Photothermal time describes common ragweed (Ambrosia artemisiifoliaL.) phenological development and growth

Weed Science ◽  
1998 ◽  
Vol 46 (5) ◽  
pp. 561-568 ◽  
Author(s):  
William Deen ◽  
L. Anthony Hunt ◽  
Clarence J. Swanton
Keyword(s):  
Leaf Area ◽  
Mechanistic Model ◽  
Field Conditions ◽  
Total Biomass ◽  
Common Ragweed ◽  
Matter Production ◽  
Growth Room ◽  
Time Accumulation ◽  
The Relationship ◽  
Crop Competition

The ability to predict weed phenological development under field conditions is fundamental to the development of mechanistic weed–crop competition models. We studied how phenological development of common ragweed grown under field conditions could be explained using temperature and photoperiod responses derived from growth room experiments. We also determined the relationship between phenological development and common ragweed leaf area, dry matter production, and partitioning. Phenological development of common ragweed emerging at different times in the field was described by photothermal time based on temperature and photoperiod responses derived from growth room experiments. Estimated dates of phenological events of common ragweed were within 4 d of recorded values. Common ragweed seedling density did not influence phenological development. Common ragweed leaf area development, biomass partitioning, and total biomass were related to photothermal time accumulation. The results of this study are consistent with our hypothesis that phenological development is a major factor influencing the outcome of weed–crop competition. Results obtained from this study can be incorporated into a mechanistic model of weed–crop competition.

Seasonal plasticity more important than population variability in effects on white clover architecture and productivity

2021 ◽  
Author(s):  
Isabelle Nölke ◽  
Bettina Tonn ◽  
Johannes Isselstein
Keyword(s):  
Leaf Area ◽  
White Clover ◽  
Seasonal Pattern ◽  
Total Yield ◽  
Seasonal Effects ◽  
Total Biomass ◽  
Mixed Stands ◽  
The Impact ◽  
The Relationship ◽  
Architectural Traits

Abstract Background and Aims The drivers of white clover (Trifolium repens) architecture and productivity are still imperfectly understood. Our aim was to investigate the impact of genetic background, neighbourhood and season on different architectural traits, clover and total biomass yield as well as the relationship between those traits and yield. Methods We grew eight white clover populations in pure stands and in mixed stands with contrasting mixture partners. Over four consecutive regrowth periods within one year, we measured trait sizes and determined clover and total yield amounts. Key Results The size of the architectural traits differed between populations and changed in response to neighbourhood and season. Population did not affect the sign and degree of those changes. Among the tested factors, season was by far the most important driver of white clover architecture, with the seasonal pattern notably differing between architectural traits. Clover and total yield were positively related to the architectural traits leaf area, petiole length, internode length and specific leaf area. Whereas the direction of the relationship was widely unaffected, its magnitude was clearly altered by neighbourhood and season. Conclusions Our results show that seasonal effects are the key for a deeper understanding of architecture of white clover individuals and to improve productivity of white clover communities.

Diclofop Resistance in Wild Oat (Avena fatua)

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 475-479 ◽  
Author(s):  
Olufunmilayo O. Joseph ◽  
Shaun L.A. Hobbs ◽  
Sakti Jana
Keyword(s):  
Leaf Area ◽  
Physiological Response ◽  
Avena Fatua ◽  
Field Conditions ◽  
Leaf Width ◽  
Wild Oat ◽  
Naphthalic Anhydride ◽  
Growth Room ◽  
Foliar Retention

The differences in tolerance, morphology, and physiological response of diclofop-resistant and -susceptible wild oat biotypes collected from fields in Saskatchewan, Canada, were investigated under growth room and field conditions. Under herbicide-free conditions the resistant biotype had more upright leaves with about 12% less leaf area and 50% less leaf width than the susceptible biotype. A marked difference in the level of tolerance to diclofop was observed. Photosynthesis was initially significantly reduced in both biotypes after treatment with diclofop at the rate of 0.70 kg ai ha−1, but the resistant biotype was able to recover. Injury to the susceptible biotype was reduced by coating the seeds with 1,8-naphthalic anhydride. Differential foliar retention was not an important factor in selectivity of diclofop among the two biotypes.

scholarly journals Paclobutrazol Improves Sesame Yield by Increasing Dry Matter Accumulation and Reducing Seed Shattering Under Rainfed Conditions

2021 ◽  
Author(s):  
Muhammad Zeeshan Mehmood ◽  
Ghulam Qadir ◽  
Obaid Afzal ◽  
Atta Mohi Ud Din ◽  
Muhammad Ali Raza ◽  
...  
Keyword(s):  
Leaf Area ◽  
Seed Production ◽  
Seed Yield ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
Total Biomass ◽  
Dry Matter Accumulation ◽  
Seed Shattering ◽  
Rainfed Conditions ◽  
Leaf Greenness

AbstractSeveral biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L−1, P2 = 200 mg L−1, P3 = 300 mg L−1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L−1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.

scholarly journals Quinoa for the Brazilian Cerrado: Agronomic Characteristics of Elite Genotypes under Different Water Regimes

