Tomato Early Blight Research Articles

284 EVALUATION OF THREE DISEASE FORECASTING SYSTEMS FOR CON-l-ROLLING EARLY BLIGHT ON STAKED OR GROUND CULTURE TOMATOES IN NEW JERSEY

Since 1990, FAST - Pennsylvania State University, CUFAST - Cornell University. and TOM-CAST - Ridgetown College, Ontario, three systems for forecasting early blight, have been field tested at The Snyder Research and Extension Farm in northwestern New Jersey for their potential use in fresh market tomato production in that area of the state. In 1993, the number of fungicide applications for tomato early blight control required by the three forecast systems was less than the number required following a weekly schedule. FAST and CUFAST scheduled applications of chlorothalonil, 1.5 lb per acre, reduced disease severity, hut TOM-CAST scheduled applications did not reduce disease severiety compared to the untreated control. Culture did not affect disease control results hut did affect disease incidence and post-harvest losses. Total and marketable yields were not affected by fungicide application schedule. Potential cost savings of $270 or $465 per acre, resulting from reduced numbers of fungicide applications following CUFAST or FAST. were estimated. Chemical name used: tetrachloroisophtalonitrile (chlorothalonil).

Isolation and characterization of a 25 kDa antifungal protein from flax seeds

We have purified a 25 kDa protein from flax seeds to homogeneity by polyethyleneimine precipitation, ammonium sulfate precipitation, chitin extraction, Mono S cation exchange and C18 reversed phase column chromatographies. The purified protein strongly inhibited the growth of the agronomically important pathogen Alternaria solani, the causative agent of tomato early blight and in synergy with nikkomycin Z strongly inhibited the human pathogen Candida albicans. Amino terminal sequence analysis of the purified protein indicated that it has a high degree of homology to other reported pathogenesis-related antifungal proteins.

Isolation and characterization of a 22 kDa protein with antifungal properties from maize seeds

We have purified a 22 kDa protein from maize seeds to homogeneity by ammonium sulfate precipitation, chitin extraction and Mono-S column chromatography. The purified protein inhibited the growth of the agronomically important pathogens of potato wilt (Fusarium oxysporum) and tomato early blight (Alternaria solani). Sequence analysis of the purified protein showed that it has 52% homology with the sweet protein thaumatin (Edens, L., Hselinga, L., Klok, R., Ledeboer, A. M., Maat, J., Toonen, M. Y., Visser, C., and Verrips, C. (1982) Gene 18, 1-12), 57% homology with the pathogenesis-related protein (Cornelissen, B. J. C., Huijsduijnen, R. A. M., and Bol, J. F. (1986) Nature 321, 531-532) and 99% homology with the 22 kDa trypsin/alpha-amylase inhibitor (Richardson, M., Valdes-Rodriguez, S., and Blanco-Labra, A. (1987) Nature 327, 432-434).

Heritability of Tomato Early Blight Resistance Derived from Lycopersicon hirsutum P.I. 126445

Abstract Early blight resistance was estimated in field plots for parents and F1, F2, and backcross progenies of crosses with NC EBR-1, a line derived from Lycopersicon hirsutum P.I. 126445. Areas under the disease progress curve (AUDPC) showed that resistance from NC EBR-1 was heritable and quantitative in nature. generation means in two families were intermediate to those of NC EBR-1 and susceptible parents. The distribution of AUDPC means for the different generations in both families indicated the presence of epistasis or gene linkage. Lack of fitness tests for curve-linearity confirmed this in one family. A, B, and C scaling tests showed similar results. A joint three-factor model and subsequently a six-factor model displayed the presence of epistasis in both families. Ignoring epistatic effects, narrow-sense heritability (h2) was 0.49 in one family and 0.40 in the other. By regressing F3 progeny AUDPC means on selected F2 plant values, h2 was 0.25 and 0.17, respectively.

Tomato Early Blight Resistance in a Breeding Line Derived from Lycopersicon hirsutum PI 126445

Tomato Early Blight Resistance in a Breeding Line Derived from Lycopersicon hirsutum PI 126445

Influence of Chronic Sulfur Dioxide Exposures on Early Blight of Tomato

Influence of Chronic Sulfur Dioxide Exposures on Early Blight of Tomato

The effect of sulphur dioxide on the incidence and severity of bean rust and early blight of tomato

The effects of relatively low concentrations of SO 2 (less than 20 pphm) on the incidence and severity of bean rust and early blight of tomato were studied. Sulphur dioxide affected bean rust and early blight of tomato under the conditions used in these experiments. The effect of SO 2 on bean rust consisted of a decrease in the incidence and severity of the disease and in the size and percentage germination of uredospores. These effects resulted from exposure of plants to SO 2 before or after inoculation with the pathogen, but exposures before inoculation were more effective.

Survey on major diseases of vegetable and fruit crops in Chittagong region

A survey was conducted during October 2006 to June 2008 to observe disease prevalence of vegetable and fruit crops in Chittagong region. Through the survey, 24 diseases with their incidence and severity were recorded. The average higher leaf infection in early blight of potato and fruit infection in soft rot of potato were recorded 37% and 39%, respectively. The highest leaf infection (43%) of early blight of tomato that was more frequented (mode) 36% in different locations with ±0.45% ranges (Standard error) for causing the disease as recorded at Sadar Anwara upazila of Chittagong. The highest fruit infection of soft rot of potato (43%) was recorded at Dohazari, Chandanaish upazila in Chittagong. The average of higher disease severity of leaf (27%) and fruit (33%) was recorded in early blight of tomato and soft rot of potato, respectively, and the highest disease severity of leaf (29%) and fruit (35%) was recorded in Phomopsis blight and early blight of tomato and soft rot of potato, respectively. Keywords: Diseases; vegetable; fruit; survey.DOI: 10.3329/bjar.v35i3.6449Bangladesh J. Agril. Res. 35(3) : 423-429

Influence of temperature and air-humidity on the development of leaf mold and early blight of tomato in the vinyl house

Influence of temperature and air-humidity on the development of leaf mold and early blight of tomato in the vinyl house

Effects of some fungicides on leaf mold and early blight of tomato

Effects of some fungicides on leaf mold and early blight of tomato

Effects of some fumigants on the conidial germination of leaf mold and early blight of tomato

Effects of some fumigants on the conidial germination of leaf mold and early blight of tomato

SPRAYING TOMATOES FOR THE CONTROL OF LEAF SPOT, EARLY BLIGHT AND LATE BLIGHT

Tomato leaf spot, early blight, and late blight were controlled effectively in the Ottawa district by six applications of the fixed copper COCS 55 or of Manzate (maneb). The split schedule consisting of three sprays with Manzate, followed by three sprays with COCS 55, or the tank mixture of these two fungicides, gave results comparable to those obtained with each of them alone. Some of the fungicides tested showed a degree of specificity in the control of certain diseases.