scholarly journals Influence of glyphosate underdoses on the suppression of Panicum maximum cultivars

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Suzete Fernandes Lima ◽  
Leandro Spíndola Pereira ◽  
Gustavo Dorneles Sousa ◽  
Simonny Araújo Vasconcelo ◽  
Adriano Jakelaitis ◽  
...  

ABSTRACT: The use of herbicide underdoses allows minimizing the competition of grasses on annual crops, enabling simultaneous cultivation. In this context, the objective of this study was to investigate glyphosate underdoses on the suppression of the initial growth of three Panicum maximum cultivars aiming at the integrated cultivation, in addition to the effects of forage species on the incidence and development of weeds. Three field experiments were conducted. The experimental design was a randomized block design with four replications and eight treatments consisting of increasing glyphosate doses (0, 54, 108, 270, 378, 540, 756, and 1,080 g a.e. ha−1). An atrazine dose of 1,200 g a.i. ha−1 was added to each treatment. Plant phytotoxicity assessments were performed at 7, 14, 21, and 28 days after application. At 80 and 125 days after sowing, the assessments of total dry matter production, leaf dry matter, stem dry matter, and leaf to stem ratio were carried out, in addition to density and dry matter production of weed community. Glyphosate underdoses below 215, 65, and 90 g a.e. ha-1 have a potential to be investigated aiming at the management of P. maximum cv. Atlas, P. maximum cv. Mombasa, and P. maximum cv. Tanzania under intercropping. The three forage species are effective in suppressing weeds.

2014 ◽  
Vol 34 (4) ◽  
pp. 738-745 ◽  
Author(s):  
Veridiana Z. de Mendonça ◽  
Luiz M. M. de Mello ◽  
Francisco C. B. L. Pereira ◽  
José O. da R. Silva ◽  
Élcio H. Yano

Corn cropping for silage, due to the plant material exportation, intercropping with forage provides greater ground cover and straw formation for the Direct Planting System (DPS) continuity. The objective of this study was to evaluate corn production for silage in DPS intercropped with four forages (Urochloa brizantha cv. Marandu, U. ruziziensis cv. Ruziziensis, Panicum maximum cv. Tanzânia and P. maximum cv. Áries). We applied three sowing methods (in row together with corn fertilizer; by no-till sowing simultaneously to corn sowing and at V4 corn stage) and corn without intercropping. The experiment was conducted in autumn/ winter of 2010, in Selvíria - MS, in a randomized block design in factorial arrangement (4 x 3 + 1) and 4 replications. For corn, we evaluated plant height, basal stem diameter, initial and final stand and silage production and for forage dry matter production. Morphological characteristics and corn yield were not affected by intercropping when compared to sole corn crop. Forage dry matter production sown in corn row with fertilizer is a highlight, which in addition to providing greater productivity, harnesses the operation during sowing.


2010 ◽  
Vol 39 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Marcio Mahmoud Megda ◽  
Francisco Antonio Monteiro

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.


2010 ◽  
Vol 34 (2) ◽  
pp. 435-442 ◽  
Author(s):  
Alberto C. de Campos Bernardi ◽  
Marisa Bezerra de Mello Monte ◽  
Paulo Renato Perdigão Paiva ◽  
Carlos Guarino Werneck ◽  
Patrick Gesualdi Haim ◽  
...  

Zeolites are hydrated crystalline aluminosilicate minerals of natural occurrence, structured in rigid third dimension net that can be used as slow release plant-nutrient source. The main objective of this study was to evaluate the effects of plant growth substrate under zeolite application, enriched with N, P and K, on dry matter yield and on nutrient contents in consecutive crops of lettuce, tomato, rice, and andropogon grass. The experiment was carried out in a greenhouse, with 3 kg pots with an inert substrate, evaluated in a randomized block design with three replications. Treatments consisted of four types of enrichment of concentrated natural zeolite: concentrated zeolite (Z) only, zeolite + KNO3 (ZNK), zeolite + K2HPO4 (ZPK) and zeolite + H3PO4 + apatite (ZP), and a control grown in substrate fertilized with a zeolite-free nutrient solution. Four levels of enriched zeolite were tested: 20, 40, 80, and 160 g/pot. Four successive crops were grown on the same substrate in each pot: lettuce, tomato, rice, and andropogon grass. Results indicated that N, P and K enriched zeolite was an adequate slow-release nutrient source for plants. The total dry matter production of above-ground biomass of four successive crops followed a descending order: ZP > ZPK > ZNK > Z.


