Effects of soil nutrient amendments on growth and grain yield performances of quality protein maize grown under water deficit stress in Ibadan, Nigeria

<p class="042abstractstekst">Drought and poor soil fertility are major limitations to crop production, globally. To investigate the impacts of water deficit stress (WS) and soil nutrient amendment (SA) on growth and yield performances of maize. A two years factorial field study was carried out, using a quality protein maize (QPM) (ILE-1-OB) and a non QPM–drought tolerant check (TZPBSR-W) varieties in Ibadan. Treatments include; six fertilizer application rates; 50 and 100 (kg N ha^-1) ofNPK-20-10-10, 10.7 kg N ha^-1of Tithonia Poultry Compost (TPC), 50 N + 10.7TPC and 100 N + 10.7TPC (kg N ha^-1), three WS; the control (FW), WS at vegetative stage (STR1), and WS at reproductive stage (STR2). Leaf area (LA) and grain yield (GY) were measured using standard procedures. From the results, across WS, LA ranged from STR1 (458.90 ± 12.4) to FW (598.81 ± 13.1 cm²), GY varied from STR2 (2.94 ± 0.2 t ha^-1) to FW (6.59 ± 0.2 t ha^-1), across fertilizers, LA varied from 0 N (397.65 cm²) to 100N + 10.7TPC (622.71 cm²) and 50 N + 10.7TPC (611.03 cm²), respectively. The GY varied from 0 N (2.37 t ha^-1) to 100 N + 10.7TPC (5.82 t ha^-1) and 50N + 10.7TPC (5.26 t ha^-1).<strong> </strong>Drought stress reduced growth and GY performances of QPM, while SA with 50 kg N ha^-1 of inorganic fertilizer and 10.7 kg N ha^-1 of<em> </em>TPC enhanced growth and grain yield of maize under WS.</p>

Multivariate and Association Analysis for Yield and Yield Attributing Traits in Quality Protein Maize (QPM) Inbred Lines

The present investigation reveals the diversity existing among thirty inbred lines of Quality Protein Maize (QPM) in terms of yield and yield attributing traits. The study further elucidates the mutual association among the various morphological traits recorded among the inbred lines. The inbred lines were evaluated during the Rabi seasons of 2016-17, 2017-18 and 2018-19. The analysis of variance calculated over the mean performances of the inbred lines across three rabi seasons revealed significant differences among the inbred lines in terms of yield and yield attributing traits. The diversity among the inbred lines were further determined using cluster analysis which classified the inbred lines into 3 phylogenetically distinct groups. Additionally, a principal component analysis was performed which revealed three principal components (i.e., PC I, II and III) elucidating eighty six percent of the total observable variance among the inbred lines, with traits like grain yield, cob length, cob diameter, number of grain rows per cob, number of grains per row and number of grains per cob contributing to nearly half of the total variance explained by the Principal Component Analysis (PCA). The correlation as well as path coefficient analysis performed for the various traits further indicated significant influence of morphological traits like cob length, cob diameter, number of grain rows per cob and number of grains per cob over the observable grain yield per plant. Overall, the observations from the current investigation can be helpful in identifying superior parental lines to be used in future hybrid maize development programs.

Study of Combining Ability and Heterosis in Quality Protein Maize using Line x Tester Mating Design

Background: High protein content with good quality maize is likely to gain wider acceptance if hybrids are produced that have agronomic performance similar to normal hybrids and retain an enhanced nutritional quality. Thus, an attempt was made to develop quality protein maize hybrids for the benefit of different sections of society depending on maize. Methods: During the Rabi season of 2016-17 (hybrids were obtained crossing ten inbred lines and four testers following Line x Tester mating design) and 2017-18 (evaluation of hybrids and parents involved along with two commercial checks based on different agro-morphological traits). Result: Highly significant differences were observed among lines, testers and crosses. Combining ability revealed SCA variances was higher indicating preponderance of non-additive gene action. The contribution of line x tester interaction was higher suggesting parents used in this study can provide high heterotic cross combinations. The parents CML 508, CML 163-D and CML 169 were superior general combiners, indicating their efficacy as parents in future maize breeding programs. Heterosis identified superior yield advantage of the crosses namely, CML508 x CML154-2, CML170 x CML169 and CML163-D x DMRQPM103 over the standard commercial checks HQPM1 and 900 M Gold.

