scholarly journals Effect of pollination on rapeseed (Brassica campestris L. var. Toria) production in Chitwan, Nepal

2014 ◽  
Vol 15 ◽  
pp. 41-45 ◽  
Author(s):  
R Pudasaini ◽  
RB Thapa

Rapeseed is an important cash crop of Nepal and an experiment was conducted to study the effect of pollination on its production in Chitwan during 2012-2013. The experiment was designed in Randomized Complete Block with four replications and five pollination treatments. The rapeseed plots were caged with mosquito nets at 10% flowering except natural pollination. Two-framed colonies of Apis mellifera L. and Apis cerana F. were introduced separately for pollination, and control plot caged without pollinators. Seed set increased by 48.72% with Apis cerana F. and 45.73% with Apis mellifera L. pollination as compared to the control. The highest seed yield was obtained from Apis cerana F. (1.11 mt/ha), followed by Apis mellifera L. (0.88 mt/ha), hand (0.75 mt/ha), natural pollination (0.66 mt/ha) and control (0.13 mt/ha), respectively. This study clearly indicated pollination deficit under natural condition, and therefore, management of honeybee is necessary for higher production and productivity of rapeseed under Chitwan condition.

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Kedar Devkota ◽  
Prashant Rijal ◽  
Charles Fernando dos Santos

Many pollination-dependent crops worldwide need bees for the highest productivity. If the crops are not pollinated, a pollination deficit will result. Consequently, low yields of fruit set and seed set of cultivated plants may be expected. Here, we evaluated how pollination with honeybee (Apis mellifera) hives may affect the production of the bittergourd (Momordica charantia), buckwheat (Fagopyrum esculentum), and mustard (Brassica campestris) in tons or quintal per hectare in Nepal. Our experimental design involved three treatments in blocks within selected areas: (i) the effect of the honeybees alone (caged with beehives), (ii) free insect access under natural field conditions, and (iii) blocks restraining insect access (caged without beehives). We also assessed the flower visiting insects within crops using pan traps and identifying insect orders. We found that the productivity of bittergourd, buckwheat, and mustard significantly increased in the treatments with beehives inside the cage. To a lesser extent, the treatment with free access to the flying insects enhanced the production of the selected crops. Proportionally, Hymenoptera (mainly bees) was the most common taxon within bittergourd, buckwheat, and mustard crops, followed by Diptera and Lepidoptera. Hence, the provision of beehives in cultivated areas such as those evaluated here could be considered as a complementary strategy for supporting the long-term productivity of these crops in Nepal.


2014 ◽  
Vol 2 (4) ◽  
pp. 483-487
Author(s):  
Rameshwor Pudasaini ◽  
Resham Bahadur Thapa

An experiment was conducted to determine the foraging behavior of Apis mellifera L. and Apis cerana F. in rapeseed under cage condition in Chitwan, Nepal during 2012-2013. This experiment showed that Apis cerana F. foraged extra 42 minute per day as compared to Apis mellifera L. Apis cerana F. were more attracted to nectar, whereas Apis mellifera L. were more attracted to pollen collection throughout the day. The activities, in into hives and out from hives, for both species were recorded more at 2:00 pm and least at 8:00 am. The highest in-out were observed at 2:00 pm on both species as Apis mellifera L. 44.33 bees entered into hives and 49.66 bees went out of hives, whereas lower number of Apis cerana F. 43.66 bees entered into hives and 48.16 bees were out of hives. Apis mellifera L. collect 1.22:1 and 0.41:1 pollen nectar ratio at 10:00 am and 4:00 am whereas at same hours Apis cerana collect 1.16:1 and 0.30:1 pollen nectar ratio. Apis cerana F. foraged significantly higher number of rapeseed flowers and plants as compared to Apis mellifera L. under caged condition. It shows that Apis cerana F. was more efficient pollinator as compared to Apis mellifera L. under caged condition. DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11238Int J Appl Sci Biotechnol, Vol. 2(4): 483-487  


