scholarly journals Incidence of Zonate Leaf Spot on Sorghum Accessions Under Disease-Conducive Growing Conditions Burleson County, Texa

2021 ◽  
pp. 35-38
Author(s):  
Louis K. Prom ◽  
Thomas Isakeit
Keyword(s):  
Leaf Spot ◽  
Growing Season ◽  
Field Trials ◽  
Breeding Programs ◽  
Resistant Genes ◽  
Parental Lines ◽  
Maximum Temperatures ◽  
Growing Conditions ◽  
Experimental Plots

The frequent rains coupled with cooler than normal maximum temperatures in the early part of the 2021 growing season created conditions for severe outbreaks of zonate leaf spot infection on sorghum plants in the experimental plots at the Texas A&M AgriLife Farm, Burleson County, Texas. As a result, the incidence of zonate leaf spot was recorded for 68 accessions planted in one of the field trials. In this study, 13 sorghum accessions, including TAM428, BTx635, PI330255, PI534157, PI570841, PI609251, PI570726, and PI267588 were free of zonate leaf spot infection, indicating that they were highly resistant to the disease. The lines identified in this study may possess genes for resistance which can be useful in breeding programs for introgression of the resistant genes to elite or parental lines.

Reaction of Sorghum Lines to Zonate Leaf Spot and Rough Leaf Spot

2015 ◽  
Vol 16 (4) ◽  
pp. 230-234 ◽  
Author(s):  
Louis K. Prom ◽  
Thomas Isakeit ◽  
Hugo Cuevas ◽  
William L. Rooney ◽  
Ramasamy Perumal ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Growing Season ◽  
Breeding Programs ◽  
Association Panel ◽  
College Station

Abundant, frequent rains along with humid and cloudy conditions during the early part of the 2015 growing season provided conducive conditions for an unusually severe outbreak of zonate leaf spot and rough leaf spot in a block of sorghum lines at the Texas A&M AgriLife Research Farm, Burleson County, near College Station, Texas. This afforded the opportunity to evaluate these lines for reaction to these diseases, which normally occur at trace levels in this area. Out of 181 sorghum lines, including a subset of the sorghum association panel, a total of 13 lines, including Dorado, Sureno, PI576434, PI656005, PI656034, PI656075, PI656024, and PI598070, were resistant to both diseases. These lines could be used in breeding programs to introgress the genes for resistance to both diseases into other adapted lines. Accepted for publication 8 December 2015. Published 14 December 2015.

scholarly journals Effect of combined seasonal coverage on northern production of strawberry (Fragaria ananassa Duch)

2017 ◽  
Vol 44 (No. 3) ◽  
pp. 148-155
Author(s):  
Eivind Uleberg ◽  
Inger Martinussen ◽  
Ragnar Samuelsen
Keyword(s):  
Ground Cover ◽  
Growing Season ◽  
Field Trials ◽  
Total Production ◽  
Fragaria Ananassa ◽  
Combined Treatments ◽  
Breeding Programs ◽  
Plant Coverage ◽  
Berry Size ◽  
Berry Quality

Two field trials with five strawberry cultivars planted on a woven black polyfibre ground cover sheet with or without translucent sheet plant coverage during winter and the growing season as combined treatments were started in 2004 and 2005. In total, nine different cultivars were included in the two fields. One early cv. ‘Polka’ and one late cv. ‘Korona’ acted as standard cultivars, while the other cultivars were new, named or labelled selections from Norwegian, Finnish and Swedish breeding programs. Winter survival, spring vigour, earliness, saleable and total berry yield, berry size and berry quality were registered for three years. The cultivars differed in earliness, berry size, yield (gram per plant) and total production (sum of all years). A combination of fibre sheet winter and spring coverage and more open net sheet harvest season coverage showed favourable results for overwintering, earliness and berry yield, and enhanced the ripening process in all cultivars.

scholarly journals A WEATHER-BASED SCHEME TO ADVISE ON LIMITED CHEMICAL CONTROL OF GROUNDNUT LEAF SPOT DISEASES IN INDIA

2000 ◽  
Vol 36 (4) ◽  
pp. 469-478 ◽  
Author(s):  
D. R. BUTLER ◽  
K. D. R. WADIA ◽  
R. K. REDDY ◽  
N. D. DAS ◽  
B. JOHNSON ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Chemical Control ◽  
Rainy Season ◽  
Growing Season ◽  
Field Trials ◽  
Main Stem ◽  
Leaf Wetness ◽  
Wetness Index ◽  
A Value ◽  
Disease Pressure

