Efficacy of Metalaxyl, Fosetyl-Aluminum, and Straw Mulch for Control of Strawberry Leather Rot Caused by Phytophthora cactorum

Chemical and cultural controls for strawberry leather rot, caused by Phytophthora cactorum, were compared in replicated plots on a commercial farm near Wooster, Ohio. Straw mulch, applied uniformly for winter protection, was removed in early spring from between the rows of all check and fungicide treatment plots. Supplemental straw mulch was applied to other plots to achieve a level of approximately 9 t/ha. Overhead irrigation, which caused the soil to puddle, was provided on alternate days during rain-free periods to promote disease development (58, 66, and 73% incidence in check plots for 1993, 1994, and 1995, respectively). Foliar sprays of fosetyl-Al, applied weekly from bloom through preharvest at rates (a.i.) of 2.24 and 4.48 kg/ha, provided 88 to 96% control, with no significant difference between fungicide rates. Metalaxyl (1.17 kg/ha), applied either once or twice as a soil drench from early growth through fruit set, provided 82 to 94% control. Straw mulch alone provided 95 to 99% control. Thus, straw mulch between the rows was equally or more effective than fungicides for controlling leather rot.

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Efficacy of Azoxystrobin, Pyraclostrobin, Potassium Phosphite, and Mefenoxam for Control of Strawberry Leather Rot Caused by Phytophthora cactorum

Plant Health Progress ◽

10.1094/php-2005-0107-01-rs ◽

2005 ◽

Vol 6 (1) ◽

pp. 17 ◽

Cited By ~ 8

Author(s):

A. Rebollar-Alviter ◽

M. A. Ellis

Keyword(s):

Plant Growth ◽

Untreated Control ◽

Fruit Set ◽

Phytophthora Cactorum ◽

Fungicide Treatment ◽

Foliar Sprays ◽

Soil Drench ◽

Potassium Phosphite ◽

Excellent Control ◽

The U.S

Efficacy of azoxystrobin, pyraclostrobin, mefenoxam, and potassium phosphite for control of strawberry leather rot, caused by Phytophthora cactorum, was evaluated on a commercial farm. Foliar sprays of azoxystrobin, pyraclostrobin, and potassium phosphite were applied weekly from bloom through harvest and mefenoxam was applied twice as a soil drench at early plant growth and at fruit set. All fungicide treatments had significantly less leather rot than the untreated control and there were no significant differences in leather rot incidence between any fungicide treatment during both years of testing. Mefenoxam (Ridomil Gold) and potassium phosphite (ProPhyt) are currently registered for control of strawberry leather rot in the U.S. Although they are registered for use on strawberry, leather rot is not on the azoxystrobin (Abound) or pyraclostrobin (Cabrio) labels. Results from these studies indicate that both of these strobilurin fungicides provide excellent control of strawberry leather rot. Accepted for publication 28 November 2004. Published 7 January 2005.

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Cold Hardiness and Options for the Freeze Protection of Southern Highbush Blueberry

Agriculture ◽

10.3390/agriculture9010009 ◽

2019 ◽

Vol 9 (1) ◽

pp. 9 ◽

Cited By ~ 1

Author(s):

Erick D. Smith

Keyword(s):

Cold Hardiness ◽

Fruit Set ◽

Vaccinium Corymbosum ◽

Early Spring ◽

Climatic Conditions ◽

Critical Temperatures ◽

Overhead Irrigation ◽

Frost Protection ◽

Southern Highbush ◽

Freeze Protection

Southern highbush blueberries (SHB; Vaccinium corymbosum interspecific hybrid) are a low chill species of blueberry that are commercially grown in sub-tropical climates. Due to the nature of SHB, the flowering and fruit set occur in mid-winter to early spring and are susceptible to freeze damage. The most effective use of freeze protection is based on climatic conditions. Identification of advective or radiative freeze, intensity of the freeze event, and the equipment deployed are the key elements for deciding if the crop can be protected and justifying the expense to operate the system. Of the various methods used in frost protection, applying overhead irrigation water is the most promising. During a freeze event, an application of 6.3 mm ha−1 (0.10 in A−1) of water per hour is required to protect blueberries from −2.8 °C (27 °F) temperature with winds from 0 to 16 km h−1 (0 to 10 mph). This is 25.4 kL h−1 ha−1 (2715 gal h−1 A−1) of water. Overhead irrigation freeze protection is dependent on large volumes of water. This paper will review methods of freeze/frost protection, importance of weather patterns, and critical temperatures based on phenology of flowering to fruit set.

