scholarly journals Impact of Fungal Gummosis on Peach Trees

HortScience ◽  
2003 ◽  
Vol 38 (6) ◽  
pp. 1141-1143 ◽  
Author(s):  
T.G. Beckman ◽  
P.L. Pusey ◽  
P.F. Bertrand
Keyword(s):  
United States ◽  
Disease Severity ◽  
Prunus Persica ◽  
Southeastern United States ◽  
Fruit Yield ◽  
Peach Tree ◽  
Botryosphaeria Dothidea ◽  
Trunk Diameter ◽  
Growing Seasons ◽  
Peach Trees

Peach tree fungal gummosis caused by Botryosphaeria dothidea [(Moug.:Fr.) Cos & de Not.] is widespread throughout the southeastern United States. Until recently, its economic impact on peach [Prunus persica (L.) Batsch] has been impossible to estimate, since no effective controls were known. Significant, though not total, suppression of gummosis on `Summergold' peach trees was achieved with an intensive 5-year spray program with captafol. Captan was far less effective than captafol. Both trunk diameter and fruit yield were negatively correlated with disease severity. After eight growing seasons, trees treated with captafol were 18% larger than the untreated trees. Yield of mature captafol-treated trees was 40% to 60% high er than that of untreated ones. Following termination of the spray program after 5 years, disease severity gradually increased on both captafol- and captan-treated trees. However, through eight growing seasons, disease severity was significantly lower on captafol-treated trees. This study demonstrates that peach tree fungal gummosis significantly depresses tree growth and fruit yield on susceptible peach cultivars.

scholarly journals Relationships Among Propagule Numbers of Botryosphaeria dothidea, Latent Infections, and Severity of Panicle and Shoot Blight in Pistachio Orchards

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 846-853 ◽  
Author(s):  
N. Ahimera ◽  
G. F. Driever ◽  
T. J. Michailides
Keyword(s):  
Disease Severity ◽  
Latent Infection ◽  
Assessment Method ◽  
Latent Infections ◽  
Botryosphaeria Dothidea ◽  
Growing Seasons ◽  
Risk Assessment Method ◽  
Shoot Blight ◽  
Fruit Disease

Experiments were conducted between 1999 and 2001 to monitor the presence of propagules of Botryosphaeria dothidea and frequencies of latent infections on pistachio leaves and fruit clusters and to determine their relationships to panicle and shoot blight severity in commercial orchards. Numbers of B. dothidea propagules recovered from washing leaves and fruit clusters varied among the growing seasons and sampling dates. Lower numbers of B. dothidea propagules were obtained in 1999 and 2001 than in 2000. For the orchard in Glenn County, up to 75 propagules per leaf and 21 propagules per fruit cluster were recorded in 1999, compared with 365 and 248 propagules per leaf and fruit cluster, respectively, in 2000. Although more propagules were detected per leaf, the infection levels were higher on fruit clusters, suggesting that pistachio fruit is more susceptible to B. dothidea infection than leaves. Latent infections were detected as soon as leaves or fruit clusters started to expand and more infections were obtained in 2000 than 1999 or 2001. Significant (P < 0.05) relationships between propagules on leaves or frequency of infections on leaves (independent variables) and propagules on fruit clusters or frequency of infected fruit clusters (dependent variables) with r values ≥ 0.50 provide support for the role of latent infection in panicle and shoot blight later in the season. Propagules on leaves and fruit clusters were not significantly correlated to disease severity, but frequencies of latent infection on leaves and fruit clusters were positively correlated (P ≥ 0.05) with leaf and fruit disease severity under field conditions with r2 ranging between 0.25 and 0.42. Quantitative relationships between latent infections and disease severity may be incorporated in a prediction model for disease development or be used to develop a risk assessment method to guide growers in their effort to control panicle and shoot blight of pistachio.

scholarly journals Field Testing Peach Rootstocks for Resistance to Armillaria Root Rot

HortScience ◽  
2001 ◽  
Vol 36 (1) ◽  
pp. 101-103 ◽  
Author(s):  
T.G. Beckman ◽  
P.L. Pusey
Keyword(s):  
United States ◽  
Root Rot ◽  
Tree Mortality ◽  
Prunus Persica ◽  
Infected Plant ◽  
Field Testing ◽  
The United States ◽  
Peach Tree ◽  
Armillaria Root Rot ◽  
Peach Rootstocks

