Effect of irrigation scheduling and nutrition on yield attributes, pod yield and economics of summer cowpea

Abstract

A field experiment was conducted at the Agricultural Research Station, Ladol, Gujarat, India, on
summer cowpea (Vigna unguiculata [L.] Walp.) to study the Effect of irrigation scheduling and
nutrition on yield attributes, yield and economics. The experiment was laid out in split plot design
with four replications during summer season (March to June), 2013-14, 2014-15 and 2015-16. The
experiment consisted three irrigation treatments viz. IW/CPE ratio 0.8, 1.0 & 1.2 and three fertility
levels namely, 100% RDF (25:50:00 NPK kg/ha), 100% RDF + Rhizobium + PSB and 75% RDF +
Rhizobium + PSB. Among the different irrigation levels crop irrigated at 1.2 IW/CPE ratio recorded
significantly higher pod numbers/plant (~51), pod weight/plant (206.9 g), length of pod (14.2 cm)
and pod yield (10.79 t/ha) of cowpea as compared to IW/CPE ratio of 0.8. The increase in green pod
yield of cowpea due the application of irrigation water at 1.2 IW/CPE ratio was 31% and 4% higher
compared to crop irrigated at 0.8 IW/CPE ratio and 1.0 IW/CPE ratio, respectively. Cowpea fertilized
with 100% RDF + Rhizobium + PSB produced the significantly higher yield of green pod (10.34 t/
ha) over 100% RDF (25:50:00 NPK kg/ha) (9.06 t/ha) and remain at par with 75% RDF + Rhizobium
+ PSB (10.02 t/ha). The pod yield increased with the application of 100% RDF + Rhizobium + PSB
was 14% and 3% higher as compared to 100% RDF and 75% RDF + Rhizobium + PSB, respectively.
Cowpea irrigated at IW/CPE ratio of 1.0 and fertilized with 100% RDF + Rhizobium + PSB had
resulted in highest net benefit: cost ratios of 2.74 and 2.70, respectively.