MSc

An experiment was conducted at the Instructional Farm attached to the College of
Agriculture, Vellayani in the summer season during 1999 to study the response of vegetable
cowpea cv.Malika to nitrogen and potassium under varying levels of irrigation. The
experiment was laid out in a 33 confounded factorial design confounding INK in
replication I and INK2 in replication H. The treatments included three levels each of
irrigation,nitrogen and potassium.
The study revealed that the crop responded to irrigation,nitrogen and potassium
levels. The growth characters like plant height,number ofleaves per plant and LAI were not
significantly influenced by the different treatments. But the earliness in flowering and the
main yield attributing character viz., the number of rods per plant were favourably
influenced when irrigation was given at a CPl ~ value of zuuun with a depth of 1 Omm water
through micro sprinkler method. The earliness in flowering and number of pods per plant
were also influenced when nitrogen and potassium were applied at the rate of20 kg ha-1 as
compared to the other levels.
The maximum yield of green pods was obtained when the crop was irrigated through
micro sprinklers at 20mm CPE with a depth of 10mm water. The nitrogen and potassium
levels at 20 kg ha-1 also enhanced pod yield. The haulm yield was not influenced by any of
the treatments or its combinations.
I

The uptake of nutrient was influenced by the treatments. The nitrogen uptake was
influenced only by variation in N levels. Potassium uptake was affected by the influence of
both Nand K. Irrigation treatments influenced the uptake ofP205 alone at a single growth
stage.
Water use efficiency was highest whenirrigation was given through micro
sprinkler. Nitrogen and potassium levels each at 20 kg ha-1 resulted in highest WUE
compared to the other two levels. Moisture depletion was higher from the top 0-15 cm
layer of the soil when the crop was irrigated at 10mm CPE with a depth of 20mm water
through micro sprinkler. At 15-30cm and 30-45 cm depth surface method recorded the
highest moisture depletion. Higher levels of potassium was found to influence the moisture
depletion pattern.
The available soil nutrient status after the experiment was influenced by nitrogen
alone. The application of 40kg N ha! resulted in the highest available soil nitrogen content
after the experiment.
Irrigation and potassium excel red a remarkable influence on the proline content of
the leaves. The maximum proline con (I: nt was recorded will 11 the crop was irrigated through
micro sprinklers and potassium was applied at the rate 0 f 'Il' kg ha-I.
The results of economic analysis revealed that the net returns was maximum by
irrigating the crop through micro sprinkler. However, the BCR was highest when irrigation
was given by surface method and at a nitrogen and potassium level of20 kg ha-1 each.