EFFECT OF K SUPPLY ON GROWTH AND DEVELOPMENT OF MAIZE (ZEA MAYS L.)

Abstract

The objective of this study was to quantitatively determine and to separate the efftcts of potassium deficiency on growth and development of a maize plant. Maize varieties Vi (Sadaf) and Vi (Sultan) were grown in a sand culture. When the coleoptile leaf was fully expanded, three level of K supply i-e Ko = 8 mM; KM - 4 mM and KZBRO = 0 mM were established by varying K concentration in the Long Ashton nutrient solution. The supply of respective nutrient media was maintained from coleoptile leaf stage through silking. A thermal time in growing degree days (GDD) was calculated to characterize the thermal environment of the corn plants. The leaf area was estimated daily non-destructively as a measure of growth of a maize plant. Number of leaves per plant, irrespective of a leaf size and the number of leaves per plant in Haun scale were used as a measure of development of a plant and were also recorded on daily basis. There was straight-line linear relationship between the number of leaves of Vi and Vi and the thermal time since sowing for each level of K supply. The development rat of Vi and Vi in KZERO level was 10 and 15%, respectively slower than that in Ko level. . At leaf stage 11, the leaf area in KZBKO was about 46% less than the leaf area in Ko ; and the leaf area in KM was about 25% less than the leaf area in Ko supply. At the stage of tasseling, the leaf area in Kziso was about 37% less compared to Ko and 26% less than the leaf area in KM. The differences established in the size of leaf area by the differential supply of K at the tasseling stage were maintained at the silking stage.