scholarly journals Post-emergence selectivity of metribuzin to carrot

Revista CERES ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 314-320
Author(s):  
Núbia Maria Correia ◽  
Agnaldo Donizete Ferreira de Carvalho

ABSTRACT When selecting a weed chemical treatment (herbicide, product mixtures, dose, or application timing), an important issue to consider is its selectivity to the crop of commercial interest. The objective of this study was to evaluate the selectivity of the herbicide metribuzin to carrot plants as a function of genotype, dose, and plant growth stage at the time of application. Two experiments were carried out, one in a greenhouse and another in the field. The greenhouse experiment was arranged in a completely randomized, 5 x 2 x 3 factorial design, with four replications. Metribuzin doses (0, 72, 96, 144, and 192 g ha-1) were sprayed on plants with 2-3 and 4-5 true leaves of the cultivars Maestro, BRS Planalto, and Verano. Cultivar Maestro was cultivated in the field in a 2 x 5 factorial experiment in randomized complete block design, with four replications. Carrot plants, at two stages of development (2 and 5 true leaves), were sprayed with the same doses of metribuzin applied in the greenhouse experiment. Metribuzin, regardless of application time and dose tested, was selective for cultivars BRS Planalto and Verano (greenhouse) and Maestro (both greenhouse and field), without reduction in quality and yield of roots.

2021 ◽  
Vol 34 (2) ◽  
pp. 350-358
Author(s):  
GUILHERME BRAGA PEREIRA BRAZ ◽  
ALINE GUIMARÃES CRUVINEL ◽  
ALAN BRUNO CANEPPELE ◽  
HUDSON KAGUEYAMA TAKANO ◽  
ALESSANDRO GUERRA DA SILVA ◽  
...  

ABSTRACT Sourgrass (Digitaria insularis) is one of the main species causing significant losses in Brazilian soybean production systems. Thus, this paper aimed to evaluate sourgrass interference on soybeans grown under Cerrado conditions. Three field experiments were conducted, of which the first two (E1 and E2) simulated sourgrass after pre-sowing burndown, using plants already emerged by the time soybeans were sown; whereas the third (E3) simulated both sourgrass and soybeans emerged simultaneously. Both E1 and E2 were conducted in a randomized complete block design (RCBD) with five treatments based on sourgrass infestation densities (0, 2, 4, 6, and 8 plants m-2) and four replications. In turn, E3 was also carried out in an RCBD but with treatments arranged in a 2 x 5 factorial and four replications. The first factor comprised two soybean cultivars, while the second was sourgrass density levels, just as in E1 and E2. The results showed that increasing sourgrass densities reduced soybean yield regardless of the plant growth stage when the crop was sown. Yield losses were higher when sourgrass plants were already established by the time soybean was sown. Soybean yield losses reached up to 80% under higher sourgrass infestation levels.


2021 ◽  
Vol 11 (01) ◽  
pp. 736-748
Author(s):  
M. M. Hossain ◽  
◽  
S. Yesmin ◽  
M. Z. Islam ◽  
M. A. Hossain ◽  
...  

