Mixture Of Maize Research Articles

Interactions between residues of maize and pigeonpea and mineral N fertilizers during decomposition and N mineralization

Nitrogen mineralization patterns of maize and pigeonpea ( Cajanus cajan) residues were examined in leaching tubes, both in isolation and mixtures, in Malawian soils of varying texture. Senesced pigeonpea leaves (C-to-N ratio 24) induced a short period of nitrogen immobilization which was followed by steady net nitrogen mineralization in all of three soils. The immobilization period lasted between 14 and 28 days and was longer in soils with larger clay contents. Maize residues contained 30% of their N in the form of water-soluble nitrate. Both the sole maize residue (C-to-N ratio 75 after adjustment for nitrate which constituted 28% of the N) and the mixture of maize and senesced pigeonpeas leaves revealed a similar prolonged strong net N immobilization up to 130 days before the two treatments started to diverge slightly. Mixing maize with pigeonpea residues with equal amounts of N failed to substantially alleviate the N immobilization capacity of the maize residues. N immobilization in the mixture was much greater than that predicted from the mineralization patterns of the individual components. When increasing amounts (50, 100 and 150 mg N kg −1 soil) of green pigeonpea leaves, senesced pigeonpea leaves and ammonia-N were added to 50 mg N kg −1 soil of maize residues, N released in the mixtures increased with the increasing amounts of N added to the maize residues with greater increases from residues with larger N concentrations. There was evidence that microbial degradation of maize carbon was limited by N availability. The implications of the results for management of crop residues and mineral N fertilizers in the field are discussed.

Return of an Old Problem: Fusarium Head Blight of Small Grains

Several species of fungus cause Fusarium Head Blight (FHB), but F. graminearum has been important in the US. The mixture of maize, wheat and barley production, and use of reduced tillage and increased residue retention encourage epidemics of FHB. Strong interest in use of fungicide sprays continues but the complete answer remains elusive. Molecular marker-assisted plant breeding is being used to breed for FHB resistance. Posted 22 June 2000.

FORAGE PRODUCTION OF INTERCROPPED MAIZE AND SOYABEAN CULTIVARS

Seven maize cultivars and seven soyabean cultivars were grown in monocultures, and in all possible 49 mixtures of maize and soyabean, at two locations to assess the intercropping advantages of mixtures. On average, intercrops produced 6% more dry matter and 17.5% more protein than the monocultures of maize, the most productive component. Both the dry matter and protein yields of intercrops were closely correlated with the yield of the maize component, but not with that of the soyabean component, indicating that there was no need for a specific breeding programme for maize to be used in intercropping systems. Although the average intercropping advantage, the monoculture yields of maize cultivars and, to a lesser extent, the monoculture yields of soyabean cultivars differed between locations, there was no evidence that the yield of various intercrop combinations differed between locations.

Muscle composition and fatty acid profile in lambs fattened in drylot or pasture

The effects of two fattening systems on muscle composition and fatty acid profile were determined in an experiment using samples of the longissimus dorsi (LD) muscle of 24 ram lambs (slaughter weight 29–31 kg). The fattening systems were: (i) drylot (a mixture of maize, soybean, wheat and minerals) and (ii) grazing ( Cynodon dactylon). The lambs fattened in the drylot system presented higher fat levels ( p<0.01), but lower concentrations of moisture ( p<0.01) and cholesterol ( p<0.05). The lipid content presented a negative correlation with moisture and protein. In lambs fattened in the drylot system increasing levels of fatness of LD muscle were associated with a decrease ( p<0.05) in myristic and palmitic acids, but myristic, palmitic and linoleic acids increased ( p<0.05) as the cholesterol levels of the muscles increased.

Protein Nutritional Quality and Consumer Acceptability of Tropical Ghanaian Quality Protein Maize

Quality protein maize (QPM) is a high-lysine, high-tryptophan variety. the essential amino acid profile, the protein efficiency ratio (PER) of mixtures of QPM and normal maize, and the hedonic response to three traditional foods were studied with four QPM varieties. the lysine content of the QPM varieties ranged from 3.7 to 4.2 g/100 g protein and was significantly (p &lt; .05) higher than that for normal maize (2.6 to 3.1 g/100 g protein), but lower than the FAO-recommended human level of 5.0 g/100 g protein, the PER values of normal maize showed significant (p &lt; .05) improvement at replacement levels of 60% or more with QPM. the overall acceptability scores showed that QPM varieties were equally acceptable as normal maize in ga kenkey and were preferred to the local normal maize in tuo zafi. The tropical Ghanaian QPM varieties have enhanced amino acid profiles and were acceptable in traditional foods.

