Productive capacity of the maize for silage crop grown in disturbed irrigation regime

An experiment was conducted with maize for silage as a main irrigation culture in the experimental field of the Agricultural Institute - Stara Zagora. The following variations have been tested: variation 1 - no irrigation (sentinel); variation 2 - optimal irrigation, 80%-85% of FC (100% irrigation); variation 3 - Irrigation as variation 2 but with first irrigation cancelled; variation 4 - irrigation as variation 2 but with second irrigation cancelled; variation 5 - irrigation as variation 2, but with third irrigation cancelled. On the basis of a chemical analysis of the sudangrass forage for the raw protein content, FUM, FUG and PDI were defined. It was found that the highest yield of raw maize protein grown as the main crop was obtained from the optimal irrigation variation, both in the non-fertilized and the fertilized variation, respectively with 1023.5 kg / ha and 1303.5 kg / ha. The optimal water supply of maize provides the highest energy efficiency of the forage expressed in FUM -15022.8 kg / ha, FUG -15584.4 kg / da, PDI - 1060 kg / ha for non fertilized variations and FUM -16873.5 kg / ha, FUG -17516.3 kg / ha, PDI-1219 kg / ha with fertilizer applied.

Expression profile of protein fractions in the developing kernel of normal, Opaque-2 and quality protein maize

Maize protein quality is determined by the composition of its endosperm proteins, which are classified as nutritionally poor zeins (prolamin and prolamin-like) and nutritionally rich non-zeins (albumin, globulin, glutelin-like, and glutelin). Protein quality is considerably higher in opaque-2 mutants due to increased content of non-zeins over zeins. However, the opaque-2 endosperm is soft, which leads to poor agronomic performance and post-harvest infestation. Endosperm modification of opaque-2 had led to the development of Quality Protein Maize (QPM), which has higher protein quality along with hard kernel endosperm. The present study was planned to analyze the expression dynamics of different protein fractions in the endospem of developing maize kernel in normal, opaque-2 and QPM in response to the introgression of endosperm modifiers. Results revealed that albumin and globulin content decreases, whereas, prolamin, prolamin-like, glutelin-like, and glutelin content increases with kernel maturity. It has been observed that opaque-2 mutation affects protein expression at initial stages, whereas, the effect of endosperm modifiers was observed at the intermediate and later stages of kernel development. It has also been noted that prolamin, glutelin, and glutelin-like fractions can be used as quick markers for quality assessment for differentiating QPM varieties, even at the immature stage of kernel development. Overall, the present study implicates the role of different protein fractions in developing and utilizing nutritionally improved maize varieties.

The Role of Agrotechnical Factors in Shaping the Protein Yield of Maize (Zea mays L.)

The subject of the work was the evaluation of maize protein yield conditioned by various agrotechnical factors. The test results are derived from two different field experiments covering a total of seven years of observation. Protein yield was significantly dependent on changing weather conditions in the growing seasons. Protein yield was significantly lower in the dry and hot years. The sum of precipitation for the month of May was positively correlated with maize protein yield. However, there was no correlation between the average air temperature and the amount of protein yield. The sum of atmospheric precipitation for the entire growing season (IV–X) shaped maize protein yield in over 96%. A non-linear relationship of the 2nd degree was determined between these traits. Sowing maize into the soil cultivated traditionally (autumn tillage), “stay-green” type cultivars and row fertilization positively influenced maize protein yield. Initial fertilization (regardless of depth) with two-component NP fertilizer, in relation to broadcast fertilization, significantly increased maize protein yield from 11.4% to 18%, respectively. The type of nitrogen fertilizer did not differentiate the value of this trait. Pre-sowing nitrogen application was more effective compared to the top dressing, and significantly increased protein yield. Row fertilization with two-component NP fertilizer clearly affected the content protein in grain. The interdependence of genetic and agronomic progress is an important factor shaping the potential of maize protein yield and cannot be attributed to either breeding (cultivar) or agronomy.

Biofabrication using maize protein: 3D printing using zein formulations

The use of three-dimensional (3D) printing for biomedical applications has expanded exponentially in recent years. However, the current portfolio of 3D printable inks is still limited. For instance, only a few protein matrices have been explored as printing/bioprinting materials. Here, we introduce the use of zein, the primary constitutive protein in maize seeds, as a 3D-printable material. Zein-based inks were prepared by dissolving commercial zein powder in ethanol with or without polyethylene glycol (PEG400) as a plasticizer. The rheological characteristics of our materials, studied during 21 days of aging/maturation, showed an increase in the apparent viscosity as a function of time in all formulations. The addition of PEG 400 decreased the apparent viscosity. Inks with and without PEG400 and at different maturation times were tested for printability in a BioX bioprinter. We optimized the 3D printing parameters for each ink formulation in terms of extrusion pressure and linear printing velocity. Higher fidelity structures were obtained with inks that had maturation times of 10 to 14 days. We present different proof-of-concept experiments to demonstrate the versatility of the engineered zein inks for diverse biomedical applications. These include printing of complex and/or free-standing 3D structures, materials for controlled drug release, and scaffolds for cell culture.

POPULATION DYNAMICS OF EUXESTA SPP. (DIPTERA: OTITIDAE) IN MAIZE (Zea Mays L.), WHEAT (Triticum aestivum L.) AND POLYCULTURE

In Brazil there is a great concern about the incidence of insect pests on reproductive organs of plants. In maize, there has been some species of Euxesta (Diptera: Otitidae) flies causing damage, especially in sweet maize. The objective of this study was to evaluate the presence of Euxesta spp. in maize, wheat and polyculture. For this, two experiments were carried out in a savanna area. The first was set in two potential hosts, the high protein white maize and the wheat, the second experiment was carried out in a polyculture system (maize, soybean, sorghum and cotton). The insects were captured weekly until the end of cultivation through McPhail traps with hydrolyzed maize protein randomly distributed in both fields..Two species, Euxesta eluta and Euxesta mazorca, were sampled. There was a greater collection of individuals in maize compared to wheat. Higher number of E. eluta was observed in soybean and cotton, followed by maize 1 and 2 and sorghum. The number of E. maize was found to be higher in the two kinds of maize, soybean, cotton and sorghum. The number of females was higher than males in both crops.

How leguminous biomass can increase yield and quality of maize grain in tropical agrosystems

The aim of this study was to evaluate the effect of soil cover with a combination of tree leguminous on increasing grain yield, grain protein content, and maize protein yield. The experiment was conducted with 10 treatments: Leucaena leucocephala + Clitoria fairchildiana + urea (L+C+U); L. leucocephala + Acacia mangium + urea (L+A+U); Gliricidia sepium + C. fairchildiana + urea (G+C+U); G. sepium + A. mangium + urea (G+A+U); L. leucocephala + C. fairchildiana (L+C); L. leucocephala + A. mangium (L+A); G. sepium + C. fairchildiana (G+C); G. sepium + A. mangium (G+A); bare soil with urea (B+U); and a control with bare soil without mineral fertiliser. Differences between G+C+U and B+U, in the agronomic efficiencies, increase in N contents, increase in grain yield. To increase the protein yields in humid regions, leguminous are used to provide nutrients and improve the root environment rather than interacting antagonistically with the crops.