scholarly journals Conyza bonariensis growth and development according to thermal time accumulation and photoperiod

2020 ◽  
Vol 55 ◽  
Author(s):  
Nereu Augusto Streck ◽  
Giliardi Dalazen ◽  
Anelise da Silva Lencina ◽  
Nelson Diehl Kruse ◽  
Michel Rocha da Silva ◽  
...  
Keyword(s):  
Plant Height ◽  
Growth And Development ◽  
Sowing Date ◽  
Thermal Time ◽  
Vegetative Stage ◽  
Development Stages ◽  
Conyza Bonariensis ◽  
Sowing Dates ◽  
Time Accumulation ◽  
Hairy Fleabane

Abstract: The objective of this work was to characterize the growth and development of hairy fleabane (Conyza bonariensis) according to thermal accumulation and photoperiod, at different sowing times, and to propose a scale representing the main plant development stages. The experiment was carried out with ten replicates in the 2011/2012 growing season. The sowing dates were: 05/31/2011, 07/04/2011, 08/03/2011, 09/09/2011, and 11/07/2011. Plant height (cm) and phenology were evaluated weekly. The duration of the different stages (days) and thermal time accumulation (°C day) were determined. The linear regression analysis showed that plant height was related to thermal time accumulation. Regardless of the sowing date, the vegetative stage had a longer duration (in days and in ºC day) than the reproductive stage. Sowing on 11/07/2011 promoted the shortening of the vegetative stage, and the rosette stage did not occur. Flowering was induced in the photoperiod between 12.5 and 13.5 hours of light, regardless of the sowing date. Slow growth was observed at lower temperature conditions, when plants accumulated 30.9 and 16.3°C day per centimeter of height for the 05/31/2011 and 11/07/2011 sowing dates, respectively. The phenology scale adequately predicts the development stages of hairy fleabane.

Plant development of triticale cv. Lasko at different sowing dates

1998 ◽  
Vol 130 (3) ◽  
pp. 297-306 ◽  
Author(s):  
R. E. L. NAYLOR ◽  
J. SU
Keyword(s):  
Stem Elongation ◽  
Seedling Emergence ◽  
Sowing Date ◽  
Thermal Time ◽  
Development Stages ◽  
Leaf Emergence ◽  
Sowing Dates ◽  
Time Requirements ◽  
Leaf Appearance ◽  
Double Ridge

The progress of leaf emergence, external morphology and apical development stages were recorded in sowings of triticale (cv. Lasko) made from February to November 1990 at Aberdeen (57° N). Leaf appearance and the number of primordia were related to thermal time (above a base of 0°C) except when photoperiods were <c. 11 h. The thermal time per phyllochron varied between leaves and the combined times for all the phyllochrons at a particular sowing accounted for the apparent response of average phyllochron to sowing date. The thermal time requirements for progression to the double ridge stage, terminal spikelet stage, onset of stem elongation and anthesis were similar except where photoperiods of <11 h occurred. The rate of grain primordium production was constant when photoperiod had been increasing at seedling emergence but the rate was reduced when the seedling experienced shortening photoperiods at emergence.

scholarly journals Growth and development of Conyza bonariensis based on days or thermal units

2017 ◽  
Vol 52 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Daniel Jorge Soares ◽  
Wladecir Salles de Oliveira ◽  
Elvio Lorençato Uzuele ◽  
Saul Jorge Pinto de Carvalho ◽  
Ramiro Fernando Lopez Ovejero ◽  
...  
Keyword(s):  
Growth And Development ◽  
Floral Induction ◽  
Sowing Date ◽  
Dry Mass ◽  
The State ◽  
Base Temperature ◽  
Conyza Bonariensis ◽  
Sowing Dates ◽  
Resistant Population ◽  
Increasing Temperature

Abstract: The objective of this work was to evaluate the growth and development of a glyphosate-resistant population of Conyza bonariensis in different sowing dates (autumn, winter, and spring) and in two agricultural environments, based on days or thermal units. Five experiments were performed in two agricultural environments in Brazil: two in the municipality of Não-Me-Toque, in the state of Rio Grande do Sul - with sowings in July and September 2011; and three in the municipality of Santa Cruz das Palmeiras, in the state of São Paulo ‒ with sowings in April, July, and September 2011. In each trial, ten evaluations of the phenological development and total dry mass of C.bonariensis were performed, fitting these variables to a unit of time in days or growing degree days. The phenological development of C.bonariensis had the best adjustment at the base temperature of 8.4oC, and was affected by sowing date and agricultural environment. In autumn, with decreasing temperature and photoperiod, plants are still able to accumulate dry mass, but without floral induction. In spring, with increasing temperature and photoperiod, dry mass accumulation is lower, but phenological development is faster, with significant floral induction.