Modeling the Dynamics of Adaptation to Transgenic Maize by European Corn Borer (Lepidoptera: Pyralidae)

A deterministic population dynamics model was modified to include single-locus, 2-allele genetics to simulate strategies for delaying resistance in the European corn borer, Ostrinia nubilalis (Hübner), population to transgenic maize. We evaluated seed mixtures of transgenic and nontransgenic maize, 2-row strips of non transgenic plants, adjacent but separate refuges of nontransgenic maize, and rotation of nontransgenic and transgenic maize. We studied how the choice of hybrid, planting time, and weather may influence the selection of a tactic for delaying resistance to transgenic maize. Our results indicate that separate refuges are superior to seed mixtures for delaying resistance. If a high toxin dose cannot be achieved and a small fraction of homozygous susceptible and heterozygous European corn borer neonates survive on transgenic maize, then resistance can develop in 10-33% of the time required under the assumption of a successful high dose that kills all heterozygous neonates. Planting 2-row strips may be as good as separate refuges in delaying resistance, but their adoption carries greater risk because of the uncertainty surrounding movement and survival of neonates. The use of transgenic hybrids is the same whether or not they express the toxin gene in silks and kernels of maize ears. Toxin titer decline must be studied because our simulations indicate that development of resistance may be greatly hastened by this process.

Relationship between the gas production profiles of mixtures of hay and maize and the patterns of rumen fermentation observed in sheep fed those mixtures

The gas production (GP) technique has been developed to assess dynamics of ruminant digestion. Relationships have been observed between a feed's GP profile and in vivo parameters such as digestibility (Khazaal et al., 1993), feed intake and growth rate (Blümmel and Ørskov, 1993), and in situ degradability (Sileshi et al., 1997). However, there are few studies which relate GP data to the in vivo pattern of rumen fermentation (in terms of the rate of pH decline 2 h post-feeding and the mean rumen pH, concentration of total VFA and molar proportion of individual VFA). The object of this experiment was to determine whether such a relationship existed between a feed's GP profile and the pattern of rumen fermentation observed in animals fed that feed.

Relationship between the gas production profiles of mixtures of hay and maize and the patterns of rumen fermentation observed in sheep fed those mixtures

The gas production (GP) technique has been developed to assess dynamics of ruminant digestion. Relationships have been observed between a feed's GP profile and in vivo parameters such as digestibility (Khazaal et al., 1993), feed intake and growth rate (Blümmel and Ørskov, 1993), and in situ degradability (Sileshi et al., 1997). However, there are few studies which relate GP data to the in vivo pattern of rumen fermentation (in terms of the rate of pH decline 2 h post-feeding and the mean rumen pH, concentration of total VFA and molar proportion of individual VFA). The object of this experiment was to determine whether such a relationship existed between a feed's GP profile and the pattern of rumen fermentation observed in animals fed that feed.

Partial Characterization of Glutathione S-Transferases from Wheat (Triticum spp.) and Purification of a Safener-Induced Glutathione S-Transferase from Triticum tauschii

Hexaploid wheat (Triticum aestivum L.) has very low constitutive glutathione S-transferase (GST) activity when assayed with the chloroacetamide herbicide dimethenamid as a substrate, which may account for its low tolerance to dimethenamid in the field. Treatment of seeds with the herbicide safener fluxofenim increased the total GST activity extracted from T. aestivum shoots 9-fold when assayed with dimethenamid as a substrate, but had no effect on glutathione levels. Total GST activity in crude protein extracts from T. aestivum, Triticum durum, and Triticum tauschii was separated into several component GST activities by anion-exchange fast-protein liquid chromatography. These activities (isozymes) differed with respect to their activities toward dimethenamid or 1-chloro-2,4-dinitrobenzene as substrates and in their levels of induction by safener treatment. A safener-induced GST isozyme was subsequently purified by anion-exchange and affinity chromatography from etiolated shoots of the diploid wheat species T. tauschii (a progenitor of hexaploid wheat) treated with the herbicide safener cloquintocet-mexyl. The isozyme bound to a dimethenamid-affinity column and had a subunit molecular mass of 26 kD based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme (designated GST TSI-1) was recognized by an antiserum raised against a mixture of maize (Zea mays) GSTs. Amino acid sequences obtained from protease-digested GST TSI-1 had significant homology with the safener-inducible maize GST V and two auxin-regulated tobacco (Nicotiana tabacum) GST isozymes.

