EFFECT OF POTASSIUM NUTRITION ON SOLUTE ACCUMULATION, ION COMPOSITION AND YIELD OF MAIZE HYBRIDS GROWN UNDER SALINE CONDITIONS

Abstract

An experiment was conducted to study the response of two maize hybrids to external potassium (K) application under saline conditions. The data showed that there was an increase in the organic solute contents and sodium ion under salinity stress, though potassium, calcium, nitrogen and phosphorus were decreased. There was a non-significant effect of K application on glycinebetaine and total soluble sugar, however; the proline, protein and total free amino acids were increased with the application of external K. The enzymatic activity like nitrate reductase and nitrite reductase activity were severely reduced under salinity stress and improved by K application. The maize hybrids differed significantly for all the parameters discussed in the study except sugar, phosphorus and number of grain rows per cob. The increase in yield parameters was more pronounced under control than under saline conditions. The enhanced yield and yield components of these maize hybrids might be due to the quick response to external K application, resulting in high contents of leaf potassium, calcium, nitrogen and phosphorus. The results indicated that the maize hybrid ‘Pioneer32B33’ might perform better than ‘Dekalb979’ under saline conditions when sufficient potassium is applied in the rooting medium.

Keywords:

• Zea mays
• organic solute accmulation
• ion contents
• enzyme activity
• plant nutrition
• potassium
• salinity tolerance
• yield

ACKNOWLEDGMENT

The author is grateful to the Higher Education Commission, Islamabad Pakistan for funding this research for his PhD degree. Their financial support is greatly appreciated.