Stiinta Agricola

12-18

Authors: Nina FRUNZE

The respiration activity of the microbial communities in the plowed chernozem was evaluated in fractions of the values of basal respiration (BR), substrate-induced respiration (SIR), as well as of specific respiration (qCO2), in relation to the soil of the natural biocenosis (standard). For study a carbonate chernozem from a field cultivated with maize in a seven-course crop rotation system was used. The investigations were carried out on the following experimental variants: 1) control (no fertilizing); 2) N60P45К45; 3) N160P120K90; 4) farmyard manure 12 t/ha+P15; 5) farmyard manure 24 t/ha+P30; 6) farmyard manure 12 t/ha+N60P45K45. The uncultivated soil from a natural biocenosis situated in the vicinity of experimenttal plots served as reference background. It was established that agricultural use of soil not only modified the values of BR and SIR but their ratio as well. The average absolute values of basal respiration and substrate-induced respiration were 0,71–1,16 μg C - CO2/g sol/h in the plowed soils and 10,3–25,9 μg C - CO2/g sol/h in the uncultivated soil. Absolute indices of BR from the plowed soil variants were less than SIR values. At the same time the relative values of BR (against uncultivated soil) exceeded the relative values of SIR by 10-21%. The specific respiration indices (qCO2) (1.99-3.07 μg C-CO2/mg Cmic/h) generally reflected the steady state of the microbial communities in the studied variants, but also indicated that between BR/microbial biomass ratios of the plowed variants and BR/microbial biomass ratio of the soil of natural biocenosis a difference was formed that was conditioned by the prolonged influence of anthropic factors. This difference characterizes as stressful the state of the microbial communities, and its amplitude (13–54%) denotes the degree of stress.

28-32

Authors: Мария ХОМЯК

The article shows the importance of experimental mutagenesis for expanding the genotypic diversity of cocksfoot (Dactylis glomerata L.) plants, the possibility of using chemical mutagenesis and its combination with hybridization to obtain starting material and create new varieties. The effect of the chemical mutagen ethyleneimine (EI) on plants of Marichka cocksfoot variety was studied. It was established that as a result of stimulation of Dactylis glomerata L. with chemical mutagenic EI, the obtained mutant plants provide, in comparison with the control, an increase in the yield of fodder mass by 52-64% and seeds by 31-38%. Реферат. В статье показано значение экспериментального мутагенеза для расширения генотипического разнообразия растений ежи сборной (Dactylis glomerata L.), возможность использования химического мутагенеза и его сочетания с гибридизацией для получения исходного материала и создания новых сортов. Изучено влияние химического мутагена этиленимина (ЭИ) на растениях сорта ежи сборной Маричка. Было установлено, что в результате стимуляции ежи сборной химическим мутагеном ЭИ получили мутантные номера, которые обеспечивают, в сравнении с контролем, прибавку урожая кормовой массы на 52-64 % и семян – на 31-38 %.

37-45

Authors: Petru BALAN

Proper management of the crop load is necessary to achieve an appropriate balance between the yield and the fruit size. The study was conducted in the period 2016-2018 with the purpose to assess the effect of various crop load management practices on the Golden Delicious apple variety, grafted on the rootstock M9, in an intensive system. The trees aged 8-10 years were trained according to improved slender spindle shape and planted at a distance of 3.5 x 1 m. Experimental design: a) control, untreated trees; b) fruit manual thinning performed after the physi­ological drop, when the fruits reached a diameter of 16-18 mm; c) chemical thinning with the preparations: 1) Urea solution 46% N, 6 kg/ha, at a temperature of 12-25oC and air humidity of 65-80%, when 75% of the flowers are open until the petals of the first flowers dropped; 2) Geramid New solution, 1.5 l/ha, at a temperature of 15-20 oC, when the central fruit reached a diameter of 4-7 mm; 3) LG Dira Max solution, 2,l/ha at a temperature of 18-25oC, when the central fruit reached a diameter of 10-15 mm. The experiment was organized in 4 repetitions, the spraying was per­formed on 8 trees in each repetition, using 11 l of solution on 32 trees or 1000 l per hectare, respectively. The authors calculated the number of red dotted buds, the number of inflorescences that set fruit, the average number of fruits per tree as well as the average weight and diameter of fruits. The used growth regulators ensured a significant increase in the average weight of a fruit (135,4-144,4 g) and a significant increase in the diameter of fruits (over 85% of fruits have been classified in the category I and Extra category), but significantly reduced the number of fruits per tree.

