scholarly journals EMERGÊNCIA DE PLANTAS DANINHAS EM FUNÇÃO DA POSIÇÃO DA SEMENTE E QUANTIDADE DE PALHA DE CANA-DE-AÇÚCAR

2011 ◽  
Vol 12 (2) ◽  
Author(s):  
Micheli Satomi YAMAUTI ◽  
Arthur Arrobas Martins BARROSO ◽  
Paulo Roberto Fidelis GIANCOTTI ◽  
Vanessa Luzia SQUASSONI ◽  
Lucas Tadeu Mazza REVOLTI ◽  
...  

O objetivo do trabalho foi avaliar os efeitos de diferentes densidades de palha de cana-de-açúcar e do posicionamento das sementes de Euphorbia heterophylla, Mucuna cinereum, Digitaria nuda e Eleusine indica sobre a emergência e o desenvolvimento inicial das plantas. O delineamento experimental utilizado foi o delineamento inteiramente casualizado, com 15 tratamentos e quatro repetições distribuídos em esquema fatorial 3 x 5 com testemunha adicional; o primeiro fator foi constituído pelas posições das sementes em relação a palha (abaixo, entre e sobre) e o segundo pelas quantidades de palha (1, 2, 4, 8 e 16 t ha -1) e a testemunha sem palha. Aos 15 dias após a semeadura (DAS) foram realizadas avaliações de altura, massa seca da parte aérea e porcentagem de emergência para E. heterophylla e M. cinereum e, aos 28 DAS, avaliações de massa seca da parte aérea e porcentagem de emergência para D. nuda e E. indica. Os dados obtidos foram submetidos ao teste F na análise de variância e as médias foram comparadas com o auxílio do teste de Tukey a 5% de probabilidade. Constatou-se que a emergência e o desenvolvimento inicial de E. heterophylla e M. cinereum foram reduzidos com o aumento da quantidade de palha e foram afetados com o posicionamento das sementes, mas não foram inibidos em nenhuma das condições, indicando uma maior agressividade destas daninhas em condições de colheita mecanizada. Já a emergência de espécies D. nuda e E. indica não sofreu interferência do posicionamento da semente e a cobertura do solo com 8 e 16 t ha -1 de palha de cana inibiu a emergência de suas plântulas.germinação. ABSTRACT This work was carried out to evaluate the effects of sugarcane straw density and positions of seeds of Euphorbia heterophylla, Mucuna cinereum, Digitaria nuda and Eleusine indica on emergence and initial development of plants. The experiment were arranged in a completely randomized design, with 15 treatments and four replications, in a factorial arrangement 3 x 5 with a additional control; the first factor was constituted by position of seeds related to the straw (under, between and on) and the second by five quantities of straw (1, 2, 4, 8 e 16 t ha -1) with a control without straw. At 15 days after sowing (DAS) it was realized evaluations of height, dry mass and emergence percentage for E. heterophylla and M. cinereum, and at 28 DAS it was analyzed dry mass and emergence percentage for D nuda e E. indica. Data obtained were submitted to F in variance analysis test and means were compared with Tukey at 5% probability. Emergence and initial development of E. heterophylla e M. cinereum were reduced with increasing of straw and were affected by seed position, but it was not inhibited in none of conditions, indicating aggressiveness of these weeds in sugarcane mechanized harvest conditions. D. nuda and E. indica emergence was not affected by seed position and coverage soil with 8 e 16 t ha -1 of sugarcane straw inhibited its emergence.

2017 ◽  
Vol 38 (3) ◽  
pp. 1187
Author(s):  
Marcelo Rafael Malardo ◽  
Patrícia Andrea Monquero ◽  
Paulo Henrique Vieira dos Santos ◽  
Nagilla Moraes Ribeiro ◽  
Paulo Vinicius da Silva ◽  
...  