Some factors influencing the development of sunflower (Helianthus annuus L.) under dry-farming systems in Sudan

1981 ◽  
Vol 97 (1) ◽  
pp. 45-53 ◽  
Author(s):  
F. M. Khalifa
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Cultural Practices ◽  
Farming Systems ◽  
Sowing Date ◽  
The Other ◽  
Row Spacing ◽  
Sowing Dates ◽  
Supplementary Irrigation ◽  
Rainfed Conditions

SUMMARYAn experiment was carried out over a 3-year period at two locations in the central rainlands of Sudan under rainfed conditions at one site and under supplementary irrigation at the other to study the effects of cultivars and cultural practices on growth and grain yield of sunflower. Four cultivars, namely, Manohurian, Peredovik, Hungarian-A and Hungarian-B and four intra-row spacings of 15, 30, 45 and 60 cm (in rows 60 cm apart) were tested with three sowing dates starting on 15 July and following at 15-day intervals. Manchurian outyielded the other three varieties under supplementary irrigation whereas under rainfed conditions the reverse was true. This was attributed to the relative earliness in flowering of the varieties and their moisture requirements. Manchurian was the tallest with the thickest stem and a larger head at both locations compared with the other three varieties. Under rainfed conditions, the early sowing date of 15 July gave a significantly higher grain yield than the other two sowing dates, with the last sowing date of 15 August giving significantly least. This is attributed to decreasing moisture availability with delayed sowings. But under supplementary irrigation the effect of sowing date was less marked. Contrasting effects of sowing dates on plant height and stem circumference were obtained under the two systems of production. Under rainfed conditions there was a decrease in plant height and stem circumference with delayed sowing, whereas under supplementary irrigation the reverse was true. A contrasting response of plant height to spacing was also obtained; wider intra-row spacing was associated with taller plants under rainfed conditions and shorter plants under supplementary irrigation. Wider spacing was associated with thicker stems and larger heads at both locations. On the evidence obtained, 45 cm intra-row spacing is recommended for rainfed planting and 30 cm intra-row spacing for irrigated production of sunflower.

scholarly journals Effect of soybean cultivars sowing dates on seed yield and its correlation with yield parameters

2021 ◽  
Author(s):  
Magdalena Borowska ◽  
Janusz Prusiński
Keyword(s):  
Plant Height ◽  
Seed Yield ◽  
Seed Weight ◽  
Sowing Date ◽  
Protein Yield ◽  
Total Precipitation ◽  
Area Index ◽  
Soybean Cultivars ◽  
Temperature And Precipitation ◽  
Sowing Dates

The article presents the effect of three sowing dates on the growth, development and yielding of four soybean cultivars of different earliness and under different temperature and precipitation conditions across the years. The seed yield from early sowing significantly correlated with the total precipitation in June and July, and at later dates, also with the total precipitation in August. The significantly highest soybean yields were collected from the sowing at a turn of April and May, and the highest seed and protein yield, as well as protein content in seed, were recorded for the mid-early Merlin cultivar. Neither the number and the seed weight per pod nor the 1 000-seed weight significantly depended on the sowing date. Over years, a significant, almost linear decrease in the plant height and the first pod setting height, the weight of nodules, the protein yield and the LAI (leaf area index) value was observed. High significant correlations were found between the seed yield and the plant height and the first pod setting height, as well as between the seed number and the seed weight per pod and the 1 000-seed weight as well as between the plant height and the first pod setting height.  