The rate and extent of cell-wall degradation in vitro for 40 silages varying in composition and digestibility

The rate and extent of cell-wall degradation was recorded in 40 silages in order to explore the variation between silages and provide material and results to use in the search for a lower cost method. The method used in the present study was selected from four compared previously (Wilman et al., 1996. Anim. Feed Sci. Technol., 63, 99–109). Freeze-dried, milled silage was incubated in buffered rumen fluid in sealed tubes for 0, 3, 8, 16, 24, 45 or 72 h and then boiled with neutral detergent. The constants a, b and c in the equation p = a + b(1 − e − ct ) (Ørskov and McDonald, 1979. J. Agric. Sci. Cambridge, 92: 499–503.) (where p is the percentage of cell wall degraded after t hours of incubation) were calculated for each silage. The rate of cell-wall degradation in the early stages of fermentation was much higher in a lucerne silage than in the grass and forage maize silages. Mixtures of lucerne and forage maize were intermediate in rate of cell-wall degradation. Among 28 grass silages, ‘ c’ varied from 0.029 to 0.066, indicating wide variation in rate of cell-wall degradation; ‘ c’ was negatively correlated with the cell-wall content of the silage ( r = − 0.81), suggesting that the cell wall from the younger, leafier crops was degraded more quickly than that from more mature crops. The cell-wall degradation curve from 3 to 72 h of incubation was well described by the equation p = ( a + b)(1 − e − c( t − t o ) ), where t o is the lage period before rapid degradation began. In the case of the 28 grass silages there were strong correlations between ‘( a + b)’ and cell-wall degradation after 72 h ( r = +0.92) and between ‘ c’ and cell-wall degradation after 24 h as a percentage of cell-wall degradation after 72 h ( r = +0.95), suggesting that, for some purposes, it may be sufficient to have only 0, 24 and 72 h of incubation.

Breeding for yield, in mixtures of common beans (Phaseolus vulgaris L.) and maize (Zea mays L.)

Breeding for yield, in mixtures of common beans (Phaseolus vulgaris L.) and maize (Zea mays L.)

The Effect of Cowpea Supplementation on the Quality of Kenkey, a Traditional Ghanaian Fermented Maize Food

Abstract The effects were evaluated of cowpea-mediated protein enrichment on factors relating to kenkey acceptability. Kenkey was prepared on a laboratory scale from a 4:1 mixture of maize (Zea mays) and red or white cowpea (Vigna unguiculata) and compared with an all-maize product in terms of parameters such as the fermentation profile of doughs, colour and fracture profiles. There was no significant difference between the fermentation profiles after 4 days' fermentation at 30°C, with final dough pH values reaching 4·07 and 4·08 for all-maize and maize/cowpea mixtures, respectively. Addition of wholegrain cowpeas resulted in an increase in the crude protein content to 12·99% (w/w) and 13·89% (w/w; dry weight basis) for kenkey supplemented with 20% white and 20% red cowpea, respectively, compared with 10·80% (w/w) for unsupplemented kenkey. Addition of cowpea reduced the whiteness (Hunter L value) of the kenkey by 12% (using white cowpeas) and by 27% (using red cowpeas). The use of dehulled red cowpeas improved the whiteness only slightly. Cowpea-supplemented kenkey was more homogeneous and less prone to fracture than all-maize kenkey. The force required to fracture cowpea-supplemented kenkey was higher than for traditional kenkey, and increased with increasing cowpea concentrations. Kenkey stored for 24 hours required over twice as much force to fracture than freshly prepared kenkey. A group of native Ghanaians familiar with the traditional maize kenkey sampled the new product and confirmed that kenkey made from a mixture of wholegrain white cowpea or dehulled red cowpea and maize compared very well with the traditional kenkey.