2000 ◽  
Vol 5 (1) ◽  
Author(s):  
A. PEGORARO ◽  
E. M. MARQUES ◽  
A.C. NETO ◽  
E.C. COSTA

Varroa jacobsoni foi descrita em 1904 por Oldenans em Java em cria de Apis cerana. O nível de infestação com V. jacobsoni mede indiretamente o grau de tolerância da A. mellifera à V. jacobsoni. O estudo foi conduzido no Município de Mandirituba-PR. Os enxames foram capturados com caixa iscas. A percentagem de infestação V. jacobsoni foi resistrada mensalmente. Aplicando-se o teste de Friedman e usando-se o rank de cada colônia, separou-se os grupos de colônias homogêneas. A tendência sazonal foi demostrada com representação gráfica. O experimento foi delineado segundo blocos inteiramente casualizados. Em todas as amostras foi encontrado o ácaro V. jacobsoni. Diferenças significativas entre as colônias foram observadas. Na população de Apis mellifera scutellata existem três grupos homogêneos de colônias quanto ao nível de infestação com esse ácaro. O inverno é a época onde o grau de infestação com V. jacobsoni é mais elevado. Natural infestation of Apis mellifera scutellata (Hymenoptera; Apidae) by Varroa jacobsoni (Mesostigmata; Varroidae) Abstract Infestation by Varroa jacobsoni in an offspring of Apis cerana was first described as early as 1904 in Java. Since the level of infestation by V. jacobsoni may be an indirect procedure to measure the Apis mellifera scutellata tolerance degree towards it, the present research was carried out in order to evaluate such biological relationship between host and parasite and its implication in the Apis mellifera scutellata productivity. This study was carried out at Mandirituba, Paraná, Brazil. The swarms were captured with bait boxes. The percentage of V. jacobsoni infestation was established monthly. According to the Friedman test ant through the rank, homogeneous colonies were single out. The experiment has been delineated as entirely randomized blocks.


2019 ◽  
Vol 63 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Asli Özkırım ◽  
Aygün Schiesser ◽  
Nevіn Keskin

AbstractNosema apis is a pathogen spesific for the European honeybee, Apis mellifera L., while Nosema ceranae is specific for the Asian honeybee, Apis cerana. Turkey provides different environmental and host conditions for both Nosema species. The aim of the study is to determine the dynamic of N. cerenae and N. apis seasonal infection. A number of samples were collected from different apiaries between 2009-2016 years. The samples were kept at −20°C in the laboratory. Light microscopy was used for spore counting and molecular techniques were used to identify the Nosema species. The results showed that winter season had an impact on the type of Nosema as well as on infection rates. The number of N. ceranae spores decreases significantly at low temperatures (≤ 5°C). The winter period was found to be the main factor affecting nosema infection level and dominancy of Nosema ceranae. Furthermore, co-infection of both species is an indicator of the dynamics of N. apis and N. ceranae. This study suggests, that there is a dynamic prevalence among the Nosema species depending of the average winter temperature and not a replacement of N. apis by N. ceranae.


2021 ◽  
Vol 905 (1) ◽  
pp. 012109
Author(s):  
R A D Pangestu ◽  
Hadiwiyono ◽  
Supriyadi

Abstract Shallot is an important cash crop in Indonesia. However, its productivity is relatively low, due to the attack of the onion caterpillar (Spodoptera exigua Hubner). This study aimed to identify the effect of the application of control techniques on the population, damage intensity, and shallots yield. This research was conducted by field experiment. Control treatment consisted of covering shallots by using gauze/net and insecticide treatment with active ingredients of profenofos, metomil, and carbosulfan. The research variables consisted of the population and the damage intensity of S. exigua, as well as the yield of shallots. The results showed that the caterpillars population of S. exigua was found at 16 DAP and increased up to before harvest at 44 DAP. Covering shallots with gauze effectively suppressed the population of S. exigua (0.0 per hills), followed by treatment with profenofos (0.14 per hills), carbosulfan (0.15 per hills), and methomyl 0.32 per hills). The damage intensity of S. exigua in the plot gauze covered was 0%, lower than 32%, 25%, 12%, 10%, respectively, in the control plot, treatment of metomil, carbosulfan, and profenofos. Covering shallots with gauze also increased the weight of wet-harvested tubers (50.83 g per hills).


