Hybrids and open pollinated varieties (OPVs) are two commercial maize seed types cultivated in Nigeria. Information on their response to mechanical damage during processing is limited. This study is thus aimed at assessing the response of hybrids and OPVs of maize seeds to mechanical damage which would facilitate fabrication of processing facilities suitable for either of the maize types. Six maize varieties: three hybids (‘New Kaduna’, ‘SDM-1’, and ‘JO-195’) and three OPVs (‘Sammaz 15’, ‘Sammaz 27’ and ‘Suwan-1-stry’) were used for the study. The seed samples were subjected to standard germination, seedling vigour analysis, accelerated ageing, conductivity and fast green tests. The result showed that all the hybrid seed varieties had more damaged seeds than their OPVs counterpart. Shoot length and root length were more affected than other parts of the seedling. There were differences in the magnitude of electrolyte leakage as well as in what time each seed type (hybrid or OPVs) passed through the phases with ‘JO-195’ having the highest rate of electrolyte leakage. Hybrid seeds had lower resistance to mechanical damage and poorer storability when compared with the OPVs. In the overall, for all the traits, ‘Sammaz 15’, the best among OPVs was more promising when compared with ‘SDM-1’ which was the best among hybrid varieties. Processing machine equipment and accessories that are suitable for hybrid seeds might be inappropriate for conditioning OPVs.

Information about the mode of inheritance of maize (Zea mays L.) seed quality traits is crucial in planning for improvement programmes for such traits. The objective study was to determine mode of inheritance and interrelationships between seed quality traits, and Fe and Zn contents in maize. Twenty-six maize genotypes were considered for evaluation in this study. Additive gene action was prevalent for most seed quality traits (>50%); while non-additive gene action was preponderant for Fe and Zn concentrations. Inbreds TZEEI82 and TZEEI64 were outstanding in terms of GCA male effects for conductivity (-0.13** and -0.06*), root number (0.79** and 0.30*), and root fresh weight (0.90*). Genotypes TZEEI81, DTE-STR-Y-SYN-POP-C3, 2009-TZEEI-OR1-STR and 2009-TZEE-OR1-STR-QPM were identified as excellent pollen parents for Fe concentration; and TZEEI58 and TZEEI64 for Zn concentration. In addition, only germination index had a significant additive genetic relationship with Fe content (r=0.57*); while both shoot fresh and dry weights had significant positive correlations with Zn content (r=0.45*, 0.53*). Overall, it is clear that different modes of gene action control inheritance of seed quality traits and Fe and Zn concentrations.

African yam bean is a nutritionally-important but neglected food crop with several health benefits. But its large scale cultivation and consumption are still limited by lack of systematic genetic improvement and breeding programme for the crop. Preliminary studies have established that the inherent field establishment potential of African yam bean is low. Hence the need to screen available accessions to identify those with outstanding seed physiological qualities for selection as parental materials for further improvement. Thirty-four African yam bean accessions were collected from different farmers in five states of Southeastern Nigeria. Seed physiological quality (viability and vigour) was assessed using hundred seed weight, water imbibition, standard germination, accelerated ageing and conductivity tests. The mean squares due to varietal effect were significant (p < 0.05) for germination index and highly significant (p < 0.01) for all other traits. Accessions ENAGag, ENAGmg 1 and, ENAGmg 2 had high standard (> 80%) and accelerated ageing (> 70%) germination percentages. Only 11 of the accessions had an accelerated ageing germination percentage of above 50%. All but one of the 34 accessions had conductivity values less than 5.00 µScm-1 g-1. On the average, African yam bean seeds require up to 76.9% moisture of their initial weight over a period of approximately 53 hours prior for the commencement of germination process. Accessions ENAGag, ENAGmg 1, ENAGmg 2, ENNKob, ENNSog, IMISis, IMOKeo 1 and IMOKeo 3 were outstanding and are therefore potential candidates for genetic improvement of seed quality in African yam bean.

Aims: The objectives of this study were to evaluate maize genotypes of different maturity groups for seedling and grain filling water use efficiency and determine relationship that exist between the water use efficiency traits and yield of different maize maturity groups. Study Design:  Sixteen maize genotypes were planted in Randomized Complete Block Design in three replicates for emergence, vegetative, water use efficiency traits at the seedling and grain-filling growth stages and yield. Place and Duration of Study: The sixteen maize genotypes of different maturity groups were evaluated during the early and late cropping seasons of 2016 at the Obafemi Awolowo University Teaching and Research Farm, Ile-Ife, Nigeria Methodology: Data collected were subjected to Analysis of Variance (ANOVA), correlation analysis among water use efficiency traits and yield for each of the maturity groups. Results: There was no significant difference among the genotypes within each maturity groups for water use efficiency at seedling and grain filling growth stages. The late maturity group of maize used more water at the seedling growth stage than the other maturity groups in the early season of this study while in the late season, the early and extra-early maturity groups used more water than the other maturity groups. Increase in emergence percentage, reduction in speed of germination, and minimal days to complete germination increased water use efficiency at the seedling stage only during the early cropping season. Efficiency of water usage at the seedling growth stage was more among the late and intermediate maturing groups than the extra-early and early maturing groups in the early season while in the late season, the extra-early and early maturing groups used water more efficiently than the late and Intermediate maturing groups Conclusion: Maturity group played a significant role in the expression and manifestation of water use efficiency traits under different environmental conditions.

Maize genotypes of different maturity groups with good seed quality had been developed, but there is little or no information on how the seed quality of the maize genotypes are affected by their maturity groups. Therefore, the objectives of this study were to evaluate maize varieties of different maturity groups for seed quality and determine genotypic variations that exist within the different maturity groups of maize for seed quality. Laboratory experiments were conducted in the Seed Science Laboratory of the Department of Crop Production and Protection, Obafemi Awolowo University, Ile-Ife, Nigeria. Seeds of sixteen maize genotypes of different maturity groups were subjected to imbibition, germination, accelerated ageing, conductivity and seedling vigor tests. The late maturity group (TZLCOMP.4DTF2,TZLCOMP. 1C6/DT.SYN-1-W, WHITEDTSTR/TZLCOMP.1-W, OBASUPER1) gave the best viability, speed of germination and days to complete germination while the extra early maturity group (2009TZEE-ORISTRQPM, 2000SYNEE-WSTR,2013TZEE-WDTSTR, TZEE-WPOPDTC2STRC5F2) had the least performance. The early (2014TZE –YDTSTR, 2013DTESTR–WSYN, EVDT-2000STRC0, 2009DTEWSTRSYN) and extra-early maturity groups had the longest root length and highest root number respectively. However, the different maturity groups of maize evaluated imbibed water at the same rate. TZEE-WPOP DT STR C5 F2, 2013 DTE STR – W SYN, AFLATOXIN R-SYN2, TZL COMP.1 C6/DT. SYN-1-W among extra early, early, intermediate and late maturity groups respectively performed best for viability and vigor tests.