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1591
Author(s):  
Patrícia Carvalho da Silva ◽  
Walter Quadros Ribeiro Junior ◽  
Maria Lucrecia Gerosa Ramos ◽  
Sonia Maria Costa Celestino ◽  
Alberto do Nascimento Silva ◽  
...  
Keyword(s):  
Grain Quality ◽  
Winter Season ◽  
Field Conditions ◽  
Water Restriction ◽  
Water Regimes ◽  
Agronomic Characteristics ◽  
Relative Water ◽  
Different Seasons ◽  
The Relationship

Quinoa stands out as an excellent crop in the Cerrado region for cultivation in the off-season or irrigated winter season. Here, we tested the effects of different water regimes on the agronomic characteristics, physiology, and grain quality of different elite quinoa genotypes under field conditions. The experiment was conducted under field conditions at Embrapa Cerrados (Planaltina, DF, Brazil). The experimental design was in randomized blocks, in a split-plot scheme, with four replications. The plots were composed of 18 quinoa genotypes and modified BRS Piabiru (the currently used genotype), and the split-plots were divided into 4 different water regimes. The following variables were evaluated: productivity and productivity per unit of applied water (PUAA), plant height, flavonoids, anthocyanins, gas exchange, chlorophyll, leaf proline, and relative water content. Our results showed that water regimes between 309 and 389 mm can be recommended for quinoa in the Cerrado region. CPAC6 and CPAC13 presented the highest yield and PUAA under high and intermediate WRs, and hence were the most suitable for winter growth under irrigation. CPAC17 is most suitable for off-season growth under rainfed conditions, as it presented the highest PUAA under the low WRs (247 and 150). CPAC9 stood out in terms of accumulation of flavonoids and anthocyanins in all WRs. Physiological analyses revealed different responses of the genotypes to water restriction, together with symptoms of stress under lower water regimes. Our study reinforces the importance of detailed analyses of the relationship between productivity, physiology, and water use when choosing genotypes for planting and harvest in different seasons.

scholarly journals Interactive Effects of Nitrogen and Sulfur Nutrition on Growth, Development, and Physiology of Brassica carinata A. Braun and Brassica napus L.

2021 ◽  
Vol 13 (13) ◽  
pp. 7355
Author(s):  
Shivendra Kumar ◽  
Ramdeo Seepaul ◽  
Ian M. Small ◽  
Sheeja George ◽  
George Kelly O’Brien ◽  
...  
Keyword(s):  
Electron Transport ◽  
Leaf Area ◽  
Photosynthetic Pigments ◽  
Net Photosynthesis ◽  
Brassica Carinata ◽  
Internode Length ◽  
Erucic Acid Content ◽  
Total Biomass ◽  
Node Number ◽  
S 100

Brassica carinata (carinata) has emerged as a potential biofuel source due to its high erucic acid content, making it desirable for various industrial applications. Nitrogen (N) and sulfur (S) are required as primary sources of nutrition for growth and development in different oilseed crops and their utilization is interdependent. The purpose of the study was to analyze the interactive effect of N and S nutrition on the growth and other physiological activities of carinata and B. napus (napus). Four treatments, i.e., optimum NS (+N+S, 100% N and 100% S); N limited (−N+S, 0% N, 100% S); S limited (+N−S, 100% N, 0% S), and NS limited (−N−S, 0% N and 0% S) of N and S in full-strength Hoagland solution were imposed in the current study. Effect of different NS treatments was observed on vegetative traits such as number of primary and secondary branches, total leaf area, total biomass production and allocation, and physiological traits such as production of photosynthetic pigments, net photosynthesis, electron transport, and other aspects for both carinata and napus. The traits of stem elongation, number of nodes, node addition rate, internode length, number of primary and secondary branches were 60%, 36%, 50%, 35%, 56%, and 83% lower, respectively, in napus in comparison to carinata. Different NS treatments also positively influenced the production of photosynthetic pigments such as chlorophyll (Chl) a and b and carotenoids in carinata and napus. The concentration of Chla was 11% higher in napus in comparison to carinata. The rate of net photosynthesis, electron transport, and fluorescence was 12%, 8%, and 5% higher based on overall value, respectively, in napus compared to carinata. On the other hand, the overall value for stomatal conductance decreased by 5% in napus when compared to carinata. Different growth-related traits such as vegetative (plant height, node number, internode length, leaf area, number of primary and secondary branches), reproductive (pod number, pod length, seeds per pod), and photosynthetic capacity in oilseed brassicas are correlated with the final seed and oil yield and chemical composition which are of economic importance for the adoption of the crop. Thus, the analysis of these traits will help to determine the effect of NS interaction on crop productivity of carinata and napus.

