Time filter

Source Type

Selvakumar T.,Silkworm Seed Production Center | Devi G.L.,Silkworm Seed Production Center
Indian Journal of Sericulture | Year: 2012

India is traditionally a multivoltine raw silk producing country. Till recently, 98% of the raw silk production in India was from multivoltine cocoons while the remaining was from bivoltine cocoons. In last 5 years, bivoltine raw silk production has picked up and during 2005 - 06,971 MT of bivoltine silk was produced out of total 15,445 MT viz., about 6.3% of the total which is a significant achievement over 2001 - 02 (840 MT of bivoltine) (Benchamin, 2002). A total of 1,229 Silkworm Seed Production Centers were established in India by three agencies namely Central Silk Board (CSB), State Departments of Sericulture (DOS) and Licensed Seed Producers (LSPs). For the production of quality eggs, the Silkworm Seed Production Centers (SSPCs) get the seed cocoons as per the norms from BSFs / seed crop rearers. To get such quality eggs, pupation rate in the seed cocoon lot should be above 80%. The shape and size of the cocoons should also be uniform. Cocoons should be handled carefully so as to avoid damage to the pupae inside the cocoons. The moths which emerge from the cocoons should be disease free, healthy and robust. The cocoon shell percentage in bivoltine races ranged from 20 to 25%. The moths straggle to emerge from cocoons and lose energy in the exclosion process in the cocoons having shell percentage between 22-25. Also, the moths may not be active and lead to low recovery of eggs. The cocoon shell percentage of multivoltine race is 13 -14 and the moths emerge easily from the cocoons. Bivoltine races have 20 - 22%. A few new bivoltine races also have 22 - 25%. At present, some of the Silkworm Seed Production Centers cut the bivoltine cocoons, keep the pupae outside for easy emergence and prepare eggs in loose form. Breeders at P4 and P3 centers also cut the cocoons at one end and take out the pupae for sex separation (Basavaraja et al., 2004).

Biram Saheb N.M.,Regional Sericultural Research Station | Biram Saheb N.M.,Silkworm Seed Production Center | Singh T.,Regional Sericultural Research Station | Bhat M.M.,Regional Sericultural Research Station
Asian Textile Journal | Year: 2010

The multiple mating behavior of silkworm Bombyx mori impacts the seed quality and thus, use of bivoltine male silk moth for two or three matings in cross breed egg production is most appropriate in order to achieve good fecundity, fertility and recovery besides stable cocoon crop. Mating is an instinct and a biological obligation for the ultimate perpetuation of the species and a must to provide stimulus for oogenesis. The objective of multiple mating is to make the silkworm egg production economical so that even the sericulture farmer is benefited as the sale price of the Disease Free Layings (DFL) could be made much reasonable. It is customary to procure multivoltine and bivoltine seed cocoons in the ratio of 2:1 for cross breed egg production MV x BV. The male silk moth should not be used indiscriminately for beyond 2-3 matings, as it has direct impact on the qualitative and quantitative aspects of seed.

Singh G.R.,Regional Muga Research Station | Tikader A.,Regional Muga Research Station | Gogoi A.K.,Regional Muga Research Station | Borpuzari R.,Regional Muga Research Station | Borpuzari R.,Silkworm Seed Production Center
Indian Silk | Year: 2012

Like mulberry, muga silkworm is also affected by pebrine disease and the crop loss reported is high. Efforts to contain this disease often falls short of the expectation as the private commercial grainages and farmers who produce the seed and commercial crops often overlook the preventive measures like moth testing by Fuziwara method. The authors suggest 'prick and see' method for pebrine detection which come handy in case of exigencies.

Krishnamoorthy T.S.,Silkworm Seed Production Center | Radhakrishnan S.,Regional Sericultural Research Station
Indian Journal of Sericulture | Year: 2012

The study was conducted in Udumalpet and Krishnagiri areas in Tamil Nadu to measure the level of knowledge and adoption of new sericulture technologies and also to find out the extent of the association of the socio-economic characteristics of the small mulberry farm size holders in determining the level of knowledge and adoption. The knowledge and adoption level in Udumalpet was found to be higher when compared to the same in Krishnagiri as evident from the knowledge and adoption indices worked out. The knowledge and adoption indices in Udumalpet were to an extent of 88.5% and 77.2% and the same in Krishnagiri were to an extent of 72.0 % and 54.7% respectively. The variables scientific orientation, extension contact and extension participation in Udumalpet and in Krishnagiri cocoon yield, extension participation, mass media participation and social participation were found to have positive and significant relationship with the knowledge. In Udumalpet the variables such as dfls consumption, cocoon yield/acre/year, income, training scientific orientation, and mass media participation were found to have positively significant and experience was found to have highly significant relationship with adoption. In Krishnagiri cocoon yield/acre/year, extension participation, mass media participation and social participation were found to have positive and significant relationship with knowledge and training alone was found to have positive and significant relationship with the adoption. The main constraints faced by the sample fanners were lack of full awareness, high cost and non-availability of quality in-puts, labour intensiveness of the technology and uncertainty in crop success.

Selvakumar T.,Silkworm Seed Production Center | Savithri M.,No. 13 99 A Naduthottam
Indian Journal of Sericulture | Year: 2013

BmIFV is a non-occludcd virus that causes infectious flacherie in silkworm. It is a chronic disease and mortality occurs mainly while spinning the cocoons. Different methods like disinfection of rearing house, development of specific disease tolerant races and thermo therapy have been studied. Earlier, different temperature (25, 27, 30, 32, 35, 37 and 40°C) treatments were utilized as thermo- therapy against infectious flacherie virus and lowest mortality of 21.00 -34.67% was observed in high temperature treatment of 37°C compared to inoculated control (65.00%) and other temperature treatments (23.00 - 46.00%). In the present study, the effect of thermo therapy on total protein content was studied by keeping second instar silkworm larvae at different temperatures for different durations (6h, 6h+, 12h, I2h+, 24h and 24h+) after inoculations with BmlFV. The total protein content was less in the hacmolymph of silkworm inoculated with BmlFV and it was 4.45mg/ml compared to normal control (7.56mg/ml) and other different temperature treatments (4.52mg/ml to 7.51mg/ml). Among the different temperature treatments, high total protein content of 7.05 - 7.51mg/ml was observed in the high temperature treatment of 37°C compared to other temperature treatments of25 - 35°C (6.06- 7.10mg/ml). The protein profiles of haemolymph of silkworm under different periods of 37°C temperature treatment as thermo therapy against infectious flacherie virus was analysed through SDS-PAGE. The haemolymph of all the silkworms of all the batches had 68 and 29.0kD protein bands. The hacmolymph of healthy silkworms had another two distinct protein bands viz., 16.01 and 17.44kD between 14.3-20.0kD protein bands. These bands were not observed in inoculated control and 6h temperature treatment However, these bands were appeared in the treatment of 6h in every instar (6h+) and in all other treatments (12h, 12h+, 24h and 24h+) with increased intensity. The intensity of protein bands between 29 to 43kD in all the treated batches was high when compared to inoculated control. This study suggests that BmlFV infected silkworm larvae can be reared at high temperature treatment of 37°C in each instar for 6 to 12h for suppression of infectious flacherie as thermal treatment.

Discover hidden collaborations