scholarly journals PERSISTENCE OF IMIDAZOLINONES IN SOILS UNDER A CLEARFIELD SYSTEM OF RICE CULTIVATION

2016 ◽  
Vol 34 (3) ◽  
pp. 589-596 ◽  
Author(s):  
M.F. SOUZA ◽  
M.D. C. NETO ◽  
M.I. MARINHO ◽  
D.T. SARAIVA ◽  
A.T. FARIA ◽  
...  

ABSTRACT The commercial mixture of imazethapyr and imazapic herbicides has been used for the control of red rice and several other species of weeds found in rice crops; this system called Clearfield. However, its use may limit the succession of non-tolerant crops for long residual activity. The research objective with this work was to determine the persistence of imazethapyr, imazapic and their mixture in three soils in the Brazilian state of Tocantins. Three experiments were conducted in a completely randomized design with four replications, each corresponding to the evaluated soil (Haplic Plinthosol (FX), red-yellow Latosol (LVA) and Haplic Gleysol (GX)). The treatments were arranged in a split plot design, with the allocated plots herbicides (imazethapyr and imazapic alone and commercial mixture) and the plots allocated the 11 evaluation times (1, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150 days after treatment (DAT)), and a control without application. Contacted up long residual effect of imazethapyr and commercial mixture of imazethapyr and imazapic, regardless of assessed soil. After 150 days of applying herbicides or the commercial mixture, their residues in the soil also inhibited approximately 94% of the mass of the dry matter accumulation of the indicator plants. When imazapic was applied alone, there was a higher dry matter accumulation of the indicator plants, indicating less residual effect of this herbicide in the soil and this was attributed to the lower dose of this herbicide applied. The attributes of the soil pH, texture and iron oxides were what most affected the persistence of the herbicides. It can be concluded that the persistence of imazethapyr and imazapic is too long in the Brazilian state of Tocantins soils and the use of these herbicides in the region should be avoided due to the high risk of the occurrence of carryover,or be well planned, as land use in rotation for susceptible crops.

2020 ◽  
Vol 7 (1) ◽  
pp. 43-48
Author(s):  
Eduardo Santana Aires ◽  
Carlos Alberto Aragão ◽  
Itala Laiane Silva Gomes ◽  
Gilmário Noberto de Souza ◽  
Isa Gabriela Vieira de Andrade

This study aimed to evaluate different substrates to produce yellow passion fruit seedlings. For this purpose, an experiment was carried out in a greenhouse, from April to June 2016. A completely randomized design with five replications, in a 6 x 5 factorial scheme was used. The first factor was the alternative substrates (poultry, cattle and equine manure, sugarcane and coconut bagasse, and Organomais compost). The second factor was the replacement levels to the commercial substrate of Plantmax® (100:0, 75:25, 50:50, 25:75, 0:100). The seedling evaluation was carried out 42 days after sowing. The following variables were analyzed: length, width, and the number of leaves; plant height and shoot dry matter. A significant effect (P0.05) for the interaction between the factors was verified. The addition of 60% cattle manure and Organomais to the commercial substrate Plantmax® promoted greater length, width, and the number of leaves, plant height, and shoot dry matter accumulation in the yellow passion fruit seedlings.


2019 ◽  
Vol 11 (16) ◽  
pp. 187 ◽  
Author(s):  
Wéverson Lima Fonseca ◽  
Augusto Matias de Oliveira ◽  
Tiago de Oliveira Sousa ◽  
Alan Mario Zuffo ◽  
Râmison Fonseca dos Santos ◽  
...  

