36th International Carrot Conference Abstract

Residual Effects of Phosphorus Sources on Carrot (Dacus carota L.) Production.

O.D. Ojo*¹ and E.A. Akinrinde²

¹NIHORT, PMB 5432, Idi Ishin, Ibadan, Nigeria.

*Correspondent Author: Email drdavidojo@gmail.com; Cell: +234(0)8023935021.

²Department of Agronomy, University of Ibadan, Ibadan, Nigeria.

Productivity of carrot (Dacus carota) can be improved at reduced cost through combined use of low-cost Rock Phosphate (RP) phosphorus sources. Very little is known about RP residual release of phosphorus (P) especially as it relates to carrot productivity in the tropics, particularly in Africa humid tropics. It is probable that the differential performances exhibited by the RPs might be a function of their P residual uptake properties after cropping. Based on these premises this study was carried out to evaluate the residual effects of P sources under continuous cropping for carrot production. The study was a completely randomized design with five replications. In order to monitor the residual effects of the P sources the experimental plots were cropped consecutively three times. Results from the study revealed that yield and Relative Agronomic Efficiency (RAE) decreased with continuous cropping for single super phosphate (SSP) phosphorus source but increased with continuous cropping for Ogun rock phosphate (ORP) and Sokoto rock phosphate (SRP) sources till second cropping, thereafter there was a decrease. Averaged over the three continuous consecutive cropping, SRP and ORP were 66.3% and 70.8% as effective as SSP in increasing carrot yield respectively. It was concluded therefore that ORP could be an alternative P source for carrot production under continuous cropping system in the humid tropics.

Keywords: Carrot, Residual Effect, Phosphorus Sources, Continuous Cropping, Humid Tropics.

Last updated Thursday, 25-Jul-2013 11:51:22 CDT