scholarly journals Long-term Effects of Rows per Bed and In-row Spacing on Yield and Spear Size of Asparagus

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 652-654
Author(s):  
D.C. Sanders ◽  
J.D. Cure ◽  
W.J. Sperry ◽  
J.C. Gilsanz ◽  
C.A. Prince ◽  
...  
Keyword(s):  
Plant Density ◽  
Asparagus Officinalis ◽  
Planting Density ◽  
Yield Response ◽  
Row Spacing ◽  
Long Term Effects ◽  
Plant Densities ◽  
Hybrid Lines ◽  
The Relationship

Three studies were conducted at Clinton, N.C., to investigate the relationship between number of rows per bed, in-row spacing, and spear yield of asparagus (Asparagus officinalis L.) over 11 to 13 years. In the first study, increasing plant densities from 21,550 to 43,100 plants/ha by doubling the number of rows/bed increased the cumulative yield from 64% to 80% for three hybrid lines (`UC 157', `WSU 1', and `WSU 2') but only 6% for `Rutgers Beacon'. The effects of doubling the plant density were still apparent 13 years later. In the second study, yields of `Princeville' (`Mary Washington' selection) crowns, grown at densities from 14,000 to 86,000 plants/ha, were also increased for 8 years by doubling rows at various in-row spacings. In a third study, in which densities ranged from 21,000 to 387,900 plants/ha, the magnitude of the response to rows/bed was dependent on in-row spacing. Efficient use of bed space and the avoidance of crowding exerted a larger influence on productivity than did average planting density. The yield response to rows/bed was greater and more persistent through the years for wider in-row spacings. Spear size was only marginally responsive to rows per bed and in-row spacing.

Estimating the economic optimal target density of hybrid canola based on data from a western Canadian meta-analysis

2020 ◽  
Author(s):  
Murray D. Hartman ◽  
Scott R. Jeffrey
Keyword(s):  
Plant Density ◽  
Meta Analysis ◽  
Yield Response ◽  
Western Canada ◽  
Seeding Rate ◽  
Optimal Density ◽  
Herbicide Resistant ◽  
Plant Densities ◽  
Optimal Target ◽  
The Relationship

Canola production in western Canada has expanded such that in many regions canola area rivals the area seeded to wheat. This change can be mainly attributed to adoption of herbicide resistant hybrid varieties, and resulting higher relative profitability. Producers responded to higher seed prices by reducing seeding rates, leading to plant densities that were often lower than industry recommendations. The study objectives were to examine canola yield response to plant density and assess economically optimal density levels relative to industry recommendations and grower practices. A meta-analysis approach was applied to yield response and plant density data with herbicide resistant hybrid canola from multiple studies. Three alternative marginal yield-density functions were estimated and used to calculate economically optimal plant density. Sensitivity of results to key parameters was assessed. Resulting optimal density levels under recent average prices, seed size and emergence were 62-73 plants m-2, consistent with industry recommendations for western Canada. Recent field surveys report lower densities than this range, suggesting that producers are seeding at less than optimal rates. However, there is significant uncertainty associated with canola production, and interaction of seeding rate with other factors. These would impact on optimal plant density, although much of the uncertainty remains until well after seeding. The empirical results represent a foundation for development of more detailed models, highlight the significance of the relationship between plant density and economically optimal yield, and suggest the need to develop decision making tools to support producers in making canola planting decisions.

scholarly journals Spatial arrangement of maize plants aiming to maximize grain yield in the hybrid BRS-3046

2020 ◽  
pp. 1662-1669
Author(s):  
Marcus Willame Lopes Carvalho ◽  
Edson Alves Bastos ◽  
Milton José Cardoso ◽  
Aderson Soares de Andrade Junior ◽  
Carlos Antônio Ferreira de Sousa
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Intercellular Co2 Concentration ◽  
Maximum Yield ◽  
Co2 Concentration ◽  
Spatial Arrangement ◽  
Co2 Assimilation ◽  
Linear Increase ◽  
Planting Density ◽  
Row Spacing

