scholarly journals Weather Variables Associated with Infection of Tomato Fruit by Colletotrichum coccodes

Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 753-756 ◽  
Author(s):  
S. Sanogo ◽  
S. P. Pennypacker ◽  
R. E. Stevenson ◽  
A. A. MacNab
Keyword(s):  
Field Experiments ◽  
Tomato Fruit ◽  
Field Conditions ◽  
Colletotrichum Coccodes ◽  
Weather Variables ◽  
Tomato Plants ◽  
Growing Seasons ◽  
Central Pennsylvania ◽  
Best Fitting ◽  
Relationship Of

Field experiments were conducted to determine the relationship of tomato anthracnose to weather variables. Sixteen potted tomato plants were exposed to field conditions within rows of tomato plants for 4 consecutive days at various time periods during the 1993 and 1994 summer growing seasons. Incidence of fruit infection by Colletotrichum coccodes was correlated with rain variables (amount and duration of rain) alone and in combination with other meteorological factors. The best fitting regression equation, accounting for 72% of the variation in anthracnose incidence (arcsine-square root transformed), was Y = 111.77 - 1.16 HNRo, in which HNRo is the numbers of hours during which no rainfall occurs within 4-day intervals that tomato fruit were exposed to field conditions in central Pennsylvania.

scholarly journals The Role of Agrotechnical Factors in Shaping the Protein Yield of Maize (Zea mays L.)

2020 ◽  
Vol 12 (17) ◽  
pp. 6833
Author(s):  
Piotr Szulc ◽  
Katarzyna Ambroży-Deręgowska ◽  
Iwona Mejza ◽  
Joanna Kobus-Cisowska ◽  
Marta Ligaj
Keyword(s):  
Field Experiments ◽  
Atmospheric Precipitation ◽  
Weather Conditions ◽  
Protein Yield ◽  
Stay Green ◽  
Growing Seasons ◽  
Two Component ◽  
Maize Protein ◽  
Relationship Of ◽  
Np Fertilizer

The subject of the work was the evaluation of maize protein yield conditioned by various agrotechnical factors. The test results are derived from two different field experiments covering a total of seven years of observation. Protein yield was significantly dependent on changing weather conditions in the growing seasons. Protein yield was significantly lower in the dry and hot years. The sum of precipitation for the month of May was positively correlated with maize protein yield. However, there was no correlation between the average air temperature and the amount of protein yield. The sum of atmospheric precipitation for the entire growing season (IV–X) shaped maize protein yield in over 96%. A non-linear relationship of the 2nd degree was determined between these traits. Sowing maize into the soil cultivated traditionally (autumn tillage), “stay-green” type cultivars and row fertilization positively influenced maize protein yield. Initial fertilization (regardless of depth) with two-component NP fertilizer, in relation to broadcast fertilization, significantly increased maize protein yield from 11.4% to 18%, respectively. The type of nitrogen fertilizer did not differentiate the value of this trait. Pre-sowing nitrogen application was more effective compared to the top dressing, and significantly increased protein yield. Row fertilization with two-component NP fertilizer clearly affected the content protein in grain. The interdependence of genetic and agronomic progress is an important factor shaping the potential of maize protein yield and cannot be attributed to either breeding (cultivar) or agronomy.

Effect of Formulations and Spray Nozzles on 2,4-D Spray Drift under Field Conditions

2018 ◽  
Vol 32 (4) ◽  
pp. 379-384 ◽  
Author(s):  
Augusto Kalsing ◽  
Caio V. S. Rossi ◽  
Felipe R. Lucio ◽  
Luiz H. S. Zobiole ◽  
Luis C. V. da Cunha ◽  
...  
Keyword(s):  
Field Conditions ◽  
Soybean Plant ◽  
Spray Drift ◽  
Spray Nozzle ◽  
Sensitive Species ◽  
Tomato Plants ◽  
Affected Area ◽  
Growing Seasons ◽  
Angle Deviation ◽  
Conventional Field

