Corn Emergence and Yield Response to Row-unit Depth and Downforce for Varying Field Conditions

2019 ◽  
Vol 35 (3) ◽  
pp. 399-408
Author(s):  
Aurelie M. Poncet ◽  
John P. Fulton ◽  
Timothy P. McDonald ◽  
Thorsten Knappenberger ◽  
Joey N. Shaw

Abstract. Optimum row-crop planter seeding depth performance is required to place seeds within proper soil conditions to ensure quick germination and maximize the likelihood of uniform emergence. Seeding depth is adjusted prior to planting by selecting a row-unit depth, followed by the adjustment of a row-unit downforce for proper seed-soil contact. Optimum row-unit depth and downforce settings required to maintain a consistent seeding depth are variable. The objective of this study was to evaluate corn ( L) emergence and yield response to row-unit depth and downforce in changing field conditions between sites and growing seasons. Corn was planted with a 6-row John Deere MaxEmerge Plus planter equipped with heavy duty downforce springs. The experiment was conducted in 2014 and 2015 in Central Alabama for non-irrigated corn. Two fields, three row-unit depths (4.4, 7.0, and 9.5 cm), and three row-unit downforce settings (0.0, 1.1, and 1.8 kN) were evaluated. Emergence was measured at 75 and 100 Growing Degree Days (GDDs). Yield was measured using a yield monitor installed on the combine harvester. Corn emergence was mainly affected by changes in weather conditions. Row-unit depth and downforce did not affect corn emergence in warmer weather conditions but the 4.4 cm row-unit depth resulted in more emergence than the other row-unit depth settings in cooler weather conditions. Yield ranged from 8,000 to 13,000 kg ha-1 across treatments and yield was mostly affected by changing growing conditions between fields and growing seasons. Plant population significantly varied with treatments, but lower plant populations did not always result in lower corn yields. These findings provided a better understanding of corn emergence and yield response to row-unit depth and downforce in varying field conditions. Keywords: Corn, Depth, Downforce, Emergence, Maize, Planter, Yield.

2018 ◽  
Vol 34 (5) ◽  
pp. 819-830 ◽  
Author(s):  
Aurelie M. Poncet ◽  
John P. Fulton ◽  
Timothy P. McDonald ◽  
Thorsten Knappenberger ◽  
Joey N. Shaw ◽  
...  

Abstract. Optimization of planter performance such as uniform seeding depth is required to maximize crop yield potential. Typically, seeding depth is manually adjusted prior to planting by selecting a row-unit depth and a row-unit downforce to ensure proper seed-soil contact. Once set, row-unit depth and downforce are usually not adjusted again for a field although soil conditions may vary. Optimization of planter performance requires automated adjustments of planter settings to varying soil conditions, but development of precision technologies with such capabilities requires a better understanding of soil-planter interactions. The objective of this study was to evaluate seeding depth response to varying soil conditions between and within fields and to discuss implications for development and implementation of active planting technologies. A 6-row John Deere MaxEmerge Plus planter equipped with heavy-duty downforce springs was used to plant corn ( L.) in central Alabama during the 2014 and 2015 growing seasons. Three depths (4.4, 7.0, and 9.5 cm) and three downforces (corresponding to an additional row-unit weight of 0.0, 1.1, and 1.8 kN) were selected to represent common practices. Depth and downforce were not readjusted between fields and growing seasons. Seeding depth was measured after emergence. Corn seeding depth significantly varied with heterogeneous soil conditions between and within fields and the planter failed to achieve uniform seeding depth across a field. Differences in corn seeding depth between fields and growing seasons were as high as 2.1 cm for a given depth and downforce combination. Corn seeding depth significantly co-varied with field elevation but not with volumetric soil water content. Seeding depth varied with elevation at a rate ranging from -0.1 cm/m to -0.6 cm/m. Seeding depth co-variation to field elevation account for some but not all site-specific seeding depth variability identified within each field trial. These findings provide a better understanding of site-specific seeding depth variability and issues to address for the development of site-specific planting technologies to control seeding depth accuracy and improve uniformity. Keywords: Depth control, Downforce, Planter, Precision agriculture, Seeding depth, Uniformity.


2016 ◽  
Vol 24 (2) ◽  
pp. 25-30
Author(s):  
Piotr Szafranek

Abstract Potentilla fruticosa L. (Rosaceae Juss.) is one of the most popular deciduous shrubs cultivated in Poland. Among pests identified so far on P. fruticosa, a serious threat is caused by two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). During three-year study, the occurrence of two-spotted spider mite T. urticae on four cultivars of P. fruticosa: ‘Goldfinger’, ‘McKay’s White’, ‘Uman’ and ‘Pink Beauty’ grown in field conditions was compared. While conducting experiment, weather conditions were monitored. The number of eggs and motile forms of two-spotted spider mite were recorded separately. The most attractive cultivar to spider mite was ‘Goldfinger’. The largest amount of motile forms of mites and their eggs were found on the leaves of this cultivar in all three years of study. The least number of pests occurred on the cv. ‘Pink Beauty’. However, differences in the abundance of this pest on all studied cultivars were variable during the growing seasons.