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Do s genes or deleterious recessives control late-acting self-incompatibility in Handroanthus heptaphyllus (Bignoniaceae)? A diallel study with four full sib progeny arrays

Annals of Botany ◽

10.1093/aob/mcab031 ◽

2021 ◽

Author(s):

Marta B Bianchi ◽

Thomas R Meagher ◽

Peter E Gibbs

Keyword(s):

Genetic Control ◽

Inbreeding Depression ◽

Fruit Set ◽

Genetic Model ◽

Pollen Tubes ◽

Self Incompatibility ◽

Significant Difference ◽

Partial Embryo ◽

Ovule Penetration ◽

S Genes

Abstract Background and Aims Genetically controlled self-incompatibility (SI) mechanisms constrain selfing and thus have contributed to the evolutionary diversity of flowering plants. In homomorphic gametophytic SI (GSI) and homomorphic sporophytic SI (SSI), genetic control is usually by a single multi-allelic locus S. Both GSI and SSI prevent self pollen tubes reaching the ovary and so are pre-zygotic in action. In contrast, in taxa with late-acting self-incompatibility (LSI), rejection is often post-zygotic, since self-pollen tubes grow to the ovary where fertilization may occur prior to floral abscission. Alternatively, lack of self fruit set could be due to early-acting inbreeding depression (EID). The aim of our study was to investigate mechanisms underlying lack of selfed fruit set in Handroanthus heptaphyllus in order to assess the likelihood of LSI versus EID. Methods We employed four full sib diallels to study the genetic control of LSI in Handroanthus heptaphyllus using a precociously flowering variant. We also used fluorescence microscopy to study the incidence of ovule penetration by pollen tubes in pistils that abscised following pollination or initiated fruits. Key Results All diallels showed reciprocally cross-incompatible full-sibs (RCI), reciprocally cross compatible full-sibs (RCC), and non-reciprocally compatible full-sibs (NRC) in almost equal proportions. There was no significant difference between the incidence of ovule penetrations in abscised pistils following self- and cross-incompatible pollinations, but those in successful cross pollinations were around twofold greater. Conclusions A genetic model postulating a single S locus with four s alleles, one of which, in the maternal parent, is dominant to the other three, will produce RCI, RCC and NRC situations each at 33 %, consistent with our diallel results. We favour this simple genetic control over an early-acting inbreeding depression (EID) explanation since none of our pollinations, successful or unsuccessful, resulted in partial embryo development, as would be expected under a whole genome EID effect.

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Bacterial Leaf Spot of Celery in California: Etiology, Epidemiology, and Role of Contaminated Seed

Plant Disease ◽

10.1094/pdis.1997.81.8.892 ◽

1997 ◽

Vol 81 (8) ◽

pp. 892-896 ◽

Cited By ~ 8

Author(s):

E. L. Little ◽

S. T. Koike ◽

R. L. Gilbertson

Keyword(s):

Pseudomonas Syringae ◽

Leaf Spot ◽

Disease Incidence ◽

Field Tests ◽

Hot Water ◽

Disease Development ◽

Bacterial Leaf Spot ◽

Overhead Irrigation ◽

Celery Seed ◽

Salinas Valley

Pseudomonas syringae pv. apii, causal agent of bacterial leaf spot (BLS) of celery, was first identified in California in 1989. By 1991, BLS was apparent in all celery-growing areas of the state. Greenhouse-produced transplants were affected most severely, and disease incidence approached 100% in some greenhouses. In this study, sources of inoculum and factors contributing to disease development were investigated in three Salinas Valley greenhouse operations during the 1991, 1992, and 1993 celery transplant seasons (January to August). Epiphytic P. syringae pv. apii was not detected on celery transplants until April or May of each year. Increased epiphytic populations preceded BLS outbreaks, and high-pressure, overhead irrigation favored bacterial infiltration and disease development. In seed-wash assays, P. syringae pv. apii was recovered from 5 of 24 commercial celery seed lots. In field tests, epiphytic P. syringae pv. apii was found on umbels of inoculated celery plants, and seeds from these plants were heavily contaminated with P. syringae pv. apii. Contaminated seed produced seedlings with large epiphytic P. syringae pv. apii populations. Hot-water treatment (50°C for 25 min) eliminated >99.9% of seed contamination. Based on these results, disease management techniques are proposed.

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EARLY SPRING APPLICATION OF AMINOETHOXYVINILGLYCINE (AVG) INCREASES FRUIT SET AND YIELD OF ‘ROCHA’ PEARS

Revista Brasileira de Fruticultura ◽

10.1590/0100-29452017982 ◽

2017 ◽

Vol 39 (4) ◽

Cited By ~ 3

Author(s):

MATEUS DA SILVEIRA PASA ◽

BRUNO CARRA ◽

CARINA PEREIRA DA SILVA ◽

MARLISE NARA CIOTTA ◽

ALBERTO FONTANELLA BRIGHENTI ◽

...