52-62

Authors: Inna BÎLICI

The research has been aimed to study the photosynthetic apparatus of five apple varieties recently introduced to culture in the Republic of Moldova: Gala Buckeye Simmons, Granny Smith, Red Velox, Golden Delicious Reinders and Fuji Kiku. The experiments were installed in the central area of the Republic of Moldova, in 4 random repetitions of 8 trees each one. The inter-row spacing was 3,2 m and the intra-row spacing – 0,8 m or 3900 trees/ha. The leaf area was examined separately on shoots, spurs and bourse shoots during vegetation, growth and growth-and-fruiting stages. The dynamics of leaf area formation in trees over time and during the vegetation period is correlated with the total length of shoots and the number of rosettes of leaves on the tree. During the growth stage of the trees, most of the leaf area (68,9-76,1%) is formed on shoots and only 23,9-31,1% - on spurs and bourse shoots. During the growth-and-fruiting stage of the trees, the leaf area registered identical values on the shoots and on the fruiting branches. The Granny Smith and Golden Delicious Reinders varieties registered a larger leaf area (8,85-8,34 m2/tree), compared to the Gala Buckey Simmons and Red Velox varieties. The values of leaf area of Golden Delicious Reinders (34827 m2/ha) and Fuji Kiku (35997 m2/ha) were distinctly significant (56,1-61,4%) in comparison with the Red Velox variety (22308 m2/ha). All the studied varieties, at the age of 4-5, made up a photosynthetic apparatus (25272-29913 m2/ha) at the optimal level for intensive orchards. The leaf area per tree varies depending on the variety, age and productivity of the trees.

67-72

Authors: Mykola MOROZ

The technological parameters of the diet for green lacewings are offered. Green lacewings cultivation is recommended on eggs, larvae and imago of host insects. First-age larvae of green lacewings are cultured on cryopre¬served eggs of Sitotroga cerealella Oliv., which have been finely dispersed with a solution of iodine concentrate plus Se. In the following age, the larvae of green lacewings were bred on the phytophages Hyperomyzus lactucae Kalt. and Aphis gossypii Glov. at the ratios of 1:1, 1:2 and 1:4. Imago green lacewings fed with a water solution of nano aqua citrate of trace elements with biologically active components. With the modification of the artificial biotechnological system, there are changes in the qualitative and quantitative indices of feed that affect the ontogeny of green lace¬wings. The increase of imago productivity indices and increase of efficiency of green lacewings as biological agents for limiting the harmfulness of native phytophages are noticed by optimization of diet.

81-88

Authors: Елена ГИНДА

The research was carried out on the vineyards of Tiraspol Wine and Brandy Factory “KVINT”. The physiologically active substances gibberellin (100 mg/l) and Mycephyt in three concentrations – 1,10 and 100 mg/l were used to treat grape plants of the technical grape variety Bianca. The treatment of grape plants before flowering with Mycephyt at a concentration of 10 mg/l was the most effective: the mass of the bunch and the number of berries in the bunch were 29.8 and 29.3% higher respectively compared to the control. The yield increase was 2.3 t/ha or 26.1%. A significant increase in the amount of sugars in the must to 22.7% versus 22.1% was noted in the variant of plant treatment during post-fertilization with Mycephyt at a concentration of 10 mg/l, while titratable acidity was at the control level. Mycephyt treatment at a concentration of 10 and 100 mg/l before flowering stimulated the accumulation of higher (by 20.2 and 7.5% respectively) potassium content in the must, compared with the control. The quantitative content of manganese, copper, iron in all cases did not exceed the permissible norms. The results obtained showed the promise of using Mycephyt to increase the productivity of grape plantings of the technical Bianca variety.