Six trials were conducted during 2014/15 and 2015/16 growing seasons in Brazil to determine the effect of 2,4-D formulations and spray nozzles on 2,4-D spray drift under conventional field conditions. An experimental 2,4-D choline formulation with Colex-D® Technology (GF-3073) and a 2,4-D dimethylamine (DMA) formulation were applied with either XR and AIXR flat-fan spray nozzles. Each plot was 30 m wide by 24 m long (720 m2) with 60 glyphosate-resistant soybean rows spaced 50 cm apart and also 35 potted tomato plants distributed on a grid across the plot 5-m apart. Applications were performed one meter away from the plot edge perpendicular to the soybean rows when wind direction was parallel to the rows with less than 30 degrees of angle deviation. Spray drift treatments were applied in 100 L ha−1 with tractor sprayers at 276 kPa equipped with a 7-m wide boom at 50 cm above the canopy of the soybean plant, operating at 6.8 km h−1. The distance from the plot edge to the farthest plant with 2,4-D symptoms was assessed for every four soybean rows at 10 and 20 days after treatment (DAT) and potted tomatoes at 10 DAT. GF-3073 reduced the distance of the farthest injured plant with 2,4-D symptoms compared to the 2,4-D DMA formulation regardless of the spray nozzle, assessment date and sensitive species. GF-3073 applied through the AIXR nozzle reduced the relative drift affected area to the standard by 68% at 10 DAT and 67% at 20 DAT for soybean and 60% at 10 DAT for potted tomatoes.

scholarly journals Combination of biological control agents and garlic (allium sativum) extract in reducing damping-off disease of tomato

2019 ◽  
Vol 44 (3) ◽  
pp. 553-567 ◽  
Author(s):  
VO Dania ◽  
JA Omidiora
Keyword(s):  
Biological Control ◽  
Seed Treatment ◽  
Field Experiments ◽  
Block Design ◽  
Tomato Fruit ◽  
Fruit Yield ◽  
Field Conditions ◽  
Biological Control Agents ◽  
Damping Off ◽  
Seedling Mortality

Damping-off (Pythium aphanidermatum) is a soil-borne disease which accounts for seedling mortality and significant yield losses in tomato production. Laboratory and screenhouse experiments were conducted in 2017, with a repeated field trial in 2018 to evaluate the efficacy of combining three biological control agents (BCAs), Trichodermaviride, T. harzianumand Bacillus subtilis with Allium sativumextract for the integrated management of the disease in tomato crop. Treatments were laid out in a completely randomized design and randomized complete block design in the screenhouse and field experiments, respectively with eighteen treatments and three replications. The BCAs and extract were formulated and applied using seed treatment and soil sprinkling methods. Treatment combinations of BCAs with A. sativumwere more effective in the reduction of mycelial growth of the pathogen with inhibitory values that ranged between 77.6-91.2% than single inoculation. Seed treatment before planting was more effective than soil sprinkle method, reducing pre-emergence and damping-off incidence to between 6.8-18.3% and 9.7-26.3% under screenhouse and field conditions, respectively than the sprinkling method. Soil sprinkle with T. harzianumin combination with A. sativumextract had the highest cumulative tomato fruit yield of 902 kg/ha-1under field conditions. This study showed that combined application of BCAs and A. sativumextract reduced damping-off disease and thereby improved the fruit yield of tomato. Bangladesh J. Agril. Res. 44(3): 553-567, September 2019

scholarly journals Relationship of the Sweetpotato Whitefly to a New Tomato Fruit Disorder in Florida

HortScience ◽  
1990 ◽  
Vol 25 (12) ◽  
pp. 1618-1620 ◽  
Author(s):  
D.J. Schuster ◽  
T.F. Mueller ◽  
J.B. Kring ◽  
J.F. Price
Keyword(s):  
Lycopersicon Esculentum ◽  
Bemisia Tabaci ◽  
Tomato Fruit ◽  
Sweetpotato Whitefly ◽  
Field Cage ◽  
Tomato Plants ◽  
White Tissue ◽  
Relationship Of

