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The main objective of this work was anaerobic digestion of maize grains and maize silage and biogas production from these crops. Maize grains were treated using one-stage and two-stage anaerobic techniques; using hydrolysis and acidification as the first stage and methanogenesis as the second stage. Processing nonacidified maize grains in an anaerobic reactor is more stable, though the anaerobic degradation start-up period is longer, specific production of biogas is lower and excess sludge production is higher as from acidified maize grains. Maximum specific biogas production was 0.72 m³・kg⁻¹ of volatile suspended solids – VSS (nonacidified maize) (at 35℃) and 0.770 m³・kg⁻¹ VSS (acidified maize) during anaerobic digestion of maize grains. At average yield of 9 t・ha⁻¹ of dry maize 5,450 Nm³・ha⁻¹ of methane can be generated from nonacidified maize and 5,828 Nm³・ha⁻¹ methane from acidified maize grains. Due to low nitrogen content in maize silage, anaerobic digestion of maize silage is rather unstable. Alkali or complementary substrates with higher nitrogen content (e.g. excess sludge from wastewater treatment plant or manure) can be used for anaerobic process stabilization. Maximum measured biogas specific production from maize silage reached 0.655 m³・kg⁻¹ VSS. At average yield of 30 t・ha⁻¹ of the dry maize silage 9,058 Nm³・ha⁻¹ of methane can be generated.
The effect of UV-C light as a means of control of natural mycobiota of grains of maize (Zea mays L.) hybrids “San Juan” and ”H-159” (productive cycle, 2009) was investigated. UV-C lamps of 15 W were used and the exposure times applied were 0, 5, 10, 15, 20, 25 and 30 min. The experiment was established in the randomised complete block design with eight and four replicates. The unit pilot was 50 grains. For the determination of mycobiota the agar plate test was used, after disinfection of the grains with sodium hypochlorite diluted to 3% for 1 min. Differences (P ≤ 0.001, P ≤ 0.05) between treatments were found, the best treatments being those of 30 and 10 min, observing reductions of 42.85 and 52.05% in the number of grains infected with Fusarium spp. with respect to control for “San Juan” and “H-159”, respectively. For Fusarium monoliforme it was found that in 30 min there was a reduction of 53.74% for the hybrid “San Juan”, while for H-159 a reduction of 61.7% in 10 minutes was observed. These results show that UV-C radiation may be useful for application as a germicide in future experiments on a wide variety of grains.
Electromagnetic fields have many applications in agriculture, but much still remains to be studied to provide scientific evidence of its potential use as an alternative for improvement of food quality from plants whose seed was irradiated, especially in the physical characteristics of the product. In this study we investigated the effects of the electromagnetic fields on the physical quality of maize grain. Twelve treatments were evaluated from a combination of two maize hybrids (San Juan and San Jose) and five times of exposure to electromagnetic field (3, 6, 9, 12 and 15 minutes) plus a control (no electromagnetic treatment) in a design of randomised complete blocks with four replications. Electromagnetic treatment of the hybrid maize seeds (San Juan and San Jose), applied as a presowing treatment, modifies the physical characteristics of maize grains. It was possible to observe that there were significant differences (p≤0.01) between the experimental treatments and between the hybrids in their grain length (LG), grain width (GW) and 1000-grain weight (TGW). The hectolitric weight (HW) of the hybrids was between 69.05 and 68.98 kg hL-1, respectively. These results could have an impact on the process and quality of the tortilla that is consumed by the population; this is a function of time of exposure to electromagnetic treatment.
Studies upon breaking the maize grain using a crusher with variable cylinder have been carried out. Grain subjected to the breaking process was of 12, 20, and 30% moisture content. Breaking has been performed applying working gaps of 0.2, 0.5, 1.0, 1.5, and 2.0 mm width as well as cylinder’s speed of 400/400, 400/440, and 400/480 rpm (both cylinders rotational speeds, respectively). Experiments revealed that increasing the rotational speed of one of cylinders in a crusher caused the increase of dusty particles in the achieved product. That increase was observed both at moisture contents change and for different widths of a working gap within the crusher.
The objective of the study was to determine the effect of replacing triticale (high rumen degradable starch) with maize grain (low rumen degradable starch) during the transition period and the first 120 days of lactation on metabolic and hormonal profile indices, milk production and fertility performance in cows. Forty-eight Holstein-Friesian dairy cows were divided into 4 groups: TT (2.5 kg triticale grain/cow per day supplemented from 14 days prepartum to day 120 postpartum), TM (2.5 kg triticale grain/cow per day supplemented from day 14 before parturition to calving, and then 2.5 kg maize grain to 120 days of lactation), MT (2.5 kg maize grain/cow per day supplemented from day 14 before parturition to calving, and then 2.5 kg triticale grain to 120 days of lactation), MM (2.5 kg maize grain/cow per day supplemented from 14 days prepartum to day 120 postpartum). Blood samples were collected 3 weeks and 1 week before calving and on days 14, 56 and 70 of lactation, and they were analyzed in terms of concentrations of glucose, insulin, leptin, insulin-like growth factor I, nonesterified fatty acids, triglycerides, cholesterol, blood urea nitrogen and activities of aspartate aminotransferase and gamma glutamyl transpeptidase. Milk samples were collected twice a day at weekly intervals and analyzed for fat, protein and lactose. Milk yield and individual dry mater intake were recorded at weekly intervals. Body condition was estimated 3 weeks before calving, on parturition day and on days 14, 56 and 120 of lactation. Replacing triticale grain with maize grain in the transition period and during lactation positively affected fertility of lactating cows. An increased first service conception rate and shortening of the days open period was observed in MM and TM groups in comparison to those found in group MT (P ≤ 0.05). The lowest number of services per conception was recorded in groups MM and TM (P ≤ 0.05). Although the impact of milk production and the most of the blood indices were not significantly affected by this treatment, the results of the study suggest that maize grain in the transition period and lactation might be a more effective energy source for dairy cows than triticale grain.
