scholarly journals Estimation of buckwheat leaf area by leaf dimensions

2021 ◽  
Vol 42 (3Supl1) ◽  
pp. 1529-1548
Author(s):  
Alberto Cargnelutti Filho ◽  
◽  
Rafael Vieira Pezzini ◽  
Ismael Mario Márcio Neu ◽  
Gabriel Elias Dumke ◽  
...  

The objective of this work was to model and identify the best models for estimating the leaf area, determined by digital photos, of buckwheat (Fagopyrum esculentum Moench) of the cultivars IPR91-Baili and IPR92-Altar, as a function of length (L), width (W) or length x width product (LW) of the leaf blade. Ten uniformity trials (blank experiments) were carried out, five with IPR91-Baili cultivar and five with IPR92-Altar cultivar. The trials were performed on five sowing dates. In each trial and cultivar, expanded leaves were collected at random from the lower, middle and upper segments of the plants, totaling 1,815 leaves. In these 1,815 leaves, L and W were measured and the LW of the leaf blade was calculated, which were used as independent variables in the model. The leaf area of each leaf was determined using the digital photo method (Y), which was used as a dependent variable of the model. For each sowing date, cultivar and thirds of the plant, 80% of the leaves (1,452 leaves) were randomly separated for the generation of the models and 20% of the leaves (363 leaves) for the validation of the models of leaf area estimation as a function of linear dimensions. For buckwheat, IPR91-Baili and IPR92-Altar cultivars, the quadratic model (Ŷ = 0.5217 + 0.6581LW + 0.0004LW2, R2 = 0.9590), power model (Ŷ = 0.6809LW1.0037, R2 = 0.9587), linear model (Ŷ = 0.0653 + 0.6892LW, R2 = 0.9587) and linear model without intercept (Ŷ = 0.6907LW, R2 = 0.9587) are indicated for the estimation of leaf area determined by digital photos (Y) based on the LW of the leaf blade (x), and, preferably, the linear model without intercept can be used, due to its greater simplicity.

2019 ◽  
Vol 35 (6) ◽  
Author(s):  
João Everthon da Silva Ribeiro ◽  
Ester dos Santos Coêlho ◽  
Francisco Romário Andrade Figueiredo ◽  
Sérgio de Faria Lopes ◽  
Manoel Bandeira de Albuquerque

Erythroxylum citrifolium is a neotropical plant species recorded in all regions of Brazil. Determining leaf area is of fundamental importance to studies related to plant propagation and growth. The objective was to obtain an equation to estimate the leaf area of E. citrifolium from linear dimensions of the leaf blade (length and width). A total of 200 leaf blades were collected in Parque Estadual Mata do Pau-Ferro in the municipality of Areia, state of Paraíba, Northeast Brazil. The models evaluated were: linear, linear without intercept, quadratic, cubic, power and exponential. The best model was determined by the criteria of: high coefficient of determination (R²), low root mean square error (RMSE), low Akaike information criterion (AIC), high Willmott concordance index (d) and a BIAS index close to zero. All of the models constructed satisfactorily estimated the leaf area of E. citrifolium, with coefficients of determination above 0.9050, but the power model using the product between length and width (L*W) ŷ = 0.5966 * LW1.0181 was the best, with the highest values of R² and d, low values of RMSE and AIC, and a BIAS index closest to zero.


1977 ◽  
Vol 57 (2) ◽  
pp. 317-321 ◽  
Author(s):  
G. H. GUBBELS

Two buckwheat (Fagopyrum esculentum Moench.) cultivars, Tokyo and Tempest, were grown in 1971, 1972 and 1973 at 8.5, 17, 34 and 68 kg/ha sowing rates and at early, mid- and late June sowing dates. Tempest lodged more than Tokyo, particularly in 1971. Yield generally declined with each delay in sowing. In 1971, yield increased with each increase in sowing rate, while in 1972 there was no difference due to rate. In 1973, yield increased to the third rate and levelled out to the fourth. Therefore, a sowing rate of over 34 kg/ha may be required to assure good yields each year. Seed weight tended to decrease with delay in sowing but was not affected by sowing rate.


Botany ◽  
2009 ◽  
Vol 87 (9) ◽  
pp. 888-892 ◽  
Author(s):  
Wisdom Japhet ◽  
Daowei Zhou ◽  
Ping Wang

Plasticity is an important attribute that enables plants to maintain fitness in heterogeneous environments. The objective of this study was to investigate plasticity in branch length in Fagopyrum esculentum Moench. Seeds of the species were sown under two contrasting conditions through the manipulation of planting density (inter-planting distances at 20, 15, 10, and 5 cm) and sowing date (25 July, 1 August, 5 August, and 15 August). Allometric analysis of the relationships between branch length and total biomass showed a significant (p < 0.05) departure from isometry. This indicates that branch length increased linearly as a function of size. However, branch length was smaller in the group of plants sown at higher densities and at late sowing dates. True plasticity, which would have been indicated by significant differences in allometric exponents within treatments, was not observed in this study. Our results suggest that the differences observed in branch length were due to the direct effect of size rather than as a result of true plastic investment in branches.