2021 ◽  
Vol 58 (2) ◽  
pp. 199-208
Author(s):  
Katarzyna Ambroży-Deręgowska ◽  
Piotr Szulc

Summary A study was carried out to determine the effect of sowing density on the yield of maize of two different varieties. The field experiment was carried out in 2012–2014 at the Department of Agronomy of Poznań University of Life Sciences. The first-order factor was the variety: SY Cooky and Drim “stay-green”; the second-order factor was sowing density: 6, 7, 8, 9, 10 plants per m2. Weather conditions during the maize growing seasons significantly influenced the values of the studied traits. Significantly the lowest green mass yield of maize was obtained at the sowing density of 6 plants m−2, and the highest for 10 plants m−2. The “stay-green” variety significantly responded to an increase in sowing density with reduced fresh weight of leaf blades of a single plant compared with the conventional variety. This indicated highly effective photosynthesis with a lower plant density per unit area, which is also the basis for effective absorption of solar radiation for these maize varieties.


2018 ◽  
Vol 45 (2) ◽  
pp. 82-86 ◽  
Author(s):  
F.D. Morla ◽  
O. Giayetto ◽  
E. M. Fernandez ◽  
G. A. Cerioni ◽  
C. Cerliani

ABSTRACT Plant density is one of the most important management factors affecting the peanut growth, modifying the capacity to capture radiation, water and nutrients. Peanut yield response to increased plant density changes according to environmental conditions, the genotype used, and planting date. Therefore, the optimum plant density (OPD) may vary with location. The aim of this project was (i) to fit the Mitscherlich's equation of diminishing productivities to the yield response of runner-type peanuts to increasing plant density under different growing conditions in the peanut growing region of Cordoba Argentina; and (ii) validate this model with independent experimental data. The first stage was based on the analysis of data from different projects of plant densities carried out in the peanut growing area of Córdoba. This information was adjusted to the decreasing yield equation and the OPD was calculated. For validation, a field experiment was conducted during the 2013/14 and 2014/15 growing seasons under irrigated and rain-fed conditions where pod yield was evaluated for 5, 12, 18, 25 and 36 plants/m2. No interaction was detected between soil moisture conditions and plant density. Yield response to plant density had a high degree of fitness for a wide range of environmental and crop conditions. In field experiments, the peanut yield decreased only at the lowest plant density (5 plants/m2). Yield response to density adjusted to the Mitscherlich equation indicated that OPD ranged from 10.5 to 24.8 plants/m2. Using a single adjustment equation y = 1(1 – e−0.1784x), OPD was estimated to be 16.8 plants/m2 at harvest (11.7 plants per linear meter in 0.7 m between rows) for the peanut growing region of Cordoba. This approach can be a valuable input, along with other variables to analyze, when choosing peanut sowing density.


1999 ◽  
Vol 64 ◽  
Author(s):  
K. M. Tabari ◽  
N. Lust

Monitoring  of natural regeneration in a dense semi-natural mixed hardwood forest on the  base    of ash, beech, oak and sycamore occurred over 3 years in the Aelmoeseneie  experimental    forest, Belgium. 40 permanent plots (4 m x 5 m) were selected in three  various humus types,    located in an ash stand and in an oak - beech stand. In all plots abundance  and top height of all    broad leaved regenerated species were determined at the end of the growing  seasons 1995 and    1998. In addition, the seedlings which appeared in the plots during 1996  and 1997 were    identified and followed up.    This study proves that in the investigated sites natural regeneration is  drastically poor and    diversity is low, in particular where the humus layer is more acidic (mull  moder) and the litter    layer is thick. No regeneration phase older than the seedling stage (h <  40 cm) is developed on    the different humus types. On average, total number of seedlings in 1995  amounts to 38    units/are in the ash stand and to 63 units/are in the oak - beech stand.  Survival rate over a 3-    year period is 37% and 42% respectively in the ash and oak - beech stands.  Total ingrowth    during the growing seasons 1996 and 1997 is virtually poor, indicating 16  and 8 units/are    respectively in above mentioned stands. Survival rate of occurring  seedlings, as well as the ingrowth of new seedlings are notably different (P < 0.05) according to the soil conditions of the    ash stand. Generally, the low presence of seedlings and the lack of  regeneration older than the    seedling stage reveal that the regeneration development encounters with a  critical problem. The    continuation of this process would likely result in a progressive  succession by the invasive and    the unwanted tree species.