96-102

Authors: Татьяна ЩЕРБАКОВА, Борис ПЫНЗАРУ, Василий МАТИЧУК, Наталья ЛЕМАНОВА, Леонид ВОЛОЩУК

The studies were carried out in laboratory and field conditions. From the infected corn plants, 25 isolates of Fusarium fungi were isolated into a pure culture. By seed bioassay, it was deter­mined that 56% of the isolated Fusarium fungi are pathogenic for maize. We determined the effective­ness of fungal biological products in inhibiting the development of root rot of corn seedlings in condi­tions of hard infectious background. The effectiveness of the biological product Trichodermin-SC was 40,3% in the suppression of the pathogen F.verticillioides and 56,6% in the suppression of the pathogen F.graminearum. The effectiveness of the biological product Gliocladin-SC was 38,4% and 43,4%, re­spectively. The effect of presowing treatment of seeds with the biological preparations Trichodermin- SC, Gliocladin-SC and Paurin on the indicators of biological yield components of sugar corn hybrids (Porumbeni-280 and Porumbeni-402) for the production of flour was determined in field experiments. Biological products increased the length of the cobs by 3,8-12,5%, the weight of 1000 seeds – by 3,8- 20,6%, the weight of seeds per cob – by 1,4-16%, the grain yield – by 1,4-14,9%.

107-114

Authors: Anatolie Daicu, Elena SCRIPNIC, Augustin VOLCONOVICI, Ala CHIRSANOVA, Onorin VOLCONOVICI, Victorin SLIPENCHI , Ina VOLCONOVICI

The aim of the study has been to determine the optimum period and the efficiency of the use of the automated installation with low energy consumption for milk cooling using natural cold. The use of the natu­ral cooling installation in the cold season and of the combined installation (refrigeration installation and natural cooling installation) in the warm season was substantiated from the point of view of energy saving. The specific consumption of electrical energy for milk cooling by using natural cold constitutes 0,3 kW h/t in the cold season against 30-35 kW h/t when using typical refrigeration installations. From the analysis of temperatures registered in the central zone of the Republic of Moldova, it was established that the natural cooling installation might be used for milk cooling, including in the months of October and April, the duration of water cooling in the cold accumula­tor constituting several hours (from 4 to 13 hours for t ≤ 40С).

127-136

Authors: Алла КИРСАНОВА, Августин ВОЛКОНОВИЧ, Викторин СЛИПЕНКИ, Онорин ВОЛКОНОВИЧ, Ина ВОЛКОНОВИЧ

This article presents the results of a study on finding factors that affect the thickness of ice freezing in ice storage facilities in natural cold plants designed for cooling milk and storing fruits and vegetables. The article presents the results of using the least squares method with preliminary orthogonalization of factors and the parabolic smoothing method with unequal values of the argument to establish the law to which the thickness of ice freezing in ice storage facilities obeys. The article proves that the thickness of ice freezing depends mainly on the number of days with a negative average daily temperature, and also proves the adequacy of the obtained mathematical model.

144-150

Authors: Savva BALANESCU

The investigations conducted on 4 lots of gestating and parturient sows and their progeny have been aimed to determine the risk factors that lead to the occurrence of toxicosis in the sows-mothers and, as a consequence, cause toxic gastroenteropathy in new-born piglets. Clinical examination included the determination of the general status (body temperature, cardiac and respiratory frequency, behaviour, etc.) and the detailed investigation of the functional state of digestive, cardiovascular and urinary systems. Since the first days after parturition the sows kept in industrial complexes showed a subfebrility state, in some cases the maximum limit reaching the level of 39,9±0,2630C (P<0,05). If the rectal temperature is over 39,50C the sows are considered as sicks and need an urgent treatment. In the majority of sows there were obvious changes in electrocardiophysiological activity of myocardium (T wave was triangular shaped and was reaching a size of 0,6-0,8 mv) which is typical for toxicosis. Paraclinic investigations demonstrated the presence of essential changes concerning the endogenous intoxication markers in the piglets with colostral toxicosis. The content of medium-weight molecules in the blood serum of these piglets was by 41,07% higher compared with their healthy congeners (M±m=18,17±0,23 u/c and 12,88±0,31 u/c respectively); p<0,001), the content of necrotic substances – by 52,5% higher (M±m=1,83±0,14 c/u and 1,2±0,22 c/u, respectively; p<0,05), while the carnosine content was reduced by 12% (M±m=78,35±3,15 μmol/L and M±m=99,13±4,6 μmol/L, respectively; p<0,01).

