TY - JOUR T1 - Effect of genistein and planting dates on seed yield and yield components of three annual medic species TT - اثر تاریخ‌ کاشت و مصرف جنستئین بر عملکرد دانه و اجزای عملکرد سه گونه یونجه یکساله JF - agrobreed JO - agrobreed VL - 11 IS - 2 UR - http://agrobreedjournal.ir/article-1-211-en.html Y1 - 2009 SP - 151 EP - 161 KW - Annual medics KW - Genistein KW - Seed yield KW - Low temperature and Planting dates. N2 - In order to study the effect of genistein and planting date on seed yield and yield components of three annual medic species, an experiment was conducted in split-split plot arrangements using randomized complete block design with four replications in experimental field of Faculty of Agriculture, Tarbiat Modarres University, in 2001 and 2002 cropping seasons. Three annual medic species Medicago polymorpha cv. Santiago, M. rigidual cv. Rigidula and M. radiate cv. Radiata) adapted to cold and temperate zones were grown in three planting dates (20 February, 29 February and 10 March) with two levels of genistein concentrations (0 and 20 μM). The planting dates, species and genistein concentrations were assigned and randomized to the main plots, sub plots and sub-sub plots , respectively. The results showed that the effect of year on all traits (except number of pod per square meter) was significant (P < 0.01). Effect of planting date on all traits (except 1000 seed weight, seed number per pod, seed : pod ratio and 100 pod weight) was also significant (P < 0.01). The highest grain yield was harvested from the third planting date (i.e. March 10) with 850 kg.ha-1. The interaction of year  planting date was only significant on 1000 seed weight and dry matter. There were significant differences among species for all traits (P < 0.01). The interactions of year  species, species  planting date and year  species  planting date were significant on all traits except seed number per pod. Results also showed that genistein effect on all traits was significant except seed : pod ratio and 100 pod weight (P < 0. 01). Results of this experiment showed that genistein decreased negative effect of environmental temperature on nitrogen fixation, growth and development and seed yield of annual medics. Seed yield of annual medics increased in the second and third planting dates in comparison with the first planting date, due to increase environmental and soil temperatures. At the second and third planting dates, severe variation in air temperature at early vegetative season delayed growth and development of annual medics. Annual medic species showed positive response to genistein application by increasing growth and development and seed yield. M3 ER -