Commercial Maize Hybrids Research Articles

Maize experiment in a traditional Zuni agroecosystem: nutrient composition

ABSTRACT Maize has sustained the Zuni and other peoples of the arid American Southwest for more than four millennia. In Zuni dryland agriculture, fields on alluvial fans and other valley-edge landforms are managed to receive supplemental water and nutrients by retaining storm runoff and associated sediment and organic material transported from adjoining uplands. An experiment with Zuni blue maize (Zea mays L.) and commercial hybrid maize was conducted in two Zuni fields to study traditional maize and its productivity as part of a larger study of Zuni agroecosystems. Following a closely related paper on maize growth and productivity, studies of maize nutrient composition and quality are presented here. More nutrient differences occurred between Zuni and hybrid maize than between runoff and other treatments. Zuni grain had higher concentrations of more nutrients than hybrid maize, and for several elements, there was an inverse pattern in grain vs. leaf nutrient concentration between cultivars. Zuni grain had a higher N (protein) concentration than hybrid maize, and a higher proportion of N in grain vs. leaf, indicating an ability to partition more N and other nutrients into grain. Parallel differences in maize and soil N and P were found between the two fields, though the cultivars had different P content patterns. Overall, agronomically sufficient concentrations of most nutrients were present across cultivars and treatments. Long-term production and nutrient management of maize grown without conventional irrigation or fertilization reflect a traditional agroecosystem that incorporates sustainable practices intended to maintain productivity with conservation of soil and water resources.

Sitotroga cerealella-resistant mexican maize races (Zea mays L.), new sources of resistance for commercial maize breeding

Sitotroga cerealella (Oliv.) (Lepidoptera: Gelechiidae) is one of the most important post-harvest pests of maize Zea mays L. Some Mexican maize races (Z. mays) could be a novel source of resistance against S. cerealella to improve commercial maize varieties, lines and hybrids. We studied the resistance of Mexican maize races, recollected at Chihuahua State to S. cerealella. We focused on antibiosis and tolerance of maize to S. cerealella. Cristalino-079 maize race shows low level of consumption in grams and percentage, increased larvae mortality before to entering the seed. In addition, Cristalino-079 reduced first adult’s generation and show the largest biological cycle. Due to the small number of emerged adults, there was very little grain weight loss in resistant maize race. The compound that causes high mortality of larvae before to entering the grain is in the pericarp of resistant maize races. The compound that causes longest development time is in the endosperm and embryo. Cristalino-079 show the better level of resistance to S. cerealella infestation in almost all traits studied and this can be used as source of resistance for maize breeding.

Suitability of Argentinian maize hybrids for polenta production

AbstractThe objective of this study was to determine the suitability of different soft‐endosperm commercial maize hybrids to obtain polenta of good technological quality. Ten commercial soft‐endosperm hybrids and two open‐pollinated varieties (quality controls) of maize were used. Grain physical characteristics were determined, and polentas from each genotype were obtained. The chemical composition of semolina was determined, and polenta was evaluated in terms of viscoelasticity, cooking characteristics and colour. The semolina yield was between 50.96 to 69.36%. The control genotypes showed the lowest values for peak viscosity, with 3670.5 and 3966.25 cP. Hybrid Next22.6 showed the highest consistency value, while C6006, Col17, Ds507 and Srm566 presented the lowest value of all samples tested. Hybrid N7822 first, followed by Ds507 and Srm553, proved to be suitable for the food industry. The good characteristics of this dish were associated with high pasting temperature and semolina yield, and low consistency and viscosity values.

