scholarly journals Expansion of palm oil (Elaeis guineensis Jacq.) in the state of Maranhão and soil water deficit limitations in the Brazilian Amazon

2017 ◽  
Vol 11 (11) ◽  
pp. 1386-1391 ◽  
Author(s):  
Lucieta Guerreiro Martorano ◽  
◽  
José Reinaldo da Silva Cabral de Moraes ◽  
Leila Sheila Silva Lisboa ◽  
Rui Alberto Gomes Junior ◽  
...  
1998 ◽  
Vol 26 (3) ◽  
pp. 289-296
Author(s):  
M. Jurišić ◽  
Ž. Vidaček ◽  
Ž. Bukvić ◽  
D. Brkić ◽  
R. Emert

1984 ◽  
Vol 103 (1) ◽  
pp. 189-199 ◽  
Author(s):  
M. J. Goss ◽  
K. R. Howse ◽  
Judith M. Vaughan-Williams ◽  
M. A. Ward ◽  
W. Jenkins

SummaryIn each of the years from September 1977 to July 1982 winter wheat was grown on one or more of three clay soil sites (clay content 35–55%) in Oxfordshire where the climate is close to the average for the area of England growing winter cereals.The effects on crop water use of different soil management practices, including ploughing, direct drilling and subsoil drainage, are compared. Cultivation treatment had little effect on the maximum depth of water extraction, which on average in these clay soils was 1·54 m below the soil surface. Maximum soil water deficit was also little affected by cultivation; the maximum recorded value was 186±7·6 mm. Subsoil drainage increased the maximum depth of water extraction by approximately 15 cm and the maximum soil water deficit by about 17 mm.Generally soil management had little effect on either total water use by the crop which was found to be close to the potential evaporation estimated by the method of Penman, or water use efficiency which for these crops was about 52 kg/ha par mm water used.Results are discussed in relation to limitations to potential yield.


1997 ◽  
Vol 24 (1) ◽  
pp. 19-24 ◽  
Author(s):  
P. J. Sexton ◽  
J. M. Bennett ◽  
K. J. Boote

Abstract Peanut (Arachis hypogaea L.) fruit growth is sensitive to surface soil (0-5 cm) conditions due to its subterranean fruiting habit. This study was conducted to determine the effect of soil water content in the pegging zone (0-5 cm) on peanut pod growth rate and development. A pegging-pan-root-tube apparatus was used to separately control soil water content in the pegging and root zone for greenhouse trials. A field study also was conducted using portable rainout shelters to create a soil water deficit. Pod phenology, pod and seed growth rates, and final pod and seed dry weights were determined. In greenhouse studies, dry pegging zone soil delayed pod and seed development. In the field, soil water deficits in the pegging and root zone decreased pod and seed growth rates by approximately 30% and decreased weight per seed from 563 to 428 mg. Pegs initiating growth during drought stress demonstrated an ability to suspend development during the period of soil water deficit and to re-initiate pod development after the drought stress was relieved.


2013 ◽  
Vol 41 (2) ◽  
pp. 524 ◽  
Author(s):  
Qiu-Dan NI ◽  
Ying-Ning ZOU ◽  
Qiang-Sheng WU ◽  
Yong-Ming HUANG

Arbuscular mycorrhizal fungi (AMF) can enhance tolerance of plants to soil water deficit, whereas morphological observations of reactive oxygen species and antioxidant enzyme system are poorly studied. The present study thereby evaluated temporal variations of the antioxidant enzyme system in citrus (Citrus tangerina) seedlings colonized by Glomus etunicatum and G. mosseae over a 12-day period of soil drying. Root colonization by G. etunicatum and G. mosseae decreased with soil drying days from 32.0 to 1.0% and 50.1 to 4.5% in 0-day to 12-day, respectively. Compared to the non-AM controls, the AMF colonized plants had significantly lower tissue (both leaves and roots) hydrogen peroxide (H2O2) and superoxide anion radical (O2•–) concentrations during soil water deficit, whereas 1.03–1.92, 1.25–1.84 and 1.18–1.69 times higher enzyme activity in superoxide dismutase, peroxidase (POD) and catalase. In situ leaf H2O2 and root POD location also showed that AM seedlings had less leaf H2O2 but higher root POD accumulation. Furthermore, significantly higher root infection and antioxidant enzymatic activities in plants colonized with G. mosseae expressed than with G. etunicatum during the soil drying. These results demonstrated that the AMs could confer greater tolerance of citrus seedlings to soil water deficit through an enhancement in their antioxidant enzyme defence system whilst an decrease level in H2O2 and O2•–.


