Open AccessNitrogen Fertilizer Affects the Severity of Anthracnose Crown Rot Disease of Greenhouse Grown Strawberries
Author(s) -
Barbara J. Smith
Publication year - 2009
Publication title -
plant health progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.565
H-Index - 9
ISSN - 1535-1025
DOI - 10.1094/php-2009-0609-01-rs
Subject(s) - biology , crown (dentistry) , inoculation , fertilizer , horticulture , nitrogen , phosphorus , agronomy , potassium , nutrient , medicine , chemistry , ecology , dentistry , organic chemistry
The influence of nitrogen, phosphorus, and potassium on the severity of anthracnose crown rot was evaluated in three greenhouse studies. Strawberry plants were fertilized three times weekly with a modified Hoagland's Nutrient Solution containing the treatments and inoculated eight weeks after treatment applications began with a conidial suspension of the causal pathogen, Colletotrichum fragariae. Disease severity was rated 30 days later on a scale of 0 (no symptoms) to 6 (plant dead). In the first study, the effect of N, P, and K levels was evaluated using 16 treatments: eight N levels with either low P and K or high P and K. Disease severity ratings and percent foliar N increased as N level increased but were not influenced by the level of P and K. In two other experiments, seven N sources were each evaluated at three levels. Plants receiving 160 ppm N had higher disease severity ratings than plants receiving 0 or 40 ppm N. Among plants receiving 160 ppm N, those treated with Ca(NO 3 ) 2 had the least disease. When N fertilizer is applied to strawberry plants as Ca(NO 3 ) 2 , anthracnose crown rot severity should be less severe than when N is applied in ammonium forms. Accepted for publication 13 April 2009. Published 9 June 2009.