scholarly journals Hand-held mechanical device improves thinning efficiency of peach trees

2020 ◽  
pp. 1519-1524
Author(s):  
Daniel Spagnol ◽  
Marcos Antônio Giovanaz ◽  
Bruno Carra ◽  
Everton Sozo de Abreu ◽  
José Carlos Fachinello ◽  
...  

The objective of this study was to evaluate the effect of mechanical-manual thinning (MmT) at different developmental stages in the thinning efficiency and productive performance of ‘Sensação’ peach trees. The experiment was performed during the 2013 and 2014 growing seasons, in a commercial orchard located in Morro Redondo (RS), Brazil. Plant material consisted of 7-year-old peach trees grafted on Capdeboscq rootstock and trained as an open-vase system. The experiment was arranged as a randomized block design, with five three-trees replications. In order to reduce the effect of personal experience, the treatments and measurements were applied by the same person in a set of replications throughout the experiment. Treatments consisted of: control I [without thinning (WT)]; control II [hand thinning (HT) 40 days after full bloom (40 DAFB)]; MmT at full bloom (FB): 50% of open flowers; MmT at the end of bloom (EB): 80-100% of open flowers; MmT at petal fall (PF); and MmT at the green fruit (GF) stage (fruit with ~1 cm of diameter). The MmT was performed using a hand-held portable device. The parameters assessed were: percentage of thinning, fruit set, thinning time, work economy, production per tree, fruit mass, estimated yield and fruit size distribution. The use of the MmT at the stages tested reduces thinning time of ‘Sensação’ peach trees, resulting in labor saving, as well as increases the percentage of fruit in category (CAT) 1. The MmT when performed at GF results in a higher percentage of thinning. The treatment MmT at FB increases the average fruit mass.

2017 ◽  
Vol 39 (4) ◽  
Author(s):  
MATEUS DA SILVEIRA PASA ◽  
BRUNO CARRA ◽  
CARINA PEREIRA DA SILVA ◽  
MARLISE NARA CIOTTA ◽  
ALBERTO FONTANELLA BRIGHENTI ◽  
...  

ABSTRACT The low fruit set is one of the main factors leading to poor yield of pear orchards in Brazil. Ethylene is associated with abscission of flowers and fruitlets. Then, the application of ethylene synthesis inhibitors, such as AVG, is a potential tool to increase fruit set of pears. The objective of this study was to evaluate the effect of AVG, sprayed at different rates and timings, on fruit set, yield and fruit quality of ‘Rocha’ pear. The study was performed in a commercial orchard located in the municipality of São Joaquim, SC, during the growing seasons of 2014/2015 and 2015/2016. Plant material consisted of ‘Rocha’ pear trees grafted on quince rootstock ‘BA29’. AVG was tested at different rates (60 mg L-1 and 80 mg L-1) and timings [full bloom, one week after full bloom (WAFB), and two WAFB), either alone or in combination. The experiment was arranged in a randomized block design, with at least five single-tree replications. The fruit set, number of fruit per tree, yield, estimated yield, fruit weight, return bloom, and fruit quality attributes were assessed. Fruit set and yield were consistently increased by single applications of AVG at 60 and 80 mg L-1 at both one and two weeks after full bloom, without negatively affecting fruit quality attributes and return bloom.


Author(s):  
Gentil Carneiro Gabardo ◽  
Lucas Pessoa de Freitas ◽  
Rafael Hermenegildo Contini ◽  
Eder Farina ◽  
Keli Cristina dos Santos ◽  
...  