160-166

Authors: Татьяна ЛУПОЛОВА, Алла ГАНДЖА, Янина КУЛЕШЕВИЧ

Systematic genetic monitoring in populations allows to control the level of genetic diversity, to use the capabilities of marker selection, including the assessment of intra-breed differentiation, the formation of an optimal genealogical structure and selection for heterosis. The article provides information about the genetic structure of the populations of Belarusian Black-and-White cows at the lactoprotein loci CSN3, LALBA, BLG. In two farms at the LALBA, BLG loci, the most frequently encountered (from 42% to 51%) is the heterozygous genotype AB. At the CSN3 locus AA homozygotes were predominant (65% – 72%). Alleles had an almost equal frequency – 61% and 62% for LALBAA and 39% – 38% for LALBAB. The frequencies CSN3A and CSN3B had almost the same values – 0.806 – 0.853 and 0.194 – 0.147, respectively. In genetically equilibrium (χ2 <3.84) cow populations, the occurrence of the BLGA allele was 0.549 and 0.486, BLGB – 0.451 and 0.514. The average heterozygosity is determined at the level of 39.6% – 43.4%.

173-179

Authors: Rita GOLBAN, Artur GOLBAN

The scientific researches reflected in this study had the purpose to analyze the microbiological aspects on the quality of the poultry meat sold in the commercial network and to interpret the indices of the surface and in-depth bacterial microflora. The quality products, which correspond to safety requirements and may be sold in the Moldovan markets, were highlighted. The saprophytic and pathogenic microflora were evaluated by bacteriological and bacterioscopic research methods. The results of the study confirmed the dominance of normal bacterial saprophytic microflora in the studied categories of poultry meat, justifying the acceptability of this product in the consumer’s food.

10-15

Authors: Oxana MULYARCHUK, Ruslan MYALKOVSKY, Petro BEZVIKONNYI

The article provides the results of studies about the effect of basic fertilizer and foliar nutrition of sugar sorghum plants on energy and bioethanol yield in the conditions of the Forest-Steppe southwestern part of Ukraine. The assimilation surface area of sorghum leaves in the variant with the application of N60P60K60 and foliar nutrition in the phase of tillering by the Yarylo preparation at the rate of 3 l/ha increased from 39.6 to 49.1 thousand m2/ha compared to the control and the net productivity of photosynthesis increased by 3.29 g/m2 per day. The sugar content of sorghum stem juice in the stage of panicle formation and wax ripeness of grain in this variant increased by 1.7% – from 15.2 to 16.9%, and the sugar collection – from 5.16 to 8.68 t/ha compared to the control without fertilizer. A high yield of bioethanol was achieved when harvesting sugar sorghum in the wax ripeness phase – ranging from 2.26 to 2.28 t/ha. In the variant using mineral fertilizers (N60P60K60) in autumn and foliar feeding in spring in the tillering phase with the complex microfertilizers Yarylo (3 l/ha) the bioethanol yield was 1.51 t/ha (panicle earing stage) and 2.58 t/ha (wax maturity stage). Реферат. В статье приведены результаты исследований о влиянии основного удобрения и некорневой подкормки растений сорго сахарного на выход энергии и биоэтанола в условиях юго-западной части Лесостепи Украины. Площадь ассимиляционной поверхности листьев сорго на варианте внесения N60P60K60 и некорневой подкормки в фазе кущения препаратом Ярыло нормой 3 л/га по сравнению с контролем увеличивалась с 39,6 до 49,1 тыс. м2 /га; чистая продуктивность фотосинтеза увеличилась на 3,29 г/м2 в сутки. Содержание сахара в соке стеблей сорго в фазы формирования метёлки и восковой спелости зерна в этом варианте увеличилось на 1,7% − с 15,2 до 16,9%, а количество сахара − с 5,16 до 8,68 т/га по сравнению с контролем (без удобрений). Высокий выход биоэтанола был при сборе сорго сахарного в фазу восковой спелости – в пределах от 2,26 до 2,28 т/га. В варианте внесения с осени минеральных удобрений нормой N60P60K60, а весной – проведение внекорневой подкормки в фазу кущения комплексным микроудобрением Ярыло 3 л/га он составил в фазе выбрасывания метелки и восковой спелости соответственно 1,51 и 2,58 т / га.