A field study of the number of main shoot leaves in wheat in relation to vernalization and photoperiod

1992 ◽  
Vol 118 (3) ◽  
pp. 271-278 ◽  
Author(s):  
E. J. M. Kirby
Keyword(s):  
Field Experiments ◽  
Seedling Emergence ◽  
Wheat Plant ◽  
Sowing Date ◽  
Thermal Time ◽  
Model Function ◽  
Main Shoot ◽  
Leaf Emergence ◽  
Sowing Dates ◽  
Developmental Feature

SUMMARYThe number of leaves formed on the main shoot of a wheat plant is an important developmental feature, and a method of predicting this is essential for computer simulation of development.A model function was used to estimate vernalization from simulated sowing dates throughout a season. When expressed in terms of thermal time, it was estimated that a plant might be fully vernalized soon after seedling emergence or take up to about 1000 °Cd, depending on sowing date. When the simulated progress of vernalization was related to main shoot development (primordium initiation and leaf emergence) it was found that there were substantial differences between sowings in the rate of vernalization at comparable stages of apex development.A number of field experiments done in Britain from 1980 to 1984 with prominent commercial varieties, sown at various times from September to March, were analysed in terms of the thermal time to full vernalization and the photoperiod at the time of full vernalization, with vernalization simulated by the model function. In both winter and spring varieties, both of these variables significantly affected the number of main shoot leaves. Multiple linear regression using these two variables accounted for between 70 and 90% of the variance in leaf number, depending on variety.

scholarly journals Effect of Sowing Date and Harvest Schedule on Organic Spinach Grown during the Winter in High Tunnels

2019 ◽  
Vol 29 (3) ◽  
pp. 320-329
Author(s):  
Robert F. Heyduck ◽  
Steven J. Guldan ◽  
Ivette Guzmán
Keyword(s):  
New Mexico ◽  
Plant Height ◽  
Plant Density ◽  
Spinacia Oleracea ◽  
Direct Marketing ◽  
Sowing Date ◽  
Growing Seasons ◽  
Sowing Dates ◽  
High Tunnels

In a two-part study, we examined the effect of sowing date and harvest schedule on the yield of spinach (Spinacia oleracea) grown during the winter in 16 × 32-ft-high tunnels in northern New Mexico. Each part of the study was conducted for two growing seasons and took place between 2012 and 2015. In Study A (2012–13 and 2013–14), spinach was sown four times at roughly 2-week intervals (mid-October, early November, mid-November, and early December) and plant density (plants per square foot), plant height (centimeters), and yield (grams per square foot) were measured for three harvests in mid-January, mid-February, and mid-March. The earliest sowing date had the least-dense stands, and plant density increased with each subsequent sowing. The two earliest sowing dates had significantly higher season-long yield than the later two sowings. In Study B (2013–14 and 2014–15), all plots were sown in mid-October, but harvest schedule treatments were staggered such that harvests began at 9, 11, 13, or 15 weeks after sowing and continued at irregular intervals. Treatment 2, with harvests beginning after 11 weeks, had the greatest season-long yield, slightly greater than when harvests began at 9 weeks, and significantly more than when harvest began 13 weeks or later. More importantly, a staggered harvest schedule can provide spinach weekly for direct marketing opportunities.

scholarly journals Performance of Chickpea Varieties Based on Growth and Yield Parameters Influenced by Different Sowing Dates at Toke Kutaye District, Ethiopia

2021 ◽  
pp. 14-21
Author(s):  
Adinew Getachew ◽  
Thomas Abraham
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Sowing Date ◽  
Growth And Yield ◽  
Physiological Maturity ◽  
Agronomic Practices ◽  
Cropping Season ◽  
Sowing Dates ◽  
High Yielding Varieties ◽  
Check Experiment

One of the basic agronomic practices to improve the yield of chickpea are ideal sowing date and high yielding varieties. Thus, a field experiment was conducted to assess the effect of different sowing dates on yield and yield components of chickpea varieties in the main cropping season of 2019 at Toke Kutaye District. Four sowing dates (September 4th, September 14th, September 24th, and October 5th) and four kabuli varieties. Four Kabuli types of chickpea varieties were Dalota, Ejere, Teji and Dube (local check). Experiment was laid out in split plot design using factorial arrangement with three replications and sowing date treatments were assigned to the main plots and varieties to sub plots. The main effect of sowing date showed highly significant effect on days to emergence, days to 50% flowering and physiological maturity. Highest days to emergence                (12.4 days) were recorded from a plot sown on October 5th, while longest days to 50% flowering (54.92 days) and physiological maturity (122.5 days) were recorded from a plot sown on September 14th. Moreover, varieties had significant effect on days to physiological maturity of chickpea. Longest days to physiological maturity (133 days) were recorded from local variety and early days to physiological maturity (113.3 days) was recorded from Dalota variety. The main effects of sowing date and variety were significant on plant height, as the tallest plant height (42.75 cm) was recorded from September 24th sown plants. Similarly, the tallest (41.42 cm) plant was recorded from Dalota variety. In addition, the highest number of primary branches (6.83) and secondary branches (16.42) per plant were recorded from Dalota variety, while the lowest number of primary branch (5.5) and secondary branches (8) were scored from Ejere and Teji varieties, respectively. Highest grain yield (2415.4 kg ha-1) was obtained from plots sown on September 14th whereas Dalota variety produced highest grain yield (2051.25 kg ha-1). Hence, Dalota variety and September 14th sowing date emerged as best among all tested treatments and can be recommended for chickpea production in the study area and similar agro-ecologies. Conclusive recommendation could be obtained if the study is repeated at more locations and seasons in the future.