Aims: Evaluate different dosages and number of applications of the commercial product Physiogrow® Color on the percentage of red coloration of the epidermis, productivity and fruit quality in 'Royal Gala' apple trees, in the Midwest region of the state of Santa Catarina, Brazil. Study Design: The experiment was arranged in a randomized block design with five replications. Place and Duration of Study: The experiment was carried out in the municipality of Fraiburgo-SC, Brazil (latitude 27º01'S, longitude 50º77’ W, altitude 950 meters), during the growing seasons of 2017/2018 and 2018/2019. Methodology: The treatments  were: Control (No application), Physiogrow® color (4, 8 and 12 L ha-1) 7 days before harvest (DBH), Physiogrow® Color 2 L ha-1 (30 DAC) + 2 L ha-17 DBH, Physiogrow® Color 4 L ha-1 (30 DBH) + 4 L ha-17 DBH, and Physiogrow® Color 6 L ha-1 (30 DBH) + 6 L ha-1 7 DBH. The variables evaluated were: Production (kg plant-1 and fruits plant-1), average fresh fruit mass (g), classification of fruits by percentage of red coloration of the epidermis (<50%, 50-80% and > 80%), firmness of the pulp (lb in-2) and soluble solids (°Brix). The harvest was carried out on January 25, 2018 and February 16, 2019, first and second year, respectively. Plant production, as well as pulp firmness of fruits, were not affected by treatments, in both years. Physiogrow® Color promoted better distribution of fruits in categories of greater red coloration of the epidermis and reduction of the percentage of fruits in the category with coloration inferior to 50%, although a different behavior among the harvests was observed. The application of Physiogrow® Color 8 L ha-1 7 DBH contributes to the improvement of the coloration of ‘Royal Gala’ apples.


2019 ◽  
Vol 37 (1) ◽  
pp. 106-111
Author(s):  
Maria José Marques ◽  
Juliana de Fátima Vizú ◽  
Danilo F da Silva Filho ◽  
César Augusto Ticona-Benavente

ABSTRACT This study aimed to select endogamic progenies of tomato cv. Yoshimatsu and to conduct a progeny test in the state of Rondônia. The experiment was carried out in a randomized block design with four replicates and eight plants per plot, spacing 1x0.5 m, with one stem. A significant variation was observed among the fifteen progenies for productivity (2.0-5.5 kg plant-1), seed mass with placenta (18-31.5 g fruit-1), number of fruits per plant (18.8-38.7) and soluble solids (3.4-4.2°Brix). No significant variation was noticed for fruit size, pericarp thickness, number of locules, pH, number of flowers and fruit set, though. P6 progeny showed to be the most productive one (110 t ha-1): average fruit mass was 142.5 g, salad type tomato, 7.5 locules, 3.5°Brix, pH 4.2, 60.9 flowers per plant and 64.2% fruit set. Thus, these data show genetic variability of cultivar Yoshimatsu, being possible to obtain lines and/or cultivars with medium to large fruits adapted to the state of Rondônia.


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.


2012 ◽  
Vol 36 (1) ◽  
pp. 283-294 ◽  
Author(s):  
Carolina Fernandes ◽  
José Eduardo Corá ◽  
Adolfo Valente Marcelo

Sugarcane production should be integrated with crop diversification with a view to competitive and sustainable results in economic, social and environmental aspects. The purpose of this study was to assess the influence of different soil uses during the sugarcane fallow period on the chemical and physical properties of eutroferric Red Latosol - LVef (Oxisol) and Acric Latosol - LVw (Acric Oxisol), in Jaboticabal, São Paulo State, Brazil (21º14'05'' S, 48º17'09'' W, 600 m asl). A randomized block design was used with five replications and four treatments, consisting of different soil uses (crops) in the sugarcane fallow period: soybean only, soybean/fallow/soybean, soybean/millet/soybean, and soybean/sunn hemp/soybean. After two soybean crops, the LVef chemical properties remained at intermediate to high levels; while those of the LVw, classified as intermediate to high in the beginning, increased to high levels. Thus, the different soil uses during the sugarcane fallow period allowed the maintenance of LVef fertility levels and the improvement of those of the LVw. Two soybean crops increased macroporosity in the 0.0-0.1 m layer of the LVef; reduced soil aggregates in the 0.0-0.1 and 0.1-0.2 m layers of both soils, and reduced aggregate stability in these two layers of the LVw. Planting pearl millet or sunn hemp between the two soybean growing seasons promoted the formation of larger soil aggregates in the surface layer (0.0-0.1 m) of the LVw.


2019 ◽  
Vol 11 (9) ◽  
pp. 21
Author(s):  
Guilherme V. Pimentel ◽  
Silvino G. Moreira ◽  
Mateus O. T. de Avila ◽  
Antonio Henrique F. de Carvalho ◽  
Alessandro A. P. da Silva ◽  
...  