The objective of this study was to evaluate the effect of the sowing depth and amount of sugarcane straw on the soil on the emergence of Chloris polydactyla (‘capim-branco’) and Eleusine indica (Indian goosegrass) and to determine the efficacy of herbicides applied pre-emergence in the control of these species under different straw amount and rainfall regime conditions. The experiments were conducted in a completely randomized design with four replications. In the first experiment, the effects of six sowing depths (0.5, 1, 2, 4, 8, and 10 cm) and six sugarcane straw amounts (0, 1, 2, 4, 8 and 10 t ha -1) were assessed on the emergence of Indian goosegrass and ‘capim-branco’ in a 6 x 6 factorial arrangement. In the second experiment, the efficacy in the control of these species was evaluated for one control without herbicide and five treatments (indaziflam, metribuzin, tebuthiuron, indaziflam + metribuzin, and indaziflam + tebuthiuron) applied pre-emergence over four straw amounts (0, 1, 2, and 4 t ha-1) in a 6 x 4 factorial arrangement. This experiment was evaluated under two rainfall regimes in separate experiments (simulation of 20 mm of rainfall 1 or 10 days after herbicide application). The ‘capim-branco’ showed a marked reduction in emergence beginning at 2 t ha-1 of straw and a 2 cm sowing depth. For the Indian goosegrass, the decline in emergence mainly occurred beginning at 4 t ha-1 of straw and a 4 cm sowing depth. Only some of the Indian goosegrass plants emerged at the greater sowing depths (8 and 10 cm) and straw amounts (8 and 10 t ha-1), whereas no emergence of the ‘capim-branco’ was observed under these conditions. The treatments with sowing at a 1 cm depth and with 0, 1, 2, and 4 t ha-1 of straw provided the highest emergence percentage for the species. Application of the herbicide indaziflam alone was the only ineffective treatment for the control of the weeds regardless of the amount of straw and the water regime used. We concluded that the increase in the sowing depth and the amount of straw significantly reduced the emergence of the species and that the presence of straw and the dry period interfered with the herbicide efficacy.


2015 ◽  
Vol 33 (3) ◽  
pp. 405-412 ◽  
Author(s):  
P. V. SILVA ◽  
P. A. MONQUERO ◽  
F. B. SILVA ◽  
N. C. BEVILAQUA ◽  
M. R. MALARDO

ABSTRACT This study aimed to understand the influence of sowing depth and the amount of sugarcane straw on the emergence of weed species Luffa aegyptiaca Miller (Cucurbitaceae); Mucuna aterrima Piper & Tracy (Fabaceae - Leguminosae) and Ricinus communis (Euphorbiaceae). A completely randomized design with a 5 x 4 x 3 factorial layout with four replications was used, at five sowing depths (0, 2, 4, 8 and 10 cm), four different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) and three different evaluation periods (7, 14 and 21 days after sowing). After sowing, different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) were deposited on soil. Seedling emergence was analyzed at 7, 14 and 21 days after sowing, counting the number of seedlings that had emerged. At the end of the trial, weed height (cm), leaf area (cm2) and shoot dry mass (g) were measured. In relation to emergence ability, studied species presented different responses according to sowing depth and to the amount of sugarcane straw deposited on the soil. For the L.aegyptiacaand M.aterrima, no significant difference was observed in the interaction between depth and sugarcane straw, showing the adaptation of these species to no-burn sugarcane system. For R.communis, seeds placed at 0 cm of sugar cane straw depth were observed to favor the emergence of seedlings.


Author(s):  
Tatiane S. Jeromini ◽  
Ana S. V. Barbosa ◽  
Givanildo Z. da Silva ◽  
Cibele C. Martins