Infection of groundnut by pathogens causing early and late leaf spot diseases is strongly affected by accumulated daily leaf wetness periods and, in the rainy season, temperature is unlikely to severely limit infection. Earlier work relating patterns of leaf wetness to infection, was used to define a daily Wetness Index (WI) which was compared with infection on inoculated plants exposed in the crop for periods of 7 d. Infection was only severe when the 7-d WI total exceeded a value of 2.3. The proportion of leaves with one or more lesions on the main stem was used to assess the amount of inoculum in the crop. When the proportion of diseased leaves exceeded 10% and the WI total exceeded the threshold, application of a fungicide was advised. Successive sprays were separated by at least 14 d and a maximum of three sprays were applied in the growing season. Field trials showed that three sprays gave limited benefit where the disease pressure was severe, but substantial increases in pod and haulm yield were possible with only one or two fungicide applications in locations with less disease pressure.

scholarly journals The Impact of Different Environmental Conditions during Vegetative Propagation on Growth, Survival, and Biochemical Characteristics in Populus Hybrids in Clonal Field Trial

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 892
Author(s):  
Valda Gudynaitė-Franckevičienė ◽  
Alfas Pliūra
Keyword(s):  
Climate Change ◽  
Phenotypic Plasticity ◽  
Environmental Conditions ◽  
Vegetative Propagation ◽  
Genotypic Variation ◽  
Hybrid Poplar ◽  
Field Trials ◽  
Biochemical Traits ◽  
Suburban Areas ◽  
Growing Conditions

To have a cleaner environment, good well-being, and improve the health of citizens it is necessary to expand green urban and suburban areas using productive and adapted material of tree species. The quality of urban greenery, resistance to negative climate change factors and pollution, as well as efficiency of short-rotation forestry in suburban areas, depends primarily on the selection of hybrids and clones, suitable for the local environmental conditions. We postulate that ecogenetic response, phenotypic plasticity, and genotypic variation of hybrid poplars (Populus L.) grown in plantations are affected not only by the peculiarities of hybrids and clones, but also by environmental conditions of their vegetative propagation. The aim of the present study was to estimate growth and biochemical responses, the phenotypic plasticity, genotypic variation of adaptive traits, and genetically regulated adaptability of Populus hybrids in field trials which may be predisposed by the simulated contrasting temperature conditions at their vegetative propagation phase. The research was performed with the 20 cultivars and experimental clones of one intraspecific cross and four different interspecific hybrids of poplars propagated under six contrasting temperature regimes in phytotron. The results suggest that certain environmental conditions during vegetative propagation not only have a short-term effect on tree viability and growth, but also can help to adapt to climate change conditions and grow successfully in the long-term. It was found that tree growth and biochemical traits (the chlorophyll A and B, pigments content and the chlorophyll A/B ratio) of hybrid poplar clones grown in field trials, as well as their traits’ genetic parameters, were affected by the rooting-growing conditions during vegetative propagation phase. Hybrids P. balsamifera × P. trichocarpa, and P. trichocarpa × P. trichocarpa have shown the most substantial changes of biochemical traits across vegetative propagation treatments in field trial. Rooting-growing conditions during vegetative propagation had also an impact on coefficients of genotypic variation and heritability in hybrid poplar clones when grown in field trials.

scholarly journals Dynamics of the Degradation of Acetyl-CoA Carboxylase Herbicides in Vegetables

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 405
Author(s):  
Miroslav Jursík ◽  
Kateřina Hamouzová ◽  
Jana Hajšlová
Keyword(s):  
Linear Models ◽  
Growing Season ◽  
Field Trials ◽  
Baby Food ◽  
Vegetable Production ◽  
The Czech Republic ◽  
Herbicide Residues ◽  
Harvest Intervals ◽  
Small Plot

(1) Background: Aryloxyphenoxy-propionates and cyclohexanediones are herbicides most widely used in dicot crops worldwide. The main objective of the study was to determine the dynamics of herbicide residues in carrot, lettuce, cauliflower, and onion in order to suggest a low level of residues in harvested vegetables. (2) Methods: Small plot field trials were carried out in four vegetables in the Czech Republic. The samples of vegetables were collected continuously during the growing season. Multiresidue methods for the determination of herbicide residues by LC-MS/MS were used. Non-linear models of degradation of individual herbicides in vegetables were calculated using the exponential decay formula. Action GAP pre-harvest intervals for the 25% and 50% maximum residue limit (MRL) and 10 µg kg−1 limit (baby food) were established for all tested herbicides. (3) Results: The degradation dynamics of fluazifop in carrot, onion, and cauliflower was significantly slower compared to quizalofop and haloxyfop. The highest amount (2796 µg kg−1) of fluazifop residues was detected in cauliflower 11 days after application. No residue of propaquizafop and cycloxydim was detected in any vegetable samples. (4) Conclusions: Aryloxyphenoxy-propionate herbicide (except propaquizafop) could contaminate vegetables easily, especially vegetables with a short growing season. Vegetables treated with fluazifop are not suitable for baby food. Lettuce and cauliflower treated by quizalofop are not suitable for baby food, but in onion and carrot, quizalofop could be used. Propaquizafop and cycloxydim are prospective herbicides for non-residual (baby food) vegetable production.