Chip-like Cod Based Crackers: Acceptability and Chemical Composition

Fish chip-like crackers were prepared from wheat flour, mixtures of maize:wheat (1:1), potato:wheat (1:1) flour and meat of minced cod (Gadus morhua) at a flour to fish ratio of 90:10, 80:20 and 70:30. Sensory evaluation scores were highest for the following mixtures: 90% wheat flour-10% minced cod, 40% maize flour-40% wheat flour-20% minced cod, 45% potato flour-45% wheat flour-10% minced cod. Chemical analysis showed significant increase in crude protein and ash contents, whereas, at the highest cod mince addition (20%), no significant increase in fat content was observed. An obvious improvement in the essential amino acid pattern of the highly accepted products was observed except for lysine and threonine being the most limiting as calculated by the chemical score. Nevertheless, at 20% addition of cod mince the lysine content of 40% maize flour-40% wheat flour formula greatly improved. The moisture content (6.38-7.42), water activity (0.32-0.52) and pH (5.9-6.1) of dried chip-like cod crackers predict a good shelf life.

Influence of Wind Speed on Residence Time of Uroleucon ambrosiae Alatae (Homoptera: Aphididae) on Bean Plants in Bean Monocultures and Bean–Maize Mixtures

The departure of winged aphids from a plant by flying or walking to neighboring plants may, in theory, be affected by wind speed or the density of leaf bridges between plants. This study explored the effects of these two factors on the departure rate of winged Uroleucon ambrosiae (Thomas) from bean plants, Phaseolus vulgaris L., in monocultures and in mixtures with maize, Zea mays L., in Costa Rica. Residence half-time, herein defined as the length of time required for half the winged aphids placed on a plant to depart, was shorter in mixed crops than in bean monocultures and was negatively correlated with wind speed at bean canopy level. Residence half-time had no detectable correlation with the number of inter plant leaf bridges. Departure by flight, based on these findings, may have been more common than walking from plant to plant via leaf bridges. Maize in mixed crops formed barriers that reduced wind speed at bean canopy level, leading U. ambrosiae alatae to depart more readily from bean plants in bean–maize mixtures than in bean monocultures.

Preparation of a low-phytate feed mixture and bioavailability of its phosphorus to chicks

Phytate phosphorus in a 4:4:1 (by weight) mixture of ground maize, soya-bean meal and wheat bran was decreased by 81% when treated with native phytase in wheat bran and ground maize by a 2-step process. The first step consisted of two successive 2-h conditioning periods at 55°C for maize and soya-bean meal; one at pH 3.5 with citric acid followed by another at pH 5.1. In the second, or hydrolysis step, wheat bran (0.25 parts), a rich source of phytase, was mixed with the wet, citric acid-conditioned maize and soya-bean meal, and the mixture was held for 8 h at 45 C and pH 5.1. After the enzymatic reaction, the increase in orthophosphate accounted for 78% of the phytate phosphorus released and the mixture contained 0.42% inorganic phosphorus in dry matter. A 17-day chick feeding trial showed that tibia bone ash weights tended to be higher ( P < 0.1) for chicks eating the low-phytate feed than for those fed on the control feed.

Nutritive value of diets containing triticale and varying mixtures of triticale and maize for growing-finishing swine

Two trials were conducted to evaluate triticale (CV Beagle 82) and various mixtures of triticale and maize in diets for growing-finishing swine. The grain source was either triticale or maize or three mixtures containing 3:1, 1:1 or 1:3 mixes of maize and triticale. Diets were formulated to be equal in lysine content (triticale averaged 0.42% lysine, air dry basis). Each trial utilized 75 pigs (26 kg) with each treatment assigned to three pens of five pigs each. Grower diets (0.77% lysine) were given from 26 to 59 kg liveweight and finisher diets (0.61% lysine) from 59 to 98 kg. Over both trials, during the grower phase, the addition of triticale to the diet caused a slight, but linear reduction in average daily gain ( P<0.01) and feed conversion efficiency ( P<0.10). During the finisher phase, there were no differences in performance due to dietary treatment. Overall, Beagle 82 triticale was found to be a suitable replacement for maize and part of the soya-bean meal (up to 50 kg of 44% crude protein per 1000 kg of diet) in diets for growing-finishing swine with an average replacement (energy) value estimated at 95–100% of that of maize.

The practical and economic consequences of integrating maize with grass production on dairy farms in southern England: a computer simulation

AbstractA mathematical model of the production, harvesting and utilization of maize and grass silage on a dairy farm with an autumn‐calving herd is described. Using the model the comparative costs and benefits of growing and feeding maize in place of grass silage are examined for three sites in southern England. It is concluded that a winter milk production system based on maize rather than grass should improve profits by at least £30, and possibly by as much as £80 cow‐1. This financial improvement is attributable to higher feed intakes and lower harvesting and fertilizer costs with maize silage. Simulating the results over a 10‐year period also revealed that the switch from grass to maize should lower the risks in terms of the annual variability of silage yields and herd profits. Furthermore, it would appear unnecessary to completely turn over from grass to maize production to realize a significant financial benefit. Setting aside just 25% of the conservation area to maize and feeding a mixture of maize and grass silage is projected to increase profits from winter milk production by £30 to £45 cow‐1.