The objectives of this study were to: (i) evaluate the effect of different spatial arrangements on morpho-physiological characteristics and (ii) determine the optimal spatial arrangement to maximize grain yield of the maize hybrid BRS-3046 grown in the Mid-North region of Brazil. We tested two row spacings (0.5 and 1 m) and five plant densities (2, 4, 6, 8, 10 plants m-2), which corresponded to 10 different plant spatial arrangements. Different morphophysiological variables, gas exchange rates and grain yield were measured. The increased planting density led to a linear increase in LAI, regardless of row spacing, while the net CO2 assimilation rate increased until the density of 4 and 6 plants m-2, under a row spacing of 0.5 and 1.0 m, respectively. On the other hand, we found a linear reduction in the stomatal conductance with increasing planting density. The intercellular CO2 concentration and the transpiration rate were higher in the widest row spacing. The instantaneous efficiency of carboxylation, in turn, showed a slight increase up to the density of six plants m-2, then falling, regardless of row spacing. Increasing plant density resulted in a linear increase in plant height and ear insertion height, regardless of row spacing. However, it had an opposite effect on stem diameter. Grain yield, in turn, increased up to 7.3 plants m-2 at a row spacing of 0.5 m and 8 plants m-2 at a row spacing of 1.0 m. This spatial arrangement was considered as ideal for achieving maximum yield

scholarly journals Scorpion Envenomation of Lactating Rats Decreases the Seizure Threshold in Offspring

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 853
Author(s):  
Marina de Oliveira Rodrigues Barbosa ◽  
Maria Eliza F. do Val de Paulo ◽  
Ana Leonor Abrahão Nencioni
Keyword(s):  
Perinatal Period ◽  
Postnatal Period ◽  
Seizure Threshold ◽  
Long Term Effects ◽  
Crude Venom ◽  
Long Time ◽  
Few Data ◽  
The Relationship ◽  
Convulsive Threshold

Few data are available in the literature describing the long-term effects of envenoming in the perinatal period. In this study, the relationship between envenoming of lactating rats and possible behavioral changes in the mother and in her offspring were investigated. Lactating Wistar rats received a single dose of T. serrulatus crude venom on postnatal days 2 (V2), 10 (V10) or 16 (V16), and had their maternal behavior evaluated. The seizure threshold was evaluated in adulthood offspring. A decrease in maternal care during envenoming was observed in V2 and V10 groups. The retrieval behavior was absent in the V2 group, and a lower seizure threshold in the adult offspring of all groups was observed. During envenoming, mothers stayed away from their offspring for a relatively long time. Maternal deprivation during the early postnatal period is one of the most potent stressors for pups and could be responsible, at least in part, for the decrease in the convulsive threshold of the offspring since stress is pointed to as a risk factor for epileptogenesis. Furthermore, the scorpionic accident generates an intense immune response, and inflammation in neonates increases the susceptibility to seizures in adulthood. Therefore, maternal envenoming during lactation can have adverse effects on offspring in adulthood.

scholarly journals ESTIMATION OF EFFICIENCY OF CONSTRUCTION OF AGRO-PHYTOCENOSES AND FERTILIZER OF THE OIL RADISH ON THE BASIS OF THE MODULAR-VITALITY METHOD

2019 ◽  
pp. 54-78
Author(s):  
Yaroslav Tsytsiura
Keyword(s):  
Plant Density ◽  
Morphological Characters ◽  
Climatic Conditions ◽  
Morphological Integration ◽  
Plant Oil ◽  
Long Term Study ◽  
Relationship Of ◽  
The Relationship ◽  
Fertilizer Rates

The article presents the results of a long-term study of the features of the phytocenology of agrophytocenoses of oil radish using different methods for assessing their condition and studying the tactics of the plant vitality strategy. A comprehensive assessment was made of the effect of changes in row spacing, seeding rates and fertilizer rates on the formation of various plant morphotypes, the variability of morphological characters and the general characteristics of plant viability. Three idiotypes of the plant oil radish were identified in a vertical study of agrophytocenosis, on the basis of which a detailed analysis of the variability of each group and a statistical assessment of the reliability of its existence were carried out. The features of the morphological integration of each tier are analyzed and its impact on the formation of the overall field productivity is evaluated. Based on the modular and vitality grouping, the effectiveness and feasibility of combining various options for plant density and fertilizer in the range of 30-90 kg of active substance per 1 ha were evaluated. Conclusions are drawn about the desired model of agrophytocenosis of oil radish based on the characteristics of its vital tactics and the goals of its growing. Grouping was carried out according to a variety of morphological traits of plants in the population and the possibilities of applying the basic patterns of phytocenology in their application to radish oilseed plants were evaluated. Through the use of regression analysis, the influence of climatic conditions on the formation of various morphological types of plants and the nature of the relationship of plants of oil radish in cenoses of various densities against the background of various fertilizer options has been evaluated. The main promising areas for further research on the peculiarities of creating highly productive and highly adaptable agrophytocenoses of oil radish have been outlined.