ABSTRACT Plukenetia volubilis is a species native to the Amazonia and has economic potential due to the high contents of polyunsaturated fatty acids and vitamins of the seeds; however, information about production of seedlings in nursery is scarce. Factors that contribute to fast emergence and generation of vigorous seedlings are desirable for plant production in the nursery. Therefore, this study aimed to identify the most favorable substrate and seed position for the production of P. volubilis seedlings. The seeds were sown in the following four positions: hilum facing up, hilum facing down, seed lying on its cotyledon suture, and seed lying flat on one of its cotyledon faces. The substrates were sand, vermiculite and commercial substrate. Treatments were distributed according to a completely randomized design in a 4 × 3 factorial arrangement (seed position and substrate) with three replicates of 25 seeds each. The following variables were evaluated: emergence percentage; first count of seedlings; number, width and length of leaves; plant height; stem diameter; dry matter of shoots and roots. It was concluded that the production of P. volubilis seedlings is not affected by either substrate or seed position at sowing. The substrates most favorable to the quality of P. volubilis seedlings were the commercial substrate and vermiculite, always for the positions of seed lying on its cotyledon suture, with faces parallel to tube walls, and seed lying flat on one of its faces.


2021 ◽  
Vol 17 (2) ◽  
pp. 09-15
Author(s):  
Neisiany Rebelo Pimentel ◽  
Daniela Pauletto ◽  
Àdria Fernandes da Silva ◽  
Thiago Gomes da Silva Oliveira ◽  
Orlanilson da Silva Brito

Moringa oleiferaLam., known as moringa, is an arboreal plant belonging to the Moringaceae family, native to India,and has a high capacity to adapt to climatic conditions and arid soils. In this study we evaluated the initial development of seedlings of M. oleiferaLam. under different substrates conditions. The experiment was conducted in a completely randomized design, consisting of eight treatments resulting from combinations of the base substrate (85% soil, 3% carbonized rice straw and 12% coconut fiber). At 60 days after sowing, plant height, stem diameter, dry mass of the aerial part and root system, total dry mass were evaluated, in addition to the Dickson quality index (IQD). The best seedling growth occurred using the combination of 20% poultry litter and 10% bovine manure. Seedlings produced with substrates formulated with 20% poultry litter and 10% bovine manure showed gains in the evaluated variables, which could be a viable alternative for the production of moringa seedlings.


2018 ◽  
Vol 10 (7) ◽  
pp. 497
Author(s):  
Augusto Matias de Oliveira ◽  
Wéverson Lima Fonseca ◽  
Tiago De Oliveira Sousa ◽  
Hingrid Raiany Santos Teixeira ◽  
Fernandes Antonio de Almeida ◽  
...  

One of the difficulties of producing native species seedlings is slow growth. The objective of this study was to evaluate the initial development of Amburana cearensis (Allem.) A. C. Smith in relation to the concentration decomposed buriti stem substratum and nitrogen doses. A completely randomized design was used in a factorial arrangement of 3 × 5 (proportions of decomposed buriti stem × nitrogen doses), with six replicates. The treatments were formulated substrates comprised of decomposed buriti stem manually mixed with soil (Dystrophic Yellow Latosol) in three proportions (0, 25 and 50%) and five nitrogen doses (0, 100, 200, 300 and 400 mg dm-3) applied in treatments. There was no significant interaction between the DRM and ND factors. However, there was an isolated effect for the following variables: Plant height (PH), stem diameter (SD), leaf number (LN), leaf area (LA), dry mass of the aerial part (DMA) and root length (RL). The best concentrations of the substrate for the variables PH, LA and DMA were 25% and 50%, whereas for SD, LN and RL, the best result was 50%. ND and other variables had good responses under recommended doses ranging from a minimum of 264.82 mg dm-3, observed in DMA, and a maximum of 400 mg dm-3, observed in RL. Both factors positively the quality of umburana seedlings.


2019 ◽  
pp. 1600-1606 ◽  
Author(s):  
Tiago de Oliveira Sousa ◽  
Wéverson Lima Fonseca ◽  
Augusto Matias de Oliveira ◽  
Alan Mario Zuffo ◽  
Marcela Carlota Nery ◽  
...  