2020 ◽  
Vol 33 (4) ◽  
pp. 1131-1139
Author(s):  
ALBERTO CARGNELUTTI FILHO ◽  
ISMAEL MARIO MÁRCIO NEU ◽  
JÉSSICA MARONEZ DE SOUZA ◽  
RAFAEL VIEIRA PEZZINI ◽  
GABRIEL ELIAS DUMKE ◽  
...  

ABSTRACT The objective of this work was to determine the optimal plot size to evaluate the fresh weight in buckwheat (Fagopyrum esculentum Moench) of the IPR91-Baili and IPR92-Altar cultivars, in scenarios formed by combinations of numbers of treatments, numbers of replicates, and levels of experimental precision. Sixteen uniformity trials (blank experiments) were carried out, eight with cultivar IPR91-Baili and eight with cultivar IPR92-Altar. The trials were performed in eight sowing dates. The fresh weight was evaluated in 576 basic experimental units (BEU) of 1 m x 1 m (36 BEU per trial). The soil heterogeneity index of Smith (1938) was estimated. The plot size was determined by the method of Hatheway (1961) in scenarios formed by combinations of i treatments (i = 5, 10, 15, and 20), r replicates (r = 3, 4, 5, 6, 7, and 8), and d precision levels (d = 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, and 20%). To evaluate the fresh weight in buckwheat of the IPR91-Baili and IPR92-Altar cultivars, in experiments under completely randomized and randomized block designs, with 5 to 20 treatments and eight replicates, plots of 8 m3of useful area are sufficient to identify significant differences between treatments, at 5% probability level, of 15% of the overall mean of the experiment.


2017 ◽  
Vol 1 ◽  
pp. 62
Author(s):  
Ali F. Almehemdi ◽  
Usama H. Mahdi ◽  
Abbas Lateef Abdulrahman

An experiment was conducted buckwheat (Fagopyrum esculentum Moench) during the growing season of 2013 in order to investigate the effect of sowing date (6th, 14th, and 24th of September) on the phenology of this plant. Leaf area was estimated by using principals of the triangle via simple model derived from triangle area. Parameters of the leaf such as height (h) and baseline (b) were combined as an equation of triangle, the area then adjusted. Two models were fitted with millimetre graph paper using simple linear regression. Regression analysis showed that the two models could be used for determining leaf area. The model equation of (((1/2BC.AG)-(1/2EF.DG)).(1/2EF.DG)/(1/2BC.AG)-(1/2EF.DG)) gave the most accurate estimation (r2=0.989, with linear equation of 0.707x+0.596). This study was applied to evaluate the response of some growth and yield parameters in two locations. Fallujah location was the best one, in which, plant height, leaves per plant, inflourences per plant and seed per plant were increased. Thus results revealed that the seed sowing at 6th of September was significantly improved leaves per plant, inflourences per plant and seed per plant and lowered the days from sowing to germination and days from sowing to inflourences. Therefore, it could be concluded that the variable x in linear equation could be replaced with derived model equation above to estimate buckwheat leaf area. Furthermore, Fallujah location was fitted to establish buckwheat and this plant could be planted at 6th Sept. Thus it could be concluded that multi-environment test is very important to evaluate this model.


2015 ◽  
Vol 21 ◽  
pp. 51-59
Author(s):  
Mst Towhida Akhter ◽  
PB Kundu ◽  
NK Paul

Context: To analyze the effect of sowing dates and weeding treatments on growth attributes such as total dry matter (TDM), leaf area index (LAI), net assimilation rate (NAR), crop growth rate (CGR), leaf area ratio (LAR) of three rapeseed (Brassica campestris L.) Objectives: The objective of the study was to identify the growth in relation to sowing dates and weed competition and identify the weeding number for better growth of rapeseed. Materials and Methods: This investigation was arranged as factorial experiment based on the split-split plot design with three replications. Four sowing dates were including 18 October (S1), 12 November (S2), 17 November (S3) and 3 December (S4) and three weeding treatments were no weeding (W0), one hand weeding (W1) and two hand weeding (W2) and three varieties viz., BINA Sarisha-5, BINA Sarisha-6 and BARI Sarisha-14 were investigated. Results: The results showed that, TDM, LAI, CGR, NAR and LAR were affected by sowing date and weeding treatments. The highest TDM, LAI and CGR were obtained in the first sowing and two weedings treatment. The highest NAR was found in S2 plants and W0 treatment. The highest LAR was found in S2 plants and W1 treatment. Conclusion: The results obtained in this study suggest that the first sowing and two weeding treatments are superior for the production of rapeseed. DOI: http://dx.doi.org/10.3329/jbs.v21i0.22519 J. bio-sci. 21: 51-59, 2013