scholarly journals Quinoa (Chenopodium Quinoa Willd.) – a Potential New Crop in Bangladesh: Agronomic Performance With Sowing Date

2020 ◽  
Vol 23 (1) ◽  
pp. 67-73
Author(s):  
PK Biswas ◽  
ZA Tanni
Keyword(s):  
Plant Height ◽  
Seed Yield ◽  
Seed Weight ◽  
Harvest Index ◽  
Sowing Date ◽  
Branch Number ◽  
Yield Attributes ◽  
Straw Yield ◽  
Sowing Dates ◽  
New Crop

The experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka with the financial support of SAURES (Sher-e-Bangla Agricultural University Research System) to study the possibility of growing quinoa in Bangladesh with different sowing dates having two cultivars. The experiment comprised of two factors; Factor A: Cultivar (2) viz., Titicaca (C1) and Vikinga (C2) and Factor B: Sowing date (5) viz. November -10 (S1), December -10 (S2), January -10 (S3), February -10 (S4) and March -10(S5). The experiment was laid out in split-plot design with three replications. Results revealed that different growth parameters, yield attributes and yield were significantly varied with different sowing dates. At harvest, the tallest plant height (63.75 cm), highest seed yield (0.77 t ha-1) and straw yield (0.89 t ha-1) was found from Titicaca but the higher number of branches plant-1 (17.71) from Vikinga. The tallest plant height (62.54 cm), highest branch number plant-1 (22.82), longest inflorescence (29.62 cm), highest 1000-seed weight (2.56 g), seed yield (1.09 t ha-1), straw yield (1.25 t ha-1) and harvest index (46.58%) was exhibited by November -10 sowing. The interaction effect of Titicaca sown in November -10 (C1S1) resulted the highest plant height at harvest (72.83 cm), branches plant-1 (25.20), 1000-seed weight (2.58 g), seed yield (1.16 t ha-1) and straw yield (1.33 t ha-1) but the highest inflorescence length (31.46 cm) and harvest index (47.02%) from C2S2 (Vikinga sown in December – 10). From the above results it can be concluded that quinoa – as a new crop is suitable to cultivate in Rabi season of Bangladesh with a complete agronomic management package. Bangladesh Agron. J. 2020, 23(1): 67-73

scholarly journals PRODUÇÃO E SOMA TÉRMICA DE CULTIVARES DE MILHO VERDE EM DUAS SEMEADURAS NO VERÃO

Nativa ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 661
Author(s):  
Jucimar Ferreira Neves ◽  
Sandra Mara Alves da Silva Neves ◽  
Santino Seabra Júnior ◽  
Rivanildo Dallacort
Keyword(s):  
Zea Mays ◽  
Plant Height ◽  
Sweet Corn ◽  
Block Design ◽  
Sowing Date ◽  
Weight Percentage ◽  
Randomized Block Design ◽  
Sowing Dates ◽  
Crop Development ◽  
Thermal Sum

