Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/1/2005
Publication Date: 4/1/2005
Citation: Johnson, R.C., Dajue, L., Foiles, C.L., Bradley, V.L. 2005. Variation In Winter Hardiness Among Safflower Accessions. In: Proceedings of the 6th International Safflower Conference, June 6-10, 2005, Istanbul, Turkey. p. 113-118.
Interpretive Summary: In many areas worldwide, winter hardy safflower would provide important management alternatives for farmers. Winter safflower would enhance fall and early spring plant development so that higher seed yield would be expected than with spring sowing. With earlier maturity, crop development of winter safflower would occur when temperatures are lower and moisture more plentiful than for spring sown safflower. Safflower, as a dicot, is potentially an excellent rotation crop with winter annual monocots such as wheat in semiarid regions. Winter hardiness of diverse safflower types were determined and related to growth factors. The results of this study lead to two overall conclusions. First, for the material studied, prostrate habit in the fall was an essential component of winter survival potential, but by itself did not ensure a high level of winter hardiness and survival. Physiological mechanisms of cold acclimation were apparently not directly linked to prostrate habit. Second, BJ-27 had the highest winter survival of the accessions tested, sufficiently high to be used to develop safflower for fall planting in many areas. Winter survival would be less than assured in locations such as Pullman, WA, but prospects for consistent winter survival appear quite good for climates such as Central Ferry, WA, at lower elevation and with consistently milder conditions.
Technical Abstract: Fall planted safflower (Carthamus tinctorius L.) would provide management alternatives in crop rotations and potentially increase yield. Our objective was to relate several fall growth factors to winter survival in a diverse set of 11 safflower accessions grown at Central Ferry and Pullman WA, USA.. Safflower was sown in September 2002 and 2003 and plant population counts were taken 6-8 weeks after emergence. A subsample from each plot was also taken for measurements of plant habit, plant height, stem diameter, and shoot dry weight. After the last forst in the spring, plant counts were taken to calculate winter survival. The Pullman plots in 2003-04 were lost during an usually cold and windy November but survival in the remaining three environments ranged from 90% for BJ-27 to zero for Saffire. Winter survival was negatively correlated with plant habit (r = -041**, n=98) and plant height (r = -0.29**, n=98) but some accessions had low habit and height values but relatively poor survival. The results show that BJ-27 had winter survival high enough to develop winter safflower, and prostrate, shorter plant habit can predict the potential for winter survival but physiological factors related to the cold acclimation process appeared to determine if that potential was realized.