Grain yield and kernel setting of multiple-shoot and/or multiple-ear maize hybrids

Rainfed maize ( Zea mays L.) crops in low-rainfall regions are cultivated at very low plant population densities that favor the production of fertile tillers or multiple ears in the main shoot. Little information exists regarding the functional processes governing grain yield and kernel setting on ears of different order of shoots of maize crops. To study these functional processes, field experiments were conducted cultivating two commercial maize hybrids (AX7784 and DM2738) under supplementary irrigation using different plant densities, N rates at sowing, shading around female flowering (silking) and tiller removal treatments. Hybrids differed in the number of tillers per plant at R 1 (AX7784 > DM2738). Early tiller removal increased main shoot growth rate around silking, suggesting competition for light among shoots. Kernel number per plant was positively and curvilinearly related with plant growth rate around silking, i.e. critical period (PGR CP ), in tillered and non-tillered plants of both hybrids. Tillered plants set higher kernel numbers than non-tillered plants at PGR CP > 9 g pl -1 d -1 (AX7784) or 11 g pl -1 d -1 (DM2738), while the opposite trend occurred at PGR CP values < 9 g pl -1 d -1 (both hybrids). In both hybrids, the combination of a higher biomass partitioning to but a lower reproductive efficiency of ears of tillers than of main shoots resulted in a lower kernel number for tillers than for main shoots. Genotypic differences were evident in kernel setting between main shoots (DM2738 > AX7784) and tillers (AX7784 > DM2738). The different pattern of kernel setting between hybrids was explained by differences in the biomass partitioning to tiller ears and the reproductive efficiency of ears of tillers (AX7784 > DM2738), and both the biomass partitioning to and the reproductive efficiency of second and third order ears of main shoots (DM2738 > AX7784). Kernel number per plant was higher for DM2738 due to a higher kernel setting on multiple ears of main shoot plus tillers (more prolific and with lower tiller fertility) than for AX7784 (less prolific and with higher tiller fertility). However, grain yield did not differ between hybrids, because of the higher kernel weight of AX7784. Therefore, this work opens avenues for exploiting higher grain yields in maize crops with low plant population densities through the combination of prolificacy and tillering. Further studies should analyze the impact of reproductive plasticity on kernel weight determination in low-density maize crops. • We studied maize tiller and main shoot grain yield and kernel set determinants. • Tillered plants set more kernels than non-tillered ones at high plant growth rates. • Tillers featured higher biomass partitioning to first order ears than main shoots. • Ears of tillers featured lower reproductive efficiency than ears of main shoots. • The tillering and prolific hybrid featured the highest plasticity, without grain yield differences between hybrids.

Water use optimization for two commercial maize hybrids for forage production in semi-arid environment

1. Ahmad I., Aftab W.S., Ahmad A., Masud Ch.M.J., Judge J., 2018. Optimizing irrigation and nitrogen requirements for maize through empirical modeling in semi-arid environmental. Environ. Sci. Pollut. Res., https://doi.org/10.1007/s11356.... CrossRef Google Scholar

Traits and underlying genetics important for low‐input organic sorghum production

AbstractSorghum [Sorghum bicolor (L.) Moench] is a potential crop for organic production that could help meet the demand increase in organic food products and feed grains, but no efforts have been made to improve sorghum breeding tools, techniques, and methods for this cropping system. Based on revelations in other crops, focal traits and their prioritization to optimize sorghum for organic use likely differs from conventional sorghum breeding targets. This study evaluated yield performance, agronomic characteristics, and biotic stress resistance under certified organic practices in a range of grain sorghum genotypes that included 70 hybrids, 72 advanced breeding lines, and 43 diverse accessions, as well as 10 sweet sorghum cultivars and four commercial maize hybrids. Multiyear, multilocation trial data demonstrated that sorghum can be effectively produced using sustainable and organic inputs, but hybrid or cultivar selection is extremely important for success as entry means for grain yield ranged from 26 to 5,970 kg ha−1. Yields of top sorghum entries rivaled commercially available maize (Zea mays) hybrids. Overall, hybrids significantly outperformed inbred lines as heterosis proved beneficial for influential agronomic traits, although a Clemson F6 advanced breeding line, PV20_0426, ranked second in yield. Sugarcane aphid tolerance, increased canopy closure, and grain mold resistance were positively correlated with grain yield and should be considered target traits for breeding sorghum hybrids and cultivars for organic use. Depending on possible seed production constraints, developing pure line cultivars with the proper trait package may be effective to diminish this potential obstacle for the organic sorghum market.