Some factors affecting the infestation of wheat and maize by Sitophilus oryzae (L.) and Sitophilus zeamais Mots. (Coleoptera: Curculionidae)

Cultures of various stocks of S. oryzae (L.) and S. zeamais Mots. were maintained for several generations at 25°C and 70% r.h. on both wheat and maize, on only one of these foods, or on rice. In every generation a subsample of adults was placed in a mixture of wheat and maize (equal weights of each) for 5 days, after which the two cereals were separated and incubated and the number of progeny counted. A substantial majority of S. oryzae and much less substantial majority of S. zeamais emerged from wheat. In both species the majority was a little less when the laying adults had passed their developmental stages upon maize or rice. In alternate generations the foods were presented to another subsample in separate piles 40 cm apart. The progeny distribution was very similar to that found with intermingled foods. In intervening generations the foods were presented to S. zeamais in suspended bags which could only be reached by flight. When this occurred, more emergences, in many cases over 90%, were found from maize than wheat. When the adults associated with the suspended bags were counted at the end of the 4-day experiment the numbers were as one would expect from the emergences. When similar counts were made daily, however, approximately equal numbers were found associated with each food and observations suggested that directional flight by females did not take place.

Influence of substitution method and of food intake on bioassays to determine metabolisable energy with chickens.

Several different methods of assaying the metabolisable energy (ME) of ground maize and a maize and glucose mixture were studied. Over a 24-h period fasted cockerels lost more energy and nitrogen in their excreta than those fed 15 g maize and 15 g glucose monohydrate. Discrepancies in ME values of maize were found between 1) Hill's method (substitution for glucose) and 2) Sibbald's method (the difference between energy ingested and excreted, corrected for endogenous losses by a comparison with fasted controls). These discrepancies were attributed to differences in endogenous energy losses between fed and fasted birds and interactions between the test substance and reference diet. No significant differences could be detected when substitution for glucose was compared to substitution for the entire diet in three experiments. Significant differences in the ME of maize because of the composition of the basal diet were found (semi-purified:practical; 17.20: 14.56 kJ/g; and 50 g/kg added fat: 100 g/kg added fat; 15.94: 16.69 kJ/g). Food intakes equal to 70, 60 or 30% of ad libitum did not affect the ME of maize when the substitution for glucose method was used. It is concluded that basal diets for ME determinations should be carefully selected because of possible interactions between dietary components. When ME is determined by feeding small amounts of the test material, endogenous losses may be over-estimated because the control birds are in a different physiological state (fasted).

Potentials and limitations of mycorrhizal inoculation illustrated by experiments with field-grown cassava

Field inoculation trials with cassava (Manihot esculenta Crantz) were conducted in Quilichao (typic Dystropept soil) and Carimagua (Haplustox soil). In Quilichao, with a large and effective native VA-mycorrhizal (VAM) population, inoculation withGlomus manihotis did not increase cassava yields significantly, neither when different sources and levels of inoculum material were used, nor with different cassava cultivars, or after stabilizing soil temperature through mulching. Field inoculation did result in a decrease of the coefficient of variation with respect to yield. The high dependency of cassava on an effective VAM association was indicated by a marked decrease in yield after eradication of native VAM by soil sterilization. In Carimagua, with a lower native VAM population, mycorrhizal inoculation withG. manihotis increased yields significantly at intermediate levels of 100 kg/ha of applied P, using either inoculum of cassava orPanicum maximum roots or inoculum of a soil-root mixture of maize or tropical kudzu. Higher or lower levels of P decreased the effect of inoculation on yield. There were no significant differences among P sources, ranging from highly soluble triple superphosphate to low solubility rock phosphates. Inoculation with different VAM isolates had a variable effect on cassava yields, and showed that there may be an interaction between P fertilizer level and isolate efficiency. It is concluded that there may be a potential to increase yields or decrease the fertilizer P requirements of cassava through field inoculation with effective VAM isolates, in the vast areas of acid infertile Oxisols and Ultisols with low native VAM fungal populations, represented by Carimagua.