in the Krebs cycle and other important biochemical pathways that are responsible for the production of important plant metabolites, including oxalic, malic, and citric acid. Many studies report increased citric and malic acid exudation when plants are P‐deficient. Because plant breeding is typically carried out under heavily fertilized conditions, it is possible that wheat (Triticum aestivum L.) breeders have unintentionally selected for varieties with decreased nutrient acquisition capability from soil organic matter and soil colloids. In this study, we evaluated a diverse panel of 10 winter wheat cultivars, which included wild‐type (tall) and semidwarf varieties, for organic acid content. Plants were grown in solution culture with and without P for 24 d. Thirty 1‐cm root tips were bulked per sample and the extracts were analyzed by high‐performance liquid chromatography for citric, malic, and oxalic acid content. Under P deficiency, total organic acid content differed between wild‐type and semidwarf varieties, with wild‐type cultivars containing more organic acids in the root tips. This difference in total production was driven by oxalic acid, whereas citric and malic acid concentrations were conserved. Unlike citric and malic acid, oxalic acid is not necessary for major metabolic processes and therefore may be expendable. Breeding for semidwarf wheat corresponds with unintentional changes to root system function that could impact nutrient acquisition and other rhizosphere processes.

Zooplankton size spectra and production assessed by two different nets in the subarctic Northeast Pacific

Abstract Normalized biomass size spectra (NBSS) are frequently used to describe pelagic communities. However, the underlying structure of NBSS may lead to varying intercepts and slopes when only a portion of the biomass range is sampled. This may be further perpetuated by the sampling efficiency of different gears/mesh sizes. Spatial and seasonal effects of mesh size on zooplankton NBSS and production were evaluated. Zooplankton were collected during winter, spring and summer (2017–2019) between Vancouver Island and Station Papa (50°N, 145°W) using a 64-μm Working Party 2 (WP-2) net and a 236-μm bongo net and analyzed using a bench-top laser optic particle counter. WP-2 and bongo NBSS overlapped in 11 size classes, for which the WP-2 more effectively sampled smaller size classes and converged with the bongo in larger size classes. Differences in NBSS slopes from the two nets were detected, yet no differences in total production. However, the contribution of individual size classes to total production varied spatially and seasonally. Total production in the coastal region exhibited strong seasonal variability. Notably, summer estimates of production in the coastal region were at least 2-fold higher than transitional and open ocean regions. This study suggests that using one mesh size may underestimate zooplankton NBSS and thus production.

Does Physician Gender Impact the Clinical Productivity and Salaries of Obstetrician-Gynecologists?

Background: Male medical student interest in the field of obstetrics-gynecology has significantly decreased in the last three decades. A perceived patient preference for female obstetrician- gynecologists (Ob-Gyn) and subsequent gender differences in clinical productivity and compensation may influence this trend. Objective: To explore how provider gender affects clinical productivity and salary among obstetrics- gynecology generalists. Methods: An analysis of productivity and salary data for generalist Ob-Gyns employed by an academic integrated health system was performed. Gross charges, net collections, physician payroll information, work relative value units (wRVUs), new and existing patient encounter volumes and clinical full-time equivalent (FTE) status were compared year over year by physician gender using a repeated measures ANOVA test. Results: On average, male providers earned a numerically higher salary in each year studied, but when the entire timeframe was evaluated, there was no significant difference in salary nor total productivity between women and men (p=0.19 and 0.15, respectively). There was a gender difference in how total productivity was achieved, with women seeing twice as many new patients (p= 0.0025), and men achieving higher average wRVUs per patient encounter (p=0.02). Conclusions: There was no significant difference in total productivity and there was no significant difference in salaries between male and female Ob-Gyns. However, there were differences in the type of care that contributed to productivity by gender. Female providers saw a higher proportion of new patient encounters, while male providers accrued a higher wRVU per encounter, likely as a result of higher procedure volumes. These findings are an encouraging sign that men are not disadvantaged in terms of productivity in obstetrics-gynecology and that compensation models such as the one in this system can promote fair payment in mixed-gender physician groups.</P>

