Preliminary assessment of selected sweet cherry hybrids regarding their resistance to black cherry aphid (Myzus cerasi Fabr.) in Bulgaria

D. Stefanova*, S. Malchev

Fruit Growing Institute, 12 Ostromila Str., 4004 Plovdiv, Bulgaria

(Manuscript received 7 July 2020; accepted for publication 11 August 2020)

Abstract. One of the main insect pests of the cherry trees in Bulgaria is Myzus cerasi (Homoptera, Aphididae). The black cherry aphids occur annually in orchards and cause yield loss or degraded quality. In 2018 and 2019, resistance to Myzus cerasi was assessed on 11 selected sweet cherry genotypes in a breeding orchard at the Fruit Growing Institute – Plovdiv. Susceptibility to aphid infestation was assessed through inspection of 100 leaf rosettes from individual tree hybrids. Some of the studied genotypes 6-132, 6-132 (1), 6-131, and 6-131 (1) were not infested by black cherry aphids in the two years of this research. Aphid colonies were observed on all other studied trees from the selected hybrids. The study is still ongoing.

Influence of enzymes with different activity on dynamics of buffalo milk coagulation parameters

Y. Karacheviev1⃰, V. Galabov1, Т. Аngelova2, D. Yordanova2, V. Karabashev2

1Department of Automation of Continuous Manufacturing, Technical University of Sofia, 1000 Sofia, Bulgaria
2Agricultural institute, 6000 Stara Zagora, Bulgaria

(Manuscript received 10 June 2020; accepted for publication 2 September 2020)

Abstract: The aim of the present study was to evaluate the effect of 5 species of chymosin with different concentrations on the dynamics of the traits measured by mechanical lactodynamograph, characterizing the coagulation ability of buffalo milk. The coagulation properties of buffalo milk were evaluated on 420 milk samples taken during morning milking from whole milk. Five enzymes (MAXIREN 600, FROMASE 750, MAHIREN XDS, MAXIREN 180 and MAXIREN PREM P) were tested with 4 concentrations each and one control group with a standard, recommended by the manufacturer of the biosensor – mechanical lactodynamometer chymosin (Polo Trade – Computerized Renneting Meter, Italy). The effect of the concentration of each enzyme was determined by examining 20 milk samples. The use of enzymes at various concentrations resulted in substantial variation in the magnitude and direction of changes. Different chymosins with different concentrations actively affect the curd firmness. The shorter coagulation time will provide sufficient time for the curd firming time and its curd firmness. Over 50% of milk samples coagulate by 6 minutes. The effects of enzymes and their different concentrations on measurement were in different groups, which in our opinion was a good prerequisite for using the obtained data for modelling of the measurement process.

Physicochemical and microbiological characteristics of goat milk from animals grown in a mountainous area in Bulgaria

D. Pamukova1, N. Rusenova2, T. Kolev3, S. Chobanova4, N. Naydenova1*

1Department of Animal husbandry – Ruminants and Dairy farming, Faculty of Agriculture, Trakia University, 6015 Stara Zagora, Bulgaria
2Department of Veterinary Microbiology, Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Trakia University, 6015 Stara Zagora, Bulgaria
3Agricultural Academy, Agricultural Institute, 6000 Stara Zagora, Bulgaria
4Department of Morphology, Physiology and Animal Nutrition, Faculty of Agriculture, Trakia University, 6015 Stara Zagora, Bulgaria

(Manuscript received 20 June 2020; accepted for publication 4 August 2020)