The effects of substrates formulated with different proportions of decomposed buriti stem (Mauritia flexuosa) and the application of nitrogen fertilizer rates in the production of cagaita (Eugenia dysenterica DC.) seedlings were investigated in this study. The treatments were arranged in a completely randomized design, in a 3 × 5 factorial: three substrates formulated from different proportions of decomposed buriti stem (0, 25 and 50%) with a clay loam soil (Oxisol), and five N fertilizer rates (0; 100; 200; 300 and 400 mg dm-3), with four replicates. At 60 days after emergence, the plant height, stem diameter, leaf area, root length, dry matter accumulation of shoots, roots, and total, shoot:root dry matter ratio (SRR), height:diameter ratio (HDR), and Dickson quality index (DQI) were measured. The substrate containing soil and decomposed buriti stem in the proportion of 3:1 (v:v), in association with the application of N rates from 167 to 190 mg dm-3 is recommended for the production of cagaita seedlings, resulting in positive effects on plant growth and development as reported by higher PH, SRR, and HDR. The application of 154 mg dm-3 of N resulted in higher DQI of the cagaita seedlings.


2019 ◽  
Vol 37 ◽  
Author(s):  
L.G.M. BORGES ◽  
F.R. MIRANDA ◽  
A.M. BORGES ◽  
J.R.O. SILVA ◽  
A.A.V. CAMPOS ◽  
...  

ABSTRACT: The goal of this study was to analyze the response of Arabica coffee cultivars grown under three levels of Bidens pilosa (beggarticks) interference. At 30 days after transplanting (DAT) of 14 Arabica coffee cultivars into 11 L pots, beggarticks was seeded in the pots and soon after emergence, three levels of weed infestation were established: none, low (two plants per pot), and high (five plants per pot). Treatments were arranged in a 14 × 3 factorial scheme under a completely randomized design, with four replicates. Coffee plant growth was evaluated at both weed emergence and blossoming (90 DAT) when the experiment was completed. Regardless beggarticks infestation levels, significant effects of cultivars occurred on almost all the coffee growth variables. Specifically, the Arabica coffee cultivars Arara, Asa Branca, and Bourbon Amarelo exhibited greater values for root, leaf, shoot, and whole plant dry matter when compared with the other cultivars. The Arabica coffee cultivars presented lower leaf area increments, and also lower leaf, shoot, and whole plant dry matter accumulation when grown under either low or high infestation levels (between which there were no statistical differences, p>0.05) in comparison with that under the weed-free treatment. However, there were no significant interactions between Arabica coffee cultivars and weed infestation levels for those crop growth variables. We conclude that all Arabica coffee cultivars tested were equally susceptible to B. pilosa competition in this phase of crop implantation.


2019 ◽  
Vol 6 (3) ◽  
pp. 155 ◽  
Author(s):  
Agung Kusuma Wijaya ◽  
Muhtarudin Muhtarudin ◽  
Liman Liman ◽  
Cloudia Antika ◽  
Dini Febriana

This research intended to determine the effect of palm oil tree shade and mixed planting on grass and leguminous on productivity.  This research has been done on March—June 2018 in Tanjung Agung Area, Katibung District, Kalianda, South Lampung. This research used Completely Randomized Design (CRD) with split plot design method.  The treatment was implemented in this research is (1) shading, consist of two levels, which are N0 (without shade) and N1 (palm oil tree shade) and (2) mixed plant species, consist of two variations; which is A1 (elephant grass and purple bush bean) and A2 (dwarf elephant grass and purple bush bean).  The data which obtained were analyzed by analysis of variance on 5% significant level, then if the result significantly difference, it were analyzed with Duncan Multiple Range Test (DMRT).  The results showed that palm oil shading has not significant effect on grass productivity. there is an interaction between the type of grass and oil palm shade on the number of elephant grass and odot grass tillers. The dry matter of grass on mixed planting on land without shade was significantly different with dry matter of grass on mixed planting in palm oil shade.  However, it has tendency to increase organic matter of grasss on palm oil shade. Keywords: Palm Oil Shade, Elephant Grass, Dwarf Elephant Grass, Mixing Grass, Productivity


Author(s):  
Hansa Lakhran ◽  
O. P. Sharma ◽  
Rohitash Bajiya ◽  
H. P. Verma ◽  
Meena Choudhary