Differential Maize Yield Hybrid Responses to Stand Density Are Correlated to Their Response to Radiation Reductions Around Flowering.

Altered stand density affects maize yields by producing changes in both numerical yield components, kernel number per plant (KNP), and kernel weight (KW). Kernel number is determined by the accumulation of ear biomass during the flowering period, whereas KW is determined by the sink potential established during flowering and the capacity of the plant to fulfill this potential during effective grain filling. Here, we tested if different short shading treatments during different stages around flowering can help discriminate genotypic differences in eco-physiological parameters relevant for maize stand density yield response and associated yield components. Our specific objectives were to: (i) identify hybrids with differential shading stress response, (ii) explore shading effects over eco-physiological parameters mechanistically related to KNP and KW, and (iii) test if shading stress can be used for detecting differential genotypic yield responses to stand density. The objectives were tested using four commercial maize hybrids. Results indicated that KNP was the yield component most related to yield changes across the different shading treatments, and that the specific shading imposed soon after anthesis generated the highest yield reductions. Hybrids less sensitive to shading stress were those that reduced their plant growth rate the least and the ones that accumulated more ear biomass during flowering. Genotype susceptibility to shading stress around flowering was correlated to stand density responses. This indicated that specific shading stress treatments are a useful tool to phenotype for differential stand density responses of commercial hybrids.

Study of maize yield stability with nonparametric methods

High and stabile yield in different production environments is priority in maize breeding. New statistical methods are constantly being sought to accompany analysis of variance, in order to achieve more reliable hybrid assessment. In this study nonparametric stability analysis is applied in order to assess GxE interaction for yield of 36 commercial maize hybrids. The experiment was set up at five locations in Serbia for three years according to the Randomised complete block design in three replications. Yield stability of investigated genotypes was analysed by stability parameters Si (1), Si (2), Si (3), Si (6) TOP and RS. Analysis of variance identified highly significant F values for all experimental factors. Bredenkamp method confirmed the existence of non-crossover GxE interaction, for maize yield. Hybrid ZPH15 achieved the most stable yield based on parameters Si (1) and Si (2). According to parameter Si (3) it was ZPH5, while based on parameter Si (6) it was ZPH34. The highest overall yield achieved ZPH36 (11.18 t ha-1), which was quite unstable (rank 24 in parameters Si (1) and Si (2)), and very unstable (rank 34 in parameters Si (3) and Si (6)). The most stable hybrids had average yields. In total, the hybrid ZPH23 had the best average rank (15.93). Based on TOP parameter, ZPH36 had the best rank (yield), followed by ZPH11, ZPH20, ZPH21 and ZPH9. However, RS parameter revealed that ZPH21 was the most stable hybrid, so taking into account both TOP and RS parameters this is the most productive and the most stable hybrid. Based on this research, TOP and RS are the best parameters for selecting new maize hybrids for production in particular environment. In case of identical TOP value, the genotype with the lowest RS value should be selected. The parameters Si (1), Si (2), Si (3) and Si (6) can be used as alternative methods for the selection of genotypes with moderate yield and high stability.

Agronomic parameters as indicators of inbred maize nitrogen status

Inbred maize (Zea mays L.) lines are grown for seed in Puerto Rico. In efforts to increase crop yields, some producers may apply nitrogen (N) fertilizer in excess of crop nutrient requirements. The use of cover crops (CC) in rotation can serve as an alternative to continuous cultivation of maize. This experiment was conducted in field plots of Güamaní (fine-loamy over sandy or sandy-skeletal, mixed, superactive, isohyperthermic Torrifluventic Haplustepts) soil in Guayama, Puerto Rico. The cropping systems evaluated were a maize-cowpea [Vigna unguiculata (L.) Walp.] cover crop rotation versus a typical practice of maize fallow (FA), each with five N fertilizer levels. The maize planting sequence was an initial spring 2014 planting, followed by a winter 2014-2015 planting and a final winter 2015-2016 planting. The cowpea cover crop was planted in the summers of 2014, 2015 and 2016. The inbred maize lines were female lines used for commercial hybrid maize production. Mean maize plant densities ranged from 59,391 to 69,182 plants per hectare for the cropping seasons. Indicators of crop N status were the Soil Plant Analysis Development (SPAD-502) Chlorophyll Meter®measuring leaf greenness; the Normalized Difference Vegetation Index (NDVI, measured with GreenSeeker®) and plant height measurements. The application of N fertilizer significantly influenced (p&lt;0.05) leaf greenness (in five out of 13 occasions) and plant height (in seven of 12 occasions) but not NDVI. The use of cover crop significantly influenced leaf greenness (in four out of nine occasions) and plant height (in three out of eight occasions). The agronomic parameters tested did not predict yield or crop N status, thus are not recommended in the decision-making process of N fertilizer management of inbred maize.