Author(s):  
Marcos R. Sachet ◽  
Idemir Citadin ◽  
Marieli T. Guerrezi ◽  
Rafael H. Pertille ◽  
Joel Donazzolo ◽  
...  

ABSTRACT Leaf area (cm2 per leaf) and leaf pigment content are important traits that can be used to better understand a plants physiology. In this study, empirical non-destructive models for leaf area and leaf pigment based on the leaf dimensions, length (L) and width (W) in centimeters, and chlorophyll meter readings were developed for feijoa (Acca sellowiana). The experiment was carried out during January 2016 using five-year-old trees of 60 genotypes, grown under field conditions in the state of Paraná, Brazil. The proposed leaf area (LA) model was L A = 0 . 0022 L 3 + 0 . 1482 W 2 + 0 . 6159 L W + 0 . 1076 (R2 = 0.99). Three current leaf area models found in the literature were also assessed. All of the already created models were less accurate than the model proposed in this article. The proposed leaf pigment models were based on the Falker Chlorophyll Index for Chlorophyll a (A) and b (B), these were C h l a = 2 . 564 A + 13 . 098 B - 42 . 605 (R2 = 0.94), C h l b = 1 . 538 A + 3 . 287 B + 8 . 847 (R2 = 0.86) and C a r o t e n o i d s = 0 . 947 B + 8 . 943 (R2 = 0.88) expressed as µmol m-2 of leaf blade. In conclusion, the proposed models in this study were shown to be a reliable non-destructivel way of estimating A. sellowiana leaf area and leaf pigment.


2000 ◽  
Vol 134 (1) ◽  
pp. 33-43 ◽  
Author(s):  
H. K. DAPAAH ◽  
B. A. McKENZIE ◽  
G. D. HILL

The growth and yield of pinto beans (Phaseolus vulgaris L.) cv. Othello in response to a total of six sowing dates (from October to December) and irrigation was examined over two seasons in Canterbury, New Zealand. In 1994/95, two irrigation treatments (nil and full) were combined with two sowing dates (27 October and 24 November). In 1995/96, Othello was examined under two irrigation treatments (nil and full) and four sowing dates (1 November, 15 November, 29 November and 13 December). The total rainfall for the two seasons was 50% and 60% of the long-term average, respectively. The mean temperatures for the seasons were similar to the long-term average. Both irrigation and sowing date had a marked effect on growth and seed yield. Averaged over both seasons, seed yield for fully irrigated crops was 337 g/m2, c. 50% higher than the yield of unirrigated crops. The irrigated crops yielded more than the unirrigated crops because they attained greater canopy closure, intercepting 84–95% of incident radiation. They also had on the average 47% higher leaf area duration (LAD), 72% higher maximum leaf area index (LAI) and greater utilization coefficient. The mid- to late November-sown crops yielded more than the late October to early November and December-sown crops because the leaf area of the former increased most rapidly, achieved a higher maximum LAI and LAD and consequently intercepted more photosynthetically active radiation (PAR). They also had faster pod growth rates and 26% of stored assimilates contributed to pod growth compared with 13% in late October to early November and 5% in December-sown crops. The results showed that pinto beans can grow and yield well in Canterbury, and that a yield advantage could be obtained when sown in mid- to late November and with irrigation.