Double‐Cropping Sorghum for Biomass

Double‐cropping systems have been suggested as a way to increase annual dry matter production per hectare, while simultaneously delivering environmental benefits. Past research seems to indicate that there is a genotypic effect for the suitability of a crop for use within double‐cropping systems; however, despite sorghum's [Sorghum bicolor (L.) Moench] diverse genetic background, there has not been a great deal of work done to explore this response for this crop. Twelve sorghum varieties were grown as sole crops and within a double‐cropping system with winter triticale [× Triticosecale Wittmack] in central and northern Iowa. Results showed that although the single‐cropping system produced slightly higher biomass yields, there were no significant differences in total production between the two systems for several of the sorghum varieties. These varieties were characterized as earlier maturing ones that had nearly maximized dry matter production at the time of harvest for the double‐cropping system, and thus, any potential loss in sorghum yield was supplemented by the biomass production from the triticale crop. However when the chemical composition of the crops was considered, the theoretical ethanol yield of the single‐cropping system was greater than the double‐cropping system for all sorghum varieties. Although triticale was capable of offsetting any potential loss in dry matter, as an ethanol feedstock it was inferior to sorghum.

Growth, yield and mineral content of Miscanthus × giganteus grown as a biofuel for 14 successive harvests

Miscanthus × giganteus, a perennial rhizomatous grass commercially used as a biofuel crop was grown in a field experiment on a silty clay loam soil for 14 years. There were 3 rates of fertilizer nitrogen (N), none (control), 60 kg N ha −1 yr −1 and 120 kg N ha −1 yr −1 as cumulative applications. The crop was harvested in winter and dry matter yield measured. N did not influence yield. Yield, which increased for the first 6 years, decreased in years 7 and 8, but then increased again and was highest in the 10th year averaging 17.7 t ha −1 across all treatments. Differences in total production over the14 years were only 5% between the highest and lowest yielding treatments and averaged 178.9 t ha −1 equivalent to 12.8 t ha −1 yr −1. In the first 10 harvests, 92% of dry matter was stem. Although the study showed N fertilizer was not required, it is considered that an application of 7 kg P ha −1 yr −1 and 100 kg K ha −1 yr −1 would avoid soil reserve depletion. Pesticides were not required every year and the crop can be considered as low input with a high level of sustainability for at least 14 years.

The Effects of Size Grading on Production Efficiency and Growth Performance of Yellow Perch in Earthen Ponds

AbstractThe culture of yellow perch Perca flavescens has received considerable interest in the Midwest and elsewhere in the USA as a result of the decline of wild populations and their high market demand. In this study, the effects of size‐grading on the production efficiency and growth performance of food‐sized yellow perch were determined in six 0.1‐ha ponds by grading fingerlings into three size‐groups (mean initial size): small (5.3 g), large (18.3 g), and unsorted (11.3 g). The mean percentage of marketable production from large‐group ponds was significantly greater than that from the small‐ and ungraded‐group ponds. The final biomass of large size‐groups was 77% and 27% greater than that of small and ungraded groups, respectively, although no significant differences in total production were detected among the three size‐groups. Size‐sorting of fingerling yellow perch did not result in improved growth of the small‐fish group. No significant differences in growth rates among the three groups were detected in either the first half‐year (winter–spring) or the second half‐year (summer–fall) period. The growth performance of the three groups indicates that yellow perch populations under culture conditions experience a bimodal growth pattern, with two distinct size‐groups. The coefficient of variation (CV) in both weight and length for the small‐group fish increased about 80%, whereas the CV in the ungraded and large groups showed some reduction. The results indicate that grading by size should be advantageous to those wishing to culture yellow perch to food fish size in the second year. The significantly different results for the percentage of fish reaching market size among the large (65%), ungraded (53%), and small (35%) groups suggest that perch should be selectively graded by at least the end of one year of intensive culture to increase the number of individuals with the potential to reach market size.