Armillaria root rot is the second leading cause of peach tree mortality (after peach tree short life) in the southeastern United States. Currently, there are no commercially available rootstocks for peach with proven resistance to this pathogen in the United States. Since 1983, we have been screening rootstock candidates for resistance to Armillaria utilizing naturally infected field sites. Inoculation of peach [Prunus persica (L.) Batsch], plum (P. cerasifera J.F. Ehrh., P. munsoniana F.W. Wight & Hedr., P. salicina Lindl. or P. angustifolia Marsh.) × peach and plum × plum hybrid rootstocks with infected plant tissue (such as acorns, Quercus sp.) prior to planting has provided a significantly increased infection and mortality of candidate rootstock lines in comparison with sole reliance on natural inoculum on an infested site.

scholarly journals Nitrogen Fertilizer Management and Cultivar Selection for Cabbage Production in the Southeastern United States

2020 ◽  
Vol 30 (6) ◽  
pp. 685-691
Author(s):  
Andre Luiz Biscaia Ribeiro da Silva ◽  
Joara Secchi Candian ◽  
Lincoln Zotarelli ◽  
Timothy Coolong ◽  
Christian Christensen
Keyword(s):  
United States ◽  
Field Experiments ◽  
Southeastern United States ◽  
Total Yield ◽  
Crop Evapotranspiration ◽  
Fertilizer N ◽  
Marketable Yield ◽  
Rainfall Events ◽  
Growing Seasons ◽  
N Rates

Soil nitrogen (N) is easily leached in cabbage (Brassica oleracea var. capitata) production areas of southeastern United States characterized by sandy soils with low water-holding capacity. Soil N leaching in these areas is increased after rainfall events; consequently, growers increase the fertilizer N application to protect against N deficiencies and yield loss. The objective of this study was to evaluate the effects of three fertilizer N rates on yield and head quality for common cabbage cultivars used by Florida and Georgia growers during four cabbage growing seasons. Field experiments were conducted in Hastings, FL, in 2016 and 2017, and in Tifton, GA, in 2018 and 2019. A randomized complete block design was used with a split-plot design of fertilizer N rate and cabbage cultivar. Fertilizer N rate treatments consisted of the application of 170, 225, and 280 lb/acre N and were assigned as the main plot. Cabbage cultivars Bravo, Bronco, Bruno, Capture, Cheers, and Ramada were assigned as the sub-plots. Weather conditions were monitored during all growing seasons, and total, marketable, and unmarketable yields, as well as cabbage head polar and equatorial diameters, and core height and width were measured. In Florida, there was a significant interaction for growing season and fertilizer N rate. The Florida 2016 cabbage season experienced 10.5 inches of rainfall, and fertilizer N rates had no effect on cabbage yields. Total and marketable yield averaged 45,391 and 38,618 lb/acre among fertilizer N rates in 2016, respectively. Rainfall accumulated 2.1 inches during the 2017 study in Florida, which was less than the crop evapotranspiration. In response, total and marketable yield were higher for the applications of 225 lb/acre N (51,865 and 49,335 lb/acre, respectively) and 280 lb/acre N (54,564 and 52,219 lb/acre, respectively) compared with the application of 170 lb/acre N (47,929 and 43,710 lb/acre, respectively). In Georgia, there were no significant interactions between production season and fertilizer N rates. In addition, there were no significant main effects of season or fertilizer N rate. Rainfall events accumulated 20.9 and 7.8 inches during the 2018 and 2019 growing seasons, respectively. Total and marketable yields averaged 37,290 and 33,355 lb/acre, respectively for the two growing seasons in Georgia. Cabbage cultivar had no interaction with fertilizer N rate in any location. ‘Cheers’ (52,706 lb/acre) had the highest total yield in Florida, and ‘Ramada’ (38,462 lb/acre) and ‘Bronco’ (39,379 lb/acre) had the highest total yields in Georgia. In conclusion, the application of 225 lb/acre N was sufficient to sustain cabbage yields, but yields of the 170- and 225-lb/acre N treatments were not different when rainfall events exceeded crop evapotranspiration.

scholarly journals Carbohydrate and Nitrogen Partitioning within One-year Shoots of Young Peach Trees Grown with Grass Competition

HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1174-1177 ◽  
Author(s):  
T.J. Tworkoski ◽  
D.M. Glenn ◽  
W.V. Welker
Keyword(s):  
Festuca Arundinacea ◽  
Prunus Persica ◽  
Leaf Growth ◽  
N Uptake ◽  
Fruit Yield ◽  
Nitrogen Partitioning ◽  
Festuca Rubra ◽  
N Partitioning ◽  
One Year ◽  
Peach Trees

Carbohydrate and nitrogen were measured during 1992 and 1993 in shoots of peach [Prunus persica (L.) Batsch.] trees that were planted in 1989 and grown in three vegetation-free areas contained within plots planted to tall fescue (Festuca arundinacea Schreber), orchardgrass (Dactylis glomerata L.), or a mixture of Lolium perenne L. and Festuca rubra L. Trees grown in 9.3-, 3.3-, and 1.5-m2 vegetation-free areas had the greatest to the least fruit yield, respectively. Fruit number and mass were negatively correlated with stem mass. Grass type had little effect on mass, carbohydrate, or N partitioning within the tree. Individual sugars and carbohydrate partitioning were not affected by grass competition. In contrast, the proportion of shoot N partitioning into stem and leaves declined markedly as the size of the vegetation-free area increased. Proximity of peach trees to grass may have limited N uptake, which, in turn, reduced fruit yield but not stem and leaf growth.

scholarly journals Genetic Influence on Flower Bud Density in Peach and Nectarine Exceeds That of Environment

HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 1010-1012 ◽  
Author(s):  
W.R. Okie ◽  
D.J. Werner
Keyword(s):  
United States ◽  
North Carolina ◽  
Prunus Persica ◽  
Southeastern United States ◽  
Genetic Influence ◽  
Genotypic Variability ◽  
Flower Bud ◽  
Spring Frosts

Spring frosts often kill all or a portion of the flowers on peach [Prunus persica (L.) Batsch] trees in the southeastern United States. Increased flower bud density increases the likelihood of sufficient flowers surviving to produce a crop. The effect of environment on flower bud density (buds/node) was studied using two locations over 3 years. Bud density of 25 peach and nectarine varieties grown in completely randomized designs was measured in Georgia and North Carolina. Genotypic variability was greater than location or year effects. Varieties selected for high bud density at one location can be expected to have high densities at other locations with similar chilling.

scholarly journals Transcriptome Analysis of Genes Involved in Cold Hardiness of Peach Tree (Prunus persica) Shoots during Cold Acclimation and Deacclimation

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Duk Jun Yu ◽  
Sung Hoon Jun ◽  
Junhyung Park ◽  
Jung Hyun Kwon ◽  
Hee Jae Lee
Keyword(s):  
Cold Acclimation ◽  
Transcriptome Analysis ◽  
Cold Hardiness ◽  
Prunus Persica ◽  
Quantitative Polymerase Chain Reaction ◽  
Differentially Expressed ◽  
Peach Tree ◽  
Triacylglycerol Lipase ◽  
Cold Hardy ◽  
Peach Trees

We analyzed the transcriptomes in the shoots of five-year-old ‘Soomee’ peach trees (Prunus persica) during cold acclimation (CA), from early CA (end of October) to late CA (middle of January), and deacclimation (DA), from late CA to late DA (middle of March), to identify the genes involved in cold hardiness. Cold hardiness of the shoots increased from early to late CA, but decreased from late CA to late DA, as indicated by decreased and increased the median lethal temperature (LT50), respectively. Transcriptome analysis identified 17,208 assembled transcripts during all three stages. In total, 1891 and 3008 transcripts were differentially expressed with a |fold change| > 2 (p < 0.05) between early and late CA, and between late CA and late DA, respectively. Among them, 1522 and 2830, respectively, were functionally annotated with gene ontology (GO) terms having a greater proportion of differentially expressed genes (DEGs) associated with molecular function than biological process or cellular component categories. The biochemical pathways best represented both periods from early to late CA and from late CA to late DA were ‘metabolic pathway’ and ‘biosynthesis of secondary metabolites’. We validated these transcriptomic results by performing reverse transcription quantitative polymerase chain reaction on the selected DEGs showing significant fold changes. The relative expressions of the selected DEGs were closely related to the LT50 values of the peach tree shoots: ‘Soomee’ shoots exhibited higher relative expressions of the selected DEGs than shoots of the less cold-hardy ‘Odoroki’ peach trees. Irrespective of the cultivar, the relative expressions of the DEGs that were up- and then down-regulated during CA, from early to late CA, and DA, from late CA to late DA, were more closely correlated with cold hardiness than those of the DEGs that were down- and then up-regulated. Therefore, our results suggest that the significantly up- and then down-regulated DEGs are associated with cold hardiness in peach tree shoots. These DEGs, including early light-induced protein 1, chloroplastic, 14-kDa proline-rich protein DC2.15, glutamate dehydrogenase 2, and triacylglycerol lipase 2, could be candidate genes to determine cold hardiness.