The Relationship Between Adverse Childhood Experiences and Recidivism in a Sample of Juvenile Offenders in Community-Based Treatment

2015 ◽  
Vol 61 (11) ◽  
pp. 1210-1242 ◽  
Author(s):  
Kevin T. Wolff ◽  
Michael T. Baglivio ◽  
Alex R. Piquero
Keyword(s):  
Juvenile Offenders ◽  
Adverse Childhood Experiences ◽  
Life Outcomes ◽  
Long Term Effects ◽  
Community Based ◽  
Childhood Experiences ◽  
Adverse Childhood ◽  
Juvenile Justice Policy ◽  
The Relationship

Adverse childhood experiences (ACEs) have been identified as a key risk factor for a range of negative life outcomes, including delinquency. Much less is known about how exposure to negative experiences relates to continued offending among juvenile offenders. In this study, we examine the effect of ACEs on recidivism in a large sample of previously referred youth from the State of Florida who were followed for 1 year after participation in community-based treatment. Results from a series of Cox hazard models suggest that ACEs increase the risk of subsequent arrest, with a higher prevalence of ACEs leading to a shorter time to recidivism. The relationship between ACEs and recidivism held quite well in demographic-specific analyses. Implications for empirical research on the long-term effects of traumatic childhood events and juvenile justice policy are discussed.

LONG-TERM EFFECTS OF ROW SPACING AND FERTILIZER ON THE PRODUCTIVITY OF RUSSIAN WILD RYEGRASS

1968 ◽  
Vol 48 (1) ◽  
pp. 75-84 ◽  
Author(s):  
T. Lawrence ◽  
D. H. Heinrichs
Keyword(s):  
Ammonium Phosphate ◽  
Phosphate Fertilizer ◽  
Fertilizer Application ◽  
Forage Yield ◽  
Row Spacing ◽  
Long Term Effects ◽  
Forage Production ◽  
Bare Ground ◽  
Drought Period

A study was conducted from 1947 to 1966 to determine the long-term effects of row spacings and applications of ammonium phosphate fertilizer (16–20–0) on the productivity and persistence of Russian wild ryegrass, Elymus junceus Fisch.The optimum row spacing for highest seed production was 0.9 m, whereas for highest forage production it was 0.6 m. The 280-kg/ha rate of fertilizer significantly increased the seed and forage yield over the 151-kg/ha rate, which in turn significantly increased the yield over the zero fertilizer treatment.Increases in precipitation in August and September increased the seed yield of Russian wild ryegrass the following year. Significant positive correlations were found between forage yields and precipitation during March, April, May, and the previous September for practically all treatments.Width of row increased with age of stand. During the 19-year period there was still bare ground between the grass rows seeded 0.9 and 1.2 m apart. These areas of bare ground were slightly narrower when fertilizer was used, indicating that fertilizer application tended to accelerate row-width development.Russian wild ryegrass was found to have excellent cold tolerance, drought tolerance and persistence. It survived through a long drought period and resisted invasion by weeds and volunteer grass seedlings after the third crop year.

scholarly journals Corn Response Across Plant Densities and Row Configurations for Different Moisture Environments

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Kipling S. Balkcom ◽  
Kira L. Bowen
Keyword(s):  
Cover Crops ◽  
Plant Density ◽  
Conservation Tillage ◽  
Summer Rainfall ◽  
Moisture Stress ◽  
Yield Response ◽  
Corn Yield ◽  
Measured Variable ◽  
Irrigation Level ◽  
Plant Densities

Corn (Zea mays L.) production in the Southeast can be negatively impacted by erratic summer rainfall and drought-prone, coarse-textured soils, but irrigation combined with conservation tillage and cover crops may support greater plant densities arranged in different row configurations to improve yield. We examined five site-years of data across two soil types in Alabama to compare corn yields in a conservation system across three plant densities for single- and twin-row configurations in dryland and irrigated moisture regimes. Treatments were arranged with a split plot treatment restriction in a RCB design with three replications. Main plots were irrigation level (no irrigation and irrigation), and subplots were a factorial arrangement of three plant densities (5.9, 7.4, and 8.9 plants m−2) and row configurations (single and twin). A moisture environment (low and moderate) variable, defined by growing season rainfall, was used to average over site-years. In general, irrigation in the moderate-moisture environment improved each measured variable (plant height, stover yield, corn yield, and test weight) and decreased grain N concentration and aflatoxin levels compared to the low-moisture environment with no irrigation. Benefits of increased rainfall and irrigation to reduce soil moisture stress across drought-prone soils were evident. Pooled results across all site-years indicated no yield response as plant density increased, but greater yields were observed with the greatest plant densities in the moderate-moisture environments. No advantage for twin-row corn production was observed across five site-years in Alabama, which indicates either row configuration can be successfully adopted.

