RESPOSTAS MORFOAGRONÔMICAS DE MILHO SUBMETIDO A DESFOLHA ARTIFICIAL

2017 ◽  
Vol 16 (3) ◽  
pp. 460
Author(s):  
EMERSON TROGELLO ◽  
LUAN FERREIRA BORGES ◽  
FÁBIO ARAÚJO DE OLIVEIRA ◽  
QUÉZIA SANCHES MUTAGUTI ◽  
INGRID GOMIDES BARROS ◽  
...  
Keyword(s):  
Zea Mays ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Analysis Of Variance ◽  
Zea Mays L ◽  
Grain Weight ◽  
Area Index ◽  
Plant Removal ◽  
And Control ◽  
Different Levels

RESUMO - O objetivo deste estudo foi avaliar as características morfoagronômicas do híbrido simples de milho em função da aplicação de diferentes intensidades de desfolha artificial, realizadas no estádio R1 de desenvolvimento. O experimento foi conduzido na área experimental do Instituto Federal Goiano,em Morrinhos-GO, na safra 2015/2016. Foi aplicado o delineamento de blocos completamente casualizados, com oito tratamentos e quatro repetições, sendo eles: remoção de uma folha acima e uma abaixo da espiga; remoção de duas folhas acima e abaixo da espiga; remoção de três folhas acima e abaixo da espiga; remoção de todas as folhas da planta; remoção de todas as folhas acima da espiga; remoção de todas as folhas abaixo da espiga; remoção da folha da espiga; e testemunha sem desfolha. Os caracteres avaliados foram: estande de plantas, número de plantas acamadas, prolificidade, densidade de colmo, comprimento e diâmetro de espiga, comprimento de grão, massa de mil grãos, massa de grãos espiga-1 e produtividade. Os dados foram submetidos à análise de variância pelo teste F a 5% de probabilidade, observando que todas as variáveis avaliadas foram influenciadas quanto aos efeitos dos tratamentos empregados. O enchimento dos grãos esteve intimamente relacionado à fotossíntese. Sem as folhas, esta fase ficou plenamente comprometida.Palavras-chave: Zea mays, fotoassimilados, translocação, índice de área foliar, rendimento. MORPHOAGRONOMIC CHARACTERISTICS OF MAIZE AS A FUNCTION OF DIFFERENT LEVELS OF ARTIFICIAL DEFOLIATION  ABSTRACT - The objective of this study was to evaluate of morphoagronomic characteristics of simple hybrids of maize, depending on the application of different intensities of artificial defoliation, carried out in R1, when the style-stigma were fertilized. The experiment was conducted in an experimental area of the Instituto Federal Goiano, Campus Morrinhos, State of Goiás, Brazil, during the agricultural year 2015/2016. We applied the design of completely randomized block with eight treatments, in four replications: removal of a leaf above and one below the ear; removal of two leaves above and below the ear; removal of three leaves above and below the ear; removal of all leaves of the plant; removal of all leaves above the ear; removal of all leaves below the ear; removal of the leaf of the ear; and control without defoliation. The traits evaluated were stand of plants, number of plant lodging, prolificacy, density, length and diameter of the cob, length of a grain, weight of a thousand grains, grain mass cob-1 and productivity. The data obtained were subjected to analysis of variance by F test at 5% probability, noting that all variables were influenced as to the effects of the treatments used. The filling of grains is closely related to photosynthesis. Without the leaves, this phase was fully damaged.Keywords: Zea mays L., photoassimilates, translocation, leaf area index, yield.

scholarly journals Changes in plant density dependence of leaf photosynthesis of maize (Zea mays L.) hybrids, 1959 to 1988

1991 ◽  
Vol 71 (1) ◽  
pp. 1-11 ◽  
Author(s):  
L. M. Dwyer ◽  
D. W. Stewart ◽  
M. Tollenaar
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Zea Mays L ◽  
Plant Density ◽  
Leaf Photosynthesis ◽  
Area Index ◽  
Photosynthetic Rates ◽  
Plant Densities

Understanding of the physiological basis for increased maize (Zea mays L.) yields over the last three decades may contribute to future genetic improvement. Recent maize production systems have tended to increase plant densities to maximize grain yield. The objective of this field study was to determine if there were changes in the response of leaf photosynthetic rates to increasing plant densities in four hybrids grown in Ontario from 1959 to 1989. The four hybrids, numbered from the oldest to most recent hybrid ((1) Pride 5, (2) United 106, (3) Pioneer 3978 and (4) Pioneer 3902) were grown at 20 000, 80 000 and 130 000 plants ha−1. Leaf photosynthetic response to irradiance (PRI) and crop growth rate (CGR) were measured near silking and during late grainfilling, leaf area index (LAI) was measured near silking and total grain yield was measured after maturity. The LAIs of recent hybrids tended to be larger than for old hybrids at comparable plant densities. Leaf photosynthetic rates declined in all hybrids at increasing densities, but the decline occurred at lower LAIs in the older hybrids. As a result, despite the higher LAIs of recent hybrids, they showed an equal or higher PRI at all plant densities. The higher PRI of recent hybrids was correlated with higher CGRs and grain yields. These results suggest that increases in optimum plant density for grain and increases in yield may be attributable, in part, to higher PRI at elevated LAIs in recent hybrids. Key words: Leaf area index, plant density, leaf photosynthesis, Zea mays L.