Keyword(s):

Fruit Quality ◽

Fruit Set ◽

Block Design ◽

Quality Attributes ◽

Fruit Weight ◽

Early Spring ◽

Full Bloom ◽

Growing Seasons ◽

Randomized Block Design ◽

Return Bloom

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.

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Agronomic and Economic Responses of Spring Wheat to Management of Fusarium Head Blight

Plant Disease ◽

10.1094/pdis-92-9-1339 ◽

2008 ◽

Vol 92 (9) ◽

pp. 1339-1348 ◽

Cited By ~ 26

Author(s):

C. R. Hollingsworth ◽

C. D. Motteberg ◽

J. V. Wiersma ◽

L. M. Atkinson

Keyword(s):

Fusarium Head Blight ◽

Spring Wheat ◽

Growth Stage ◽

Red River ◽

Disease Development ◽

Cultivar Resistance ◽

Head Blight ◽

Fungicide Treatment ◽

Red River Valley ◽

Moderately Resistant

Spring wheat (Triticum aestivum) crop losses in the Red River Valley of Minnesota and North Dakota caused by Fusarium head blight (FHB) epidemics incited by Fusarium graminearum are common. Fungicide application is often recommended when environments promote disease development but benefits have not been fully evaluated when environment, cultivar resistance, and economic outcome are considered. Agronomic and economic characters were determined for cultivars with various resistance levels when treated with no fungicide; propiconazole at 63 g active ingredient (a.i.)/ha applied at Feekes growth stage (FGS) 2, tebuconazole at 126 g a.i./ha applied at FGS 10.51, or propiconazole at 63 g a.i./ha applied at FGS 2 followed by tebuconazole at 126 g a.i./ha applied at FGS 10.51. Revenue returned from FHB moderately susceptible (MS) cultivars was 8% greater than moderately resistant (MR) cultivars in low-disease environs but differences were not significant when disease was moderate. Deoxynivalenol accumulation in grain of MS and MR cultivars was unchanged by fungicide treatment. MS cultivars were economically more adventitious to grow than MR cultivars in both disease environments.

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Xylophilus ampelinus. [Descriptions of Fungi and Bacteria].

IMI Descriptions of Fungi and Bacteria ◽

10.1079/dfb/20056401050 ◽

1991 ◽

Author(s):

J. F. Bradbury

Keyword(s):

South Africa ◽

Geographical Distribution ◽

Bacterial Blight ◽

Early Spring ◽

Distribution Map ◽

Stunted Growth ◽

Leaf Spots ◽

Overhead Irrigation ◽

Sources Of Infection ◽

Xylophilus Ampelinus

Abstract A description is provided for Xylophilus ampelinus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Vitis vinifera. DISEASE: Bacterial blight of the grapevine; 'Tsilik marasi' in Greece; 'Maladie d'Oleron' in France; 'Mel nero' in Italy; 'Vlamsiekte' in South Africa. In early spring buds on infected spurs fail to open or make stunted growth which eventually dies. Affected spurs often appear slightly swollen because of hyperplasia of the cambial tissue. Cracks appear along such spurs and enlarge to form cankers. Young shoots may develop pale yellowish-green spots on the lowest internodes. These expand upwards on the shoot, darken, crack and develop into cankers. Cracks and later cankers also form on more woody branches later in spring. In summer, cankers are often seen on the sides of petioles causing a characteristic one-sided necrosis of the leaf. They may also appear on main and secondary flower and fruit stalks. Leaf spots and marginal necrosis sometimes occur. Gum formation is not necessarily a symptom. GEOGRAPHICAL DISTRIBUTION: South Africa, France, Greece (including Crete), Italy (including Sardinia and Sicily), Spain, Turkey (68, 367). (IMI Distribution Map 531, ed 2, 1986). TRANSMISSION: Bacteria are carried by moisture to wounds, leaf scars and other sites where infection may take place. Primary infection can take place without wounding. Grafting and pruning can cause much spread of the disease. Overhead irrigation contributes to spread and development (51, 551). Observations indicate that sources of infection survive in vines even after removal of visibly infected parts.