Effect of subsoiling on soil physical properties and dry matter production on a Brown Soil in Southland, New Zealand

This study examined the effect of shallow subsoiling on soil physical properties and ryegrass‐white clover pasture production on a Waikiwi silt loam (Brown Soil) over 2.5 years. Macroporosity, hydraulic conductivity, and air permeability were measured in 6‐cm increments down to 30 cm soil depth. The topsoil was loosened by pulling both conventional tines or wing‐shaped tines set at 50 cm apart through the soil, at a depth of 25–30 cm. Subsoiling increased macroporosity by up to 39% of the soil volume, and increased saturated hydraulic conductivity and air permeability by up to two orders of magnitude. Improvements in soil physical conditions were evident for up to 2 years after subsoiling with both the winged tines and conventional tines, although there were few differences between the tine types. Some recompaction and settling over time occurred in the upper 12 cm of the soil profile. For the second year, the conventional tine subsoiling treatment reduced total production by 9%. Pasture dry matter production for the winged tine subsoiling treatment was variable with no significant differences in total production compared with non‐subsoiled controls.

00/00305 A biomass energy flow chart for Sierra Leone

A gap-model was modified in order to utilise ground-true forest data to predict the effect of climate change on forests in Finland. The model's resonse to climate change was evaluated by using test scenarios of changing temperature and precipitation in Finland. Model computations indicated that in Southern Finland conifers, Norway spruce in particular, suffered from rapidly increasing temperature (0.5°C in a decade), but Scots pine derived a small benefit from a temperature increase of 0.1°C in a decade. Pendula birch profited by increasing temperature. In Northern Finland all tree species (Scots pine, Norway spruce, Pendula birch and Pubescent birch) used in simulations increased their stand volume and total production due to increased temperature. Precipitation changes had only little effect on stand volume and total production of trees on sites with coarse moraine as soil texture. The effect of soil texture on model performance was examined at a southern site under current climate using moraine, sand and silt as soil textures. Stand volume and total production of coniferous trees remained at a lower level on sand than on moraine soils or on silt. Response of birches to soil texture was similar to that of the conifers, but differences in total production between soil textures remained smaller.

Fungal endophyte symbiosis and plant diversity in successional fields

Increasing evidence suggests that microbial interactions are important determinants of plant biodiversity. The hypothesis that fungal endophyte symbiosis reduces diversity in successional fields was tested by manipulating infection of tall fescue, the most abundant perennial grass in the eastern United States. Over a 4-year period, species richness declined and tall fescue dominance increased in infected plots relative to uninfected plots without differences in total productivity. A host-specific endophyte, with negligible biomass, altered plant community structure in this long-term field experiment and may be reducing plant diversity throughout its expanding range.

Development and assessment of a gap-type model to predict the effects of climate change on forests based on spatial forest data

A gap-model was modified in order to utilise ground-true forest data to predict the effect of climate change on forests in Finland. The model's resonse to climate change was evaluated by using test scenarios of changing temperature and precipitation in Finland. Model computations indicated that in Southern Finland conifers, Norway spruce in particular, suffered from rapidly increasing temperature (0.5°C in a decade), but Scots pine derived a small benefit from a temperature increase of 0.1°C in a decade. Pendula birch profited by increasing temperature. In Northern Finland all tree species (Scots pine, Norway spruce, Pendula birch and Pubescent birch) used in simulations increased their stand volume and total production due to increased temperature. Precipitation changes had only little effect on stand volume and total production of trees on sites with coarse moraine as soil texture. The effect of soil texture on model performance was examined at a southern site under current climate using moraine, sand and silt as soil textures. Stand volume and total production of coniferous trees remained at a lower level on sand than on moraine soils or on silt. Response of birches to soil texture was similar to that of the conifers, but differences in total production between soil textures remained smaller.

A multiple form word production checklist for assessing early language.

We describe the development of a set of five equivalent checklists to assess word production of children in their second year. The words on each list do not overlap, but represent comparable levels of difficulty. Thus, individual lists may be used to estimate the child's production vocabulary, and the set of lists may be used serially in a longitudinal design. A validation study on 25 infants suggests that the five lists produce comparable mean production scores, reflect differences in age, and preserve individual differences in total production and production of linguistic categories such as nouns, verbs, open class items, and closed class items. This finding provides further support for the reliability of parental report instruments in this developmental domain.

An Intercountry Comparison of Agricultural Production Efficiency

AbstractIntercountry cross‐section comparison of total productivity in agriculture showed that differences in production efficiency were small relative to differences in labor productivity among countries at a same stage of economic development but very large among different stages of development. Moreover, the large differences in total productivity between the developed and the less developed countries widened further during the past two decades. The results suggest a hypothesis that agriculture in the less developed countries as a whole has not yet entered the phase of “modern economic growth” à la Kuznets.