An experiment was conducted at the Sher-e-Bangla Agricultural University farm from April to June 2017 in Kharif season to evaluate the performance of two mungbean varieties under different NPK fertilizers doses in field conditions. The experiment was laid out in Randomized Complete Block Design (RCBD), comprising six treatments with three replications. In the experiment, varieties used were BARI mung-6 and BARI mung-5 and the combination of the treatment were T0 = (control), T1 (10-40-25 NPK kg ha-1), T2 (10-60-45 NPK kg ha-1), T3 (20-50-35 NPK kg ha-1), T4 (30-40-25 NPK kg ha-1) and T5 (30-40-45 NPK kg ha-1), respectively. Mungbean cultivars responded noticeably to the supplementary NPK fertilizers as the crop characters were significantly influenced by different levels of NPK fertilizers. Data were recorded on plant height, leaves plant-1, branches plant-1, pods plant-1, seeds pod-1, 1000-seed weight, seed, and straw yield at different days after sowing. Of the two varieties, BARI mung-6 gave the highest seed yield (1.72 t ha-1) next to the higher plant growth and straw yield On the contrary, BARI mung-5 cultivar produced the lowest seed yield (1.57t ha-1), plant growth, and straw yield. The results showed that T3 (20-50-35 NPK kg ha-1) treatment was the best treatment as regards plant growth and yield parameters. The highest seed yield was produced by treated plot T3 (20-50-35 NPK kg ha-1) over the untreated control plot, T1, T2, T4, and T5, respectively. As for the combined effect, V1T3 (BARI mung-6 and T3 = 20kg N + 50kg P + 35kg K ha-1) performed the best results in all growth and development characters. Therefore, the combined application of 20-50-35 kg NPK ha-1 might be considered to be found optimal to get a considerable seed yield of mungbean variety BARI mung-6.


2016 ◽  
Vol 51 (8) ◽  
pp. 942-949 ◽  
Author(s):  
Gilberto Nava ◽  
Karine Louise dos Santos ◽  
Murilo Dalla Costa ◽  
Marlise Nara Ciotta

Abstract: The objective of this work was to investigate the effect of liming and phosphorus fertilization on the growth, mineral composition of the leaves, fruit yield, and mycorrhizal colonization of young feijoa (Acca sellowiana) plants. Treatments consisted of four liming levels - 0, 25, 50, and 100% of the dose required to raise the soil pH to 6.5 - and of five levels of P - 0, 60, 120, 180, and 240 kg ha-1 P2O5 -, placed in a randomized complete block design, in a split-plot arrangement, with three replicates. The orchard was established in 2010 with the Helena cultivar. In 2012, 2013, and 2014, plant growth was evaluated by measuring trunk perimeter, plant height, and tree canopy width. Mineral composition of the leaves, regarding P, N, K, Ca, and Mg contents, was assessed annually. Mycorrhizal colonization was evaluated in 2012, and fruit yield was determined in 2014. No interaction was observed between the studied factors. P contents had no effect on the evaluated variables. Liming, however, increases plant growth, mycorrhizal colonization, fruit yield, and Ca and Mg leaf contents, besides reducing K leaf contents.


2015 ◽  
Vol 33 (3) ◽  
pp. 491-497
Author(s):  
A. T. FARIA ◽  
E. A. FERREIRA ◽  
P. R. R. ROCHA ◽  
D. V. SILVA ◽  
A. A. SILVA ◽  
...  

ABSTRACT Growth regulators can be used to further retard or inhibit vegetative growth. In this sense, the objective of this study was to determine the effects of age and number of trinexapac-ethyl applications on the growth and yield of sugarcane. The experiment was in a randomized complete block design with four replications. The treatments were in a 3 x 2 + 2 factorial arrangement, where factor A corresponded to the application times of the plant growth regulator (120, 200 and 240 days after bud burst (DAB) of sugarcane) and factor B to the number of applications (one or two applications). In addition, two controls (one with three applications and another application without the regulator) were added. The application of trinexapac-ethyl decreased the number and the distance between buds, height, root volume and sugarcane yield. The sequential application (2 or 3 times) induced an increase in stem diameter and three applications of the product increased the number of plant tillers. The use of growth regulators applied at 240 DAB has reduced plant height, however without changing the number of buds. It can be concluded that trinexapac-ethyl changes sugarcane growth and yield, regardless of season and number of applications.


2020 ◽  
Vol 9 (7) ◽  
pp. e130973911
Author(s):  
Roberto Cleiton Fernandes de Queiroga ◽  
Zaqueu Lopes da Silva ◽  
Odair Honorato Oliveira de ◽  
Elidayane da Nóbrega Santos ◽  
Higínio Luan Oliveira Silva ◽  
...  

