Abstract: (7737 Views)
Rainfed wheat is one of the major agricultural crops in Kurdistan province
that includes most of the cultivated area. Agricultural production is affected
by risks, resulted from weather and international markets. Although these
risks could never completely been removed, we can minimize their effects
by realizing the affecting parameters involved in plant growth and crop
yield. In this study the impacts of effective agroclimatological indices and
climatic elements have been identified for each phenophase of rainfed wheat
yield in Kurdistan province. For this purpose, rainfed wheat yield data for
Kurdistan province, and its counties were obtained from The Ministry of
Jahde Agriculture for the period 1991-2006. Moreover, Necessary weather
parameters of all the weather stations in Kurdistan province for the period
1991-2006(1993-2006 for Marivan station) were obtained from Iranian
National Meteorological Organization. Correlation and nearest neighboring
methods were used for retrieval of the missing data. Then, linear and
nonlinear correlations between rainfed wheat yield and 6 agroclimatological
indices (TD, GDD, HTU, PTU, VPD, PET) and 11 climatic elements
(T
max,Tmin, R, Rday, RH, Tabsmin, Tabsmax, FFmean, FFabsmax, TS, Tmean
) in 6
pheneological phase of rainfed wheat growth from sowing to harvest, were
extracted. The results of this study show that the effective variables in each
phenophase of rainfed wheat yield growth are; temperature in the first
phenophase (Early Seedling stage, from October 7 to November 6);
precipitation in the second phenophase (the First Stage of Active Vegetative
before Dormancy stage, from November 7 to December 11); temperature
variations in the third phenophase (Dormancy Stage, from December 12 to
March 15); relative humidity and the absolute amount of minimum
temperature in the fifth phenophase (Reproductive Stage, from May 11 to
June 9); and relative humidity in the sixth phenophase (Maturity Stage, from
June 10 to July 10). In the fourth phenophase (the Second Stage of Active
Vegetative after dormancy stage, from March 16 to May 10) none of the
extracted variables and indices have a significant relation with rainfed wheat
yield. This shows that wheat plant obtains necessary climatic elements from
previous phenophases and continues its growth in this stage.
Received: 2010/02/17 | Accepted: 2010/05/4 | Published: 2012/09/10