A field experiment was carried out during the rabi seasons of 2016-17 and 2017-18 at Agronomy Farm, S.K.N. Agriculture University, Jobner, Jaipur, Rajasthan, to evaluate the effect of sowing at different thermal regimes and foliar sprays of bio-regulators on growth and yield of wheat. The treatments comprised three sowings (22ºC, 20ºC and 18ºC) and eight bio-regulators (control, water spray, SA @ 100 ppm, SA @ 200 ppm, TSA @ 100 ppm, TSA @ 200 ppm, TGA @ 100 ppm and TGA @ 200 ppm). The experiment was conducted in split plot design with 4 replications. Wheat sown at 20ºC showed superior performance in respect of dry-matter partitioning and yield parameters, i.e. grain, straw biological and yields as compared to sowing at 22ºC and 18ºC. Amongst the bio-regulators options, an application of SA @ 200 ppm resulted in better performance, being comparable with those of TSA @ 200 ppm and TGA @ 200 ppm. Crop sown at 20ºC along with SA @ 200 ppm was found to be a better option for maximum dry matter accumulation and productivity of wheat under heat stress.


Author(s):  
Lanunola Tzudir ◽  
Shrabani Basu ◽  
Srijani Maji ◽  
Purnendu S. Bera ◽  
Rajib Nath ◽  
...  

A two year experiment was conducted at the BCKV with four mungbean varieties (Pant Mung-5, Bireswar, RMG-62 and Sukumar) sown under three dates (15th February, 1st and 15th March) in a split plot design where dates of sowing and varieties were allotted to main and sub plot treatments respectively with three replications. PAR was recorded with the help of line quantum sensor. Dry matter accumulation, yield attributes and yield were measured. Canonical correlation and correspondence analysis showed that absorbed PAR during 32 to 46 days after emergence (DAE) increased dry matter, pod and seed yield. PAR use efficiency (PARUE) of mungbean ranged from 0.75 to 0.88 g MJ-1 for seed yield. PARUE for dry matter production was maximum during 39 to 46 DAE. According to PARUE and heat use efficiency, Pant Mung-5 should be sown within 1st March in this zone. Growing degree day requirement gradually increased with delayed sowing.


2002 ◽  
Vol 20 (4) ◽  
pp. 626-629 ◽  
Author(s):  
Jorge E. Rattin ◽  
Jerônimo L. Andriolo ◽  
Márcio Witter

The nitrogen concentration in dry matter of the fifth leaf during growth of a greenhouse tomato crop was determined. Plants of hybrid Monte Carlo were grown in 4.5 L bags, using a commercial substrate, in a plant density of 3.3 plants m-2. A nutrient solution containing, in mmol L-1: KNO3, 4.0; K2SO4, 0.9; Ca(NO3)2, 3.75; KH2PO4, 1.5; MgSO4, 1.0; iron chelate 19. 10³, was used as reference. Microelements were added by a commercial mixture. The T3 treatment was equal to the reference nutrient solution, whereas in treatments T1, T2, T4 and T5 quantities of all nutrients from T3 were multiplied by 0.25, 0.50, 1.25 and 1.50, respectively. In each treatment, the volume of 1 L of nutrient solution was supplied to each plant once a week by fertigation. Periodically destructive measurements were made from anthesis to ripening of the first truss, to determine dry matter and N concentration in shoot and in fifth leaf tissues, counted from the apex to the bottom of the plant. Five dilution curves were fitted from data of N concentration in the fifth leaf and shoot dry matter accumulation during growth of plants. A general relationship was adjusted between actual N concentration in shoot (Nt) and in the fifth leaf (Nf): Nt = 1.287 Nf (R² = 0.80). This relationship could be used to estimate the N status of plants by means of a nitrogen nutrition index (NNI), from analysis of the fifth leaf sap.


2017 ◽  
Vol 52 (11) ◽  
pp. 1042-1049
Author(s):  
Karla Andréia de Melo ◽  
Rosilaine Carrenho