2017 ◽  
Vol 13 (01) ◽  
Author(s):  
Silvio Alex Pereira Mota ◽  
Andréia De Andrade Mancio ◽  
Luiz Eduardo Pizarro Borges ◽  
Nélio Teixeira Machado

2016 ◽  
Vol 1 (2) ◽  
pp. 55
Author(s):  
Nasamsir Nasamsir ◽  
Mei Indrayadi

AbstractThis research aims to know the physical characteristics and the palm oil production on a variety of land suitability. Randomized block design by survey method was used in this research that had been carried out in society’s enterprise. The research object was the palm oil crop cultivated in the lowlands (0-100 m above sea level), moderate land (100-500 m above sea level), and the highland (>500 m above sea level). The plant wich is taken as a sample is a plant which was 10 years old (already production). The villages in the survey, set in accordance with the height. The observed variables in this study i.e.; the circumference of the trunk, tall trunk, leaf stem length, color and thickness of the leaf, heavy of fresh fruit bunches, the age of starting production, production and productivity. Other observed data is temperature and soil acidity. To see the difference between production and productivity of palm oil on three ecology types of land, observed data were analyzed using analisys of varians that followed by Duncan test (α = 5%). The land suitability has significant on physical characteristics and palm oil production. Palm oil production in moderate land was significantly higher than those in both the high and lowland. Keywords; crop production, physical characteristics, land suitability, palm oil. AbstrakPenelitian ini bertujuan untuk mengetahui karakteristik fisik dan produksi kelapa sawit (Elaeis guineensis Jacq) pada berbagai agroekologi lahan. Percobaan dirancang menggunakan Rancangan Acak Kelompok (RAK), dilakukan di kebun rakyat dengan metode survey. Objek yang diteliti adalah tanaman kelapa Sawit yang dibudidayakan di dataran rendah (0-100 m dpl), dataran sedang (100-500 m dpl_, dan dataran tinggi (>500 m dpl). Tanaman yang diambil sebagai sampel adalah tanaman yang berumur 10 tahun (telah berproduksi). Desa-desa yang di survey, ditetapkan sesuai dengan ketinggian tempat. Peubah yang diamati dalam penelitian ini yaitu ; lingkar batang, tinggi batang, panjang pelepah, warna dan ketebalan daun, berat tandan buah segar, umur mulai berproduksi, produksi dan produktivitas, serta tindakan agronomi. Data lain yang diamati adalah suhu dan kemasaman tanah. Untuk melihat perbedaan produksi dan produktivitas kelapa sawit pada tiga jenis agroekologi lahan, data hasil pengamatan lapangan dianalisis menggunakan analisis ragam yang dilanjutkan dengan uji Duncan dengan α 5%. Agroekologi lahan berpengaruh nyata terhadap karakteristik fisik dan produksi kelapa sawit. Produksi tanaman kelapa sawit di daerah dataran sedang lebih tinggi dan berbeda nyata dengan produksi tanaman kelapa sawit daerah dataran tinggi dan daerah dataran rendah. Kata Kunci ; produksi tanaman, karakteristik fisik, kesesuaian lahan, kelapa sawit


2015 ◽  
Vol 8 (2) ◽  
pp. 130-134 ◽  
Author(s):  
Ruy Guilherme Correia ◽  
Antonio Cesar Silva Lima ◽  
Antonio Carlos Centeno Cordeiro ◽  
Francisco Clemilto Da Silva Maciel ◽  
Walmer Bruno Rocha Martins ◽  
...  

Esta pesquisa teve como objetivo avaliar a flutuação populacional de Rhynchophorus palmarum L. (Coleoptera: Curculionidae) em plantios de Elaeis guineensis Jacq, em ecossistemas de savana e floresta no estado de Roraima. A pesquisa foi desenvolvida durante o período de janeiro de 2011 a fevereiro de 2012 nos campos experimentais da Embrapa Roraima: Monte Cristo e Caroebe, numa área de 2 hectares com a cultura da Palma de Óleo, em cada campo. Foram distribuídas armadilhas iscadas com roletes de cana-de-açúcar e feromônio de agregação para captura dos insetos no entorno dos plantios. Ocorreu flutuação de R. palmarum com picos populacionais nos meses de julho e agosto no ecossistema de savana e de abril a setembro no ambiente de floresta. A população de R. palmarum foi menor em meses de baixa precipitação pluviométrica nos dois ambientes avaliados com a Palma de Óleo em RoraimaPopulation Fluctuation of Rhynchophorus  palmarum  L.  (Coleoptera: Curculionidae) in Plantations of Oil Palm in RoraimaAbstract. This research aimed to evaluate the population fluctuation Rhynchophorus palmarum L. (Coleoptera: Curculionidae) in Elaeis guineensis Jacq plantations in forest and savanna ecosystems in the state of Roraima. The research was conducted during the period from January 2011 to February 2012 in the experimental field of Embrapa Roraima: Monte Cristo and Caroebe in an area of 2 hectares with culture Oil Palm in each field. Traps baited with rollers cane sugar and aggregation pheromone for capturing insects in the vicinity of the plantations were distributed. Fluctuation occurred R. palmarum with population peaks in the months of July and August in the savanna ecosystem and from April to September in the forest environment. The population of R. palmarum was lower in months of low rainfall in the two environments assessed with a palm-oil-in Roraima.


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