PERFORMANCE OF 'GRASSLANDS MATUA' PRAIRIE GRASS UNDER CLOSE MOWING IN THE CENTRAL NORTH ISLAND

'Grasslands Matua' prairie grass (Bromus catharticus) was evaluated under close mowing (a) against cocksfoot, phalaris, and tall fescue as a companion grass for lucerne, on a pumice soil from 1974 to 1977 at sowing rates of 4, 13 and 22 kg/ha and (b) against ryegrasses in grass/white clover pastures on a sandy loam from 1975 to 1977. (a) In the first year lucerne/Matua sown at 13 and 22 kg/ha outyielded lucerne/Matua sown at 4 kg/ha by 19%, lucerne alone by 61%, and other mixtures by at least 21%. There were no significant differences in total production between the three lucerne/ Matua treatments, luccrne alone, and other mixtures over the second and third year. The inclusion of Matua reduced weed ingress. In the third year, Matua had a higher weed content than lucerne/tall fescue, which was almost weed free. (b) Annual production of Matua and Nui ryegrass swards was not significantly different. Matua swards were, however, superior to Nui from midsummer to early spring, whereas over spring/early summer Nui swards outproduced Matua swards.

Productivity of Crimson and Arrowleaf Clovers Grown in a Coastal Bermudagrass Sod1

AbstractA split‐plot field experiment compared annual seeding and self‐reseeding of crimson and arrowleaf clovers in a Coastal bermudagrass sod. Clover species did not differ significantly for seedling counts. Earlier growth was produced by self‐reseeding stands. However, stands from both methods of seeding were good and growth was relatively uniform in all plots. Differences in total production were not significant for method of seeding. Crimson clover averaged 33% more forage than arrowleaf. The lower yields of arrowleaf were caused by poor recovery and regrowth under drought stress.Grass following clover produced 18% more forage than grass receiving 224 kg/ha N without clover. Total grass yields following crimson and arrowleaf clovers were not significantly different. However, the first grass harvest following arrowleaf was always reduced. This was caused by greater competition from arrowleaf clover than from the earlier maturing crimson clovers.Total forage production was 47% higher from the sequence of clover‐Coastal bermudagrass than from grass — 224 kg/ha N — no clover. Highest total forage was produced by crimson clover‐bermudagrass. Crimson clover contributed 22% to total yield compared to 17% for arrowleaf. This study suggests the utilization of winter annual clovers to partially supply the nitrogen requirement of summer growing grasses. In addition to a reduction in the mineral nitrate requirement, other benefits would be an extended grazing season, increased total forage production, increased forage quality, and better utilization of land resources.

A comparative study of the performance of dairy cows during summer and winter in a subtropical climate

Two groups of acclimatized Australian Illawarra Shorthorn cows, one of which calved in May and the other in November, were studied for 196 days at Biloela, central Queensland. They were individually stall-fed a similar quantity of feed of known composition and, though not given access to pasture, were exposed to normal climatic conditions. Although the May group produced significantly more milk (4 per cent fat corrected milk (F.C.M.)) during the first two months, the difference in total production was not significant. The May group were, on average, heavier initially, and after adjustment for this by covariance analysis differences in production of 4 per cent F.C.M. between groups during the first two months were eliminated. Elevations in rectal temperature, respiratory rate, and water intake during summer were comparatively small. During a particularly hot period there was a significant regression of relative humidity on rectal temperature and respiratory rate and dry bulb temperature on respiratory rate. The combined effect of dry bulb temperature and relative humidity on both rectal temperature and respiratory rate was also significant. The indications from this experiment are that, if fed adequately, acclimatized European-type cattle produce equally well during summer and winter in a subtropical environment.

