COCONUT PALM (Cocos nucifera L.) is grown in littoral sandy and coastal sandy soils. These soils are poor in fertility and water holding capacity. They also get heated up quickly which affects water and nutrient uptake. Palms grown in coastal sandy soils, experience stress during summer which lowers yield.
Good irrigation practices are needed to sustain productivity. The efficacy can be increased by mulching the irrigated area and its favourable effect on soil temperature regulation, soil moisture conservation and soil temperature reduction have been established.
The response of coconut to combined effect of micro irrigation and mulching were studied under littoral sandy soil at the Central Plantation Crops Research Institute (CPCRI), Kasaragod, during non rainy seasons with West Coast Tall variety.
Pooled data on nut yield for six years (1993-99) showed no significant difference among drip irrigation treatments at 66 per cent, 100 per cent and 133 per cent of evaporation and between the drip and basin irrigation treatment (at 200 litre once in 4 days). All irrigated treatments were on a par with each other but were superior to the rainfed control.
The highest nut yield was observed in the drip irrigated treatment at 100 per cent of Eo and was on par with the treatment drip irrigation with 66 per cent of Eo 133 per cent of Eo (67.2 nuts) and basin irrigation (66.3 nuts).
The soil being porous and poor in organic matter, the response for the quantity of water applied was less conspicuous, and thus the treatment where 66 per cent of Eo applied through drip could produce the same effect as that of 100 and 133 per cent Eo through drip and 100 per cent of Eo through hose irrigation in coconut basin.
Mulching with coconut leaves (fifteen leaves covering 1.8 m radius of coconut) combined with irrigation treatments recorded significantly higher yield compared to no mulch with irrigation. The dried coconut leaves when applied as mulch to the littoral sandy soil boosted growth and nut yield.Mulching did not have any significant effect under rainfed treatment.
H. P. Maheswarappa, R. Dhanapal & P. Subramanian