A new disorder of fruit has been observed on tomato (Lycopersicon esculentum Mill.) in Florida. The disorder, termed irregular ripening, was associated with field populations of the sweetpotato whitefly, Bemisia tabaci (Gennadius) and is characterized by incomplete ripening of longitudinal sections of fruit. An increase in internal white tissue also was associated with whitefly populations. In field cage studies, fruit on tomato plants not infested with the sweetpotato whitefly exhibited slight or no irregular ripening, whereas fruit from infested plants did. Fruit from plants on which a whitefly infestation had been controlled before the appearance of external symptoms exhibited reduced symptoms compared to fruit from plants on which an infestation was uncontrolled.

scholarly journals Screening Cabbage Cultivars for Resistance to Black Rot under Field Conditions

2020 ◽  
Vol 30 (3) ◽  
pp. 448-455
Author(s):  
Andre Luiz Biscaia Ribeiro da Silva ◽  
Joara Secchi Candian ◽  
Elizanilda Ramalho do Rego ◽  
Timothy Coolong ◽  
Bhabesh Dutta
Keyword(s):  
Xanthomonas Campestris ◽  
Field Experiments ◽  
Management Practice ◽  
Field Conditions ◽  
Black Rot ◽  
Marketable Yield ◽  
Growing Seasons ◽  
Progress Curve ◽  
Initial Symptoms ◽  
Significant Difference

The use of resistant cultivars against Xanthomonas campestris pv. campestris (Xcc) is considered a critical management practice for black rot (BR) management in cabbage (Brassica oleracea var. capitata). Although most studies that have evaluated resistance to BR were conducted in greenhouses without accounting for yield, there is a clear need to investigate cultivar performance under field conditions. The objectives of this study were to evaluate commercial cabbage cultivars for resistance to BR and determine yield and head quality under field conditions. Field experiments with eight cultivars (Acclaim, Bravo, Capture, Celebrate, Cheers, Melissa, Monterey, and TCA-549) were conducted in two cabbage growing seasons, Fall 2018 and Spring 2019. Fields were spray-inoculated with Xcc (3 × 105 cfu/mL) at 35 and 49 days after transplanting in Fall 2018 and Spring 2019, respectively. Cabbage BR severity was evaluated at weekly intervals starting from 7 days postinoculation (DPI) until harvest. Marketable and unmarketable yields and cabbage head quality were measured at harvest. Cabbage BR symptoms were detected in all tested cultivars for both growing seasons with initial symptoms observed as early as 28 and 21 DPI in Fall 2018 and Spring 2019, respectively. Severity of cabbage BR at harvest was significantly greater in Fall 2018 compared with Spring 2019, whereas marketable yield was significantly higher in Spring 2019 (45,169 lb/acre) compared with Fall 2018 (26,370 lb/acre). In both growing seasons, ‘TCA-549’ had the lowest severity of BR and ‘Melissa’ had the highest severity of BR. Area under the disease progress curve (AUDPC) was 175 and 13 for ‘TCA-549’ in Fall 2018 and Spring 2019, respectively. The AUDPC for ‘Melissa’ in Fall 2018 and Spring 2019 were 2376 and 905, respectively. Regardless of growing season, cabbage marketable yield was higher for ‘Acclaim’ (51,760 lb/acre) compared with all other cultivars; however, there was no significant difference between Acclaim and TCA-549 (42,934 lb/acre) for cabbage marketable yield. Cabbage marketable yield was the lowest for cultivars Melissa (18,275 lb/acre) and Capture (24,236 lb/acre). Overall, there was a significant correlation between BR disease severity and cabbage marketable and unmarketable yields. Increasing the BR severity decreased cabbage marketability due to an increase in unmarketable yields. Continued development of cultivar resistance to BR is important for cabbage production in the southeastern United States, given the favorable conditions for disease development. The use of cultivars with low susceptibility, pathogen-free seeds, crop rotation, and proper spraying programs should be considered the best management practice for BR disease.

