واكنش گندم به نقش حرارتي در شرايط مزرعه با استفاده از تاريخ كاشت هاي بهاره

چكيده انگليسي :

Wheat Responses to Temperature Stress under Field Conditions Using Spring Planting Dates Samira Sadat Tabatabaei Pozveh ss tabatabai@yahoo com 04 03 2009 Department of Agronomy and Plant Breeding Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiM R Khajehpoor Assoc Prof Supervisior mrkhpor@yahoo comAbstract Wheat responses to temperature stress were investigated at the Agriculture Research Station IsfahanUniversity of Technology in 2007 The experiment was laid out using a split split plot arrangement withina randomized complete block design with three replications Planting dates March 13 April 9 May 12 June 12 and July 13 were considered as the main plots The sub plots consisted of full sunlight andreduced sunlight 75 of full sunlight and the sub sub plots were Ghods and Roshan Back crosscultivars Developmental stages including days from planting to emergence emergence to jointing jointing toflowering and flowering to physiological maturity were measured Days from planting to emergence were reduced as planting was delayed Days from emergence to jointingwere reduced with delay from the first to fourth planting dates but increased in the fifth planting date Days from jointing to flowering and flowering to physiological maturity reduced with delay from the firstto third planting dates but increased in the fourth and fifth planting dates All developmental stagesincluding days from planting to physiological maturity were correlated with mean air temperatures Except for the days from planting to emergence other developmental stages were longer in reducedsunlight than full sunlight Plant developmental stages were similar between cultivars Plant dry weight at jointing leaf dry weight stem dry weight spike dry weight number of stems numberof spikes and plant dry weight at anthesis number of unfertile stems number of spikes number of seedsper spike and 1000 kernel weight plant dry weight grain yield and harvest index at maturity weremeasured Plant dry weight at jointing leaf dry weight stem dry weight number of stems number of spikes andspike dry weight at anthesis number of unfertile stems number of spikes and plant dry weight atmaturity grain yield and harvest index were reduced with delay from the first to fourth planting dates butincreased in the fifth planting date Number of seeds per spike and 1000 kernel weight were reduced withdelay from the first to the third planting dates but increased in the fourth and fifth planting dates Plant dry weight at jointing leaf dry weight stem dry weight number of stems number of spikes andspike dry weight at anthesis number of unfertile stems number of spikes and plant dry weight atmaturity seeds per spike 1000 kernel weight grain yield and harvest index were higher in reducedsunlight than full sunlight Leaf dry weight at anthesis and number of unfertile stems at maturity were higher in Roshan Backcrossthan Ghods cultivar No significant differences for other traits were observed between cultivars Grain yield was positively correlated with days from planting to emergence emergence to jointing jointing to flowering and flowering to physiological maturity Also grain yield was positively correlatedwith number of spikes at maturity number of seeds per spike and 1000 kernel weight It might be concluded that heat stress reduces plant yield and reduction in heat load by shading delaysdevelopment and increases yield components and grain yield Key words Wheat Temperature stress Full sunlight Reduced sunlight Planting date

طباطبائي پزوه، سميرا سادات

واكنش گندم به نقش حرارتي در شرايط مزرعه با استفاده از تاريخ كاشت هاي بهاره

نور كامل , سايه نسبي