Abstract. The aim of the study was to determine the goat milk quality from animals grown in a mountainous area in Bulgaria based on physicochemical and microbiological parameters. The study was carried out in a farm that breeds local goats and goats of the Bulgarian White Dairy Goat (BWD). Individual milk samples were taken on a monthly basis from morning milking. A total of 100 individual and 10 bulk milk samples were examined for fat, solids non fat, protein and density. A total of 62 samples were collected at a time to determine the microbiological characteristics of milk. For the period May-September 2017, the percentage of fat in the milk of local goats averaged 3.61% and of goats from BWD goat – 3.54%. The solids non fat were 8.27% and 8.19%, total protein – 3.13% and 3.10%, and the dry matter – 11.89% and 11.74%, respectively. For the period May-August 2017 the individual constituents of milk changed to varying degrees with the most variable being milk fat (decrease of 0.97% in local goats’ milk and 1.09% in milk from BWD goat) followed by solids non fat (0.56% and 0.7%, respectively). The slightest change was in protein – 0.21% and 0.26%, respectively. Coagulase-negative staphylococci were the predominant bacterial species in the goats’ milk samples.

Study on the biology of groundnut bruchid, Caryedon serratus Olivier [Coleoptera: Bruchidae] on stored groundnut in Ganye area, Adamawa State, Nigeria

C.S. Oaya*

Department of Crop Science, Adamawa State University, P.M.B. 25, Mubi, Adamawa State, Nigeria

(Manuscript received 4 May 2020; accepted for publication 27 July 2020)

Abstract. Study on the biology of groundnut bruchid, Caryedon serratus Olivier was carried out in the Laboratory of the Department of Agricultural Technology, Adamawa State College of Agriculture, Ganye, Adamawa State from June to September, 2015. The sex of the bruchid (male and female) was assigned the sub-treatment while the period of development was the main treatment and was replicated three times. The work considered the pre-oviposition stage, incubation stage, larval stage, pupal stage, adult stage and the total life cycle of the bruchid (male and female). The experiment was carried out under Laboratory conditions at 30-35°C temperature and 70-90% relative humidity. After the experiment was established, weekly counting of the total number of eggs laid was carried out at intervals. The results showed that, the mean developmental stages in both female and male bruchids were: 6.50 and 6.00 days; 17.00 and 18.00 days; 13.50 and 13.50 days; 12.00 and 13.50 days; 48.00 and 50.00 days for incubation stage, larval stage, pupal stage, adult stage and total life cycle of the bruchids, respectively. Moreover, the mean pre-oviposition and oviposition stages in female adult bruchid were 1.50 and 5.50 days, respectively.

Some physical properties of lentil seeds affected by harvest time

S. Gürsoy*

Department of Agricultural Machinery and Technologies Engineering, Faculty of Agriculture, Dicle University, 21280-Diyarbakır, Turkey

(Manuscript received 29 April 2020; accepted for publication 10 July 2020)

Abstract: The physical properties and the hardness of lentil seeds, which can also be affected by harvest times, are very important variables in the designing and adjustment of machineries used during harvest, handling and other processes. The objective of this study is to determine the effects of different harvest times on some physical and mechanical properties of lentil seeds. A field experiment was conducted at six harvest times including the harvesting at physiological maturity (H1) and 5, 10, 15, 20 and 25 days after physiological maturity (H2, H3, H4, H5 and H6, respectively). The variables determined were moisture content, diameter, thickness, sphericity, seed mass, bulk density, true density, porosity and hardness of lentil seeds. It was found that seed moisture content, seed dimensions, seed mass and bulk density decreased with delayed harvest time. However, sphericity, true density, porosity and hardness of lentil seeds increased with increased harvest time.

Effects of location, gender and indole butyric acid on rooting of Laurus nobilis L. semi-hardwood stem cuttings

A. Saeed*, T. Amin

Department of Environment and Forestry, Faculty of Agriculture, Tishreen University, Latakia, Syria

(Manuscript received 15 April 2020; accepted for publication 1 July 2020)

Abstract. The research was conducted in 2018 in order to investigate the effect of location, tree gender and indole butyric acid (IBA) 4000ppm on rooting of semi-hardwood stem cuttings. Two locations (Al-Samrah and Al-Nabaeen) in Latakia province, Syria, different in latitude and above sea level (500 m and 827 m, respectively) were studied. The results showed significant effect (p<0.05) of the location and tree gender on rooting capacity. No rooting was observed in control (without IBA treatment). Location also affected the number of roots/cuttings. No effect of location or tree gender on root length and diameter was established. The highest rooting rates (%) were for cuttings taken from female trees from Al-Samrah location when treated with IBA 4000 ppm (82.2%).