scholarly journals COR/LEA Proteins as Indicators of Frost Tolerance in Triticeae: A Comparison of Controlled versus Field Conditions

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 789
Author(s):  
Klára Kosová ◽  
Miroslav Klíma ◽  
Ilja Tom Prášil ◽  
Pavel Vítámvás
Keyword(s):  
Cold Acclimation ◽  
Field Experiments ◽  
Quantitative Relationship ◽  
Field Trials ◽  
Frost Tolerance ◽  
Late Embryogenesis Abundant ◽  
Field Conditions ◽  
Lea Proteins ◽  
Winter Cereals ◽  
Vernalisation Requirement

Low temperatures in the autumn induce enhanced expression/relative accumulation of several cold-inducible transcripts/proteins with protective functions from Late-embryogenesis-abundant (LEA) superfamily including dehydrins. Several studies dealing with plants grown under controlled conditions revealed a correlation (significant quantitative relationship) between dehydrin transcript/protein relative accumulation and plant frost tolerance. However, to apply these results in breeding, field experiments are necessary. The aim of the review is to provide a summary of the studies dealing with the relationships between plant acquired frost tolerance and COR/LEA transcripts/proteins relative accumulation in cereals grown in controlled and field conditions. The impacts of cold acclimation and vernalisation processes on the ability of winter-type Triticeae to accumulate COR/LEA proteins are discussed. The factors determining dehydrin relative accumulation under controlled cold acclimation treatments versus field trials during winter seasons are discussed. In conclusion, it can be stated that dehydrins could be used as suitable indicators of winter survival in field-grown winter cereals but only in plant prior to the fulfilment of vernalisation requirement.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Effect of Spaceflight on Tomato Seed Quality and Biochemical Characteristics of Mature Plants

Horticulturae ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 89
Author(s):  
Elena Dzhos ◽  
Nadezhda Golubkina ◽  
Marina Antoshkina ◽  
Irina Kondratyeva ◽  
Andrew Koshevarov ◽  
...  
Keyword(s):  
Seed Quality ◽  
Space Station ◽  
Field Conditions ◽  
Tomato Seed ◽  
Tomato Plants ◽  
Biochemical Characteristics ◽  
Tomato Seeds ◽  
Genetic Modifications ◽  
Total Antioxidant

Intensive space exploration includes profound investigations on the effect of weightlessness and cosmic radiation on plant growth and development. Tomato seeds are often used in such experiments though up to date the results have given rather vague information about biochemical changes in mature plants grown from seeds subjected to spaceflight. The effect of half a year of storage in the International Space Station (ISS) on tomato seeds (cultivar Podmoskovny ranny) was studied by analyzing the biochemical characteristics and mineral content of mature plants grown from these seeds both in greenhouse and field conditions. A significant increase was recorded in ascorbic acid, polyphenol and carotenoid contents, and total antioxidant activity (AOA), with higher changes in the field conditions compared to greenhouse. Contrary to control plants, the ones derived from space-stored seeds demonstrated a significant decrease in root AOA. The latter plants also showed a higher yield, but lower content of fruit dry matter, sugars, total dissolved solids and organic acids. The fruits of plants derived from space-stored seeds demonstrated decreased levels of Fe, Cu and taste index. The described results reflect the existence of oxidative stress in mature tomato plants as a long-term consequence of the effect of spaceflight on seed quality, whereas the higher yield may be attributed to genetic modifications.

FACTORS AFFECTING ADULT EMERGENCE AND MATING BEHAVIOR OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1975 ◽  
Vol 107 (9) ◽  
pp. 967-977 ◽  
Author(s):  
C. J. Sanders
Keyword(s):  
Field Experiments ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Field Conditions ◽  
Continuous Illumination ◽  
Degree Days ◽  
Factors Affecting ◽  
Eastern Spruce Budworm ◽  
Duration Of Copulation

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

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