On the relationship of NDVI with leaf area index in a deciduous forest site

2005 ◽  
Vol 94 (2) ◽  
pp. 244-255 ◽  
Author(s):  
Quan Wang ◽  
Samuel Adiku ◽  
John Tenhunen ◽  
André Granier
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Deciduous Forest ◽  
Forest Site ◽  
Area Index ◽  
Relationship Of ◽  
The Relationship

scholarly journals Nitrogen and potassium supply and the morphogenic and productive characteristics of marandu palisadegrass

2010 ◽  
Vol 39 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Marcio Mahmoud Megda ◽  
Francisco Antonio Monteiro
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
System Development ◽  
Block Design ◽  
Dry Mass ◽  
Dry Matter Production ◽  
Root System Development ◽  
Randomized Block Design ◽  
Matter Production ◽  
Specific Length

The objective of this work was to study morphogenic characteristics, and dry matter production of roots and shoots of marandu palisadegrass (Brachiaria brizantha cv. Marandu) submitted to combinations of nitrogen and potassium, in a nutritive solution, employing silica as substrate. The experiment was carried out in a greenhouse during the summer. It was used a 5² fractionated factorial scheme with 13 combinations of nitrogen and potassium, which were distributed in a randomized block design, with four replications. The nitrogen × potassium interaction was significant for the number of tillers and leaves, for leaf area, for shoots and root section dry mass, for total length and surface and specific length and surface in the roots. Production of aerial part dry mass positively correlated with the number of tillers and leaves and grass leaf area. Nitrogen rates modulated the root system development, and the root specific length and surface decreased when high rates of nitrogen and potassium were supllied. Nitrogen and potassium influence Marandu palisadegrass morphogenic characteristics, which are determinant for grass dry matter production.

scholarly journals Heritability of peach tree resistance to bacterial leaf spot

2017 ◽  
Vol 52 (5) ◽  
pp. 366-369 ◽  
Author(s):  
André Luiz Varago ◽  
Idemir Citadin ◽  
Marcos Robson Sachet ◽  
Gener Augusto Penso ◽  
Maria do Carmo Bassols Raseira
Keyword(s):  
Leaf Area ◽  
Disease Severity ◽  
Leaf Spot ◽  
Field Conditions ◽  
Broad Sense Heritability ◽  
Peach Tree ◽  
Bacterial Leaf Spot ◽  
Tree Resistance ◽  
Leaf Area Duration ◽  
Xanthomonas Arboricola

Abstract: The objective of this work was to evaluate the broad-sense heritability reaction to bacterial leaf spot (Xanthomonas arboricola pv. pruni), in peach tree populations obtained from directed crosses. Disease severity and defoliation of the genotypes were evaluated in field conditions, with posterior measurement of the healthy leaf area duration (HAD). The observed average heritability (0.51) indicates that the use of the evaluated genitors can be effective for the development of cultivars with higher resistance to the disease.

scholarly journals Variations in Growth Performance and Nitrogen Uptake of Sugarcane Cultivars Under Rain-Fed Conditions

2020 ◽  
Vol 3 (2) ◽  
pp. 571-579
Author(s):  
Dinh Thai Hoang ◽  
Hiroo Takaragawa ◽  
Le Trong Lu ◽  
Eizo Taira ◽  
Yoshinobu Kawamitsu
Keyword(s):  
Genetic Variation ◽  
Growth Performance ◽  
Leaf Area ◽  
Nitrogen Uptake ◽  
Yield Components ◽  
Water Shortage ◽  
Cane Yield ◽  
Total Biomass ◽  
High Nitrogen ◽  
Sugarcane Varieties

The experiment was conducted to evaluate growth and nitrogen uptake of the twelve sugarcane varieties, viz. NiF3, NiF8, Ni9, Ni12, Ni15, Ni17, Ni21, Ni22, Ni25, Ni27, Ni28, and Ni29, under rain-fed conditions during the period from 70 to 160 days after transplanting (DAT) at the experimental field, Faculty of Agriculture, University of the Ryukyus, Okinawa, Japan. The results showed that water shortage from a rain-fed condition caused reductions, but not significant in plant height and SPAD of sugarcane varieties. The genetic variation in leaf area, yield components, partial and total biomass, and cane yield was found among the investigated varieties. The positive associations between total nitrogen uptake with total biomass production and cane yield suggested that higher nitrogen uptake supports better growth performance of sugarcane under rain-fed conditions. From this study, NiF3 and Ni27 could be introduced as the promising sugarcane varieties for better growth performance and high nitrogen uptake under rain-fed conditions.

scholarly journals Determination of leaf area coefficient in sunflower.

1977 ◽  
Vol 25 (4) ◽  
pp. 238-242
Author(s):  
A.S.R. Pereira
Keyword(s):  
Leaf Area ◽  
Yield Components ◽  
Plant Density ◽  
Photosynthetic Capacity ◽  
Leaf Position ◽  
Area Estimation ◽  
End Use ◽  
The Relationship

For studies on the relationship between photosynthetic capacity and yield components in sunflower a method for estimating leaf area was required. To this end use of the leaf area coefficient (LAC), i.e. the quotient area/(length X max. width), was evaluated. It was found that LAC may be a function of leaf position and plant density, depending on the cv. concerned. For the Russian cv. Armavirec, LAC was independent of leaf position and plant density. For the Rumanian hybrid HS 18, LAC was dependent on leaf position but not plant density. For the French hybrid INRA 4701, LAC depended on both leaf position and plant density, but even in this case, it was concluded that LAC can be a useful aid in leaf area estimation. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Sign in / Sign up

Export Citation Format

Share Document