Botanical and production changes in phytocenosis after cessation of mineral fertilizing
Ján JANČOVIČ, Ľuboš VOZÁR, Eva ĎURKOVÁ (Slovak Agricultural University, Nitra)
Paper is in English
(6 tab., 15 ref.)
Field trials were conducted to study the effect of fertilization and its absence on floristic composition and production of dry
matter of semi-natural grasslands. Diversified grass community is changed during eight years of fertilization by gradated nitrogen rates into grassland
with 71 to 84% share of grasses. Phosphorus-interruption fertilization supports the development of dicotyledonous species and a share of grasses is falling.
After three-year cessation of fertilization the unfertilized stand is typical of almost a 50% share of dicotyledonous species, grass species (Festuca pratensis
Huds., Festuca rubra L.) are disappearing and moss (20%) is spread in the stand. In the stand fertilized with PK-fertilizers, before cessation the share of
leguminous crops is significantly falling (by 24%), and the representation of the other meadow herbs and grasses is increasing. Absence of fertilization affected
minimally the stand with 240 kg N/ha though the stand was thinned due to a reduction in the representation of grasses (by 8%) and the other herbs (by 2.5%).
Absence of fertilization affected dry matter production, which manifested particularly in the second and third years of cessation. However, a sharp decrease of 40
to 70% in dry matter yields was recorded in the year after cessation. Absence of fertilization affects negatively the development of productivity, quality and floristic
composition of grass fytocenosis. Due to minimum utilization of grassland the process of secondary succession starts as early as in the second year after cessation
Key words: semi-natural grassland, floristic composition, dry matter production, cessation of mineral fertilization
AGROVOC descriptors: grassland; natural pastures; fertilizer application; nitrogen fertilizer; plant population; botanical composition; organic matter; crop yield
Adress: doc.Ing. Ján Jančovič, PhD., Katedra krmovinárstva, Agronomická fakulta, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, tel. +421-87-6508 234
The effects of slow-acting nitrogenous fertilizers on leaching N-NO3- and N-NH4+: A laboratory
lysimetric experiment
Jaroslav NOSKOVIČ, Jana PORHAJAŠOVÁ, Jana URMINSKÁ (Slovak Agricultural University, Nitra)
Paper is in English
(6 tab., 10 ref.)
A laboratory lysimetric experiment was carried out to study the effect of slow-acting nitrogenous fertilizers on nutrient migration. Dependence of the migration of anorganic nitrogen
forms on a sort of the nitrogenous fertilizer applied (nitrate of ammonia + dolomite, urea-formaldehyde condensates with a different activity index) was investigated. The results obtained confirmed that the leaching
of anorganic nitrogen forms is dependent on a kind of the fertilizer applied. The activity index of urea-formaldehyde fertilizers was found to have a significant influnce on nitrogen migration. The most intensive
migration was noted for the treatments with easy soluble fertilizers.
Key words: nitrates, urea-formaldehyde condensates, activity index, migration, leaching, lysimetric experiment
AGROVOC descriptors: nitrogen fertilizers; slow release fertilizers; nitrates; leaching; lysimeters
Adress: Ing. Jaroslav Noskovič, CSc., Katedra ochrany životného prostredia a zoológie, Agronomická fakulta, Tr. A. Hlinku 2, 949 76 Nitra, tel. +421-87-6508 422
The influence of artificial sound stimulation with varied beginning of action on ISA 715 VEDETTE hybrid chicks hatching
Ladislav VETERÁNY, Svätoslav HLUCHÝ, Ján WEIS (Slovak Agricultural University, Nitra)
Paper is in English
(1 tab., 9 ref.)