Comprehensive analysis of multiple mycotoxins and Aspergillus flavus metabolites in maize from Kenyan households

This study assessed the levels of mycotoxins in maize from Kenyan households. Further, local open pollinated maize varieties were compared with commercial hybrids to evaluate which variety is less susceptible to mycotoxin contamination. Four hundred and eighty (n = 480) maize samples were collected in the years 2018–2020 from households in Eastern, Western, Coastal and Lake Victoria regions of Kenya. Liquid chromatography coupled to tandem mass spectrometry was used to detect and quantify 22 mycotoxins, along with 31 Aspergillus flavus metabolites in the samples. Eastern Kenya had the highest aflatoxin (AF) contamination with 75% of samples having AF levels above the Kenyan regulatory limits (10 μg/kg), the highest concentration was 558.1 μg/kg. In Western Kenya, only 18% of samples had concentration levels above the Kenyan regulatory limits for AF with highest sample having 73.3 μg/kg. The Lake Victoria region had the most fumonisins (F) contamination, with 53% of the samples having fumonisin B1 (FB1) < 1000 μg/kg. However, only 20% of the samples surpassed the Kenyan regulatory limit for total fumonisins (2000 μg/kg) with the highest concentration being 13,022 μg/kg. In addition, 21.6% of samples from the Lake Victoria region had zearalenone (ZEN) and deoxynivalenol (DON) above regulatory limits for European countries (1000 μg/kg). Western region had the least A. flavus metabolites contamination (18%) while the Eastern region had the highest incidence of A. flavus metabolites (81%). Among the A. flavus metabolites, cyclopiazonic acid (CPA), beta-cyclopiazonic acid (β CPA), flavacol (FLV) and methylcitreo-isocoumarin (MIC) positively correlated with each other but negatively correlated with the other metabolites. Significant positive co-occurrence was also noted among Fusarium mycotoxins: nivalenol (NIV) positively correlated with DON (r = 0.81), fusarenon-X (FX) (r = 0.81) and ZEN (r = 0.70). Negative correlations were observed between Aspergillus and Fusarium mycotoxins: aflatoxin B1 (AFB1) negatively correlated with FB1 (r = −0.11), FX (r = −0.17) and ZEN (r = −0.20). Local open-pollinated maize varieties (L-opv) were less susceptible to mycotoxin contamination compared to the commercial hybrids (C-hy). This study reveals that Kenyan maize is contaminated with multiple mycotoxins most of which are not regulated in Kenya despite being regulated in other parts of the world. A comprehensive legislation should therefore be put in place to protect the Kenyan public against chronic exposure to these mycotoxins. In addition to high yield, there is a need for commercial hybrid maize breeders to incorporate mycotoxin resistance as an important trait in germplasm improvement in seeds production.

Modulating Drought Stress Response of Maize by a Synthetic Bacterial Community.

