scholarly journals CRESCIMENTO E PRODUTIVIDADE DA CULTURA DO MILHO (Zea mays L.) SUBMETIDO A VÁRIOS INTERVALOS DE IRRIGAÇÃO, NA REGIÃO DA PRÉ-AMAZÔNIA

Irriga ◽  
2006 ◽  
Vol 11 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Emanoel Gomes de Moura ◽  
Ana Paula Rosa Teixeira ◽  
Valdirene Do Socorro Ribeiro ◽  
Alana Das Chagas Ferreira Aguiar ◽  
Maryzélia Furtado de Farias

CRESCIMENTO E PRODUTIVIDADE DA CULTURA DO MILHO (Zea mays L.) SUBMETIDO A VÁRIOS INTERVALOS DE IRRIGAÇÃO, NA REGIÃO DA PRÉ-AMAZÔNIA  Emanoel Gomes de Moura; Ana Paula Rosa Teixeira; Valdirene do Socorro Ribeiro; Alana das Chagas Ferreira Aguiar; Maryzélia Furtado de FariasPrograma de Pós-Graduação  em Agroecologia, Universidade Estadual do Maranhão, São Luís, MA,  [email protected]   1 RESUMO Com o objetivo de avaliar o efeito da variação do intervalo entre irrigações no crescimento e produtividade da cultura do milho, foi conduzido este experimento em um ARGISSOLO da Pré-Amazônia, com freqüências de 6, 8, 10, 12 e 14 dias, em parcelas de 12 x 3,20m. Durante a fase de crescimento foram avaliadas, semanalmente, a área foliar, e a matéria seca e estimadas a taxa de assimilação líquida, taxa de crescimento e o índice de área foliar. Na colheita foram determinados o peso de 100 grãos, o peso das espigas, o número de grãos por espiga e peso de grãos. Antes de cada irrigação foi avaliada a umidade do solo por gravimetria e com base na curva característica foi estabelecido o limite de -500kPa como sendo o potencial de água em que a evapotranspiração relativa atinge o nível crítico na região do experimento.Concluiu-se que um moderado déficit de água no solo diminuiu a taxa de crescimento da parte aérea, sem prejudicar, no entanto, a capacidade reprodutiva. A maior eficiência do uso da água foi obtida com o tratamento irrigado com a freqüência de 10 dias, por ter produzido espigas 80% mais pesadas e um aumento na produção econômica em 72% quando comparado, aos demais tratamentos. UNITERMOS: milho, crescimento, produtividade, irrigação.  MOURA, E.G.DE; TEIXEIRA, A.P.R.; RIBEIRO, V. DO S.; AGUIAR, A. DAS C. F.; FARIAS, M.F. GROWTH AND PRODUCTIVITY OF MAIZE (Zea mays L.) SUBMITTED TO SEVERAL IRRIGATION INTERVALS IN THE PRE-AMAZON AREA  2 ABSTRACT This study evaluates the effect of different irrigation intervals on maize growth and productivity on an Argisol in the southeastern periphery of the Amazon. The experiment consisted of five treatments with irrigation frequencies of 6, 8, 10, 12 and 14 days, each treatment was replicated in five 12 x 3.2m plots. During the growth phase, foliar area and dry matter were measured on a weekly basis for estimation of NAR, growth rate and leaf area index; at harvesting the weight of 100 grains, ear weight, number of grains per ear and grain biomass were determined. Preceding each irrigation, soil humidity was gravimetrically measured and, based on characteristic curve moisture, a critical threshold of -500kPa soil water potential, below which relative evapotranspiration becomes critical in the study area, was established. Irrigation frequency of every 10 days turned out to be the most efficient treatment, because it produced ear that were 50% heavier and increased productivity up to 72% when compared to the other treatments.  It was concluded that moderate soil water deficit reduces shoot growth rates, but does not affect the plant reproductive capacity. KEYWORDS: maize, growth, productivity, irrigation. 

2018 ◽  
Vol 17 (2) ◽  
pp. 190
Author(s):  
IGNACIO ASPIAZÚ ◽  
FERNANDO GOMES DA SILVA ◽  
RENATO MENDES OLIVEIRA ◽  
KAREN MARCELLE DE JESUS SILVA ◽  
SILVÂNIO RODRIGUES DOS SANTOS ◽  
...  

  RESUMO O objetivo deste trabalho foi determinar em campo a tensão de água do solo adequada para o reinício da irrigação do milho verde no semiárido. O experimento constou de seis valores de tensão matricial da água do solo (20 kPa, 40 kPa, 60 kPa, 80 kPa, 100 kPa e 120 kPa) testadas em uma cultivar de milho, o hibrido duplo AG 1051. O experimento foi instalado no período de inverno de 2013, nos meses de agosto a novembro, num delineamento experimental de blocos casualizados (DBC), com quatro repetições, conduzidos na fazenda experimental da Embrapa Milho e Sorgo em Nova Porteirinha, MG. Foram avaliadas as variáveis: produtividade de espigas sem palha (t ha-1), número de espigas totais e comerciais por hectare, comprimento de espigas com palha e sem palha e diâmetro de espigas comerciais. Dentre os resultados pode-se constatar que os maiores valores para as variáveis de morfologia e de produtividade foram obtidos quando a irrigação foi efetuada com tensão próxima de 50 kPa, tornando-a a tensão mais adequada para o uso racional da água no manejo da irrigação do milho verde.Palavras-chave: Zea mays L., déficit hídrico, manejo da irrigação, resistência elétrica. SOIL WATER TENSION FOR REWATERING GREEN CORN IN THE SEMIARID  ABSTRACT _ The objective of this work was to determine the adequate water tension for rewatering green corn at field conditions in the semiarid. The experiment consisted of six values of matric soil water tension (20 kPa, 40 kPa, 60 kPa, 80 kPa, 100 kPa and 120 kPa) and one maize cultivar, the double hybrid AG1051. The experiment was installed in the 2013 winter season, from August to November, in a randomized blocks design (DBC), with four replicates, and conducted at the experimental farm belonging to Embrapa Maize and Sorghum in Nova Porteirinha, MG. Morphological parameters were evaluated such as plant height, leaf area index and dry mass, and also the yield parameters such as weight of spikes with straw and without straw (t ha-1), number of total and commercial spikes per hectare, diameter of commercial spikes and length of commercial spikes with and without straw. The highest values for the morphology and productivity variables were obtained when irrigation was carried out with a tension close to 50 kPa, which proved to be the most suitable tension for the rational use of water in the irrigation management of green corn.Keywords: Zea mays L., water deficit, irrigation management, electrical resistance.