Detection of Potato virus Y associated with African nightshade leafy vegetable (Solanum scabrum miller) in Kenya

S.L.Kimaru*, D.C. Kilalo, J.W. Kimenju, W.M. Muiru

1Department of Plant Science and Crop Protection, University of Nairobi, P.O. box 30197, Nairobi, Kenya

(Manuscript received 20 June 2020; accepted for publication 27 August 2020)

Abstract. The African nightshades (ANS) have been part of the food systems in sub-Saharan Africa for generations. They are particularly attractive to small scale farmers because the risks of crop losses are much lower compared to the exotic vegetables. Plant viruses are economically important pathogens affecting African nightshade production. More than 200 plant viruses are reported to infest solanaceous family crops. This study was carried out to detect Potato virus Y associated with African nightshade. Symptomatic leaf samples were obtained from four agro-ecological zones in Kenya. The viral pathogens were detected using serology and molecular techniques. Laboratory experiments were carried out at the University of Nairobi and Kenya Plant Health Inspectorate Service (KEPHIS) from February 2017 to August, 2018. Field samples had the highest mean viral percentage frequency of 44.8% compared to greenhouse samples having 29.8% using serology methods. Molecular testing revealed that greenhouse and farm field sample were positive for the three Potato virus Y strains PVYN:O (necrotic recombinant), PVYO (ordinary) and PVYNTN (necrotic). Detection of Potato virus Y in ANS suggests that it is prevalent in the sampled regions and could cause problems to other solanaceous crops.

Growth and yield of orange (Washington Navel 141) grafted on different citrus rootstocks

Alaa Suhiel Ibrahim*

Research station of Ciano, Jableh, the agricultural scientific research center in Lattakia, General corps of scientific agricultural researches, Syria

(Manuscript received 26 May 2020; accepted for publication 27 July 2020)

Abstract. This investigation was conducted during 2014, 2015 and 2016 in the field of the citrus experimental station in Ciano, the general corps of scientific agricultural researches. The growth and yield of orange trees (Washington navel 141) budded on seven citrus rootstocks (Sour orange, Troyer citrange, Carrizo citrange, Citrumelo 4475, Citrumelo 1452, Macrophylla and Cleopatra mandarin) and farmed since 1989 have been studied. The results for the average of yield showed that the trees grafted on Cleopatra mandarin (58.33 kg. tree-1) were significantly superior to those grafted on Macrophylla (34.17 kg. tree-1). Orange trees grafted on Citrumelo 4475 and Citrumelo 1452 were significantly superior to other treatments in trunk section area of the rootstock (922.41 and 841.02 cm2, respectively). The greatest fruit fresh weight was in trees grafted on Citrumelo 4475 (284.85 g. fruit-1) which were significantly superior to those grafted on Carrizo and Troyer citrange (232.49 and 236.06 g. fruit-1, respectively). The biggest total soluble solids (%) was in trees grafted on Carrizo and Troyer citrange (12.83% for both treatments) which were significantly superior to those grafted on Sour orangе and Macrophylla (11.5% for both treatments), while the greatest total acids (%) was by Sour orange (2.08%) without significant differences.