The aim of the study was to evaluate a possibility of propolis production by honey bee Apis mellifera (Horn) (Hymenoptera: Apidae) and its potential for the management of the larger grain borer (LGB) Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) on maize grains. Bee propolis was collected from hives kept on the field for twelve months; they were thereafter diluted with ethanol to obtain 5%, 10%, 15% and 20% concentrations. 5 ml each of the concentrations was applied to 150 g clean maize grains infested with 10 pairs of 1-5 days old LGB in 250 cm3 Kilner jars. The control jars were treated with ethanol. At 90 days post-infestation, data were collected on percentage of weight loss, percentage of grain damage, weight of frass generated (g), number of pupae, larvae and adult LGB. The results indicated that monthly propolis yield was significantly (p < 0.05) lower in the period of honey flow (December-March) relative to other periods. Propolis at all the concentrations tested reduced the population of LGB in propolis-treated maize grains relative to non-propolis treated-ones. The highest effects of propolis was shown at the highest concentration of 20% and it was significantly (p < 0.05) different from its effects at other concentrations. Bee propolis may be integrated with other ecological friendly control methods to manage LGB infestation in maize.
W pracy przedstawiono wyniki badań z lat 2004-2006, których celem była ocena wpływu różnych terminów siewu na zawartość podstawowych składników w ziarnie czterech odmian kukurydzy uprawianej w rejonie południowo-wschodniego Podlasia. Otrzymane wyniki badań pozwalają stwierdzić, że głównie przebieg warunków pogodowych w okresie wegetacji kukurydzy miał decydujący wpływ na zawartość analizowanych składników pokarmowych. Wcześniejszy siew sprzyjał gromadzeniu tłuszczu surowego i włókna surowego w ziarnie.
Badano wpływ spęczniania nasion w chłodzie (7°C; tzw. chłodna imbibicja) na przebieg ich kiełkowania oraz dalsze procesy wzrostowe i rozwojowe części nadziemnych siewek kilku wytworzonych bądź zarejestrowanych po roku 2000 polskich genotypów kukurydzy: odmian i rodów. Ziarniaki wysiano do szalek Petriego z podłożem: gleba organiczna + piasek + torf (3:1:1; v/v/v) i inkubowano przez 7 dni w temperaturze 8°C lub 20/17°C (dzień/noc) bez dostępu światła, a następnie przełożono do skrzynek z analogicznym podłożem na głębokość 5 cm, i umieszczono w szklarni (temperatura 20/17°C, fotoperiod 15/9 godz. (dzień/noc), wilgotność względna (RH) 30%), gdzie siewki rosły do fazy w pełni wykształconego trzeciego liścia (21 dni). W tej fazie rośliny poddano działaniu temperatury chłodowej (7°C) lub 20/17°C (dzień/noc). Po kolejnych 7 dniach chłodzone siewki poddano siedmiodniowej remisji w temperaturze 20/17°C (dzień/noc). Wpływ chłodnej imbibicji ziarniaków na zdolność do kiełkowania, oszacowany na podstawie procentu nasion skiełkowanych po 7 dniach w temperaturze 20/17°C (dzień/noc), wahał się od 0 do 90%. Wyniki porównano z wartościami uzyskanymi dla nasion kiełkujących przez cały czas w temperaturze 20/17°C; w tym przypadku zakres zdolności do kiełkowania wynosi 0-75%. U dwóch genotypów zanotowano stymulację, u dwóch spowolnienie kiełkowania, u czterech brak reakcji. Procent prawidłowo wykształconych siewek uzyskany po 14 dniach wegetacji w temperaturze 20/17oC był mniejszy w przypadku nasion spęcznianych w chłodzie u wszystkich form genetycznych z wyjątkiem odmiany KB 1903. Wśród badanych rodów i odmian kukurydzy wystąpiły jednak takie, które w sposób ekstremalny reagowały na chłodną imbibicję, bowiem u dwóch odmian (KB 1903 i PR39G12) zabieg ten dodatkowo przyspieszał wzrost i rozwój siewek w fazie remisji po chłodzie, ale też spowodował obumarcie pęczniejących nasion u rodu K223 × K227. Badanie wigoru nasion poprzez wyznaczenie zdolności do kiełkowania nie odzwierciedla zatem wigoru siewek. Nie ma także zależności między odpornością ziarniaków na chłodną imbibicję a odpornością siewek na stres chłodu.
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