Maize hybrids have different levels of tolerance to the herbicide nicosulfuron, depending on the dose, the environment, the phenological stage of the plant and the timing of nitrogen fertilization, and phytotoxic effects can occur without proper management. There is also limited information on the selectivity of current genetically modified hybrids for other recommended herbicides, such as tembotrione. Thus, the objective of this study was to evaluate the effects of herbicides (tembotrione and nicosulfuron) and the timing of nitrogen fertilization on the yield of maize hybrids. The experimental design was a randomized block design, in a 4 &times; 2 factorial arrangement, with 4 replicates. The treatments consisted of four treatments [weeding; nicosulfuron + atrazine (20 and 32 + 1250 g ha-1 ai) and tembotrione + atrazine (75.6 + 1250 g ha-1 ai)] and two nitrogen fertilization times (0 and 7 days after application). Maize hybrids P30F53 Leptra, DKB 230PRO3 and KWS 9004PRO2 were assessed in two growing seasons (1st and 2nd harvest) during the 2016/2017 growing season. The percentages of weed control; phytotoxicity at 7, 14 and 21 days after application (DAA); plant height; number of rows per ear; and yield at harvest were evaluated. All herbicides were more effective in controlling weeds at the 1st harvest because of favourable climatic conditions. Nitrogen fertilization can be carried out on the same day as the application of the herbicides nicosulfuron and tembotrione with no reduction in yield for the hybrids P30F53 Leptra, DKB 230PRO3 and KWS 9004PRO2.


Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 720-728 ◽  
Author(s):  
David W. Clausnitzer ◽  
Michael M. Borman ◽  
Douglas E. Johnson

Two field experiments were conducted from 1993–1994 through 1995–1996 growing seasons in Harney County, OR, to determine the relative competitive abilities ofElymus elymoides(squirreltail) a native perennial range grass, andTaeniatherum caput-medusae(medusahead), an exotic annual grass weed. The 1993–1994 growing season was very dry, 1994–1995 was dry, and 1995–1996 was wetter than average. One experiment tested seedlings vs. seedlings in each of three seasons. The second experiment tested seedlings plus second- and third-year establishedE. elymoidesplants vs. 77caput-medusaeover 2 yr. Biomass, seed production, and soil moisture utilization 15, 30, 45, and 60 cm deep by the two species were measured. A randomized block design with factorial arrangement was used, with 25 2.25-m2plots per block. Initial seeding densities of each species were 0, 10, 74, 550, and 4,074 seeds m−2in all combinations of density. In the seedling vs. seedling experiment, intraspecific competition by 77caput-medusaeon itself was always significant (P ≤ 0.10) for both biomass and seed production. Interspecific competition byE. elymoidesseedlings onT. caput-medusaebiomass and seed production was not significant (P ≥ 0.10) in 2 of 3 yr and was always less than intraspecific competition by 77caput-medusae. Only 0.4% ofE. elymoidesseed germinated, and no seed was produced in the very dry first year, but 84% of remaining seed was viable for the next year, which had better moisture conditions for germination and establishment. Interspecific competition affected (P ≤ 0.10)E. elymoidesseedling biomass and seed production throughout the study. Intraspecific competition affected (P ≤ 0.10) seedlingE. elymoidesseed production in the dry year but not in the wetter than average year. In the matureE. elymoidesexperiment, intraspecific competition byT. caput-medusaeon weight and seed production per plant was greater than interspecific competition fromE. elymoides. Seedling/matureE. elymoidesreducedT. caput-medusaeweight per plant in the dry year but the effect was not biologically significant. Larger, matureEelymoidesplants produced 600 to 3,000 seeds per plant during the wet year; neither intra- nor interspecific competition was a factor.Taeniatherum caput-medusaewas better able to access deeper soil moisture and was more aggressive at extracting soil moisture than wereE. elymoidesseedlings in the wet year. Cold soils and low oxygen due to wet soils may have restrictedE. elymoidesseedling root activity. MatureE. elymoidesplants did not appear restricted by cold soils or low oxygen. Established second- and third-yearE. elymoidesplants were able to compete for soil moisture down to 45 cm. The generally greater interspecific competitive effects ofT. caput-medusaeonE. elymoidesthan vice versa suggested that it will be difficult to establish anE. elymoidesstand in an existingT. caput-medusaecommunity without first suppressingT. caput-medusae. IndividualE. elymoidesplants did establish and were productive with and withoutT. caput-medusaecompetition.