In this work, the effects of artificial sound stimulation with varied start on incubation of the hatching eggs of ISA 715 Vedette hybrid were studied. For stimulation, an electronic sound
generator with an amplitude of power of 1250 mV and the time of 176 ms was used. Hatching eggs of the control group (88 pieces) were not stimulated, while those of the four experimental
groups (88 pieces in each) were sound stimulated. In group 1 stimulation started at 385 h of incubation, in group 2 at 409 h, in group 3 at 433 h and in group 4 at 457 h. The experiment had
four replications. The shortest time of beacklapping was observed in group 3 (sound stimulation started on day 19/433 h of incubation), where chicks started beaklapping after 495.75±2.41
hours of incubation. The difference was significant (P<=0.01) in comparison with the control. Beakclapping time of the whole group 3 was 11.75±0.83 h, and the whole group of chicks took
507.50±3.02 h to hatch. The differences were statistically significant (P<=0.05) and (P<=0.01) as compared to the control, which also indicates the synchronization of hatching. Our results show
that the best time for beginning of stimulation through artificial sound was day 19/433 h of incubation
Key words: hatching, sound stimulation, chicks
AGROVOC descriptors: chicks; egg incubation; hatching; stimuli; sound
Adress: Ing. Ladislav Veterány, Katedra pedagogiky a sociológie, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, e-mail:hluchy@afnet.uniag.sk
The influence of organic components of the liquid fertilizer Avir 35 on the yield of winter wheat
Jozef HUDEC (Slovak Agricultural University, Nitra)
Paper is in English
(2 tab., 8 ref.)
In the period 1989-90 and 1990-91, field microplot experiments were carried out to study the influence of a ratio of organic compounds in mixture, present in the
liquid fertilizer Avit 35 on the yield of winter wheat. From the results it follows that a 9.9: 0.1 ratio is optimal for the components in mixture. A smaller or bigger proportion
of the components in mixture is not optimal, though in the range studied it increased the grain yield. For the application at the beginning of ear formation, it is most
convenient to apply the mixture in the amount of 0.99 kg of alkanolamine, structurally similar to polyamines, and 0.01 kg of organic, structurally different compound per
hectare. The mixture has considerably a greater effect on the grain weight than a number of grains. Using the optimal mixture, a statistically significant growth of 0.6 t/ha
was obtained in the mean grain yield on the soil in Kolinany while the control variant produced a grain yield of 6.02 t/ha. In the site of Horná Malanta, a statistically non-significant
increase of 0.31 t/ha in the yield of grain was observed in the average of experimental years, with the grain yield of 6.02 t/ha in the control variant
Key words: winter wheat, organic compounds, synergetic effect, antistress effect
AGROVOC descriptors: triticum aestivum; winter crops; fertilizer application; liquid fertilizers; organic nitrogen compounds; synergism; yield factors; crop yield
Adress: doc. Ing. Jozef Hudec, CSc., Katedra chémie, Agronomická fakulta, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, tel. +421-87-6508 371
Studies on the embryology of the grasshopper Chrotogonus lugubris Blanchard (Orthoptera, Acridodea, Pyrgomorphidae). II. Early development
Khaled Mohamed Abdel RAHMAN (Entomol. Dept., Fac. Sci., Cairo University)
Paper is in English
(9 obr., 23 ref.)
Early development of the embryo is discussed. The 2-cell stage occurred about four hours after oviposition. Cleavage continued and the blastoderm was formed in stage 11 .52%D.
The germ band was formed and was better defined by stage 13.0%D. Gastrulation resulted by cells proliferated from the roof of a gastral groove by stage 15.53%D. Also, during this
stage, the embryonic membranes were formed. Coelomic sacs were formed in stage 21.29%D by turning of the lateral edges of the ectoderm dorsally and medially. In the abdomen, they
were formed by the appearance of clefts in the inner layer and were completed by stage 28.9%D. Anatrepsis took place in stage 23.21 %D and ended in 34.7%D. Katatrepsis started in
stage 51.34%D and ended in 58.3%D. The second was formed by the amnion and the first dorsal closure in stage 59.68%D. This closure was replaced by the ectoderm, the serosa was
pushed forward and dorsal, and formed a tubular dorsal organ by stage 80.71 %D. The mesoderm was differentiated by stage 36.01 %D.
Key words: embryogenesis, grasshoppers, Pyrgomorphidae, Chrotogonus lugubris
AGROVOC descriptors: acrididae; embryonic development; precocity
Adress:Khaled M. Abdel Rahman, Fac. Sci., Entomol. Dept., Cairo University, Cairo, Egypt
Isozyme analysis of multishoot culture of cytoplasmic male fertility lines and O-types of sugarbeet (Beta vulgaris L.)
Marek ENGELHARDT, Milan BEŽO (Slovak Agricultural University, Nitra)
Paper is in Slovak
(2 obr., 11 ref.)