Author(s):  
Tram T.N. Thai ◽  
Danny G. Le Roy ◽  
Manjula S. Bandara ◽  
James E. Thomas ◽  
Francis J Larney

With soybean [Glycine max (L.) Merr.] seed cost increasing in Alberta, understanding economic optimum plant density (EOPD) could help growers save on input expenses. A study was conducted at two irrigated locations in southern Alberta (Bow Island and Lethbridge), in three growing seasons (2014–16), using two maturity group (MG) 00 soybean genotypes, two row spacings (RS; narrow, 17.5 cm; wide, 35 cm), and three seeding densities (SD; 30, 50 and 80 seeds m-2). Exponential plant density-yield relationships were used to estimate EOPD. The earlier MG 00.4 genotype compensated yield at lower plant density (39 vs. 43 plants m-2) and emergence (74 vs. 80%) than the later MG 00.8 genotype. The EOPD gaps between environments, genotypes, and RS were minimal (from 1–3 plants m-2), resulting in only 1.3–2.0% differences in grain yield (37–56 kg ha-1), and gross revenue at EOPD ($16–24 ha-1). The overall EOPD estimate was 46 plants m-2, regardless of environment, genotype or RS. The study highlighted the difference between agronomic production and profit maximization in choosing an optimum plant density, and the need to establish a seeding density calculator for irrigated soybean in southern Alberta.


Author(s):  
Matiashuk R. ◽  
Tkachenko I.

The sensitivity of the reproductive structures of Forsythiasuspensato the complex influence of undifferentiated environmental factors has been studied.The monitoring sites are located in 15 different park ecosystems in 6 administrative districts of Kyiv. Data from the Borys Sreznevsky Central Geophysical Observatory (air pollution index (API) and meteorological conditions for 2018-2020) were used to assess the conditions of the growthenvironment. The influence of a complex of ecologically important factors during the flowering offorsythia on the quality of the formedpollen is noted. Thus, growing plantsfor a long time in conditions with a low level of air pollution (APIup to 5.0) in abnormal weather conditions in 2020,40-50% less fertile grainswere formed. And forplants, which grow in areas with increasedlevel (API5.0-7.0) and high level (API7.0-14.0) of air pollution, the share of fertile grains in the pollen population decreased by 60-80%. In the closed bud,the pollen has higher resistance to a complex of exogenous growth factors. Forsythia plants, which are located in large parklands, lose less pollen quality in adverse weather conditions and affected byurbotechnogenic factors. F. suspensa is an acceptable indicator of the level of environmental pollution by the deviation of pollen fertility from the control value. In areas with high aerogenic load, for example, areas with large highways (Bus Station «Darnytsia»), as well as with a significant recreational load (HolosiivskyiPark, Recreation Park on the Olena Teliha Street) much smaller pollen is formed. Itis noted that the conditions of forsythia growth affect the quantitative indicators of the formed pollen not only in the flower but also in the closed bud, which confirms the chronic effect of the complex of ingredients of aerotechnogenic emissions on plants of this species. The coefficient of sterility of pollen (CS) was used to objectively compare the data of 2019 and 2020 on the condition of the generative organs of F. suspensa in the studied areas. The calculation of the CS confirmed that in the closedbud pollen has a higher resistance to exogenous factors. In areas with high and increased levels of air pollution,during budding and flowering of plants (March-May,) there is a much higher CS of pollen of F. suspensа. Significant parkland territoriesof the city (for example, HolosiivskyiPark, Botanical Garden named after O. V. Fomin) provide less stressful conditions for growth and development of plants, even with the "very high" level of air pollution (ISA above 14.0) observed in April 2020 on this territory.The study of the susceptibility of F. suspensаpollen to growing conditions will be continued, as the prospects of using this species for bioindication of ecological status and zoning of park ecosystems of Kyiv according to the gradient of anthropogenic impact have been revealed.Key words:forsythia, fertility, coefficient of sterility of pollen, bioindication. Проведене дослідження чутливості репродуктивних структур Forsythiasuspensaдо комплексного впливу недиференційованих факторів навколишнього середовища. Моніторингові ділянки розташовані в 15 різних паркових екосистемах 6 адміністративних районівКиєва. Для оцінки умов середовища вирощування рослин використані дані Центральної геофізичної обсерваторії імені Бориса Срезневського (індекс забруднення атмосферного повітря (ІЗА) та метеорологічні умови за 2018-2020 рр.). Відмічено вплив комплексу екологічно важливих факторів (за показниками відхилення від норми середньої місячної температури повітря та місячної кількості опадів у Києві) уперіод квітування форзиції на якість сформованого пилку. Так, за тривалої експозиції рослин в умовах з низьким рівнем забруднення повітря (ІЗА до 5,0) в аномальних погодних умовах 2020 р. сформувалось на 40-50% менше фертильних зерен. А у форзиції, яка росте на територіях з підвищеним (ІЗА 5,0-7,0) та високим (ІЗА 7,0-14,0) рівнями забруднення частка фертильних зерен в популяції пилку зменшилась на 60-80%. У закритому бутоні пилок має вищу стійкість до комплексу екзогенних факторів середовища зростання. Рослини форзиції, які розташовані у значних за площею паркових насадженнях, менше втрачають якість пилку за несприятливих погодних умов та дії урботехногенних чинників. За відхиленням показника фертильності пилку від контрольного значення F. suspensaє допустимим індикатором рівня забруднення середовища. На територіях з підвищеним аерогенним навантаженням, наприклад, ділянки з автотранспортними магістралями (Автостанція «Дарниця»), а також зі значним рекреаційним навантаженням (Голосіївський парк імені М. Рильського, Парк відпочинку по вул. Олени Теліги)формується значно дрібніший пилок. Відмічено, що умови росту позначаються на кількісних показниках сформованого пилку не лише в квітці, але й в закритому бутоні, що підтверджує хронічний вплив комплексу інгредієнтів аеротехногенних викидів нарослини цього виду. Для об’єктивного співставлення даних 2019 і 2020 рр. щодо стану генеративних органів F. suspensaна досліджених ділянках був використаний коефіцієнт стерильності (КС) пилку. Розрахунок КС підтвердив, що в закритому бутоні пилок має вищу стійкість до впливу екзогенних чинників. Вищий КС був у F. suspense, з ділянок, на яких в період бутонізації і квітування рослин (березень-травень) відмічений високий і підвищений рівень забруднення атмосфери. Значні за площею паркові насадження міста (наприклад, Голосіївський парк, Ботанічний сад ім.акад. О.В. Фоміна) забезпечують менш напружені умови росту і розвитку рослин навіть при відміченому в квітні 2020 р. «дуже високому» рівні забруднення повітря (ІЗА вище 14,0) на цих територіях. Дослідження чутливості пилку F. suspenseдо умов вирощування буде продовжене,оскільки виявлена перспективність використання цього виду для біоіндикації екологічного стану та зонування паркових екосистем Києва за градієнтом антропогенного впливу.Ключові слова: форзиція, фертильність, індекс стерильності, біоіндикація.


Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 753-756 ◽  
Author(s):  
S. Sanogo ◽  
S. P. Pennypacker ◽  
R. E. Stevenson ◽  
A. A. MacNab

Field experiments were conducted to determine the relationship of tomato anthracnose to weather variables. Sixteen potted tomato plants were exposed to field conditions within rows of tomato plants for 4 consecutive days at various time periods during the 1993 and 1994 summer growing seasons. Incidence of fruit infection by Colletotrichum coccodes was correlated with rain variables (amount and duration of rain) alone and in combination with other meteorological factors. The best fitting regression equation, accounting for 72% of the variation in anthracnose incidence (arcsine-square root transformed), was Y = 111.77 - 1.16 HNRo, in which HNRo is the numbers of hours during which no rainfall occurs within 4-day intervals that tomato fruit were exposed to field conditions in central Pennsylvania.


2016 ◽  
Vol 42 (2) ◽  
Author(s):  
Emma Schaffert ◽  
Glynn Percival

High mortality rates result from transplanting bare-rooted plants into urban landscapes where unsuitable soil conditions, such as low fertility and poor structure, often exist. Coupled with little aftercare, these losses can cause high economic losses to the industry. Previous studies have shown lowered transplant stress and higher survival rates through the addition of soil amendments at the time of planting to improve soil conditions. The efficacy of three soil amendments applied singly and in combination—biochar, slow-release molasses, and an organic N:P:K fertilizer—were investigated for their potential to reduce transplant losses of Pyrus communis ‘Williams’ Bon Chrétien. Results of this investigation showed that use of these soil amendments in virtually all cases had significant positive effects on tree growth and vitality across two growing seasons. For example, all amendments reduced mortality of Pyrus communis ‘Williams’ Bon Chrétien’ by 20% compared to none in treated controls, while increases in fruit yield and crown canopy coverage per tree ranged from 19.3% to 46.7% and 14.4% to 31.1% over non-amended soils when averaged over two growing seasons. Amendments of biochar with an organic N:P:K fertilizer and an organic N:P:K fertilizer alone showed, on average, the highest improvements in vitality and growth. Results indicate use of biochar, slow-release molasses, and organic N:P:K fertilizer amendments offer potential for increasing bare-root transplant survival and establishment of Pyrus communis ‘Williams’ Bon Chrétien.


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