Analysis of leaf parameters of rain-fed maize cultivars

Leaf area index (LAI), specific leaf area (SLA) and leaf dry matter content (LDMC) are plant/crop physiological variables which could be used to differentiate among and select maize cultivars suitable for specific environmental conditions, particularly in rain-fed agriculture. The leaf area index, SLA, LDMC and total dry matter (TDM) were estimated for the three rain-fed maize cultivars (Golden Crystal, Mamaba and Obatanpa) during the major and minor cropping seasons. The experimental design used was the completely randomized block design in four replicates, with maize cultivars as treatments. This study was undertaken to assess differences or similarities in the time course of LAI, SLA and LDMC as an assessment of the response of the three maize cultivars to rain-fed conditions during the major and minor cropping seasons in a coastal savannah agro-ecological environment. Additionally, the linear correlation analysis was used to assess the association between LAI and SLA, LAI and LDMC, SLA and LDMC, SLA and LDMC, TDM and LAI as well as between TDM and LDMC for the three rain-fed maize cultivars. Generally, Obatanpa and Mamaba maize cultivars produced comparatively higher LAI which peaked at about 1.30 and 2.00 on 84 DAE during the major and minor cropping seasons, respectively. The maize cultivars had mean peak SLA values of 1.20 m^2g^-1 on 14 DAR and 1.60 m^2g^-1 on 28 DAE during the major and minor cropping seasons, respectively. With regards to LCMD, all the maize cultivars had peak values on 28 DAE, with the value of Golden Crystal being 0.70 g g^-1 during the major season and 0.65 g g^-1 for Mamaba during the minor cropping season. During the major cropping season the linear regression between SLA and LDMC for Obatanpa (R = 0.948) and for Mamaba (R = 0.222) were positive but positive and poor for Golden Crystal (R = 0.059). For the minor cropping season, the correlation between SLA and LDMC remained positive and fairly good for Obatanpa (R = 0.702), Mamaba(R = 0.861) and positive but poor for Golden Crystal (R = 0.363). However the combined cropping seasons, R value was positive and good for Obatanpa (R = 0.701) and Mamaba (R = 0.861) while that for Golden Crystal was poor (R = 0.363). Such a poor linear correlation between SLA and LDMC for Golden Crystal is an indication that the maize cultivar is poorly adapted to the rain-fed coastal savannah agro-ecological environment and, therefore, not suitable for the cropping environment. Additionally, the correlation between TDM and LAI was positive but poor in all the crop growing seasons, with R values ranging from 0.423 for Obatanpa, 0.524 for Mamaba and 0.562 for Golden Crystal. Furthermore, R value was 0.507 for the combined cropping seasons and all the maize cultivars. Analyses of leaf paramaters have provided insight into the different responses of these maize cultivars to rain-fed conditions in a coastal savannah agro-ecological environment

D.K. Asare, J.O. Frimpong and E.O. Ayeh