JWSS - Journal of Water and Soil Science

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In this study, conducted in Isfahan region over a period of two years, six oilseed sunflower cultivars named Record, Venimek 8931, Chernianka, Zaria, Perdovik and Mehr hybrid were investigated in a split-split plot design. These cultivars were planted on March 29 and April 29, with and without the presence of pollinator insects. The results showed that the yield of different cultivars were significantly different (p<0.01). The planting date of March 29 caused a higher yield than that of April 29. Also the presence of pollinator insects during the bloom increased the amount of yield in all cultivars planted on both dates. Venimek and Record cultivars planted on March 29 with the presence of pollinator insects during the bloom produced the highest, i.e. an average of 3910 and 3821 kilograms of seeds per hectare and Chernianka with an average of 2944 kilograms of seeds per hectare had the lowest amount of seed. In this study, Record and Venimek cultivars in the first place and then Mehr hybrid planted on March 29 with the presence of pollinator insects during the bloom were better than the other cultivars in terms of attractiveness to honeybees, yield per hectare, seed hollowness percent, weight of 1000 seeds, germination percentage, speed of germination and the amount of oil production.

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The first step in fundamental breeding of any living organism is the determination of its genetic make-up. To investigate the genetic make-up of the European honeybee (Apis mellifera L.) in Iran, some research attempts were made during the years 1992-1996 in which the bee's relationship with some exotic races were determined through the application of morphological methods. For this purpose 13000 samples of worker bees from 1320 colonies of 212 apiaries in 104 cities at 25 provinces were taken and twelve morphological characters were measured by using the international method (Ruttner, 1978). Furthermore, seven morphological characters of 900 drone samples taken from 403 colonies of 111 apiaries in 42 cities at 10 provinces were studied through the same method. The principle component analysis (PCA) was used for statistical analysis of the data obtained. The results indicated that the existing populations of honeybees under study were of the Iranian honeybee race (Apis mellifera meda) which were completely distinguishable from those of imported races such as A.m. carnica, A.m. ligustica, A.m. caucasica and exotic races such as A.m. anatoliaca, A.m. syriaca A.m. yemenitica and A.m. lamarkii. The imported races had not had great genetic impact on the Iranian race, as the Iranian honeybees have had good consistency and stability. In addition, import of the exotic queens has been ceased in the last decade.

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In order to estimate the heritability of morphological characters of worker honey bee and honey yield, 30 queen-mothers were selected randomly from the apiary of Research Center of Animal Science and Natural Resources in Isfahan Province. From each queen-mother, five queen-daughters were reared and introduced to equalize colonies after natural mating of queens. Summer honey yield was measured, while fall honey production was calculated from area of sealed honey combs. The total honey was calculated by adding summer honey production to fall honey production. Morphological characters were measured under a stereo-dissecting microscope fitted with a calibrated micrometer reticle according to Ruttners method (1985).

 Heritabilities were estimated by intraclass correlation method. Heritabilities of summer, fall and total yearly honey yields were estimated to be 0.64, 0.51 and 0.30, respectively. Estimates of heritability of morphological characters for probscis length, tibia length, femur length, metatarsus length, metatarsus width, forewing length, forewing width, cubital index, hindwing length and number of hamuli were 0.64±0.08, 0.45±0.07, 0.50±0.07, 0.47±0.07, 0.33±0.06, 0.42±0.06, 0.89±0.10, 0.5±0.07, 0.94±0.10 and 0.45±0.07, respectively. It could be concluded that in order to increase honey yield in either season (summer or fall), selection must be based on the amount of honey yield in the corresponding season. Thus, heritabilities of forewing and hindwing lengths were high selection according to these morphological characters would, therefore, change the size of these characters.

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Small honeybee (Apis florea) is one of the common species in Iran. Apis florea lives in southern Iran and plays an important role in the polination of plants in this region. In a series of studies during the years 1997-1998, the genetic populations of the Iranian small honeybee and the effects of geographic and climatic conditions on the morphological variation and separation of Iranian small honeybee were investigated. For this purpose, 400 samples of worker bees from 40 colonies from 26 cities in 9 provinces were collected and twelve morphological characters were measured, using Ruttner method (1978). To determine geographical and climatological variables, average values collected by synoptic stations and other meteorological stations of Iran Meteorological Organization were used. The principal components analysis was used in the statistical analysis of the data obtained. The results show that there exist two distinct groups of small honeybee populations in Iran. Southwest of Iran hosts a class of bigger bees forming one distinct group while southeast of Iran hosts smaller bees forming the second group. Latitude has a positive correlation with size of body, wings and legs. Amount of precipitation has a nagative correlation with size of body, wings and legs. Temperature, wind speed. relative humidity, freezing days and other parameters did not show any correlations with size of body. The results from this research proved that the more northern areas with higher altitudes and more precipitation have bigger honeybees. This finding is in accordance with the Bergman law about other animals.