O presente estudo objetivou avaliar a produtividade de cultivares de milho verde e definir a data de semeadura mais propícia ao desenvolvimento da cultura no município de Cáceres-MT. O experimento foi conduzido no delineamento de blocos casualizados, arranjados em esquema fatorial 5x2, com quatro repetições. Foram avaliados cinco cultivares de milho verde (AG 1051, AG 4051, BM 3061, RG 01 e Cativerde 02) cultivados em duas datas de semeadura (30 de dezembro de 2013 e 29 de janeiro de 2014). Avaliou-se a altura das plantas, altura da inserção da espiga, comprimento, diâmetro e peso de espigas empalhadas e despalhadas e a percentagem de espigas verdes comercializáveis, além do ciclo e a soma térmica em graus dia (GD) entre a emergência e a colheita da espiga verde. Verificou-se maior altura de planta e inserção de espiga nas plantas cultivadas em 30 de dezembro. Os híbridos BM 3061 e RG 01 foram colhidos com menor ciclo, e consequentemente, necessitaram de menor soma térmica. Os híbridos BM 3061, AG 1051 e AG 4051 foram os mais produtivos, sendo, portanto, mais indicados para o cultivo. A semeadura em dezembro proporcionou melhores resultados produtivos às plantas.Palavras-chave: Zea mays; ciclo; graus dia; avaliação de cultivares. PRODUCTION AND THERMAL SUM OF CULTIVARS OF GREEN CORN IN TWO SOWINGS IN THE SUMMER ABSTRACT: The aims of the current study are to evaluate the yield of sweet corn cultivars and to define the most favorable sowing date for crop development in Cáceres County - MT. The experiment has followed a randomized block design, with factorial arrangement 5x2 and four repetitions. Five sweet corn cultivars (AG 1051, AG 4051, BM 3061, RG 01 and Cativerde 02) sown at two different sowing dates (December 30, 2013 and January 29, 2014) were evaluated. The following parameters were assessed: plant height; ear insertion height; ear (with and without husk) length, diameter and weight; percentage of marketable green ears; cycle and thermal sum (in GD - degrees day) between green ear emergence and harvest. The highest plant height and ear insertion values were observed in plants grown on December 30. Hybrids ‘BM 3061’ and ‘RG 01’ were harvested in the shortest cycle and, consequently, they required lower thermal sum. BM 3061, AG 1051 and AG 4051 were the most productive hybrids; therefore, they were the most suitable for cultivation. Plants sown in December recorded the best yield rates.Keywords: Zea mays; cycle; degree days; cultivar evaluation.

scholarly journals Seedling development and growth of white clover, caucasian clover and perennial ryegrass grown in field and controlled environments

2002 ◽  
pp. 197-204 ◽  
Author(s):  
A.D. Black ◽  
D.J. Moot ◽  
R.J. Lucas
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Sowing Date ◽  
Rapid Onset ◽  
Seedling Development ◽  
Thermal Time ◽  
Axillary Shoots ◽  
Sowing Dates ◽  
Environment Study ◽  
Controlled Environments

Autumn sowing on 4 February (SD1) and 31 March (SD2) 2000 was used to compare the establishment success of white and caucasian clovers sown with 0, 3, 6 or 12 kg seed/ha of perennial ryegrass. Total dry matter (DM) production from sowing to 3 October 2000 averaged 5770 and 3470 kg DM/ha for the two sowing dates, respectively. Clover species did not affect herbage production in monocultures which averaged 2610 kg DM/ha. The total DM increase from the addition of ryegrass was 87, 109 and 114% for 3, 6 and 12 kg/ha, respectively. On 3 October 2000, white clover content averaged 15% when sown with 3-12 kg/ha ryegrass on SD1 but less than 2% for SD2. Caucasian clover never exceeded 9% in either sowing and weed content was 2% when ryegrass was included for SD1 but 18% for SD2. A complimentary controlled environment study examined seedling development and growth of the three species. For each species the leaf appearance interval (phyllochron) in days differed across temperatures but was constant in thermal time at 94ºCd for white clover, 109ºCd for caucasian clover and 101ºCd for ryegrass. Axillary leaves and tillers of ryegrass first appeared after 375ºCd compared with 439ºCd for axillary leaves of white clover and 532ºCd for stolon initials. No secondary leaf development or rhizome initiation was detected in caucasian clover up to 774ºCd. At this time ryegrass seedling shoots were 635 mg/plant compared with 167 and 184 mg/plant for white and caucasian clovers, respectively. Thus, the success of ryegrass seedlings during autumn pasture establishment was explained by its high relative growth rate, and rapid onset of axillary leaf and tiller development compared with white and particularly caucasian clovers. Successful caucasian clover establishment is most likely to occur in the absence of either ryegrass or white clover. Keywords: axillary shoots, Lolium perenne, pasture establishment, phyllochron, sowing date, sowing rate, thermal time, Trifolium ambiguum, Trifolium repens

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