scholarly journals SEVERITY OF RAMULARIA LEAF SPOT AND SEED COTTON YIELD IN DIFFERENT SOWING TIMES

2016 ◽  
Vol 29 (3) ◽  
pp. 603-610 ◽  
Author(s):  
JOÃO PAULO ASCARI ◽  
DEJÂNIA VIEIRA DE ARAÚJO ◽  
LEONARDO DIOGO EHLE DIAS ◽  
GIOVANI JUNIOR BAGATINI ◽  
INÊS ROEDER NOGUEIRA MENDES
Keyword(s):  
Disease Control ◽  
Leaf Spot ◽  
Cotton Yield ◽  
Yield Losses ◽  
Seed Cotton ◽  
Sowing Time ◽  
Fungicide Application ◽  
Progress Curve ◽  
Ramularia Leaf Spot ◽  
Diagrammatic Scale

ABSTRACT The ramularia leaf spot (RLS) disease causes cotton yield losses. Choosing a less susceptible cultivar and a sowing time that are less favorable to the pathogen contribute to the management of this disease. The objective of this work was to evaluate the severity of ramularia leaf spot on cotton cultivars sowed in two different times. The experiment was conducted in a triple factorial design (4x3x2), consisted of four cultivars, the three thirds of the plant and two sowing times, with four replications. Each plot was divided in two twin plots, one with fungicide application (with disease control) and the other without fungicide application (without disease control). The severity assessments were performed every seven days, considering each third of the plant with a diagrammatic scale. Yield was evaluated in each plot. There was a significant interaction between sowing times and the thirds of the plant in the plots without disease control for RLS severity, with the highest values of area under the disease progress curve (AUDPC) in the first sowing time (ST1) and in the lower third of the plant. The FMT705 cultivar had the highest and FM951LL the lowest value of AUDPC. The AUDPC of these cultivars were no statistically different in the second sowing time (ST2), but they had higher AUDPC values in the lower third. Highest yields were found with ST1 in plots with disease control, with no differences between the cultivars, however, lower yields were found in plots without disease control.

scholarly journals Ramularia leaf spot severity and effects on cotton leaf area and yield1

2016 ◽  
Vol 46 (4) ◽  
pp. 434-441
Author(s):  
João Paulo Ascari ◽  
◽  
Inês Roeder Nogueira Mendes ◽  
Vanessa Costa da Silva ◽  
Dejânia Vieira de Araújo
Keyword(s):  
Leaf Area ◽  
Leaf Spot ◽  
Yield Loss ◽  
Cotton Leaf ◽  
Cotton Yield ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Progress Curve ◽  
Ramularia Leaf Spot ◽  
Upper Third

ABSTRACT Cotton monoculture favors the development of diseases such as ramularia leaf spot, which causes early defoliation and boll rotting, thus decreasing yield. This study aimed at evaluating the severity of ramularia leaf spot and its effects on cotton leaf area and yield. The experiment was conducted in a triple (4 x 3 x 2) factorial design, consisting of four cultivars (FM940GLT, FM944GL, TMG42WS and TMG43WS), three thirds of the plant (lower, middle and upper) and two management conditions (with and without fungicide application). To the variable area under the disease progress curve, the lowest values were observed in the upper third of the TMG42WS and TMG43WS cultivars, with the lower and middle thirds presenting the highest severity. The condition managed with fungicide and the upper third showed the lowest values for area under the disease progress curve. The leaf area was negatively affected by the ramularia leaf spot. Concerning the seed and fiber yields, the highest averages were observed for the middle third and the condition managed with fungicide. There was no statistical difference for cotton yield loss.

Calendar and AU-Pnuts Advisory Programs Compared for Leaf Spot Diseases and Rust Control on Peanut in Southwest Alabama

2006 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
A. K. Hagan ◽  
H. L. Campbell ◽  
K. L. Bowen ◽  
M. Pegues
Keyword(s):  
Disease Control ◽  
Leaf Spot ◽  
Weather Conditions ◽  
Treatment Schedule ◽  
Advisory Programs ◽  
Fungicide Application ◽  
Leaf Spots ◽  
Production Area ◽  
Peanut Production ◽  
Rain Events

