Field survival of Xanthomonas cucurbitae, the causal agent of bacterial spot of pumpkin, and efficacy of selected chemicals and biocontrol agents for control of the diseases
type: CreativeWork
description: Bacterial spot, caused by Xanthomons cucurbitae, has become one of the most important diseases of pumpkins in Illinois. This research was conducted to assess survival of X. cucurbitae in commercial fields, and to evaluate efficacy of selected chemicals and biocontrol agents for control of bacterial spot of pumpkin. To assess survival of X. cucurbitae in the field, a factorial experiment was setup at the University of Illinois Fruit and Vegetable Research Farm in Urbana, IL. Field location, plant tissue, burial depth, and recovery date were the experimental factors. The experimental unit was either five infected leaves or two infected fruit pieces (10 cm × 10 cm), which were placed in fiber glass mesh and buried either at 0-10 cm or 10-20 cm deep on 7 October 2011. The samples were recovered on 7 April, 7 July, and 7 October 2012; and 7 January, 7 April, and 7 October 2013 and processed for presence of X. cucurbitae. The location of the field did not significantly (P = 0.7895) affect the number of X. cucurbitae CFUs recovered from the samples. However, survival of X. cucurbitae was significantly affected by burial depths (P = 0.08), the plant tissue (P = 0.001) and time period of plant tissue in soil (P = 0001). X. cucurbitae survived for 24 months in both infected pumpkin leaf and fruit tissues in the soil. Seventeen chemicals and five biocontrol agents were tested in laboratory and field for their efficacy for control of bacterial spot. Ten isolates of X. cucurbitae were tested in nutrient broth (NB) and casitone yeast extract broth (CYE). Laboratory studies of chemicals were conducted to determine effective concentrations for 50% and 100% reduction in cell multiplication (EC50 and EC100) of X. cucurbitae. The EC50 values of the chemicals ranged from 0.17 ppm mancozeb (Dithane) to 64.53 ppm cuprous oxide (Nordox) in NB, and from 0.23 ppm mancozeb (Dithane) to 38.87 ppm cuprous oxide (Nordox) in CYE. Similarly, the EC100 values of the chemicals ranged from 1 ppm man…
abstract: Bacterial spot, caused by Xanthomons cucurbitae, has become one of the most important diseases of pumpkins in Illinois. This research was conducted to assess survival of X. cucurbitae in commercial fields, and to evaluate efficacy of selected chemicals and biocontrol agents for control of bacterial spot of pumpkin. To assess survival of X. cucurbitae in the field, a factorial experiment was setup at the University of Illinois Fruit and Vegetable Research Farm in Urbana, IL. Field location, plant tissue, burial depth, and recovery date were the experimental factors. The experimental unit was either five infected leaves or two infected fruit pieces (10 cm × 10 cm), which were placed in fiber glass mesh and buried either at 0-10 cm or 10-20 cm deep on 7 October 2011. The samples were recovered on 7 April, 7 July, and 7 October 2012; and 7 January, 7 April, and 7 October 2013 and processed for presence of X. cucurbitae. The location of the field did not significantly (P = 0.7895) affect the number of X. cucurbitae CFUs recovered from the samples. However, survival of X. cucurbitae was significantly affected by burial depths (P = 0.08), the plant tissue (P = 0.001) and time period of plant tissue in soil (P = 0001). X. cucurbitae survived for 24 months in both infected pumpkin leaf and fruit tissues in the soil. Seventeen chemicals and five biocontrol agents were tested in laboratory and field for their efficacy for control of bacterial spot. Ten isolates of X. cucurbitae were tested in nutrient broth (NB) and casitone yeast extract broth (CYE). Laboratory studies of chemicals were conducted to determine effective concentrations for 50% and 100% reduction in cell multiplication (EC50 and EC100) of X. cucurbitae. The EC50 values of the chemicals ranged from 0.17 ppm mancozeb (Dithane) to 64.53 ppm cuprous oxide (Nordox) in NB, and from 0.23 ppm mancozeb (Dithane) to 38.87 ppm cuprous oxide (Nordox) in CYE. Similarly, the EC100 values of the chemicals ranged from 1 ppm man…
author: Thapa, Sita
language: en
keywords: Chemicals, Biocontrol agents, Xanthomonas cucurbitae, Survival
date published: 2014-05-30T16:49:38Z
date modified: 2026-07-22T22:25:38Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/49553