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 maysL.) 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 inbredlines, and (3) determine their response to P application in the P-deficient acid soils of western Kenya. Ninety-eight inbred lines and 4 9single crosses were developed and screened at P-deficient (2.0to2.2 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