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In order to study the nectar quantity and quality of some onion cultivars and honeybees foraging activity on them, a complete randomized block design with three replications was conducted. Ten selected onion cultivars consisting of Ghom, Kashan, Azarshahr, Dorcheh, Tarom, Kazeroon 1, Kavar, Abarkooh, Hurand, and Yellow Sweet Spanish were used. Sixty mm mother bulbs of different onion cultivars were planted in 3×4 m plots on 6 lines. The distance between rows was 35 cm and plants were spaced 25 cm apart on each row. At flowering time, bees’ activity on the inflorescences was studied and flower nectar was collected in 10 micro-liter capillary tubes. Nectar volume was determined and analyzed. Mean numbers of honeybees visiting on inflorescence every 10 minutes and the mean residing time of each honeybee on a seed stalk (inflorescence) were significantly different in different cultivars. Hurand flowers had the least number of visitors and Dorche flowers had the longest visiting time. The amount of nectar varied in different cultivars, so did glucose (G), fructose (F), and sucrose (S) contents. Except for the Abarkuh cultivar that had more glucose than it had other sugars, all the cultivars had higher quantities of fructose than they had other sugars while sucrose had the least quantities among the sugars. Nectar sugar ratio in most of the cultivars was hexose dominant, which was identified by the low S/(F+G) ratio. Potassium, calcium, and sodium contents in nectar were different in different cultivars, too. Finally, the results showed that foraging activity of honeybees on onion inflorescences depends on the interactions of several factors such as nectar quantity and, more importantly, on sugar quantity and ratio as well as potassium content. .

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During the honeybee breeding project in central Iran, sex alleles homozygoty and sex alleles number in the third generation of 364 colonies were studied in 2003. Sex alleles homozygoty was measured based on Ruttner (1988) and Tarpy and Page (2002) methods. The total area of worker brood area, stored pollen, and drone brood area were measured on the combs. The whole extracted honey weight and remaining honey in the combs were evaluated as honey production of colonies. Adult population was evaluated based on the number of full combs of adult honeybees. The results showed that sex alleles, average homozygoty and number in the colonies were 18.83% and 5.32 respectively. The results showed no significant correlation between homozygoty of sex alleles or sex alleles number and stored pollen ( P > 0.05 ) , but significant negative correlation between sex alleles homozygoty and colony population, total brood area and honey yield ( P < 0.01 ) was observed. So introduction of new sire colonies in the mating Isolated area is essential to prevent sex alleles homozygoty and also performance of honeybee colonies from decreasing.

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Due to injuries of pesticides to natural enemies of pests and pollinator insects, especially honeybees, during the flowering periods, it is essential to protect them. Application of chemical compounds along with the pesticides on the plants could repel the non-target insects from the sprayed areas for sometime and lessen the hazards of pesticides to them. In this study, ten repellent chemicals whose repellency effect was proven in the laboratory in previous studies were screened in the field. Among tested repellents including, Acetophenon, Methyl ethyl ketone, Methyl isobutyl ketone, Cyclohexanone, Acetyl acetone, Methylsalicylate, Propionic anhydride, Maleic anhydrate, 2- Ethylhexylamine, and Dibutylamine, it was revealed that amino group compounds including 2- Ethylhexylamine and Dibutylamine and esteric compound, Methylsalicilate had the highest repellency effect on the honeybees under the field conditions. Repellency effect of these compounds was greater at 15 pm than other sampling times. Repellency effects of different concentrations of these three compounds, when mixed with 0.5% concentration of fixative compounds, showed that the mixture of 2- Ethylhexylamine with Benzylbenzoate, Dibutylphthalate and Benzylalcohole with concentration of 0.17, 0.4 and 0.03 % respectively, the mixture of Dibutylamine at the concentration of 1% with Benzylbenzoate and Dibutylphthalate and at the concentration of 0.08% and higher with Benzylalcohole, and also mixture of Methylsalicilate at the concentration of 1.8 % and higher with Benzylalcohole, all have repellency effect of more than 70% under the field conditions.