scholarly journals Effects of Variable Nitrogen Source and Rate on Leaf Area Index and Total Dry Matter Accumulation in Maize (Zea mays L.) Genotypes under Calcareous So

2014 ◽  
Vol 19 (2) ◽  
pp. 276 ◽  
Author(s):  
Shahen SHAH ◽  
Zahir SHAH ◽  
Shad Khan KHALAIL ◽  
Amanullah JAN ◽  
Muhammad Tariq JAN ◽  
...  
Keyword(s):  
Zea Mays ◽  
Leaf Area Index ◽  
Nitrogen Source ◽  
Leaf Area ◽  
Dry Matter ◽  
Zea Mays L ◽  
Dry Matter Accumulation ◽  
Area Index

scholarly journals Improving indirect measurements of the leaf area index using canopy height

2020 ◽  
Vol 55 ◽  
Author(s):  
Alexandre Ortega Gonçalves ◽  
Evandro Henrique Figueiredo Moura da Silva ◽  
Letícia Gonçalves Gasparotto ◽  
Juliano Mantelatto Rosa ◽  
Stephanie do Carmo ◽  
...  
Keyword(s):  
Zea Mays ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Positive Relationship ◽  
Saccharum Officinarum ◽  
Canopy Height ◽  
Mean Square ◽  
Indirect Measurements ◽  
Area Index ◽  
Strong Positive Relationship

Abstract: The objective of this work was to evaluate the use of plant height as a calibration variable for improving indirect measurements of the leaf area index (LAI). Three experiments were conducted with different crops - corn (Zea mays), soybean (Glycine max), and sugarcane (Saccharum officinarum) -, to compare the performance of the LAI measured indirectly (LAIind) and corrected by the calibration variable with the LAI measured directly (LAIref). Without the proposed correction, the LAIind tended to be overestimated by 20%, on average, compared with the LAIref, for the three crops. After crop height was used to adjust the LAIind, a strong positive relationship was observed between the LAIref and the corrected LAIind (R2 = 0.96); overestimation was reduced to 4% and the root-mean-square error decreased to 0.35 m2 m-2. The variable canopy height is promising for the correction of the LAI of the soybean, corn, and sugarcane crops.

scholarly journals Performance of Transplant Aus Rice Varieties under Different Nitrogen Management Practices

2021 ◽  
pp. 52-62
Author(s):  
Md. Omar Faruk ◽  
A. S. M. Iqbal Hussain ◽  
Md. Abu Yusuf ◽  
Md. Nazmul Hasan Mehedi
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Nitrogen Management ◽  
Grain Weight ◽  
Panicle Length ◽  
Rice Varieties ◽  
Area Index ◽  
1000 Grain Weight

Management of applied nitrogen in rice field is one tool that could lead to increase in rice yield, but often ignored by most farmers. The experiment was carried out from April to July 2015 at the Agronomy Field Laboratory of Patuakhali Science and Technology University, Dumki, Patuakhali to find out the influence of different nitrogen management and variety on the yield performance of transplant Ausrice. The study consisted of four levels of nitrogen viz. Control (without N), 30 kg N ha-1, 60 kg N ha-1 and urea super granule @ 52 kg N ha-1 and four Transplanted aus rice varieties viz. KaliHitta, ChaitaBoro, Abdul Hai and Gota IRRI, and was laid out in a split-plot design with three replications. The levels of nitrogen were assigned in the main plot and varieties were allocated in the sub-plots. Nitrogen management, variety and their interactions exerted significant (P ≤ 0.05) influence on plant characters, yield contributing characters and yield of transplanted Aus rice. In the case of nitrogen management, the tallest plant was 161.60 cm, maximum leaf area index(2.97, the highest number of effective tillers hill-115, longest panicle 24.30 cm with the maximum number of filled grains as94.73, 1000-grain weight gave 29.97 g. Grain yield of 2.48 t ha-1 were obtained from USG @ 52 kg N ha-1 and the shortest plant height of 136.90 cm with lowest leaf area index of 1.78, lowest number of effective tillers hill-1 (8.43), shortest panicle (18.84 cm) with the lowest numbers of filled grains panicle-1 (53.18), 1000-grain weight (24.33 g) and grain yield (1.40 t ha-1) were obtained in control (N1=O, kg N ha-1). Among the varieties, ChaitaBoro gave the tallest plant height (151.60 cm) and maximum leaf area index (2.54). While the highest number of effective tillers hill-1 (12.20), longest panicle (22.42 cm) with the maximum number of filled grains panicle-1 (73.50), highest 1000-grain weight (27.41 g) and highest grain yield (2.39 t ha-1) were recorded from Gota IRRI than other varieties. In case of interaction, Gota IRRI Fertilized with USG at 52 kg N ha-1 produced the highest number of effective tillers hill-1 (16.87), panicle length (25.13 cm), number of grains panicle-1 (105.70) and grain yield (3.13 t ha-1). The lowest number of effective tillers hill-1 (8.13), lowest panicle length (17.47 cm) with minimum numbers of filled grains 47.67) and grain yield (1.12 t ha-1) were produced by the interaction of control (N1=O, kg N ha-1) and Kali Hitta. So, cultivation of transplant Aus rice (Gota IRRI) appeared to be the best performance with USG @ 52 kg N ha-1 and recommended to the end users.

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