Plant perception and responses to environmental stresses are known to encompass a complex set of mechanisms in which the microbiome is involved. Knowledge about plant physiological responses is therefore critical for understanding the contribution of the microbiome to plant resilience. However, as plant growth is a dynamic process, a major hurdle is to find appropriate tools to effectively measure temporal variations of different plant physiological parameters. Here, we used a non-invasive real-time phenotyping platform in a one-to-one (plant–sensors) set up to investigate the impact of a synthetic community (SynCom) harboring plant-beneficial bacteria on the physiology and response of three commercial maize hybrids to drought stress (DS). SynCom inoculation significantly reduced yield loss and modulated vital physiological traits. SynCom-inoculated plants displayed lower leaf temperature, reduced turgor loss under severe DS and a faster recovery upon rehydration, likely as a result of sap flow modulation and better water usage. Microbiome profiling revealed that SynCom bacterial members were able to robustly colonize mature plants and recruit soil/seed-borne beneficial microbes. The high-resolution temporal data allowed us to record instant plant responses to daily environmental fluctuations, thus revealing the impact of the microbiome in modulating maize physiology, resilience to drought, and crop productivity.

Estimations on Trait Stability of Maize Genotypes

The purposes of this study were to define the kind of trait inheritance through stability estimations of various traits in maize, to define the relationship between different environments and maize hybrids, and to propose the best environments and hybrids for farmers. Field experiments were conducted in two years (2011 and 2012) at four different locations in Greece: Florina, Trikala, Kalambaka and Giannitsa which were selected as they represent different environments. The genetic materials tested in a Randomized Complete Block (RCB) design, were 15 F1 commercial maize hybrids and 15 open-pollination lines developed from 4-cycle Honeycomb evaluation. Materials were sown and harvested by hand at different dates according to local conditions. Trait stability index (x¯∕s)2 across environments was computed for each maize trait studied: yield, specific weight, 1000-kernel weight, axis (spindle) weight, spike weight, number of kernels per spike, spike length and diameter, number of kernel rows, spindle diameter, main spike and plant height, prolificacy and number of kernels per row. The findings showed great differences in stability index between traits and also for the same trait across environments or between maize genotypes. GGE biplot for yield distributed genotypes in a different way for Florina on the basis of one main factor and managed to depict Trikala’s differential response on the basis of two factors. Almost the same trend was found for 1000-kernel weight and specific weight, where there was a wide core for similar responding genotypes. Basic conclusions of this research are summarized in great differences of various traits, indicating qualitative, medium or quantitative inheritance. Estimations for trait stability can be easily performed in a multi-genotype experiment using trait stability index. The most stable hybrids were proved to be 31Y43, COSTANZA and FACTOR. The environment favouring a general stable performance proved to be Florina.

Kernel filling and desiccation in temperate maize: Breeding and environmental effects

Sowing date (SD) modifies the environmental conditions during the kernel-filling period as well as during kernel dry down after physiological maturity (PM), particularly for late-sown maize (Zea mays L.) crops that currently cover 50 % of the maize area in Argentina. The main goal of this work was to evaluate breeding effects on kernel filling and kernel desiccation traits in a set of five commercial maize hybrids released by a single breeding program between 1980 and 2016 when grown under contrasting environments in the temperate Central Pampas region. The evolution of kernel weight (KW) and kernel moisture (KM) were assessed. Maximum KW (KWMAX), maximum kernel water content (KWCMAX), kernel filling rate (KFR), kernel filling duration (KFD) and KM at silking+20 days (KMR1+20) and PM (KMPM) were computed together with husks number. Pre-PM kernel desiccation was described using an exponential decay model with k1 as the proportionality drying coefficient. For the post-PM period, kernel desiccation was modelled assuming that the change in KM in a given period is proportional to the difference between the kernel and the equilibrium moisture contents, where k2 was the corresponding proportionality drying coefficient. For KWMAX, a genetic progress of 0.26 % year −1 (p < 0.05) was estimated from 1993 to 2016. This trend was explained by the increase registered in KFD (0.32 % year−1, p < 0.01), which was partially compensated by a reduction in KFR (−0.08 % year−1, p < 0.05). No genetic progress was detected for husks number, KWCMAX, KMR1+20, KMPM, k1 and k2, but introduction of dent germplasm produced an increase in KWCMAX, KMR1+20 and KMPM and a decrease in k2. KFR and KFD as well as kernel desiccation dynamics were strongly affected by SDs. Breeding effects that extended KFD, together with the broad adoption of late sowings, promote a reduction in k2, which must be considered for the correct assessment of trade-offs between drying costs and kernel quality penalization by pests and diseases.