scholarly journals An Economic Evaluation of Soybean Stink Bug Control Alternatives for the Southeastern United States

1992 ◽  
Vol 24 (2) ◽  
pp. 83-94 ◽  
Author(s):  
David Chyen ◽  
Michael E. Wetzstein ◽  
Robert M. McPherson ◽  
William D. Givan
Keyword(s):  
United States ◽  
Experimental Data ◽  
Economic Evaluation ◽  
Methyl Parathion ◽  
Southeastern United States ◽  
The United States ◽  
Stink Bug ◽  
Growing Seasons ◽  
Lambda Cyhalothrin ◽  
Environmentally Sound

AbstractMethyl parathion or Penncap M (an encapsulated methyl parathion) are used extensively throughout the United States for controlling stink bug pests in soybeans, Glycine Max (L.) Merrill. However, this insecticide is highly toxic to mammals, birds, and non-target arthropods, and thus is less environmentally sound than other insecticides. For environmental and human health considerations, investigating alternative insecticides for control is desired. For this investigation, research based on field experimental data from Florida, Georgia, and Louisiana during the 1988 and 1989 growing seasons were employed. Results indicate that alternative, currently available, and less toxic insecticides may reduce producer costs, increase yield, and improve soybean quality. These alternative insecticides include Scout (tralomethrin), Karate (lambda-cyhalothrin), Orthene (acephate), and Baythroid (cyfluthrin). In terms of improved profits these alternative insecticides may dominate methyl parathion or encapsulated methyl parathion.

Phomopsis amygdali causes peach shoot blight of cultivated peach trees in the southeastern United States

Mycologia ◽  
1999 ◽  
Vol 91 (6) ◽  
pp. 1008-1015 ◽  
Author(s):  
David F. Farr ◽  
Lisa A. Castlebury ◽  
Rebecca A. Pardo-Schultheiss
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Shoot Blight ◽  
Peach Trees

scholarly journals Evaluation of Pearl Millet Grain Hybrids for Resistance to Meloidogyne spp. and Leaf Blight Caused by Pyricularia grisea

Plant Disease ◽  
2002 ◽  
Vol 86 (8) ◽  
pp. 909-914 ◽  
Author(s):  
P. Timper ◽  
J. P. Wilson ◽  
A. W. Johnson ◽  
W. W. Hanna
Keyword(s):  
United States ◽  
Disease Severity ◽  
Pearl Millet ◽  
Pennisetum Glaucum ◽  
Southeastern United States ◽  
Leaf Blight ◽  
Pyricularia Grisea ◽  
Race 1 ◽  
Grain Crop ◽  
Meloidogyne Spp

Pearl millet, Pennisetum glaucum, has potential as a grain crop in the southeastern United States. Our objectives were to (i) determine the resistance and/or tolerance of pearl millet hybrids to Meloidogyne incognita race 3 and M. arenaria race 1; (ii) compare reproduction of Meloidogyne spp. on pearl millet and corn; and (iii) determine the disease severity of leaf blight caused primarily by Pyricularia grisea. In a field naturally infested with M. incognita, experimental pearl millet hybrids with inbreds 114 and 117 as the pollinators had fewer numbers of second-stage juveniles and more severe leaf blight than did HGM-100, a nematode-susceptible hybrid; hybrids with inbred 115 as the pollinator were similar to HGM-100 in both nematode numbers and foliar disease severity. Grain yields in pearl millet were greater in plots treated with 1,3-dichloropropene than in control plots and were negatively correlated with leaf blight severity. In a greenhouse experiment, both M. incognita and M. arenaria produced fewer eggs on pearl millet hybrids with pollinators 114, 117, 101, 102, and 103 than on hybrid HGM-100. Reproduction of M. incognita was less on the resistant pearl millet hybrids than on corn. Because both M. incognita and P. grisea can reduce grain yield of pearl millet, hybrids developed for the southeastern United States should be resistant to both pathogens.

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