Influence of Baikal EM1 preparation on the productive parameters of bee colonies (Apis mellifera L.) during spring and autumn feeding

R. Shumkova1*, R. Balkanska2

1Research Center of Stockbreeding and Agriculture – Smolyan, 4700 Smolyan, Bulgaria
2Institute of Animal Science – Kostinbrod, 2232 Kostinbrod, Bulgaria

(Manuscript received 23 June 2020; accepted for publication 3 August 2020)

Abstract. The aim of the present study is to investigate the effect of Baikal EM1 on the productive parameters of the bee colonies (Apis mellifera L.) during spring and autumn feeding and the chemical composition of the worker bee bodies. Two groups of bee colonies were formed (1 experimental group and 1 control group). During the spring feeding the experimental group was fed with Baikal ЕМ1 at a dose of 5 ml/0.500 L added in the sugar syrup (sugar:water 1:1) for 4 consecutive days at the start of the experiment. Each bee colony received 5 L sugar syrup. During the autumn feeding the experimental group received Baikal ЕМ1 at a dose of 20 ml/10 L sugar syrup. Each bee colony received 10 L sugar syrup. The control group received only sugar syrup. The spring and autumn feeding of the group fed with Baikal EM1 significantly increases the strength of the bee colonies and the amount of the sealed worker brood compared to the control group. According to the results obtained for the strength of the bee colonies and the bee brood supplementary feeding with Baikal EM1 is very effective in the autumn feeding. For these two parameters there are significant differences between the experimental and control on 29.08. (p<0.01), 10.09. (p<0.05) and 22.09.2018 (p<0.01). Statistically significant differences were reported for the strength of the bee colonies (p<0.01) and the amount of sealed worker brood (p<0.001) in the experimental group receiving Baikal EM1 before wintering compared to the control group. It can be expected to reveal a tendency for better spring development in the next year. Feeding with Baikal EM1 does not affect the chemical composition of worker bee bodies.

Complex toxin binder mycotox® ng influence on the hepatotoxic effect of aflatoxin B1 in experimental treated goslings

I. Valchev*, К. Stojanchev, N. Nicolov, R. Binev

Department of Internal Non-Infectious Diseases, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 12 April 2020; accepted for publication 29 June 2020)

Abstarct. The aim of the present investigation was to evaluate the effects of aflatoxin B1 and Mycotox NG applied either independently or together, on blood total protein, albumin, blood glucose, total bilirubin, triglycerides, cholesterol, enzyme activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP), gamma-glutamyl transferase (γ GT), lactate dehydrogenase (LDH) and changes in liver morphology. At the same time, the potential of supplementation of feed with a mycosorbent (Mycotox NG) was evaluated. Experiments were carried out with 40 1-day-old Toulouse geese from mixed sexes divided into one control and three treatment groups (n=10). Groups were as followed: Group I – control (0 mg/kg AFB1 not supplemented with Mycotox NG); Group II (0.5 g/kg Mycotox NG), Group III (0.5 mg/kg AFB1) and Group IV (0.5 mg/kg AFB1 and 0.5 g/kg Mycotox NG). In this study, commercially available geese of Toulouse strain were reared from day one to forty two days in the deep litter system of management and the birds were divided into four groups. Normal feed tested free of aflatoxin (AFB1), was given to the control (Group – 1). 0.5 g/kg Mycotox was supplemented with the feed to Group 2, Aflatoxin (0.5 mg/kg feed) was supplemented with the feed to Group 3 and Mycotox Ng (0.5 g/kg feed) + 0.5 mg/kg feed AFB1 was supplemented with the feed to Group 4. The duration of the experiments was 42 days. The monitored blood chemical parameters were analysed on post treatment days 21 and 42. In birds treated only with AFB1, (group III) increased blood activities of studied enzymes. At the same time, blood total protein, albumin, cholesterol, glucose and triglycerides were reduced as compared to controls. The observed histopathological changes in the liver consisted in various extent of dystrophy (congestion, vacuolar and granular dystrophy, round cell proliferation, necrobiotic changes, hyperplasia of gallbladder epithelium). The addition of mycosorbent (Mycotox NG) to the feed of Groups IV reduced substantially the changes in blood chemistry and the severity and frequency of liver histological lesions. The addition of mycosorbent (Mycotox NG) to the feed of Groups IV reduced substantially the changes in blood chemistry and the severity and frequency of liver histological lesions.