Nitrogen response and agronomic use efficiency of N fertilizer in diverse commercial maize hybrids at Bako, Western Ethiopia

Agronomic Efficiency indicated the grain yield production potential of variety in response to the applied nutrients. Field experiment was conducted at the research Farm of Bako National Maze Research Center Western Ethiopia during 2020/2021 in order to investigate the nitrogen response and agronomic efficiency of various maize genotypes.

Unravelling the Effect of Provitamin A Enrichment on Agronomic Performance of Tropical Maize Hybrids.

Maize is consumed in different traditional diets as a source of macro- and micro-nutrients across Africa. Significant investment has thus been made to develop maize with high provitamin A content to complement other interventions for alleviating vitamin A deficiencies. The current breeding focus on increasing β-carotene levels to develop biofortified maize may affect the synthesis of other beneficial carotenoids. The changes in carotenoid profiles, which are commonly affected by environmental factors, may also lead to a trade-off with agronomic performance. The present study was therefore conducted to evaluate provitamin A biofortified maize hybrids across diverse field environments. The results showed that the difference in accumulating provitamin A and other beneficial carotenoids across variable growing environments was mainly regulated by the genetic backgrounds of the hybrids. Many hybrids, accumulating more than 10 µg/g of provitamin A, produced higher grain yields (>3600 kg/ha) than the orange commercial maize hybrid (3051 kg/ha). These hybrids were also competitive, compared to the orange commercial maize hybrid, in accumulating lutein and zeaxanthins. Our study showed that breeding for enhanced provitamin A content had no adverse effect on grain yield in the biofortified hybrids evaluated in the regional trials. Furthermore, the results highlighted the possibility of developing broadly adapted hybrids containing high levels of beneficial carotenoids for commercialization in areas with variable maize growing conditions in Africa.

Capturing in-field root system dynamics with RootTracker.

Optimizing root system architecture offers a promising approach to developing stress tolerant cultivars in the face of climate change, as root systems are critical for water and nutrient uptake as well as mechanical stability. However, breeding for optimal root system architecture has been hindered by the difficulty in measuring root growth in the field. Here, we describe the RootTracker, a technology that employs impedance touch sensors to monitor in-field root growth over time. Configured in a cylindrical, window shutter-like fashion around a planted seed, 264 electrodes are individually charged multiple times over the course of an experiment. Signature changes in the measured capacitance and resistance readings indicate when a root has touched or grown close to an electrode. Using the RootTracker, we have measured root system dynamics of commercial maize (Zea mays) hybrids growing in both typical Midwest field conditions and under different irrigation regimes. We observed rapid responses of root growth to water deficits and found evidence for a “priming response” in which an early water deficit causes more and deeper roots to grow at later time periods. Genotypic variation among hybrid maize lines in their root growth in response to drought indicated a potential to breed for root systems adapted for different environments. Thus, the RootTracker is able to capture changes in root growth over time in response to environmental perturbations.

Phytosanitary evaluation of commercial maize hybrids in Italy

Phytosanitary evaluation of commercial maize hybrids in Italy

Hydration kinetics of commercial white maize (Zea mays L.) hybrids, and associations with grain intrinsic and wet-milling properties

The hydration kinetics of 26 commercial white maize hybrids/varieties were investigated, satisfactorily (r > 0.9; P < 0.01) described by the Peleg model and related to the physical, chemical and wet-milling properties of the maize hybrids. The Peleg constants K1 [0.142–0.294 h(g/100 g solids)−1], K2 [0.030–0.037 (g/100 g solids)−1] and equilibrium moisture content, ME, [41.76–47.83 g/100 g solids] showed genotypic differences. The distributions, associations and groupings of the maize hydration, physical, chemical and wet-milling properties were evaluated with Principal Component Analysis (PCA), Pearson's correlation coefficients and clustering analysis using Agglomerative Hierarchical Clustering (AHC). The Peleg K2 was influenced by the grain protein content and kernel density, and concomitantly impacted the starch yield. The ME also related to the starch yield, in addition to the starch recovery. The AHC analysis was extended to include 16 commercial yellow maize hybrids from our previous study. The groupings of the resulting 42 of the most widely grown maize hybrids/varieties in México confirmed the close association between maize water absorption, physical, chemical and wet-milling properties. The findings on the hydration kinetics, and the starch yield and recovery from wet-milling are of specific interests to the maize industry.