The objective of this study was to evaluate the productivity and quality of melon fruits as a function of the dose and time of application of biostimulant in the conditions of the semi-arid region of Paraíba. The experiment was carried out at the Federal University of Campina Grande, campus of Pombal - PB, Brazil, in a randomized block design in a 4 x 5 split plot scheme, with doses of biostimulant (0; 0.5; 1.0; 1, 5 and 2.0 L ha-1) and in the subset of the biostimulant application times (15; 20; 25 and 30 days before harvest - DAC), in four replications. Characteristics related to fruit production and quality were evaluated. There was no interaction between the factors of dose and application time of the biostimulant in any of the evaluated characteristics. Thus, the highest estimated values of number of fruits per plant, fruit mass and total melon production were obtained with the application of doses ranging from 0.9 to 1.5 L ha-1 and at the time of application it varied from 22,5 to 23.6 DAC. The content of soluble solids increased 5.5% when the biostimulant dose of 2.0 L ha-1 was used and 4.4% when the product was applied 15 days before harvest.


2018 ◽  
Vol 45 (3) ◽  
pp. 278 ◽  
Author(s):  
Firmansyah Aznur ◽  
Suwarto , ◽  
Dan Heni Purnamawati

Light use efficiency (LUE) determines biomass production based on interception energy during photosynthesis. The product of photosynthesis is allocated to the plants organs based on the partitioning of carbohydrates. The LUE and carbohydrate partitioning are two important parameters in crop modelling. The research was conducted at Cikabayan experimental station of IPB, Bogor from July to November 2015. The experiment was designed according to a randomize block design with five replications. The fertilizer treatments rate were 0%, 50%, 100%, 150%, and 200% of reference N fertilization of 120 kg ha-1.  The  value  of  light use efficiency and the partition coefficient of sorghum were not affected by N fertilization. The value of light use efficiency is 1.41 g MJ-1. The carbohydrates partitioning was developed based on plant growth stage. The partition from the planting to the emergence stage (0 ≤ s ≤ 0.25) was 0.81 x s/0.25 root, 0 stem, 0.19 x s/0.25 leaves, and 0 panicle. The partition from the emergence to the maximum vegetative stage (0.25 &lt; s ≤ 0.5) was 0.81-(0.59 x s/0.5) root, 0.14 x s/0.5  stem, 0.19 + (0.45 x s/0.5) leaves, and 0 panicle. The partition from the maximum vegetative stage to the flowering stage (0.5 &lt; s ≤ 0.75) was 0.22 - (0.09 x s/0.75) root, 0.14 + (0.39 x s/0.75) stem, 0.64 - (0.46 x s/0.75) leaves, and 0.16 x s/0.75 panicle. The partition from flowering to the harvest stage (0.75 &lt; s ≤ 1) was 0.13 - (0.13 x s) root, 0.53 - (0.52 x s) stem, 0.18-(0.18 x s) leaves, and 0.16 + (0.84 x s) panicle.<br /><br />Keywords: crop modelling, light use efficiency, N fertilizer, partitioning carbohydrates<br /><br />


1990 ◽  
Vol 4 (2) ◽  
pp. 314-317 ◽  
Author(s):  
Michael G. Patterson ◽  
C. Dale Monks ◽  
Thomas Rayburn ◽  
Glenn Wehtje

Chlorimuron applied postemergence at 2.2, 4.4, 8.8, 18, and 35 g ai/ha to cotton at either the 4-leaf, pinhead-square, first-bloom, or full-bloom growth stage was evaluated for potential as a plant growth regulator. Chlorimuron did not reduce bolls per plant at any rate or time of application, but the proportion of open to closed bolls decreased as rate increased. Seed cotton yields decreased with increasing chlorimuron rate and cotton age. The use of chlorimuron as a plant growth regulator for cotton appears limited.


HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 760g-761
Author(s):  
Jonathan R. Schultheis ◽  
Dennis E. Adams

Boron has been used to overcome the disorder blister in varieties such as `Jewel'. `Hernandez' is an attractive, good-yielding variety with uniform shape that will consistently pack out at 80% to 90%. Over time in storage, however, roots develop blister-like symptoms, rendering roots unmarketable for fresh market. Our objective was to evaluate the effect of different B rates and application times on the yield and quality of `Hernandez' roots. Rates were varied up to 2.24 kg actual B/ha 6 days after planting, while various soil and foliar application times (6, 34, and 69 days after planting) were evaluated at 1.12 kg·ha–1. In 1994, three row plots were arranged in a randomized complete block design and replicated four times. Planting was on a deep sand to maximize the effect of the B carrier Solubor. Roots were harvested, graded, and weighed 120 days after planting and storage roots evaluated for blister-like symptoms in Mar. 1995. No significant differences in yield were attributed to B rate or application method. Blister-like symptoms were more severe when no B was applied; however, application of B did not eliminate symptoms, as most roots had the blister-like appearance. Boron application did not solve the problem, but symptoms were less apparent when some B was applied.


2019 ◽  
Vol 11 (6) ◽  
pp. 407
Author(s):  
T. Schneider ◽  
M. A. Rizzardi ◽  
A. P. Rockenbach ◽  
S. T. Peruzzo

Soybean cultivars without tolerance can suffer injury from exposure to tank herbicide residues. This study aimed at assessing the potential effects of the broad spectrum herbicide dicamba on sensitive soybean during its vegetative and reproductive stages. The trial was performed in a randomized complete block design with four replications. Six rates (1.4, 2.8, 5.6, 11.2, 16.8 and 28.0 g ae ha-1) of dicamba were applied at two soybean growth stages (V3 and R2). The soybeans were planted in Passo Fundo, Rio Grande do Sul state in 2015/16 agricultural year. The dicamba induced symptoms of soybean phytotoxicity showed a steady rise at all the assessment times. The soybean decreased in height as the subdose of the herbicide increased. Dicamba was observed to negatively affect the number of nodes alone, during the V3 and R2 stages. The grain yield was adversely affected at the 28.0 g ae ha-1 subdose, in the V3 application stage, and in response to the 16.8 and 28.0 g ae ha-1 subdoses in the R2 stage.


2021 ◽  
Vol 36 (2) ◽  
pp. 283
Author(s):  
Dewi Fatria ◽  
Andre Sparta ◽  
Deni Emilda ◽  
Bambang Hariyanto ◽  
Tri Budiyanti ◽  
...  

<p class="KataPengantar">There are factors contributed to the growth and development of fruit crop seedling. Microbes are well known as plant growth promotors such as symbiotic mycorrhizae and antagonist fungi, <em>Trichoderma </em>spp. The main objective of this experiment is to find out the best medium composition enriched by beneficial microbes to improve papaya seedling growth. The experiment was conducted at Sumani Experimental Station, Indonesian Tropical Fruit Research Institute, Solok, West Sumatera, Indonesia from August until December 2017. The experiment was arranged in a Randomized Complete Block Design with ten treatments and three replicate blocks. The treatments were ten combinations of media for papaya seedling growth enriched by plant growth promotor microbes. In this experiment, medium soil with additional manure, rice husk charcoal and compost (single or combination) combined with mycorrhizae were used. Also, the effect of <em>Trichoderma </em><em>sp</em><em>.</em> enrichment into media composition were tested in this experiment. Treatments SCRMc and SCRMcT; with its complexity; were the best media composition to promote papaya seedling growth. These treatments resulted in best performance of plant height, stem diameter and number of leaves of papaya seedlings. The additional of <em>Trichoderma </em><em>sp</em><em>.</em> into medium did not show beneficial effect for all parameters in this experiment.</p>


Sign in / Sign up

Export Citation Format

Share Document