In vitro regenerated plants of sugar beet (Beta vulgaris L.) with cytoplasmic male sterility (CMS) lines (SI 76 S, SI 74 S,
SI 62 S, R 4533) and O-types (SI 76 O, SI 74 O, K 17 O) were
analysed for enzyme polymorphism using starch gel horizontal
electrophoresis. The analysis was performed on the isozymes of
malate dehydrogenase (MDH), phosphoglukomutase (PGM),
phosphoglukoisomerase (PGI), isocitrate dehydrogenase (IDH),
and glucose-6-P-dehydrogenase. Three PGI isozymes and two
isozymes of MDH and PGM were examined. No polymorphism was
observed for IDH and PGD isozymes
Key words: sugar beet, isoenzymes, polymorphism
AGROVOC descriptors: beta vulgaris; genetic polymorphism; isoenzymes
Adress: prof. RNDr. Milan Bežo, Katedra genetiky a šľachtenia rastlín, Agronomická fakulta, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, tel. +421-87-6508 241
Female nutria fertility of different genotypes during three estral cycles
Milan BARTA (Slovak Agricultural University, Nitra)
Paper is in Slovak
(3 tab., 10 ref.)
The reproduction characteristics of standard, Gronland and
silver nutrias were studied during three estral cycles, with
reference to a number of youngs born in successive litters.
The average number of younglings of the given nutria genotypes
born during these cycles was in a range of 4.20 to 6.80 pcs. A
relatively high outage of females from the regular
reproduction process was observed already in litter III. The
mean number of youngs borner litte lifters ranged from 4.73 to
6.03 pcs. At the same time, a high dispersion was observed for
a number of born youngs in individual lifters, ranging from 1
to 9 pcs. No significant differences in the number of born
youngs were detected among and between the genotypes of
nutrias. However, there were significant differences in the
number of younglings between litter I and litter III, the
latter exhibiting a higher number. Also, a significant
interaction of genotype and litter order was noted for the
fertility of nutrias
Key words: nutrias, genotypes, fertility
AGROVOC descriptors: coypus; fertility; productive performance; genetic variation
Adress: doc. Ing. Milan Barta, CSc., Katedra hydinárstva a malých hospodárskych zvierat, Agronomická fakulta, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, tel. +421-87-6508 317
The influence of storage time and temperature on weight loss in eggs and yolk pigmentation
Martin HALAJ, Peter HALAJ (Slovak Agricultural University, Nitra)
Jozef GOLIAN, František VALÁŠEK, František MORAVČÍK, Martin MELEN (TEKRO spol. s r.o. Dvory nad Žitavou)
Paper is in Slovak
(2 tab., 21 ref.)
The influence of storage time and temperature on losses in egg
weight and yolk pigmentation was evaluated. Laying hens of
Shaver Starcross 288 hybrid at 42 weeks of age were fed the
mash supplemented with 0.5% of Carophyll synthetic pigment
(Cl, C2 and C3). A total of 960 eggs of 4 groups of hens, each
comprising 15 birds (control, experiments 1, 2 and 3) were
stored at 2 and 20 deg C and relative humidity of 55 and 60%,
respectively, for 7, 14 and 21 days and then analyzed for
weight, yolk weight and pigmentation, and shell weight. The
weight loss in eggs stored at 20 deg C and a 50% relative
humidity was significantly higher over those stored at 20 deg
C and a relative humidity of 60%. Losses in egg weight after 7
days storage were 2.29% resp. 0.60%, after 14 days 2.31 and
0.78%, and after 21 days 4.25 and 1.16%. The mesh itself with
5% pigment had no effect on egg loss weight. The yolk
pigmentation intensity was greater in the eggs laid by hens
fed the mesh which contained Carophyll 3, with a higher amount
of Carophyll Red (C3), as compared to those of hens fed mashes
with C1, and C2. This intensity increased at higher storage
temperature
Key words: laying, hens, storage, temperature, time, loss, weight, yolk colour
AGROVOC descriptors: eggs; storage losses; egg yolk; pigmentation; weight losses
Adress: Dr. Ing. Jozef Golian, Katedra výživy SPU v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, tel. +421-87-6508 751