Drip irrigation in cotton (Gossypium sp.)

• Drip irrigation can be a viable option under constraints of irrigation water in zone 3 and 8 for hybrid cotton cultivation.
• It can save electricity, labour and 50% of irrigation water as against the surface furrow irrigation
• Planting geometry of 90 cm x 60 cm (normal planting) can be adopted under drip irrigation, but paired row planting at 60 cm - 120 cm - 60 cm can save 50% laterals as against the normal planting
• Operate drip system daily or once in three days and replenish 75 per cent cumulative ET of corresponding days by drip for hybrid cotton and 50 percent for hirsutum varieties.

Fertilizer management in drip irrigation system

• Apply 10 percent of recommended fertilizers as basal at the time of sowing and apply remaining fertilizers in equal splits through fertigation between 30 to 120 DAS at six days interval.
• Urea, MOP and DAP can be used for fertigation instead of costly liquid fertilizers.
• Follow weed, pest and diseases management practices as mentioned in irrigated cotton.

Time schedule of drip operation based on daily Evapotranspiration (ET) (Zone 3 and 8)

Month	Evaporation (mm/day)		*Time of drip operation based on ET (Minutes)
			Zone 3		Zone 8
	Zone 3	Zone 8	Hybrids	Varieties	Hybrid	Varieties
January	6.1	5.1	16	10	13	9
February	6.3	6.2	17	11	16	11
March	8.1	7.3	21	14	19	12
April	9.7	7.2	25	17	19	12
May	10.1	5.9	26	17	15	10
June	7.4	3.1	19	13	8	5
July	5.2	1.9	13	9	5	3
August	4.7	1.7	12	8	5	3
September	4.8	2.3	12	8	6	4
October	5.2	2.8	13	9	8	5
November	4.7	3.4	12	8	9	6
December	4.5	4.3	11	8	11	7

Note:

• Replenishing 75% and 50% daily ET for hybrids and varieties respectively.
• Drippers having discharge capacity of 4 lit/sec to be used.
• Laterals to be placed at 90 cm apart and drippers at 60 cm under normal planting
• In case of paired row planting (60 cm -120 cm - 60 cm) the above time of drip operation has to be doubled as the number of laterals and drippers are reduced to 50 % as compared to normal planting of 90 cm x 60 cm