Development of maize single cross hybrids for tolerance to low phosphorus

Abstract

Low available phosphorus (P) is one of the major hindrances to maize (Zea mays L.) productivity in acid soils. The objectives of this study were to: (1) develop P-efficient maize inbred lines, (2) develop single cross hybrids from the P-efficient inbred lines, and (3) determine their response to P application in the P-deficient acid soils of western Kenya. Ninety-eight inbred lines and 49 single crosses were developed and screened at P-deficient (2.0 to 2.2 mg P/kg soil) soils of Sega and Bumala. Mean grain yield (GY) for the hybrids was 75.3% higher with P-fertilizer than without P for the same hybrids. Thirty-three percent (33%) of these hybrids were inefficient but responsive to P application, 27% were efficient and none responsive, only 13% were efficient and responsive, while the rest were inefficient and non-responsive. GY was positively correlated (r = 0.57**) with plant height (PH) and ear height (EH) (r = 0.60**) and PH was correlated with EH (r = 0.86***). This study has developed and identified P-efficient maize germplasm that can be utilized directly or in developing other hybrids for use in acid soils of western Kenya and in other acid soils where P is limiting.