Genetic Analysis of Early White Quality Protein Maize Inbreds and Derived Hybrids under Low-Nitrogen and Combined Drought and Heat Stress Environments

An increase in the average global temperature and drought is anticipated in sub-Saharan Africa (SSA) as a result of climate change. Therefore, early white quality protein maize (QPM) hybrids with tolerance to combined drought and heat stress (CDHS) as well as low soil nitrogen (low-nitrogen) have the potential to mitigate the adverse effects of climate change. Ninety-six early QPM hybrids and four checks were evaluated in Nigeria for two years under CDHS, low-nitrogen, and in optimal environments. The objectives of this study were to determine the gene action conditioning grain yield, assess the performance of the early QPM inbred lines and identify high yielding and stable QPM hybrids under CDHS, low-nitrogen and optimal environment conditions. There was preponderance of the non-additive gene action over the additive in the inheritance of grain yield under CDHS environment conditions, while additive gene action was more important for grain yield in a low-nitrogen environment. TZEQI 6 was confirmed as an inbred tester under low N while TZEQI 113 × TZEQI 6 was identified as a single-cross tester under low-nitrogen environments. Plant and ear aspects were the primary contributors to grain yield under CDHS and low-nitrogen environments. TZEQI 6 × TZEQI 228 and the check TZEQI 39 × TZEQI 44 were the highest yielding under each stress environment and across environments. Hybrid TZEQI 210 × TZEQI 188 was the most stable across environments and should be tested on-farm and commercialized in SSA.

Combining Ability Study for Grain Yield and Agronomic Traits of Quality Protein Maize (Zea mays L.) Inbred Lines Adapted to Mid-Altitude Agroecology of Ethiopia

In spite of the importance of quality protein maize to alleviate protein deficiency, almost all maize varieties cultivated in Ethiopia are normal maize varieties, which are devoid of lysine and tryptophan. Perusing the combining ability of QPM inbred for grain yield and its components is vital to design appropriate breeding strategies for the development of nutritionally enhanced maize cultivars. A line x tester analysis involving 36 crosses generated by crossing 9 elite maize inbred lines with 4 testers were evaluated for different desirable agronomic traits during the 2019 main season at BNMRC and JARC. The experiment was conducted using alpha lattice design with 3 replications. The objectives were to determine the combining ability of quality protein maize inbred lines, adapted to mid altitude agroecology of Ethiopia for agronomic traits. The crosses were evaluated in alpha lattice design replicated 3 times. Analyses of variances showed significant mean squares due to crosses for almost all the traits studied. GCA mean squares due to lines and testers were significant (P<0.05 or P<0.01) for most studied traits. SCA mean squares were also significant for most attributes across locations. The comparative importance of GCA and SCA variances observed in the current study for most studied traits indicated the preponderance of additive genetic variance in governing these attributes. Only L3 was the best general combiner for grain yield. Inbred line L3, for days to anthesis and L5 for days to silking had negative and significant GCA effects. L5 and L6 displayed negative and significant GCA effects for plant and ear height. Crosses, L2xT4, L3xT4, L4xT4, L5xT2, L6xT3, L7xT2, L9xT1 and L9xT4 were good specific combiners for grain yield. In general, these genotypes help as a source of promising alleles that could be used for forthcoming breeding work in the development of quality protein maize cultivars with desirable traits.

Evaluation candidate of test cross hybrid QPM under ecosystem of Polewali Mandar West Sulawesi

Abtract. Quality Protein Maize (QPM) was specialty maize which is high content of lysine and tryptophan. These are two essential amino acids better nutritional for human body to anticipated of disease (kwashiorkor) on severe among children, and could be corrective use in balancing diets. The experiment on 2018 has been conducted to evaluated of nine candidate test cross hybrid of QPM vs. check Bima 13Q with CRD three replications under lowland in distrit of Polman West Sulawesi. Genetic material were planted in four rows 5.0 m lenght, spacing 75x20 cm, and applied fertilizer Urea, Ponska (300-200) kg/ha. The result shown that two test cross F1 QPM were (MSQ(S1)C0-26-1-1 x MR14Q) and (MSQ(S1)C0-43-1-1-1 x MR13Q) which the best with potential yield 10.66-10.95 t/ha. The LSD shown that there are significant different with check Bima 13Q on yield (wc.15%) and highly 30.0% and 31.6%. The two candidates were founded shelling percentage 77.9% and 79.0%, asi less than five days and could be promising as new variety and continuing in evaluation variety trial (evt) in west Sulawesi.