2017 ◽  
Vol 52 (11) ◽  
pp. 1006-1016 ◽  
Author(s):  
Paula Duarte de Oliveira ◽  
Gilmar Arduino Bettio Marodin ◽  
Gustavo Klamer de Almeida ◽  
Mateus Pereira Gonzatto ◽  
Daniel Chamorro Darde

Abstract: The objective of this work was to evaluate the effect of shoot heading and of hand thinning in different development stages of flowers and fruits on the fruit production and quality of 'BRS Kampai' peach (Prunus persica) trees. The experiment was performed during three crop years, under the conditions of the “Depressão Central” region in the state of Rio Grande do Sul, Brazil, and the treatments were: T1, heading of half of the mixed shoot; T2, heading of one third of the mixed shoot; T3, flower thinning in the pink bud stage; T4, thinning at full bloom; T5, thinning of fruit with 5 mm; T6, thinning of fruit with 20 mm; and T7, no thinning or heading (control). Fruit production and quality were evaluated. Plants with no thinning were more productive, but showed high frequency of fruits with a diameter smaller than 60 mm. Shoot heading reduced production per tree and resulted in small-sized fruit. Thinning time did not affect production, and fruit size was greater when thinning was performed at the bloom stage. 'BRS Kampai' peach trees can be thinned starting at bloom, which provides greater fruit size, with no production loss.


2016 ◽  
Vol 46 (10) ◽  
pp. 1737-1742
Author(s):  
Josana Andreia Langner ◽  
Nereu Augusto Streck ◽  
Genei Antonio Dalmago ◽  
Lia Rejane Silveira Reiniger ◽  
Angelica Durigon ◽  
...  

ABSTRACT: The objective of this study was to determine the maximum development rates for the phases of emergence, vegetative and reproductive, and to test the performance of the Wang and Engel (WE) model for simulating the development of landrace and improved maize cultivars sown on different dates. Model calibration was with data collected from a field experiment with a sowing date on December 13, 2014, and the model was tested with independent data from experiments with five sowing dates (August 20 and November 4, 2013, February 3 and August 15, 2014, and January 7, 2015) in Santa Maria, RS. The experiment was a complete randomized block design with four replicates. The dates of emergence (EM), silking (R1), and physiological maturity (R6) of two landraces ('Cinquentinha' and 'Bico de ouro') and two improved maize cultivars ('BRS Planalto' and 'AS 1573PRO') were recorded. Maximum daily developmental rates varied among cultivars from 0.2400 to 0.3411 d-1 for the emergence phase, from 0.0213 to 0.0234 d-1 for the vegetative phase, and from 0.0254 to 0.0298 d-1 for the reproductive phase. The WE model adequately estimated the developmental stages of landraces and improved maize cultivars with a mean error of 3.7 days. The cardinal temperatures used in the WE model were appropriate to estimate the developmental stages of landraces and improved maize cultivars.


2003 ◽  
Vol 83 (2) ◽  
pp. 357-362 ◽  
Author(s):  
J. L. Bodega ◽  
M. A. De Dios ◽  
M. M. Pereyra Iraola

Canarygrass (Phalaris canariensis L.) crops are sown from June to mid-September in the southeastern area of the province of Buenos Aires, Argentina. Sowing dates in this range result in different growing temperatures and photoperiods that affect the duration of developmental stages, biomass production, and seed yield and its components. For Argentina, there are no reported studies that address these effects. This study on the effects of sowing date was conducted during four growing seasons (1996–1999) at the Instituto Nacional de Tecnologí a Agropecuaria (INTA) Experimental Station at Balcarce, Argentina, using a population provided by Dr. Jaime Lloveras, University of Leyda, Spain. Different seeding dates were chosen from June to mid-September. The experiment was a randomized complete block design with four blocks. When the sowing date was delayed, total dry matter (DM) decreased. For early sowing dates seed yield was constant, but after 10 August it was reduced by 1.5% for each day of delay. Earlier sowing increased the duration of pre-anthesis development with greater uniformity in panicle size and the number of seeds. Seed yield was related lin early to the number of seeds and plant dry matter yield (DMY). The rate of progress from emergence to anthesis (1/days from emergence to anthesis) was proportional to the mean photoperiod. Under the environmental conditions in Balcarce, the accumulated required thermal units for anthesis was reduced when sowing was delayed from June to September. This reduction was related to the photoperiod and was estimated as –189.3 growing degree-days per hour of photoperiod increment. Key words: Canarygrass, seed yield, sowing date, yield components


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