پاسخ نموی ارقام بهاره گندم نان اقلیم معتدل به تعجیل و تأخیر در کاشت و ارتباط آن با تحمل سرما

To investigate effects of planting dates (early, regular, and late) on phenological changes of shoot apical
development and its relation to cold tolerance; an experiment was carried out on Islamabad Agricultural
Research Station as split-plot based on Randomized Complete Block Design (RCBD) with three replicates at
2013-14 cropping cycle. Four new spring-bread-wheat cultivars (ChamranII, Parsi, Sivand & Sirwan) with
Bahar and Pishtaz (as check) as sub-plots were compared at three different planting dates (early, regular and
late) as main-plots. Based on the results, on early planting date, Pishtaz and Sirwan were prior than other
cultivars to single ridge stage; and also these two, were more sensitive cultivars to cold stress versus
ChamranII, that was more tolerant to cold. On regular planting date, terminal spikelet stage was took place
at Sirwan, and rest of cultivars were arranged respectively as ChamranII, Parsi, Pishtaz, Sivand and Bahar.
Cold damage signs were visible on Pishtaz and Sirwan leaves, and it seemed that ChamranII was again more
tolerant cultivars. On late planting date, terminal spikelet stage was took place on Sirwan earlier, and rest
cultivars were arranged respectively as Parsi, Pishtaz, ChamranII, Sivand and finally Bahar; and also there
were not any cold injury symptoms on leaves of these plants, because of low temperature affects on seeds
germination postponement.