2016 ◽  
Vol 41 (4) ◽  
pp. 759-772
Author(s):  
SS Kakon ◽  
MSU Bhuiya ◽  
SMA Hossain ◽  
Q Naher ◽  
Md DH Bhuiyan

Field experiments were conducted during rabi (winter) seasons of 2010-11 and 2011-12 at the Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur to study the effects of nitrogen and phosphorus on growth, dry matter production and yield of French bean. A randomized complete block design was followed with 10 combinations of N (0,50, 100, 150 and 200) and P (0,22, 33, 44 and 55) kg ha-1 along with a blanket dose of control. All the treatments showed the maximum leaf area index (LAI) at 65 days after sowing (DAS). All the treatments showed the maximum total dry matter production, crop growth rate and net assimilation rate at harvest and at 55-65 DAS, respectively in both the years. LAI, dry matter production, CGR, NAR and seed yield significantly increased with the increase in nitrogen and phosphorus level upto 150 kg N and 44 P kg ha-1 , respectively. Similar trend was followed in maximum number of pods (9.45) and seed yield (1563.33 kg ha-1). The treatment comprises with 150 kg N and 44 P Kg ha-1 gave the highest seed yield which was 51.40 and 54.30 % higher than control plots.Bangladesh J. Agril. Res. 41(4): 759-772, December 2016


2020 ◽  
Vol 41 (6supl2) ◽  
pp. 3335-3350
Author(s):  
Grazielle de Carvalho Reis ◽  
◽  
Wildiney Freire de Oliveira ◽  
Camila Cunha da Silva ◽  
Bruno Pereira da Silva ◽  
...  

This study aimed to evaluate the effects of a biostimulant on the morphogenesis, structure, productivity, and chemical composition of Urochloa brizantha cv. Marandu, managed under two nitrogen fertilization levels. Collections were carried out during the dry (June to September) and the rainy season (September to April). The experimental area was divided into 48 plots of 8 m2 each, using a randomized block design in a 4 × 2 factorial arrangement (0, 1, 2, and 3 L ha−1 of biostimulant × 50 and 150 kg N ha−1 year−1), and subdivided over time into dry and rainy seasons. Treatments were applied in a single dose. An interaction was observed between biostimulant and nitrogen fertilization for the total forage dry matter production and daily forage dry matter production, in which an increase of 30.1 and 25.3% was observed in the total dry matter production and 33.7 and 27.6% in the daily dry matter production when using 1 and 2 L ha−1 of biostimulant, respectively, compared to the non-application of biostimulant and with fertilization of 50 kg N ha−1 year−1. The leaf life-span showed a triple interaction (biostimulant × nitrogen fertilization × season), and a decomposition of the interaction showed that the fertilization of 150 kg N ha−1 year−1 provided a shorter leaf life-span during the dry season, with no difference for the other combinations of factors. No interactions were found for the chemical-bromatological composition, with no differences for the biostimulant application. Biostimulant doses of 1 and 2 L ha−1 increase the dry matter production per hectare in the nitrogen fertilization of 50 kg N ha−1 year−1, but its action is not effective with the highest nitrogen fertilization (150 kg N ha−1 year−1).


2016 ◽  
Vol 37 (4Supl1) ◽  
pp. 2487
Author(s):  
Giselle Abadia Campos Pereira ◽  
Leni Rodrigues Lima ◽  
Joelson Antônio Silva ◽  
Rosemay Lais Galati ◽  
Joanis Tilemahos Zervoudakis ◽  
...  

The study was carried out in a greenhouse with a 4X4 factorial arrangement randomized block design in order to evaluate the effects of nitrogen rates (0, 50, 100 and 150 mg dm-3) associated with cutting heights (10, 15, 20 and 25 cm) on dry matter production and the chemical composition of Massai grass. The seeding was done in pots with 11 kg of soil. 10 plants were kept per pot, and there were two cuts every 35 days. Nitrogen fertilization was split between the two cuts, where the first N application occurred after the uniformity cut and the second after the first cut. In each cut the plants were separated and weighed for botanical component evaluation: leaf blade and stem + sheath. After this, the samples were homogenized and analysed for dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF) content. In the first cut, the N fertilization caused a linear increase in DM production of 0.058 g pot-1 per each 1 mg dm-3 of N applied, as well as causing an increase of 0.549% in CP percentage, a 0.0124 pot-1 g increase in CP production and a reduction of 0.055% in NDF. In the second cut, N rates promoted a quadratic effect on DM production. A maximum DM production of 16.48 g pot-1 with 107.27 mg dm-3 of N was observed while CP production content was increased by 0.0092 g pot-1 for each 1 mg dm-3 N applied. In terms of linear responses to DM and PB, as well as the use efficiency calculated for Massai grass, recommended N doses range between 50 and 100 g dm-3.