Abstract: The objective of this work was to evaluate the influence of aqueous extracts of nonmycorrhizal weedy species on dry matter accumulation and assimilate partitioning of maize plants, with or without Cetraspora pellucida inoculation. The experiment was carried out in pots, in a completely randomized design, in a 5x2 factorial arrangement consisting of four plant extracts (purple nutsedge, guinea-hen weed, slender amaranth, and knotweed), a control irrigated with water, and two conditions (mycorrhizal and nonmycorrhizal maize plants), with four replicates of each treatment. Plants were irrigated with aqueous extracts diluted at 15%. Root colonization (RC), shoot dry matter (SDM), root dry matter (RDM), and RDM/SDM were evaluated. Root colonization was not influenced by the extracts, and ranged from 41.5 to 65.2%. Shoot dry matter of mycorrhizal (AM) and nonmycorrhizal (NM) plants was not influenced by the extracts; however RDM showed varying responses. Mycorrhization favored the production of RDM, and increased plant sensitiveness to the extracts. Guinea-hen weed extract increased RDM of AM plants, while the other extracts inhibited it. In NM plants, the production of RDM was benefited by slender amaranth extract, to the detriment of SDM. Mycorrhizal and nonmycorrhizal maize plants respond differently to aqueous extracts of nonmycorrhizal weeds.


2019 ◽  
Vol 37 ◽  
Author(s):  
L. OLIVEIRA ◽  
A.C. SILVA JR ◽  
C.G. GONÇALVES ◽  
M.R.R. PEREIRA ◽  
D. MARTINS

ABSTRACT: Weeds are one of the main obstacles in the recovery of degraded areas. This research aimed to study the selectivity of herbicides on Trema micrantha (Jamaican nettletree), Schinus molle (Peruvian peppertree), and Apuleia leiocarpa (garapeira) seedlings. An experiment was installed in Junqueirópolis and another in Jaboticabal/SP, Brazil. The experimental design used was completely randomized design with four replications. Treatments consisted of clethodim + fenoxaprop-p-ethyl (50 + 50 g a.i. ha-1), sethoxydim (184 g a.i. ha-1), quizalofop-p-ethyl (75 g a.i. ha-1), nicosulfuron (50 g a.i. ha-1), fluazifop-p-butyl (125 g a.i. ha-1), fomesafen (225 g a.i. ha-1), haloxyfop-methyl (48 g a.i. ha-1), bentazon (720 g a.i. ha-1), chlorimuron-ethyl (15 g a.i. ha-1), and control without herbicide. The analyzed characteristics were stem diameter, plant height, and phytointoxication at 7, 14, 21, 28, 35, and 42 days after herbicide application (DAA), in addition to shootdry matter accumulation in seedlings at the end of the study. Nicosulfuron and chlorimuron-ethyl caused intoxication in all the studied tree species. In Jaboticabal, these herbicides impaired the initial growth of Jamaican nettletree seedlings, while no herbicide delayed its initial development in Junqueirópolis.A similar result was obtained regarding dry matter accumulation for garapeira in both cities. The herbicides clethodim + fenoxaprop-p-ethyl and sethoxydim decreased dry matter accumulation in Peruvian peppertree plants in Jaboticabal and Junqueirópolis, respectively, thus not being recommendedtheir use for these species.


Author(s):  
Schaianne A. Gomes ◽  
Sayonara A. do C. M. Arantes ◽  
Ednaldo A. de Andrade ◽  
Kelte R. Arantes ◽  
Daniela N. Viana ◽  
...  

ABSTRACT To increase the efficiency in the control of weeds, it is common the use of a mixture of the herbicides glyphosate and 2,4-D in the desiccation. This paper aimed to evaluate the residual effect of these two herbicides on the development of maize plants, in soils of different textures. The experiment was conducted in a greenhouse, in 2015, in a completely randomized design in a 2 x 2 x 7 factorial scheme, corresponding to two soils (Red Yellow Latosol and Quartzarenic Neosol), two herbicide application times (5 and 10 days before maize sowing) and seven doses of herbicides (recommended dose of glyphosate, recommended dose of 2,4-D; mixing the recommended doses of glyphosate and 2,4-D; two, ten and fifty times the recommended doses in admixture; and one control), with 4 replicates. After emergence of maize plants, the following variables were evaluated: phytotoxicity, plant height, chlorophyll a and chlorophyll b, shoot fresh and dry matter and root dry matter. In general, there was lower residual effect on the Red Yellow Latosol at all the doses of the herbicides and in the interval of 10 days between the desiccation and sowing.


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