scholarly journals Epidemiology and management of bacterial leaf spot on watermelon caused byPseudomonas syringae

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1222-1229 ◽  
Author(s):  
E. A. Newberry ◽  
L. Ritchie ◽  
B. Babu ◽  
T. Sanchez ◽  
K. A. Beckham ◽  
...  
Keyword(s):  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Negative Relationship ◽  
Disease Outbreaks ◽  
Field Trials ◽  
Multiple Regression Model ◽  
Bacterial Leaf Spot ◽  
Progress Curve ◽  
Cool Conditions

Bacterial leaf spot of watermelon caused by Pseudomonas syringae has been an emerging disease in the southeastern United States in recent years. Disease outbreaks in Florida were widespread from 2013 to 2014 and resulted in foliar blighting at the early stages of the crop and transplant losses. We conducted a series of field trials at two locations over the course of two years to examine the chemical control options that may be effective in management of this disease, and to investigate the environmental conditions conducive for bacterial leaf spot development. Weekly applications of acibenzolar-S-methyl (ASM) foliar, ASM drip, or copper hydroxide mixed with ethylene bis-dithiocarbamate were effective in reducing the standardized area under the disease progress curve (P < 0.05). Pearson’s correlation test demonstrated a negative relationship between the average weekly temperature and disease severity (–0.77, P = 0.0002). When incorporated into a multiple regression model with the square root transformed average weekly rainfall, these two variables accounted for 71% of the variability observed in the weekly disease severity (P < 0.0001). This information should be considered when choosing the planting date for watermelon seedlings as the cool conditions often encountered early in the spring season are conducive for bacterial leaf spot development.

Entyloma serotinum. [Descriptions of Fungi and Bacteria].

1988 ◽  
Author(s):  
J. E. M. Mordue
Keyword(s):  
New Zealand ◽  
North America ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
Infected Plant ◽  
Growing Season ◽  
Republic Of Georgia ◽  
Borago Officinalis ◽  
Plant Remains ◽  
Water Splash

Abstract A description is provided for Entyloma serotinum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Symphytum spp., including S. asperrimum, S. bulbosum, S. cordatum, S. officinale, S. ottomanum and S. tuberosum; Borago officinalis; also recorded on Amsinckia, Lappula and Mertensia spp. (in USA) and Pulmonaria (in Europe, but see 64, 4163). DISEASE: Leaf spot of Symphylum, less frequently (though with similar symptoms) of other members of the Boraginaceae.GEOGRAPHICAL DISTRIBUTION: Africa: Algeria. Asia: Israel, USSR (Republic of Georgia). Australasia: New Zealand. Europe: widespread, including Austria, British Isles, Czechoslovakia, Denmark, France (including Corsica), Germany, Hungary, Italy, Netherlands, Poland, Portugal, Romania, Spain, Switzerland, USSR (Latvia), Yugoslavia. North America: USA. TRANSMISSION: Ustilospores survive on infected plant remains and in soil, and germinate to infect seedlings and the new seasons's leaves. In Europe conidia may also over-winter and initiate new infections in spring (Kaiser, 1936). During the growing season, conidia are disseminated by air currents and water-splash.

scholarly journals Rust and leaf spot diseases on American elderberry plants

2017 ◽  
Author(s):  
◽  
Kaley Hensel
Keyword(s):  
Leaf Spot ◽  
Dry Weight ◽  
Growing Season ◽  
Significant Loss ◽  
Leaf Wetness ◽  
Conservative Estimate ◽  
Sambucus Nigra ◽  
Shoot Dry Weight ◽  
Harvest Dates ◽  
High Level