2019 ◽  
Vol 99 (1) ◽  
pp. 80-91 ◽  
Author(s):  
Amy A. Pawlick ◽  
Claudia Wagner-Riddle ◽  
Gary W. Parkin ◽  
Aaron A. Berg

Agricultural ecosystems are one of the largest global contributors to nitrate (NO3−) contamination of surface- and groundwater through fertilizer application. Improved fertilizer practices are needed to manage crop nutrient supply in corn (Zea mays L.) while minimizing impacts to clean water reserves. The goal of this study was to compare current nitrogen (N) fertilizer practices (urea at planting) with “packages” of improved management practices (a combination of right timing and product) that farmers potentially use. We conducted measurements in a continuous corn system from November 2015 to May 2017 at a large field scale (four 4 ha plots). Nitrate concentration was measured below the root zone and drainage estimated using a soil water budget approach in which evapotranspiration was measured using the eddy covariance method. The objective was to compare NO3−-N leaching from fields receiving urea vs. urea + combination of nitrification and urease inhibitors (NUI) fertilizer applications at planting, urea–ammonium nitrate (UAN) vs. UAN + NUI applied at sidedress, and a combination of these practices: urea + NUI at planting vs. UAN at sidedress. Drainage was only significant in the non-growing season. Neither fertilizer products applied with NUI at planting or sidedress proved to significantly reduce NO3−-N leaching. The combination of delaying fertilization to sidedress and applying UAN significantly reduced the soil water NO3−-N concentration compared with urea + NUI at planting (mean of 5.2 vs. 6.7 mg L−1) but only in 2015–2016. Based on these results, applying UAN at sidedress is recommended, although additional study years are needed to confirm those results.


2017 ◽  
Vol 16 (3) ◽  
pp. 460
Author(s):  
EMERSON TROGELLO ◽  
LUAN FERREIRA BORGES ◽  
FÁBIO ARAÚJO DE OLIVEIRA ◽  
QUÉZIA SANCHES MUTAGUTI ◽  
INGRID GOMIDES BARROS ◽  
...  

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.


1988 ◽  
Vol 68 (3) ◽  
pp. 597-606 ◽  
Author(s):  
R. CEULEMANS ◽  
I. IMPENS ◽  
M. C. LAKER ◽  
F. M. G. VAN ASSCHE ◽  
R. MOTTRAM

With the objective to evaluate and compare different physiological plant parameters as indicators of water stress, net CO2 exchange rate (NCER), leaf temperature, predawn and daytime leaf water potential were monitored diurnally on last fully expanded leaves of corn (Zea mays L.) plants under two different soil water treatments (stressed and nonstressed) during a 10-d period at anthesis in a semi-arid region in South Africa. Profile available water capacity (PAWC) was used to express the soil water contents during the experiments. A significant decrease in NCER was noticed as soon as 30% of PAWC was extracted, i.e. 2 or 3 d after irrigation. Although the results were limited to a short, well-defined measuring period, NCER, and especially NCER at noon, seemed to be a more sensitive and more reliable indicator of corn water stress than, for example, predawn or daytime leaf water potential, at least under the conditions studied here. This reduction in NCER might have a significant impact on total biomass, rooting density, flower and ear formation.Key words: Corn, irrigation scheduling, photosynthesis, leaf water potential, profile available water capacity, soil water content


Author(s):  
T. Ananthi ◽  
C. Vennila

Experiments were conducted during rabi season of 2019 and 2020 at the Department of Agronomy, Madras Veterinary College, Chennai to assess the performance of fodder maize (Zea mays L.) under varying combinations of organic manures and inorganic fertilizers. An experiment was laid out in split plot design with four organic treatments in main-plots viz., No manure, farm yard  manure (25 t/ha), vermicompost (12 t/ ha),  poultry manure (12 t /ha) and four fertilizer treatments in subplots with levels of No fertilizer, 125% RDF, 100% RDF, 75% RDF.  Recommended dose of fertilizer (RDF) for fodder maize crop is 60 kg N ha-1: 40 kg P2O5 ha-1: 20 kg K2O ha-1. The organic manures were applied as per the N equivalent basis to inorganic nutrient recommendation. The results revealed that all the maize growth parameters, green and dry fodder yield were significantly affected with the application of organic manures and fertilizer levels. Growth parameters viz., taller plants, more number of leaves per plant, higher leaf area index, stem girth, leaf stem ratio were observed under the combined application of poultry manure @ 12 t/ha  and fertilizer level of 75% RDF. The highest green matter yield and dry fodder yield were recorded with the integrated application of poultry manure @ 12 t/ ha along with the fertilizer level of 75 % RDF.


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