scholarly journals Short- and Long-Term Effects of Lime and Gypsum Applications on Acid Soils in a Water-Limited Environment: 1. Grain Yield Response and Nutrient Concentration

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1213 ◽  
Author(s):  
Geoffrey C. Anderson ◽  
Shahab Pathan ◽  
James Easton ◽  
David J. M. Hall ◽  
Rajesh Sharma
Keyword(s):  
Grain Yield ◽  
Soil Layer ◽  
Acid Soils ◽  
Triticum Aestivum L ◽  
Nutrient Concentrations ◽  
Yield Response ◽  
Long Term Effects ◽  
Grain Yields ◽  
Growing Seasons

Surface (0–10 cm) and subsoil (soil layers below 10 cm) acidity and resulting aluminum (Al) toxicity reduce crop grain yields. In South Western Australia (SWA), these constraints affect 14.2 million hectares or 53% of the agricultural area. Both lime (L, CaCO3) and gypsum (G, CaSO4) application can decrease the toxic effect of Al, leading to an increase in crop grain yields. Within the region, it is unclear if G alone or the combined use of L and G has a role in alleviating soil acidity in SWA, due to low sulfate S (SO4–S) sorption properties of the soil. We present results from three experiments located in the eastern wheatbelt of SWA, which examined the short-term (ST, 2 growing seasons), medium-term (MT, 3 growing seasons), and long-term (LT, 7 growing seasons over 10 years) effects of L and G on grain yield and plant nutrient concentrations. Despite the rapid leaching of SO4–S and no self-liming impact, it was profitable to apply G, due to the significant ST grain yield responses. The grain yield response to G developed even following relatively dry years, but declined over time due to SO4–S leaching. At the LT experimental site had received no previous L application, whereas, at the ST and MT sites, L had been applied by the grower over the previous 5–10 years. For the LT site, the most profitable treatment for wheat (Triticum aestivum L.) grain yield, was the combined application of 4 t L ha−1 with 2 t G ha−1. At this site, the 0–10 cm soil pHCaCl2 was 4.6, and AlCaCl2 was greater than 2.5 mg kg−1 in the 10–30 cm soil layer. In contrast, at the ST and MT sites, the pHCaCl2 of 0–10 cm soil layer was ≥5.5; it was only profitable to apply G to the MT site where the soil compaction constraint had been removed by deep ripping. The use of L increases soil pHCaCl2, resulting in the improved availability of anions, phosphorus (P) in the LT and molybdenum (Mo) at all sampling times, but reduced availability of cations zinc (Zn) in the LT and manganese (Mn) at all sampling. The application of G reduced Mo concentrations, due to the high SO4–S content of the soil.

EFFECT OF ROW SPACING AND SEEDING RATES ON SUMMER RAPE IN SOUTHERN MANITOBA

1990 ◽  
Vol 70 (1) ◽  
pp. 127-137 ◽  
Author(s):  
M. J. MORRISON ◽  
P. B. E. McVETTY ◽  
R. SCARTH
Keyword(s):  
Brassica Napus ◽  
Seed Quality ◽  
Plant Density ◽  
Chlorophyll Concentration ◽  
Plant Distribution ◽  
Row Spacing ◽  
Seeding Rate ◽  
Brassica Napus L ◽  
Plant Densities ◽  
Lower Plant

To determine the effects of varying plant densities on summer rape (Brassica napus L.), the cultivar Westar was seeded in 15- and 30-cm row spacings at seeding rates of 1.5, 3.0, 6.0, and 12.0 kg ha−1. Plants seeded in 15-cm rows yielded more per area, produced more pods per plant and lodged less than those in 30-cm rows. Higher yields were associated with a more even plant distribution and a lower degree of intra-row competition. There were no significant protein, oil and chlorophyll concentration differences between the row spacing treatments. The highest yields (kg ha−1) were achieved with the 1.5 and 3.0 kg ha−1 seeding rates. Summer rape compensated for lower plant densities with the production of more branch racemes. As seeding rate increased, competitive mortality increased, resulting in greater etiolation at bolting, and greater lodging at harvest. Seed oil and protein concentrations were not affected by seeding rate. However, seed chlorophyll concentration decreased with increased seeding rate.Key words: Brassica napus, plant density, seed quality, rape (summer)

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