Elderberry rust (Puccinia sambuci Schewin.) Arthur (=P. bolleyana) and leaf spot diseases are frequently found in commercial American elderberry (Sambucus nigra L. subsp. canadensis L.) plantings throughout the growing season in Missouri. Thus, studies were conducted to ascertain if rust infections affect plant growth, fruiting, or berry puree quality. Rust symptoms were observed in early April at 9 to 18[degrees] C, [greater than or equal to] 3 h leaf wetness, and [greater than or equal to] 85% relative humidity. When young, potted elderberry plants averaged 3 to 6 rust pustules/plant, vegetative growth was not adversely affected. However, field-grown elderberry plants heavily infected with rust (137 pustules/cane) lost nearly twice as many leaves as controls during the growing season, indicating rust-induced defoliation. Shoot dry weight of these heavily infected canes was also 32% less than that of controls. First and last harvest dates were advanced by the high level of rust infection on 'Wyldewood' elderberry canes, but not by low pustules numbers ([less than] 6 pustules/plant) on 'Bob Gordon' or 'Ozark' plants. Similarly, berry yields were not significantly different at low infection levels, even though rust-infected 'Bob Gordon' plants had a 31% reduction in yield with an estimated $440/ha loss of income. Heavily-infected 'Wyldewood' canes had a significant loss in berry yield (47%) and potential income ($2,295/ha), assuming a conservative estimate of five canes/plan. In another study, Colletotrichum was isolated from elderberry leaf spot lesions and identified before subsequent re-inoculation of elderberry plants with this pathogen. Three species of Colletotrichum (C. salicis Funkel, C. kahawae subsp. ciggaro Wollenw., and C. aenigma C.M. Tian and Z. Li) were putatively identified as being casual agents of leaf spot indicating the diversity of species within this genus on elderberry plants.

scholarly journals Evaluation of experimental designs in durum wheat trials

2015 ◽  
Vol 52 (2) ◽  
pp. 105-114
Author(s):  
Anastasios Katsileros ◽  
Christos Koukouvinos
Keyword(s):  
Durum Wheat ◽  
Block Design ◽  
Field Trials ◽  
Experimental Designs ◽  
Incomplete Block ◽  
Wheat Genotypes ◽  
Randomized Complete Block Design ◽  
Experimental Plots

Abstract Variability among experimental plots may be a relevant problem in field genotype experiments, especially when a large number of entries are involved. Four field trials on 24 durum wheat genotypes were conducted in 2013/14 in order to evaluate the efficiency of Incomplete Block, Alpha and Augmented designs in comparison with the traditional Randomized Complete Block Design (RCBD). The results showed that the RCBD can be replaced by an Alpha design, which provides better control of variability among the experimental units when the number of treatments to be tested in an experiment exceeds twenty. The ranking of the genotypes across the four designs was not constant.

scholarly journals Enviromic assembly increases accuracy and reduces costs of the genomic prediction for yield plasticity

2021 ◽  
Author(s):  
Germano MF Costa-Neto ◽  
Jose M F Crossa ◽  
Roberto F Fritsche-Neto
Keyword(s):  
Phenotypic Variation ◽  
Field Trials ◽  
Proof Of Concept ◽  
Tropical Maize ◽  
Early Screening ◽  
Environmental Similarity ◽  
Genetic And Environmental Factors ◽  
Growing Conditions ◽  
Algorithm Scheme

Quantitative genetics states that phenotypic variation is a consequence of genetic and environmental factors and their subsequent interaction. Here, we present an enviromic assembly approach, which includes the use of ecophysiology knowledge in shaping environmental relatedness into whole-genome predictions (GP) for plant breeding (referred to as E-GP). We propose that the quality of an environment is defined by the core of environmental typologies (envirotype) and their frequencies, which describe different zones of plant adaptation. From that, we derive markers of environmental similarity cost-effectively. Combined with the traditional genomic sources (e.g., additive and dominance effects), this approach may better represent the putative phenotypic variation across diverse growing conditions (i.e., phenotypic plasticity). Additionally, we couple a genetic algorithm scheme to design optimized multi-environment field trials (MET), combining enviromic assembly and genomic kinships to provide in-silico realizations of the future genotype-environment combinations that must be phenotyped in the field. As a proof-of-concept, we highlight E-GP applications: (1) managing the lack of phenotypic information in training accurate GP models across diverse environments and (2) guiding an early screening for yield plasticity using optimized phenotyping efforts. Our approach was tested using two non-conventional cross-validation schemes to better visualize the benefits of enviromic assembly in sparse experimental networks. Results on tropical maize show that E-GP outperforms benchmark GP in all scenarios and cases tested. We show that for training accurate GP models, the genotype-environment combinations' representativeness is more critical than the MET size. Furthermore, we discuss theoretical backgrounds underlying how the intrinsic envirotype-phenotype covariances within the phenotypic records of (MET) can impact the accuracy of GP and limits the potentialities of predictive breeding approaches. The E-GP is an efficient approach to better use environmental databases to deliver climate-smart solutions, reduce field costs, and anticipate future scenarios.

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