Evaluating wheat yield potential determination in the Argentine Pampas.

MENÉNDEZ, F.J. & E.H. SATORRE

AGRICULTURAL SYSTEMS

Año: 2007 vol. 95 p. 1 - 10

0308-521X

The Argentinean Pampas are considered among the most productive areas of the world. However, few research has been done to explore its potential and constraining factors for wheat production. The objective of this paper was to evaluate variability of wheat yieldyield and yield components potential in the Pampas. For this purpose, a modelling approach was used using 30 years climatic series of various locations distributed along the Pampas. Two biologically founded assumptions related to wheat yield determination were used: (1) potential grain number (GN) is associated with a photothermal quotient (PTQ); and (2) potential grain weight (GW) depends on mean temperature during the grain .lling period (TGF). Mean wheat yield potential in the Pampas varied between 5000 kg ha1 in northern locations to 7300 kg ha1 in southern ones. GN showed greater variability than GW both, among locations (spatial scale) and years (temporal scale). Anthesis date appeared as a strong yield potential determinant factor; A 10-day delay in anthesis date produce substantial changes in GN and GW, depending on location latitude. This was related to the speci.c combination of crop phenological development and radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.yield components potential in the Pampas. For this purpose, a modelling approach was used using 30 years climatic series of various locations distributed along the Pampas. Two biologically founded assumptions related to wheat yield determination were used: (1) potential grain number (GN) is associated with a photothermal quotient (PTQ); and (2) potential grain weight (GW) depends on mean temperature during the grain .lling period (TGF). Mean wheat yield potential in the Pampas varied between 5000 kg ha1 in northern locations to 7300 kg ha1 in southern ones. GN showed greater variability than GW both, among locations (spatial scale) and years (temporal scale). Anthesis date appeared as a strong yield potential determinant factor; A 10-day delay in anthesis date produce substantial changes in GN and GW, depending on location latitude. This was related to the speci.c combination of crop phenological development and radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.yield determination were used: (1) potential grain number (GN) is associated with a photothermal quotient (PTQ); and (2) potential grain weight (GW) depends on mean temperature during the grain .lling period (TGF). Mean wheat yield potential in the Pampas varied between 5000 kg ha1 in northern locations to 7300 kg ha1 in southern ones. GN showed greater variability than GW both, among locations (spatial scale) and years (temporal scale). Anthesis date appeared as a strong yield potential determinant factor; A 10-day delay in anthesis date produce substantial changes in GN and GW, depending on location latitude. This was related to the speci.c combination of crop phenological development and radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.yield potential in the Pampas varied between 5000 kg ha1 in northern locations to 7300 kg ha1 in southern ones. GN showed greater variability than GW both, among locations (spatial scale) and years (temporal scale). Anthesis date appeared as a strong yield potential determinant factor; A 10-day delay in anthesis date produce substantial changes in GN and GW, depending on location latitude. This was related to the speci.c combination of crop phenological development and radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.1 in southern ones. GN showed greater variability than GW both, among locations (spatial scale) and years (temporal scale). Anthesis date appeared as a strong yield potential determinant factor; A 10-day delay in anthesis date produce substantial changes in GN and GW, depending on location latitude. This was related to the speci.c combination of crop phenological development and radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.yield potential determinant factor; A 10-day delay in anthesis date produce substantial changes in GN and GW, depending on location latitude. This was related to the speci.c combination of crop phenological development and radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.latitude. This was related to the speci.c combination of crop phenological development and radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.radiation and temperature changes in the region. A temporal decrease in PTQ during the period 1971–2002 was observed. This decrease was more associated with a radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.radiation decrease than with a temperature increase during this period. TGF did not show any trend during the same period. The importance of estimating wheat yield potential yield and yield-gap reduction is discussed.yield potential yield and yield-gap reduction is discussed. 2007 Elsevier Ltd. All rights reserved.2007 Elsevier Ltd. All rights reserved. Keywords: Wheat; Pampas; Photothermal quotient; Yield potential; Temperature; Radiation; Grain number; Grain weightWheat; Pampas; Photothermal quotient; Yield potential; Temperature; Radiation; Grain number; Grain weight