Peanut production acreage has increased substantially in southwest Alabama in the past several years. Since prevailing weather conditions in this newer production area are conducive to peanut diseases, primarily due to frequent rainfall during summer months, a 2-week calendar fungicide treatment schedule is considered essential to controlling leaf spot diseases and rust in order to optimize yields. In 2003, 2004, and 2005, extended calendar application intervals and the AU-Pnuts leaf spot advisory were compared with the recommended 2-week calendar schedule for peanut disease control on partially disease-resistant peanut cultivars (DP-1 in 2003 and Florida C99R in 2004 and 2005). Fungicide programs included recommended rates of azoxystrobin, chlorothalonil, and tebuconazole. Numbers of fungicide applications for the 2-, 3-, and 4-week calendar schedule treatments were 7, 5, and 4, respectively in each year. Fungicide applications made according to AU-Pnuts are based on rain events and resulted in 5 sprays in 2003 and 7 sprays in 2004 and 2005. Fungicide application schedule had a significant impact on leaf spots, rust, southern stem rot and yield in at least two of the three study years. Results indicate that recommendations for the 2-week fungicide application schedule should be maintained in this area. Fungicide program also had a consistent effect on measured variables, with the azoxystrobin program providing better disease control and higher yields. Accepted for publication 16 August 2006. Published 10 November 2006.

scholarly journals Evaluation of yield, yield components and incidence of CLCV disease through planting times and varietal interaction in cotton in the Multan region

2019 ◽  
Vol 1 (1) ◽  
pp. 33
Author(s):  
Salma Naimatullah
Keyword(s):  
Plant Height ◽  
Yield Components ◽  
Bt Cotton ◽  
Cotton Yield ◽  
Seed Cotton ◽  
Sowing Time ◽  
Seed Cotton Yield ◽  
Boll Weight

Five Bt cotton varieties were evaluated for five different parameters (plant height, number of bolls per plant, boll weight, seed cotton yield and CLCV incidence after 105 days of planting) under six different sowing times (01 March, 15 March, 01 April, 15 April, 01 May and 15 May) at CCRI, Multan during the year 2018.Results revealed highly significant differences among the varieties, sowing times and their interaction for all the traits under study. Regarding sowing times, highest yield (3676 kg/ha) was produced when the sowing was done on 01 March followed by March 15 sowing (3496 kg/ha) with 4.3 and 6.1 CLCuV incidence% respectively after 105 days of sowing.However, lowest yield of 2483 kg/ha was achieved through 15 May planting with 96.7% CLCuV incidence. Regarding varietal performance, CYTO-313 excelled all other varieties by producing 3356 kg/ha seed cotton yield followed by CIM-343 (3195 kg/ha) with CLCuV percent incidence of 53.1 and 50.9 respectively at 105 days of planting.It was concluded from the present investigations that first March sowing is the optimum sowing time with zero percent CLCuV incidence for Multan region. Furthermore, variety CYTO-313 should be given primacy on other four varieties when farmer is going to adopt first March sowing.

scholarly journals Comparative epidemiology of late blight and early blight of potato under different environmental conditions and fungicide application programs

2019 ◽  
Vol 40 (5) ◽  
pp. 1805 ◽  
Author(s):  
Henrique da Silva Silveira Duarte ◽  
Laércio Zambolim ◽  
Franklin Jackson Machado ◽  
Hitor Rafael Pereira Porto ◽  
Fabricio Avila Rodrigues
Keyword(s):  
Late Blight ◽  
Environmental Conditions ◽  
Early Blight ◽  
Block Design ◽  
Yield Losses ◽  
Yield Data ◽  
Fungicide Application ◽  
Progress Curve ◽  
Comparative Epidemiology ◽  
Application Programs

Three experiments were carried out in an experimental field from Viçosa city, Minas Gerais, Brazil, to compare late blight (LB) (Phytophthora infestans) and early blight (EB) (Alternaria grandis) epidemics under different environmental conditions and fungicide application programs. Each experiment consisted of two side-by-side trials that were arranged in a randomized complete block design with five treatments and five replications. At 30 days after planting the potato (‘Ágata’ cultivar) plants in plots of trials 1 and 2 were inoculated with an isolate of P. infestans (A2 mating type) and four isolates of A. grandis, respectively. Fungicide applications were initiated at seven days after inoculation and repeated at 7- or 15-day intervals. The severity of LB and EB was assessed every two days, and the area under disease progress curve (AUDPC) was calculated for both diseases. The yield was quantified by weighing the tubers of all the plants from each plot after their maturation. Yield data were converted into kg ha-1 and the percentage of loss was calculated for each treatment. Based on the AUDPC, the LB severity was greater than the EB severity under all three environmental conditions, and this was reflected in the yield. LB and EB caused yield losses as high as of 82 and 45%, respectively. The fungicide effects on both LB and EB and the associated yield losses changed according to the environmental conditions, therefore, indicating the importance of using tools such as a forecast system to help farmers to decide the best time for fungicide application.

scholarly journals Timing of Fungicide Applications for Control of Husk Spot Caused by Pseudocercospora macadamiae in Macadamia

Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1675-1681 ◽  
Author(s):  
O. A. Akinsanmi ◽  
A. K. Miles ◽  
A. Drenth
Keyword(s):  
Disease Control ◽  
Developmental Stage ◽  
Developmental Stages ◽  
Disease Incidence ◽  
Full Size ◽  
Logistic Regression Models ◽  
Fungicide Application ◽  
Fruit Drop ◽  
Progress Curve ◽  
Control Application

Pseudocercospora macadamiae is an important pathogen of macadamia in Australia, causing a disease known as husk spot. Growers strive to control the disease with a number of carbendazim and copper treatments. The aim of this study was to consider the macadamia fruit developmental stage at which fungicide application is most effective against husk spot, and whether application of copper-only applications at full-size fruit developmental stage toward the end of the season contributed to effective disease control. Fungicides were applied to macadamia trees at four developmental stages in three orchards in two subsequent production seasons. The effects of the treatments on disease incidence and severity were quantified using area under disease progress curve (AUDPC) and logistic regression models. Although disease incidence varied between cultivars, incidence and severity on cv. A16 showed consistent differences between the treatments. Most significant reduction in husk spot incidence occurred when spraying commenced at match-head sized-fruit developmental stage. All treatments significantly reduced husk spot incidence and severity compared with the untreated controls, and a significant positive linear relationship (R2 = 73%) between AUDPC and severity showed that timing of the first fungicide application is important for effective disease control. Application of fungicide at full-size fruit stage reduced disease incidence but had no impact on premature fruit drop.

Control and Competitiveness of Johnsongrass (Sorghum halepense) in Cotton (Gossypium hirsutum)

Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 356-359 ◽  
Author(s):  
P. E. Keeley ◽  
R. J. Thullen
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Field Experiments ◽  
Yield Loss ◽  
Sorghum Halepense ◽  
Cotton Yield ◽  
Yield Losses ◽  
Seed Cotton ◽  
Average Yield ◽  
Labor Costs

Four field experiments conducted over 3 yr indicated that cultivation alone failed to prevent johnsongrass [Sorghum halepense(L.) Pers.] from reaching densities that severely reduced yields of cotton (Gossypium hirsutumL. ‘Acala SJ-2’). Density of johnsongrass in plots cultivated four times and hoed weekly for 8 weeks after emergence was reduced to 1 shoot/m2at harvest compared to 74 shoots/m2for plots that were only cultivated. In addition to a 60% average yield loss of seed cotton, yield losses ranging from 40 to 76%, ginning losses were also greater from cultivated than from hand-weeded plots. Compared to cultivated plots, supplementing cultivation with two postemergence applications of 3.0 kg/ha of DSMA (disodium methanearsonate) increased the average yield of cotton by 20% and reduced perennial johnsongrass densities by 64% at harvest. Although yields were improved by applying DSMA, they averaged 40% less than those of hand-weeded plots. The temporary weed control obtained with DSMA was profitable in terms of the additional lint and seed obtained, but insufficient cotton was produced to pay expenses for producing the crop by any of the methods of weed control. High labor costs for hoeing prevented this treatment from being profitable.

scholarly journals Cotton phenology and production response to sowing time, row orientation and plant spacing using CROPGRO-cotton model

MAUSAM ◽  
2021 ◽  
Vol 72 (3) ◽  
pp. 627-634
Author(s):  
ABHISHEK DHIR ◽  
R. K. PAL ◽  
P. K. KINGRA ◽  
S. K. MISHRA ◽  
S. S. SANDHU
Keyword(s):  
Field Experiments ◽  
Growth And Yield ◽  
Yield Response ◽  
Bt Cotton ◽  
Plant Spacing ◽  
Cotton Yield ◽  
Seed Cotton ◽  
Sowing Time ◽  
Seed Cotton Yield ◽  
East West

The DSSAT module for cotton crop has been evaluated as a tool to predict the crop growth and yield response to microclimatic modifications. In this context, multi-location field experiments were laid out at Bathinda and Faridkot, districts of Punjab during Kharif 2018 with Bt-cotton hybrid RCH 773 BGII and sown at three times, i.e., April 30, May 15 and May 30 with two row orientations (North-South : N-S and East-West : E-W) and three plant spacing’s (67.5 cm × 45.0 cm, 67.5 cm × 60.0 cm and 67.5 cm × 75.0 cm) in factorial split plot design and replicated by three times. The model output in terms of simulated phenology showed close proximity over observed value having R2 of 0.51 and 0.61 at Bathinda and 0.43 and 0.87 at Faridkot anthesis and maturity, respectively. Among study locations, observed and simulated LAI ranged from 2.7 to 3.7 and 1.8 to 3.0. Simulated seed cotton yield was found significantly higher with the crop sown on 30th April (3053 and 3274 kg ha-1) than 30th May sowing (2392 and 2511 kg ha-1) at Bathinda and Faridkot, respectively, which was in good agreement with observed yield having higher value of d-stat (0.84 for Bathinda and 0.89 for Faridkot) and R2 (0.75 for Bathinda and 0.83 for Faridkot). Moreover, higher seed cotton yield was simulated under East-West row direction along with wider plant spacing (67.5 × 75 cm) at both locations. Overall, CROPGRO-cotton model can be used as research tool for the prediction of cotton phenology and yield and to explore site-specific adoption strategies such as appropriate sowing time, row orientation and plant spacing to sustain cotton productivity under changing climatic conditions.

