Vol. 11, Issue 9 (2022)

The major constraints encountered in Dendrobium orchid cultivation is lack of detail knowledge about exact fertigation scheduling in different stages of growth. An experiment was conducted to investigate the effects of fertigation at 7, 10 and 13 days interval with different rates at different plant growth stages on vegetative growth of Dendrobium orchid cv Sonia-17 during 2017-2018 at Howrah Krishi Vigyan Kendra, Jagatballavpur, Howrah, West Bengal. Height of pseudobulb (33.47 cm), number of pseudobulbs per plant (6.02), intermodal length (4.30), leaf length (13.92 cm), leaf breadth (2.62 cm), Leaf Area (39.35 cm²), Leaf Area Index (5.25), leaf chlorophyll content (67.21 SPAD value) were found with fertilizer applications at 7 days interval (F₁) than 10 or 13 days interval. Fertigation with NPK @ 300 mg.lt^-1 at vegetative phase, NPK (4:1:2) @ 300,75, 150 mg.lt^-1 at further development phase & flowering phases, no fertilizer at cool phase had registered maximum pseudobulb height (36.82 cm), Leaf Area (44.66 cm²), LAI (5.95) and chlorophyll content (71.29 SPAD value) whereas NPK @ 200 mg.lt^-1 at vegetative phase, NPK (4:1:2) @ 200, 50, 100 mg.lt^-1 at further development phase & flowering phases, no fertilizer at cool phase recorded highest girth of pseudobulb (4.40 cm), length of internodes (5.05 cm), leaf length (15.04 cm) and leaf breadth (2.93 cm). When it was about interaction between frequencies and rate of applications, fertigation of NPK @ 300 mg.lt^-1 at vegetative phase, NPK (4:1:2) @ 300,75, 150 mg.lt^-1 at further development phase & flowering phases, no fertilizer at cool phase at 7 days interval resulted maximum pseudobulb height (40.22 cm), highest leaf length (15.87 cm), Leaf Area (48.28 cm²), Leaf Area Index (6.44) and chlorophyll content (78.57 SPAD value). Leaf breadth (3.14 cm) and intermodal length (5.35 cm) were found maximum with application of NPK @ 200 mg.lt^-1 at vegetative phase, NPK (4:1:2) @ 200, 50, 100 mg.lt^-1 at further development phase & flowering phases, no fertilizer at cool phase at 7 days interval.