Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4510222 | Field Crops Research | 2013 | 9 Pages |
Maize grains are formed after silking, but not all dry matter (DM), nitrogen (N), phosphorus (P) and potassium (K) deposited in grains are accumulated during grain filling. There is a conflict between sustaining post-silking photosynthesis and the remobilization and recycling of N, P and K from leaves to grain. To study the accumulation and partitioning patterns of DM, N, P and K after silking in maize with different leaf longevity, two field experiments with six maize varieties including early-senescing (old varieties) and stay-green leaves (new varieties) were conducted in successive years. The results demonstrated that new varieties had larger total leaf area and longer green leaf duration, and took up more N, P and K after silking than old varieties. Post-silking leaf appeared to provide sufficient assimilates for grain formation, while large amounts of N, P and K accumulated pre-silking were remobilized and exported from vegetative tissues, especially from leaves, in all varieties during grain filling. Post-silking leaf N export caused a large decrease in leaf N concentration in all maize varieties. Post-silking uptake of N and P account for 11–43% and 16–55% to total content of whole plants at maturity, but a post-silking loss of K from maize plants was observed, especially in old varieties. The export of N, P and K from leaves was similar in all varieties and an un-synchronized accumulation and partitioning of N, P and K during plant development was observed.
► We examined whether stay-green maize exported less N, P and K from leaves than early-senescing maize after silking. ► Post-silking gain and partitioning of DM, N, P and K were compared in six maize varieties in two years. ► Stay-green maize accumulated more NPK post-silking than early-senescing maize, but exported a comparable amount of NPK from leaves. ► There was a large decrease in leaf N concentration form silking to maturity in all maize varieties. ► N, P and K accumulation and partitioning during whole growth period of maize plants was un-synchronized.