Factors Influencing Phytophthora infestans Mont. de Bary Attack Degree in Potato

摘要

The strong relationship between the late blight and climatic factors (namely temperature and rainfall)? has? important? consequences? on? potato? crops.? In? Romania,? in? early? spring? and? early? fall? the attack? degree? of? the? Phytophthora infestans? Mont.? de? Bary,? late? blight? pathogen,? is? low? because? in European? climate? average? temperature? is? not? more? than? 10 0C,? and? usually? the? rainfall? supply? is reduced;? it? increases? in? late? spring? and? summer? when? average? temperatures? are? around? 20 0C? and rainfall average more that 65 mm/month. The aim of this paper is to describe the relationship between temperature, rainfall regimen and late blight attack degree in potato cultures. The research was carried on? during? two? years,? 2009? and? 2010,? in? three? experimental? fields? from? Transylvania:? R??h??u,? Alba; Maieru,? Bistri?￡a-N??s??ud;? Dragu?,? Bra?ov.? Classical? methodology? was? used? for? monitoring.? The? data were statistically processed using STATISTICA? v. 7.0 programme. The interrelation attack degree - abiotic? factors? reflects? a? maximum? intensity? of? the Phytophthora infestans? Mont.? de? Bary? attack degree by the entire year 2009 around 42 % recorded when the rainfall average values begin with 110 mm? and? thermic? conditions? correspondent? to? values? bigger? than? 20 0C.? In? the? year? 2010? the multiregression? analyze? of? the? monitored? interactions,? led? to? a? very? strong? multiple? correlation coefficient? of? 0.938? representative? in? share? of? 87.90%.? In? 2010,? by? the? entire? monitored? period,? the rainfall supply had a bigger influence on the attack degree compared to thermic conditions. In 2009, the predicted biggest recorded attack degree of Phytophthora infestans de Bary was of 44% while in 2010 it was of 40 %, correspondent to rainfall and temperature regimens.