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Seasonality of Mansonia titillans during dam construction, Biritiba-Mirim, São Paulo State, Brazil

Biota Neotropica ◽

10.1590/s1676-06032013000100007 ◽

2013 ◽

Vol 13 (1) ◽

pp. 70-73 ◽

Cited By ~ 2

Author(s):

Frederico Alves D'Avila ◽

Almério de Castro Gomes

Keyword(s):

Early Spring ◽

Dry Season ◽

Southeastern Brazil ◽

Rank Test ◽

Late Winter ◽

Dam Construction ◽

Wet Season ◽

Paulo State ◽

Significant Difference ◽

Wilcoxon Rank Test

A two and a half year survey was conducted at a dam in southeastern Brazil. Shannon Traps were used for sampling. Kruskal-Wallis test showed little relation between rainfall and abundance. The data clearly show three abundance peaks, all of them in the end of the dry season, in consonance with the scarce literature existent. Although Kruskal-Wallis Test did not find a clear preference for the dry season, Pairwise Wilcoxon Rank Test revealed a significant difference between Fall and Spring samples. Ma. titillans population had a peak on late winter/early spring, close to the begin of wet season.

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Pollinator Insects and their Impact on Crop Yield of Mustard in Kusma, Parbat, Nepal

Journal of Institute of Science and Technology ◽

10.3126/jist.v24i2.27259 ◽

2019 ◽

Vol 24 (2) ◽

pp. 68-75

Author(s):

Narayan Subedi ◽

Indra Prasad Subedi

Keyword(s):

Crop Yield ◽

Fruit Set ◽

Apis Cerana ◽

Qualitative And Quantitative ◽

Significant Difference ◽

The Difference ◽

Four Blocks ◽

And Control ◽

The Impact ◽

Pod Length

The diversity of insect pollinators and their impact on crop yield of mustard were studied in Kusma, Parbat, Nepal from December 2018 to April 2019 in four blocks with each having 12 m2 areas. Two plots; treatment and control, were established in each block. Insect diversity was observed from 8 to 16 hrs, with the interval of an hour for three consecutive months (Jan-Feb). Eighty mustard plants were randomly selected, 40 from each plot just before flowering to find the impact of insect pollination on crop yield and these selected plants were examined for various qualitative and quantitative parameters. Altogether 16 species of pollinator insects belonging to five orders and nine families were recorded. Hymenoptera (36 %) was the most abundant order visiting mustard flowers followed by Diptera (34 %), Coleoptera (17 %), Lepidoptera (12 %) and Heteroptera (1 %). The most abundant family was Apidae (35.64 %), followed by Syrphidae (31.84 %). Apis cerana and Eristalis sp. were the most important pollinator insects of mustard. Seven species were found foraging both on pollen and nectar, four species foraging only on nectar and remaining five as casual visitors. The peak foraging activities of majority of the insects were observed between 12 hr to 14 hr. A significant difference was observed in the number of pods (59.80 ± 1.967 and 70.47 ± 2.431), fruit set (70.55 ± 1.362 and 80.94 ± 0.638), number of seeds per pods (16.70 ± 0.248 and 19.30 ± 0.330), diameter of seed (0.133 ± 0.2547 and 0.275 ± 0.0051) and weight of 100 dry seeds (0.33 ± 0.058 and 0.48 ± 0.023) in control and treatment plots whereas, the difference was non-significant in case of pod length between control and treatment plots (P=0.163).

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Seedling vigour in wheat - sources of variation for genetic and agronomic improvement

Australian Journal of Agricultural Research ◽

10.1071/ar00147 ◽

2002 ◽

Vol 53 (1) ◽

pp. 41 ◽

Cited By ~ 107

Author(s):

R. A. Richards ◽

Z. Lukacs

Keyword(s):

Linear Correlation ◽

Slow Growth ◽

Early Growth ◽

Seedling Vigour ◽

Breeding Programs ◽

Significant Difference ◽

Positive Linear Correlation ◽

Sources Of Variation ◽

And Performance ◽

Seed Characteristics

The early growth of wheat is slow compared with that of barley and triticale. This is expected to limit the yield of wheat in environments where greater seedling vigour is advantageous. To overcome the slow growth of wheat, genetic sources of seedling vigour are required for use in breeding programs, and/or ways to increase seedling growth by manipulating seed characteristics. This study reports (i) new sources of and 3 heights at cutting (cutting was done when the grass reached 0.5, 1, and 1.5 m above the ground). The N fertiliser treatment did not yield any significant difference in DMD, ND, or IVDMD. Height at cutting had a significant (P < 0.05) effect on rumen DMD and ND and their degradability characteristics for all incubation times. There was a reduction in DMD and ND and their degradability characteristics as plant height increased at cutting. Similarly, as height at cutting increased there was a decline in IVDMD. There was a positive linear correlation between IVDMD and both DMD and ND at 48, 72, 96, and 120 h (r = 0.917, 0.923, 0.921, and 0.850 for DMD; r = 0.795, 0.814, 0.787, and 0.787 for ND). Hence, further study on intake and performance of animals is suggested to develop Napier-based diets for smallholders.

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