Differential accumulation patterns of phosphorus and potassium by canola cultivars compared to wheat

The phosphorus (P) and potassium (K) accumulation patterns of canola ( Brassica napus L.) are poorly understood, although such information is essential for determining optimal P‐ and K‐fertilizer strategies. This study investigated the patterns of P and K uptake and distribution among plant organs of three early or midmaturing canola cultivars (Tribune, Trigold, and Boomer) differing in K efficiency compared to wheat ( Triticum aestivum L. cv. Nyabing). Plants were grown in a glasshouse with nonlimiting P and K supply and harvested at eight growth stages until maturity. Maximum P accumulation by all canola cultivars occurred during late flowering (GS 5,5; 84 d after sowing), whereas P accumulation in wheat plants peaked just prior to anthesis (Z59; 73 d after sowing). Maximum accumulation of K in canola cultivars Tribune and Trigold occurred 73 d after sowing (GS 4,8), but peaked earlier (61 d after sowing) in Boomer canola (GS 4,2) and Nyabing wheat (Z55). The results highlight the importance of early P and K supply to both species; however, the extended uptake of P and K by the canola cultivars Trigold and Tribune compared to wheat suggests that availability of soil P or K postflowering may be of more importance to canola than to wheat.