Author(s):  
М. С. Ульянченко

На фоні нестабільних погодних умов весняного періоду, що відмічаються останнім часом, встановлення оптимальних строків сівби районованих сортів гречки набуває актуального значення. У статті експериментальним шляхом вивчали шість сортів гречки (Fagopyrum esculentum Moench) вітчизняної селекції: Ярославна, Слобожанка, Руслана, Українка, Крупинка, СИН-3/02 залежно від строків сівби в умовах нестійкого зволоження центрального Лісостепу. Для проведення досліджень використовували загальноприйняті та спеціальні методики: продуктивність сортів гречки та аналіз зернового матеріалу за елементами продуктивності визначали після очищення зерна методом повітряної сепарації та перерахунку на стандартну 14 % вологість. Для умов 2015 року встановлено, що елементи продуктивності гречки (крупність та кількість зерен з рослини) мають суттєвий вплив на формування продуктивності культури. За масою 1000 зерен виокремилися сорт Крупинка за раннього строку сівби, суттєво менші значення отримали за цим показником у сортів Слобожанка та Українка, відповідно, за сівби в перший та другий строк. Усі інші сорти за крупністю зерна мали середнє значення. Строки сівби сорту СИН-3/02 не мали впливу на елементи продуктивності. В умовах 2016 року за крупністю зерна виокремилися сорти Ярославна, Руслана та Крупинка за раннього та середнього строків сівби. Всі сорти, що  вивчалися, забезпечили вищу крупність зерна за раннього строку сівби, за виключенням сортів Ярославна та Українка. За результатами дворічних досліджень визначено, що ранньостиглі сорти гречки Ярославна і Руслана доцільно висівати з середини першої декади травня. Сорти Слобожанка і Крупинка формують найбільшу продуктивність за сівби в перший та другий строк. Чіткого впливу терміну сівби на даний показник у сортів СИН-3/02 та Українка не виявлено. The set of optimal sowing dates of the buckwheat is to the actual value on the background of unstable weather of the springtime. In the article, six species of buckwheat (Fagopyrum esculentum Moench) of domestic breeding: Yaroslavna, Slobozhanka, Ruslana, Ukrainka, Krupynka, SIN-3/02 were studied experimentally, depending on the time of sowing in conditions of unstable moisture of the Central Forest-Steppe. For research, conventional methods and special methods were used: productivity of buckwheat varieties and analysis of grain material by the elements of productivity were determined after purification of the grain by air separation method and converted to a standard 14 % moisture content. For the 2015 conditions it has been established that the elements of the buckwheat productivity: the size and number of grains from the plant have a significant effect on the formation of the productivity of the crop. By weight of 1000 grains, Krupynka variety was distinguished at early term sowings; significant lower values ​​were obtained for this variety in Slobozhanka and Ukrainka, respectively for sowing in the first and second terms. All other varieties according to grain size had an average value. The lines of sowing of the variety SIN-3/02 did not influence the elements of productivity. In the conditions of 2016, the varieties Yaroslavna, Ruslana and Krupynka were distinguished by grain size for early and medium term sowing. All varieties put on the study ensured a higher grain size in early sowing, with the exception of Yaroslavna and Ukrainka varieties. According to the results of two-year studies, it has been determined that early varieties of buckwheat Yaroslavna and Ruslana should be sown from the middle of the first decade of May. Sloboda and Krupynka grades produce the highest seed yields in the first and second lines. The exact effect of the sowing date on this indicator in the varieties SIN-3/02 and Ukrainka was not detected.


1998 ◽  
Vol 78 (1) ◽  
pp. 35-49 ◽  
Author(s):  
G. K. Hotsonyame ◽  
L. A. Hunt

In some cereal simulation models, canopy leaf area development is calculated using relationships that summarize how leaf size changes with position. The nature and extent to which various environmental factors interact with ontogenetic variations in leaf size, however, is not clearly understood. This study was undertaken, therefore, to evaluate how temperature, photoperiod and nitrogen impact on leaf to leaf relationships in wheat grown under field conditions. Four contrasting genotypes of wheat comprising two spring and two unvernalized winter types were sown on five dates, supplied with one of two levels of nitrogen (150 kg N ha−1 and 0 kg N ha−1), and grown under natural and extended photoperiod conditions. For the spring wheats, individual mature leaf area increased along with leaf number up to leaf 5 (a stage that coincided with rapid stem elongation) but varied for subsequent leaves in a manner that was dependent on genotype and environment.In the period prior to the expansion of the fifth leaf, neither nitrogen nor photoperiod significantly influenced the pattern of change in leaf size. Thereafter, leaves under low nitrogen and extended photoperiod progressively became smaller, an effect that was due primarily to changes in length rather than in width. For the winter genotypes, which did not reach the stage of rapid stem elongation, mature leaf dimensions increased along with leaf number during the whole period of study and were not markedly affected by photoperiod but, after leaf 5, were smaller for the low nitrogen level. For all genotypes, the size of the first leaf and the coefficients derived by regressing the area of successive leaves on the area of the previous leaf during the vegetative phase varied among sowing dates due partly to the temperature environment under which the leaves at each node developed. The results, however, indicated that the potential leaf size at any of the lowermost leaf positions can be obtained by using a logarithmic function that relates the potential size of one leaf to its predecessor. Such relationship can be used to calculate actual leaf size if account is taken of environmental and assimilate supply factors that operate during leaf expansion. Key words: Wheat, sowing date, leaf area, temperature, photoperiod


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