2019 ◽  
pp. 1756-1763
Author(s):  
Armindo Neivo Kichel ◽  
Luiz Carlos Ferreira de Souza ◽  
Ademar Pereira Serra ◽  
Roberto Giolo de Almeida

This research aimed to evaluate the maize grain yield and forage of grass species under intercropping system using nicosulfuron herbicide. In order to assess the parameters related to maize, a randomized block design was defined. The treatments were arranged in a (5 × 2+ 1) × 2 factorial design with four repetitions resulting in 11 treatments, where maize was cultivated under intercropping condition with different forage species (5) (Brachiaria brizantha cv. Marandu, Piatã, Xaraés, Brachiaria ruziziensis and Panicum maximum cv. Mombaça) and maize monoculture (1) as control treatment, with and without nicosulfuron herbicide application (2) in two growing seasons (2014 and 2015). The off-season intercropping of maize with tropical forage grasses with and without herbicide suppression decreased maize grain yield. The suppression with nicosulfuron herbicide decreased the dry matter production of forage grasses. Intercropping of P. maximum cv. Mombaça with maize showed higher decrease in maize grain yield. On the other hand, it showed higher forage grasses production for livestock feeding. B. brizantha cv. Piatã was the forage which less affected maize grain yield under intercropping, even with absence of nicosulfuron suppression. Off-season maize under intercropping with tropical forages can be used to recover degraded pastures; increasing forage dry matter production for livestock, remaining the soil covered with straws with possibility of no-till seeding for the next cultivation.


2016 ◽  
Vol 50 (3) ◽  
Author(s):  
B. Sandhya Rani ◽  
T. Giridhara Krishna

An experiment was conducted during <italic>rabi</italic> season of 2010-12 to study the response of chickpea varieties to nutrients levels on a calcareous vertisols. The experiment comprised of four varieties i.e., NBeG-3, NBeG-28, JG-11 and KAK-2 and with four nitrogen levels i.e., 0, 20, 30 and 40 kg/ha laid out in factorial randomized block design with three replications. Among the varieties significantly higher dry matter production at harvest was recorded with JG-11 while it was lowest with KAK-2. More number of pods per plant and seed yield were recorded with JG-11 followed by NBeG-3 and NBeG-28, while lowest with KAK-2. Interaction effect among the different varieties and nitrogen levels was non significant with yield attributes. Significantly higher seed yield was recorded with JG-11 @ 40 kg of N/ha but was at par with N @ 20 and 30 kg /ha, followed by NBeG-3 and NBeG-28.


Author(s):  
Thiago C. Silveira ◽  
Rodinei F. Pegoraro ◽  
Marcos K. Kondo ◽  
Arley F. Portugal ◽  
Álvaro V. Resende

ABSTRACT Phosphate fertilization has increased sorghum yield, but few studies are available on sorghum production and efficient fertilizer management related to liming and phosphorus (P) sources. This work evaluates production, dry matter partitioning and agronomic efficiency (AEI) in successive sorghum cycles after application of limestone and combinations of phosphorus sources. Two cycles were conducted in sequence in the same experimental field, in a 2 x 6 factorial scheme, corresponding to soil with or without liming and six combinations of P2O5 sources: control (0 kg ha-1 P2O5), 100% Itafós natural phosphate (NP), 75% NP + 25% single superphosphate (SS), 50% NP + 50% SS, 25% NP + 75% SS and 100% SS. Pots with capacity for 8 dm3 were used in a randomized block design with four replicates. The first cycle, conducted in the summer/autumn season, reached the highest dry matter production and P accumulation in treatments with higher SS proportions, leading to higher AEI. Subsequently, in the second cycle, conducted considering only the residual phosphate fertilization of the first cycle, highest dry matter production and AEI were obtained in the treatment with 100% or higher proportions of natural phosphate in the presence of liming, most likely due to the gradual release of P.


2018 ◽  
Vol 40 (1) ◽  
pp. 37692 ◽  
Author(s):  
Weudes Rodrigues Andrade ◽  
Eleuza Clarete Junqueira de Sales ◽  
Flávio Pinto Monção ◽  
Virgílio Mesquita Gomes ◽  
Leidy Darmony de Almeida Rufino ◽  
...  

The objective of this study was to evaluate the yield, nutritional value and potential ruminal degradation of Tifton 85 hay (Cynodon spp.) harvested at four regrowth ages (28, 35, 42 and 49 days) and fertilized with two nitrogen doses (N; 100 and 300 kg N ha-1). The experimental design was a randomized block design, arranged in a 4 x 2 factorial scheme, with six replications each. Nitrogen fertilization increased (p < 0.05) dry matter yield and digestible dry matter production of hay and also lignin and crude protein contents. Nitrogen fertilization increased (p < 0.01) the dry matter yield and the digestible dry matter production of hay, as well as lignin (p = 0.01) and crude protein (p = 0.01). The neutral detergent fiber corrected for ash and protein (p = 0.01), acid detergent fiber (p = 0.01) and cellulose (p = 0.02) adjusted to the quadratic function regression model of the regrowth ages. For potential rumen degradability hay, it was observed quadratic effect (p = 0.01) with maximum value of 73.1% at 37 days of regrowth. Tifton 85 hay fertilized with 300 kg ha -1 of N and harvested up to 37 days of regrowth results in higher hay dry matter yield, higher crude protein content, and better dry matter rumen degradability. 


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