Papaya is a tropical fruit of great importance in the international and national market. For crop success, the use of quality seedlings is of paramount importance and substrates formulated from organic sources may be a viable alternative. In this context, the objective of this study was to evaluate the initial development of papaya seedlings in different formulations and levels of organic substrates. A completely randomized design was used in a 4x4+1 factorial scheme, corresponding to four substrate formulations, containing decomposed buriti stem (CDB). The treatments included of the following: (CDB, ½ CDB + ½ poultry manure, ½ CDB + ½ cattle manure and ½ CDB + ½ gray with plant origin sourced from materials resulting from the burning of plant material (stem, branches); four proportion levels of the formulations of the substrates mixed to the soil (25; 50; 75 and 100%) and the additional control (100% soil). The following variables were measured: plant height, leaf area, number of leaves, shoot dry matter, root length and root dry matter at 42 days of seedling cultivation. The results showed that use of an ideal source of organic matter is feasible in the production of papaya seedlings. The substrate consisting of CBD + poultry manure had great potential to be used in the production of papaya seedlings.


2020 ◽  
Vol 8 (3) ◽  
pp. 134
Author(s):  
Oscar Mitsuo Yamashita ◽  
Danillo De La Queyferr Goncalves ◽  
Marco Antonio Camillo de Carvalho ◽  
Rivanildo Dallacort ◽  
Ricardo Adriano Felito ◽  
...  

Sunflower is a crop of great economic interest both nationally and internationally, due to its use especially in oil production. However, factors such as water restriction are commonly found in growing areas and exert a negative influence on the productive performance of the crop, especially in critical periods, such as the germination and initial development of the seedlings. Thus, the objective of this study was to evaluate the germinate behavior of seeds of sunflower cultivars as a function of lower osmotic potentials. The experiment was installed in a completely randomized design, in a 3x5 factorial scheme, three sunflower cultivars (Charrua, Nussol and Olisiun 4) and five osmotic potentials (0, -0.2, -0.4, -0.8, -1.2 MPa) with 3 replicates. For the study, solutions of polyethylene glycol (PEG 6000) were repaired. Rolls of paper towels were moistened with the concentrations and later kept in a germination chamber at 25 °C, where they remained for ten days. First counts (4th day) and total counts (10th day) were performed, and the germination rate (%) was verified. In addition, in the last evaluation, aerial and root length, green mass and dry mass of seedlings were determined. Based on the results obtained it can be verified that in osmotic potential higher than -0.8 MPa, no germination occurred. Nussol germinated more in more negative concentrations, with a germination rate of 90%, differing from the cultivars Charrua and Olisiun 4, which, in larger potentials, reached only 30% of germination.


2013 ◽  
Vol 31 (2) ◽  
pp. 281-289 ◽  
Author(s):  
A.C.D. Wandscheer ◽  
M.A. Rizzardi ◽  
M. Reichert

Competition between plants is one of the main interferences that occurs in agricultural systems and accounts for significant crop yield reductions. The aim of this study was to assess the competitive ability of corn in coexistence with the weed species Eleusine indica. The experiments were conducted in a greenhouse, in the growing season 2010/2011, and were arranged in a completely randomized design with four replications. The experimental units consisted of plastic pots with a volumetric capacity of 8 L. Treatments were arranged in a replacement series with five proportions of corn plants and weed: 100:0, 75:25, 50:50, 25:75, and 0:100, respectively, with a constant population of eight plants per pot, at the end of each treatment. The competitiveness analysis was conducted through diagrams applied to the replacement series experiment and competitiveness index, and the variables evaluated were root, shoot, and total dry mass, and plant height. When in equal proportions, corn showed competitive ability equivalent to goosegrass in relation to the variables shoot, root, and total dry mass. Goosegrass was more competitive than the crop in relation to plant height.