Carotenoid Content and Bioaccessibility in Commercial Maize Hybrids

The objective of the present study was to determine the content and bioaccessibility of carotenoids in 104 maize hybrids available at the market. Lutein, zeaxanthin, α- and β-cryptoxanthin, and β-carotene were determined in whole grains and micelles produced during standardized INFOGEST digestibility analysis, and their bioaccessibility was calculated as the ratio of micellar and grain carotenoids. Tested hybrids varied in total carotenoid content, with 34% having total carotenoid content in the range of 15–20 µg/g dry matter (DM) and 41% in the range of 20–25 µg/g DM. The amount of bioaccessible carotenoids increased linearly (p &lt; 0.05) with increasing content in the grain, and decreased among determined carotenoidsd in the order: lutein (52%) &gt; zeaxanthin (43%) &gt; β-carotene (43%) &gt; α-cryptoxanthin (27%) &gt; β-cryptoxanthin (26%). Bioaccessibility of lutein, zeaxanthin, and β-carotene decreased with increasing content in the grain (p &lt; 0.05). On average, only 43% of the total carotenoids were bioaccessible in commercial maize hybrids tested, which should be considered when formulating an animal diet.

II. Ürün Mısır Yetiştiriciliğinde Farklı Gübre Kaynaklarının Verim ve Besin Elementleri İçeriğine Etkisi

Bu çalışma, Mardin ilinin Artuklu ilçesine bağlı Göllü köyünde iki yıl süreyle 2015 ve 2016 yıllarında 2. ürün olarak (Haziran-Kasım dönemi) yürütülmüştür. Tarla uygulamasında ticari hibrit mısır çeşidi Dekalp 5401 (Ç1) ve Limagrain Helen (Ç2) materyal olarak kullanılmıştır. Deneme ‘‘Tesadüf Bloklarında Bölünmüş Parseller’’ deneme planına göre üç tekrarlamalı olarak yürütülmüştür. Çalışmada, gübresiz kontrol parseli, standart ticari gübre (8 kg da-1 P2O5, 20 kg da-1 N), tavuk gübresi (1000 kg da-1), çiftlik gübresi (1500 kg da-1) ve solucan gübresi (1200 kg da-1) sırasıyla G1, G2, G3, G4 ve G5 olarak gruplandırılmıştır. Bu çalışmada tane veriminin yanında bazı makro (K, Na, Mg ve Ca) ve mikro (Fe, Cu, Zn ve Mn) elementlerin tanedeki içeriklerine bakılmıştır. Araştırmada elde edilen sonuçlara göre; tane verimi en yüksek 1223 kg da-1 ile Ç1’in G2 (standart gübre) uygulamasında elde edilirken, K oranı Ç1’in G2 ve G5 uygulamalarında, Na oranı Ç1’de G2 ve Ç2’nin G4 uygulamalarında, Mg oranı ise her iki çeşidin G2 uygulamalarında, Ca oranı ise Ç2’nin G2 uygulamasında en yüksek oranlar elde edilmiştir. Demir (Fe) ve Zn oranı Ç1’in G3 uygulamasında, Cu oranı Ç2’in G2 ve G4 uygulamalarında, Mn oranı ise Ç1’in G2 uygulamasında elde edilmiştir. Tane verimi bakımından G2 uygulamasının başarılı olduğu, N, P, K, Ca ve Mg gibi makro elementler ile Fe, Cu, Zn ve Mn gibi mikro elementlerin içeriği bakımında G2 uygulamasının diğer organik gübre kaynaklarında önemli bir yere sahip olduğu kanaatine varılmıştır.