Influence of Cotton (Gossypium hirsutum) and Soybean (Glycine max) Planting Date on Weed Interference

Weed Science ◽  
1994 ◽  
Vol 42 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Tracy E. Klingaman ◽  
Lawrence R. Oliver
Keyword(s):  
Field Experiments ◽  
Yield Loss ◽  
Planting Date ◽  
Cotton Yield ◽  
Yield Losses ◽  
Seed Cotton ◽  
Weed Species ◽  
Planting Dates ◽  
Seed Cotton Yield ◽  
Weed Interference

Separate field experiments were conducted for cotton and soybean in 1990 and 1991 to determine the influence of planting date on yield loss due to interspecific interference from entireleaf morningglory and sicklepod and to determine the relative competitiveness of each weed species. Percent soybean yield loss due to weed interference increased as planting date was delayed from early May to early June. Averaged over weed species, yield losses from 1.7 weeds m−1row were 10, 18, and 20% for soybeans planted in early May, mid-May, and early June, respectively. Yield loss from 6.7 weeds m−1row were 17, 31, and 35% at the early May, mid-May, and early June planting dates, respectively. Percent seed cotton yield losses averaged over weed species in 1990 were 33 and 28% for the early May and early June planting dates, respectively, at 1.7 weeds m−1and 50% for both planting dates at weed densities of 6.7 plants m−1. The only experimental factor that significantly affected seed cotton yield in 1991 was weed density. Unlike soybeans, planting date had little effect on weed interference in cotton. Entireleaf morningglory was more competitive than sicklepod in both crops. Results suggest that selection of optimum soy bean planting dates may be a viable means of reducing losses due to weed interference.

scholarly journals Fungicide Application Timing Essential for the Management of Leaf Spot and Fruit Rot on Pomegranate (Punica granatum L.) in Florida

Plant Disease ◽  
2020 ◽  
Vol 104 (6) ◽  
pp. 1629-1637
Author(s):  
K. V. Xavier ◽  
A. N. KC ◽  
G. E. Vallad
Keyword(s):  
United States ◽  
Leaf Spot ◽  
Punica Granatum ◽  
Field Trials ◽  
Fruit Rot ◽  
Application Timing ◽  
Fungicide Application ◽  
Progress Curve ◽  
In The Beginning ◽  
Punica Granatum L

Pomegranate (Punica granatum L.) has emerged as an alternative fruit crop for growers dealing with devastating threats to citrus and avocado in the southeastern United States. However, foliar and fruit diseases are major constraints to commercial pomegranate production. Replicated field trials were performed in 2015 at three separate sites in Florida (Dover, Plant City, and Parrish) to evaluate Merivon (pyraclostrobin and fluxapyroxad), Luna Experience (fluopyram + tebuconazole), and a rotational program consisting of these two fungicides as well as Penncozeb 75DF (mancozeb) for the management of leaf spot and fruit rot of pomegranate. The fungicide programs were evaluated on the varieties Vietnam in Dover, FL; Angel Red in Plant City, FL; as well as Christina, Azadi, Vikusnyi, Alsirinnar, Sakerdze, and Wonderful in Parrish, FL. Mean leaf spot severity varied across sites at the end of each trial in August, with values ranging from 4.5 to 62.5% in Plant City, 7.5 to 45.8% in Dover, and 4.5 to 54.2% in Parrish. Based on area under the disease progress curve, all treatments that included at least one at bloom application significantly reduced disease levels compared with postbloom treatments and the nontreated control across all trial sites. Based on fruit rot incidence, Luna Experience and Merivon, when applied twice at bloom in the beginning of the season, reduced disease by 66.6 and 88.4%, respectively, in comparison with the nontreated control in Plant City. A rotational program further reduced disease by at least 97% at the end of the season in Parrish. The proper timing of fungicide application and rotation with different modes of action provided a feasible disease management option for pomegranate growers in the Southeast United States.

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