2021 ◽  
Vol 9 ◽  
Author(s):  
Masayoshi Uefune ◽  
Kinuyo Yoneya ◽  
Masaki Yamamoto ◽  
Junji Takabayashi

We evaluated the effectiveness of using a blend of volatiles that attract Cotesia vestalis, a specialist parasitoid wasp of diamondback moth (DBM) larvae, to control DBM larvae on cabbage plants under open field conditions. We set three dispensers of the synthetic C. vestalis attractant together with one sugary-food feeder in a cabbage plot (10 m × 1 m; the treated plot) on one side of a pesticide-free open agricultural field (approximately 20 m × 20 m) from June to September in 2010 and July to August in 2011. On the other side of the field, we created a control cabbage plot of the same size in which neither dispensers nor a feeder was set. The incidences of DBM larvae and C. vestalis cocoons in the control and treated plots were compared. In 2010, the incidence of DBM larvae in the treated plot was significantly lower than that in the control plot. Poisson regression analyses in 2010 showed that the rate of increase in the number of C. vestalis cocoons along with an increase in the number of DBM larvae in the treated plot was significantly higher than that in the control plot. In 2011, the incidence in both the treated and control plots remained low (five larvae per plant or less) with no significant difference between the plots. Poisson regression analyses in 2011 showed that the number of C. vestalis cocoons in the treated plot was significantly higher than that in the control plot, irrespective of the number of DBM larvae. This 2-year field study suggested that the dispensers recruited native C. vestalis from the surrounding environment to the treated plot, and the dispensers controlled the number of DBM larvae in 2010 when the density of DBM larvae exceeded the economic injury levels for the cabbage crop. We also compared the incidences of other arthropods in the control and treated plots. The incidences of Pieris rapae larvae and Plusiinae spp. were not affected by the treatments. The number of aphids in the treated and control plots was inconsistent between the 2 years. Based on these 2-year results, the possible use of C. vestalis attractants in open agricultural fields is discussed.


2016 ◽  
Vol 47 (3) ◽  
Author(s):  
Khrbeet & Al-Beiruty

A field experiment was conducted at the experimental farm, College of Agriculture, Abu-Ghraib, Baghdad, Iraq during the period from mid. of March 2012 to mid. of July 2014 to investigate the effects of plant growth regulators and foliar application stages on ovules abortion, seed set and its germination of two alfalfa cultivars. Layout of the experiment was R.C.B.D. arranged in split-split plot with three replications. Cultivars (local and hamedan) were assigned as a main plot and foliar application stages (vegetative growth, flower buds emergence, 50% flowering and 80% flowering) were assigned as sub-plots, while growth regulators (Alar, Ethephon, Naphthalene acetic acid(NAA) and control treatment) were assigned in the sub-sub-plots. Result showed that there were no significant differences between cultivars in all traits. Foliar application of NAA increased No. of ovules per floret (9.11) compare with other treatments, but it was not significantly different compare with Alar. In 1st and 2nd seed crop, plants sprayed with Alar at flower buds emergence stage gave highest seed set (5.17, 6.93) respectively. Percentage of ovules abortion significantly influenced by growth regulaters, folair application stages and their interaction. Since, foliar application of Alar at beginning of flower buds emergence reduce % of ovules abortion (30.89). In general, plants sprayed at vegetation growth stage increased % of seed germination. It was clear from this study that more than 40% of ovules were aborted, this may be one of the reasons for reduction of seed yield in alfalfa, therefore, we recommended to do more researches in this field in order to know the causes of ovules abortion.


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