2021 ◽  
Vol 17 (11) ◽  
Author(s):  
Joyce Naiara Da Silva ◽  
Monalisa Alves Diniz da Silva ◽  
Rafael Mateus Alves ◽  
Elania Freire Da Silva

The adoption of agroforestry systems or reforestation programs contributes to the economy of a region in a sustainable way, since the adopted species can be exploited by the cosmeceutical and pharmaceutical industries. For the establishment of plant species in a given area, studies are needed on the interaction that can develop between them, with emphasis on research on allelopathy. Given the above, the aim of this study was to evaluate the allelopathic effect of the aqueous extract of leaves of the native species Piptadenia moniliformis on the initial development of the forest species Amburana cearensis. The aqueous extract was used at different concentrations. (0 - water, 25, 50, 75 and 100%), adopting a completely randomized design. The following characteristics were evaluated: emergence percentage, emergence speed index, mean emergence time, shoot and root length and total shoot, root and total dry part of normal seedlings. The 100% concentration of the aqueous extract of P. moniliformis leaves reduced the emergence percentage of A. cearensis seedlings. A smaller number of normal seedlings was observed at concentrations of 75 and 100%. The initial development of seedlings was hampered by the increase in extract concentrations. The aqueous extract of fresh leaves of P. moniliformis provides a negative allelopathic effect for both emergence and early development of A. cearensis seedlings, therefore intercropped cultivation among the forest species is not recommended.


2015 ◽  
Vol 10 (2) ◽  
pp. 206-212
Author(s):  
C. A. Freitas ◽  
C. J. Silva ◽  
C. A. Silva ◽  
J. A. Almeida ◽  
N. S. Rincon

O objetivo do trabalho foi avaliar o desenvolvimento de mudas de baruzeiro (Dipteryx alata Vog) em função de proporções de gesso (0%; 1,6%; 3,2%; 4,8% e 6,4%) com base em volume e adubação com cinza de madeira (ausência e presença) misturadas ao substrato Bioplant®. Constituiu-se assim um esquema fatorial 5x2, em delineamento inteiramente ao acaso, com três repetições e quatro plantas por parcela. O experimento foi conduzido de janeiro a março de 2009, em viveiro com cobertura e laterais de sombrite preto (50% da luminosidade natural), situado na Fazenda Japão, município de Orizona, Goiás. Como recipiente foram utilizados sacos de polietileno de 15 x 25 cm, onde colocou-se uma sementes por recipiente, ficando a extremidade superior da semente cerca de 2,0 cm de profundidade. As irrigações foram realizadas diariamente, no período da tarde. Aos 152 dias após a semeadura, avaliou-se altura de muda (AM), diâmetro de caule (DC), número de folha (NF), número de folíolos por folha (NFF), número de folíolos por planta (NFP), comprimento da raiz principal (CR), massa da matéria seca das raízes (MSR), massa seca da parte aérea (MSPA), massa seca total (MSTO) e índice de qualidade de Dickson (IQD). O gesso agrícola proporcionou melhor desenvolvimento inicial das mudas de baruzeiro, no entanto sua associação com cinzas de madeira, juntamente com o substrato, não favoreceu o desenvolvimento das mudas.Addition of agricultural plaster and wood ash to substrate in baruzeiro (Dipteryx alata Vog) seedlings developingAbstract: This study aimed to evaluate the baruzeiro seedlings development in function of plaster proportions (0%, 1.6%, 3.2%, 4.8% and 6.4 %) based on volume and fertilization with wood ash (absence and presence) added to the substrate Bioplant ®. It constitutes therefore a 5x2 factorial arrangement, in a completely randomized design with three replications and four plants per plot. The experiment was conducted from January to March 2009, in coverage nursery and side with shade screen (50% of natural light), located in Fazenda Japão, Orizona county, Goiás. As container was used polythene bags of 15 x 25 cm, which was placed one seeds per container, with the upper end of the seed approximately 2.0 cm depth. The irrigation was performed daily in the afternoon. At 152 days after sowing, was evaluated seedling height (SH), stem diameter (SD), sheet number (SN), number of leaflets per leaf (NLL), number of leaves per plant (NLP), length the main root (LR), dry mass of roots (DMR), dry mass of aerea part (DMAP), total dry matter (TDM) and Dickson quality index (DQI). The plaster provided better initial development of seedlings baruzeiro, however its association with wood ashes, along with the substrate, didn't favor the growth of seedlings.


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