Productivity of Inbred Strains of Tribolium Confusum and Tribolium Castaneum

Studies of the variation in productivity in inbred strains of Tribolium confusum and Tribolium castaneum were undertaken to determine the effects of inbreeding on different strains of common ancestry. Six strains of each species were tested after eight to ten generations of inbreeding by full sibling crosses. The founding parents of each strain were taken from synthetic populations, on of T. confusum, another of T. castaneum, each of which had been established by systematic crosses involving stocks of different origin. Three pairs of sibling strains, two of T. confusum, one of T. castaneum, each pair derived from the same ancestral parents in the founding generation of inbreeding, were included in the 12 stains investigated. In length of productivity period, significant interstrain variation in means and variances was found for the strains of T. castaneum investigated. Differences between the strains of T. confusum examined were found to be not significant. In total 120—day productivity, significant intraspecies, between—strain variation in means and variances was found for both T. confusum and T. castaneum. Analysis of per—day productivity for a 40—day period revealed significant strain differences in productivity in T. confusum; interstrain differences in variance could not be demonstrated. In T. castaneum, significant interstain variation in means and variances was found. Interstrain differences in productivity reflect genotypic differences due to inbreeding as well as genotypic differences of the founding parents of the different strains. Differences between sibling strains, having the same founding parents, are attributable to inbreeding only. The two sibling strains of one pair T. confusum tested exhibited remarkable similarity in all traits compared. The other pair of T. confusum showed slight though significant differences only in total 120—day productivity period and per—day productivity. Difference in total productivity fell short of significance, but the difference in variances was significant. Apparent interstrain variation is greater in T. castaneum than in T. confusum for all three traits analyzed. T. castaneum appears to perform relatively better and T. confusum relatively less well in competition experiments than would be indicated by their basic productivity.

SEASONAL CHANGES IN THE ATTACHED ALGAE OF FRESHWATER AND SALINE LAKES IN THE LOWER GRAND COULEE, WASHINGTON1

A two year investigation of two freshwater alkaline lakes and two saline lakes in the Lower Grand Coulee has provided a quantitative and qualitative record of many of the seasonal changes occurring in the non‐planktonic algae. A glass plate method satisfactorily recorded quantitative changes in the attached algae. The plates (28 by 28 cm) were submerged for 2 to 4 weeks at various depths. Dry weight and ash‐free dry weight of the predominantly algal attachment materials on plates were determined, and the ash‐free weight was expressed as a production rate. The ash from freshwater lakes was composed normally of intact diatom frustules. The ash from saline lakes was also diatomaceous, but the weakly silicified frustules were deformed during ashing. Proportional counts of the various species in freshwater lakes were made using the ash. The evaluation of relative dominance was based on the mathematical product of the cell count and a calculated volume factor for each species. The glass‐plate production technique was examined at some length and it was concluded that a 2‐week submergence period was most satisfactory, that glass was not unduly selective, that a horizontal position was satisfactory, and that the method was best suited to the freshwater lakes.In freshwater lakes (200–450 ppm T.D.S.) results clearly show a bimodal production curve with the peak generally higher in the spring than in the fall. Lowest production invariably occurred in late summer. High production values in the spring were commonly near or above 500 mg/m2/day. Comparison of the results of two years shows sizable differences in total production at comparable times of year, but the seasonal distribution of species followed the same general pattern both years. Cymbella affinis, C. cistula, C. mexicana, Diatoma elongatum, Fragilaria vaucheriae, Gomphonema eriense, Nitzchia spp., Synedra acus, and S. ulna were characteristic spring dominants in the freshwater lakes. These diatoms were replaced in summer mainly by Epithemia sorex, E. turgida, and Rhopalodia gibba. A few “spring” species were common in one lake in summer but only at greater depths. TheNine per cent of the 275 algal taxa collected in the Lower Grand Coulee occurred in both freshwater and saline lakes. Although the saline lakes were not rich in numbers of species, production rates were similar to and even higher than production rates in the freshwater lakes. In the two saline lakes (Lake Lenore‐10,000 ppm and Soap Lake—25,000 ppm) there was a pronounced diatom pulse in the fall. Production rate values as high as 550 mg/m2/day were achieved during this season. In Soap Lake a winter pulse reached a value of 1000 mg/m2/day which was followed by a distinct spring pulse, both absent in Lake Lenore. The dominants on glass plates in both lakes were species of Nitzschia and Amphora. Blue‐green algae were also common and were conspicuous for their lack of seasonality.