Screening of maize single cross hybrids for tolerance to low phosphorus

Abstract

Maize (Zea mays L.) is one of the world's most important staple food crops; however, its productivity is limited by phosphorus (P) deficiency in acid soils. The objective of this study was to develop single cross hybrids from P-efficient inbred lines and screen them for tolerance to P efficiency in the acid soils at Sega and Bumala in Western Kenya known to be low in available P. Forty nine single cross hybrids were developed from high P parental lines and screened for tolerance to low P (2-2.2mgPlKg soil) in the field. The effect of P application (26kgPlha) on maize grain yield, ear and plant height was assessed. Mean grain yield for the hybrids was 42.3% higher with P fertilizer than without P for the same hybrids. Plant and ear heights were reduced by about 14.8%. Thirty three per cent of these crosses were inefficient but responsive to P application, 27% were efficient and none responsive and only 2% were efficient and responsive. Grain yield was positively correlated (r = 0.57**) with plant height and ear height (r =0.60**) and plant height with ear height (r =0.86***). However, grain yield had low and negative correlation with days to 50% silking (r =-0.32) and days to 50% tasseling (r = -0.32). This study has developed and identified P-efficient single cross hybrids that can be used either directly or in developing 3-way and/or 4-way cross hybrids for use in acid soils of Western Kenya and in other acid soil within the region.