Variable Irrigation Scheduling Effects on Growth Parameters of Celosia Argentea in Humid Tropical Environment

ABSTRACT

This work experimentally determines crop water requirements as well as effects of varying irrigation schedules on growth parameters of Celosia Argentea. Irrigation treatments of refilling the soil back to 100%fc, 75%fc and 50%fc were applied to predominant three soil samples from different locations within the South Western part of Nigeria having the same sandy loam textural class. Irrigation application was based on daily maximum crop evapotranspiration. Leaf Area, Number of Leaves, Plant Height and Stem Girth were measured twice a week. Cummulative irrigation treatments of 100%fc, 75%fc, and 50%fc amounted to 749, 583, and 454mm depth of water at 6 weeks after planting (WAP) with a yield of 11.8, 8.9, and 8.6 Kg per 5m2 respectively. Statistical results of crop growth parameters and yields indicated that significant differences existed at P>0.05 when 50%fc treatment was compared to 75%fc and/or 100%fc treatments. Biomass yield (edible weight) showed significant differences across the three treatments and also falls within the recommended range of 8 – 14 Kg per 5m2 for optimal propagation of Celosia Argentea in West Africa. However, for biomass yield at 6WAP; treatment of 100%fc was significantly different from 75%fc and likewise, treatment of 75%fc was significantly different from 50%fc for the three soil samples. Results also indicated that bulk weight (edible weight plus root weight) appeared best under treatment at 100%fc when compared with the other two treatments. It was thus concluded that if irrigation scheduling is aimed at maximizing Celosia yields per unit of irrigated area, 100%fc treatment is recommended. But if scheduling is to maximize yield per depth of water applied, preference should be given to 75%fc treatment for propagation of Celosia Argentea.