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The sustained production of quality cocoons is adversely affected due to the scare use of chemical fertilizer in mulberry cultivation by small and marginal sericultural farmers, mainly due to the escalating prices and non-availability in appropriate time. The required quantity of NPK nutrients for mulberry was supplemented through locally available different organic sources viz., farm yard manure (FYM), sericompost, poultry manure, neem cake, green manure, bio-inoculants (Azotobacter biofertilizer, vesicular arbuscular mycorrhiza (VAM), rock phosphate and phosphate solubilizing bacterial biofertilizer (PSB)). The nutritional status of mulberry leaf produced through organic cultivation is on par with that of leaf produced in the chemical fertilizer based farming as the results showed the leaf NPK, chlorophyll, carbohydrate and protein contents from the organic treatment are on par with that of control. Similarly, the bioassay studies also revealed that there is no compromise in the quality of cocoon production as cocoon parameters did not showed any statistical significant difference between treatments and control. Thus, the present study confirms that by adopting absolute organic farming in mulberry cultivation, it is possible to produce quality mulberry leaf suitable for silkworm rearing which in turn produces quality cocoons. [ABSTRACT FROM AUTHOR]

Mulberry (Morus sp.) is cultivated mainly for its foliage and is the sole food for the silkworm, Bombyx mori L. Due to the development of high yielding mulberry varieties (S36 and V1), requirement of chemical fertilizers and water has been increased in recent past to achieve higher yield. As a result of advanced research, the high yielding mulberry variety viz.,V 1 under irrigated condition has been developed and can produce 60-65 MT leaf/ha/yr over the conventional varieties (Mysore local and K2) which need high dose of chemical fertilizer @ 350:140:140 kg/ha/yr. The extensive use of chemical fertilizers and its improper selection in mulberry cultivation cause a great concern on the survivability of soil fauna and flora besides the soil health. Thus, the cost of mulberry leaf production becomes high and sustained yield of cocoon production is adversely affected. Hence, the present experiment was conducted to study the effect of various organic and biological sources of nutrients as supplement to chemical fertilizers in mulberry cultivation as a means of organic farming. The study revealed that there was no significant difference in growth and yield of mulberry in the treatments where all the nutrients were supplied through different organic and biological sources as against the control besides the lesser cost of production. Thus, the present study suggests an ample scope of organic farming in mulberry cultivation to make sericulture more sustainable. [ABSTRACT FROM AUTHOR]

The input cost involved in any crop will have a direct bearing on the cost of production. High yielding mulberry variety V1 requires high dose of nutrients (350:140:140 kg N:P:K/ha/yr) which is mainly substituted through chemical fertilizers. The continuous application of chemical fertilizers not only makes the cost of mulberry production high, but also hampers the sustainability of leaf production. Hence, the adoption of organic farming comes to the rescue to improve the soil health and the sustainability in mulberry production. In this context, the cost of mulberry leaf production was worked out against different organic and biological inputs as source of plant nutrients vis a vis control in an organic farming experiment conducted at Central Sericultural Research and Training Institute, (CSR&TI), Mysore. The cost of mulberry leaf production was worked out to be least in the system wherein all the required quantity of plant nutrients were supplemented only through different organic and biological sources as against the control comprised of mainly chemical fertilizers. In the present study, effort has been made to draw a comparative economics of mulberry cultivation under different inputs of organic farming. [ABSTRACT FROM AUTHOR]

In this article the authors discuss research investigating the performance of an improved mulberry variety Sahana as an intercrop at a coconut plantation. They note that mulberry is primarily cultivated as a mono-crop, but can provide many benefits when used in an intercropping system, such as increased total yield, land use efficiency, and control of weeds and pests. Results of a study investigating the feasibility of a growing mulberry as an intercrop under coconut shade are discussed.

The article discusses a study on near isogenic lines of the silkworm, Bombyx mori for identification of random amplification of polymorphic DNA (RAPD) markers linked to digestive amylase genes. Primers were used for the study out of which six showed RAPD products linked to the amylase genes of the Donor Parents introgressed in the Near Isogenic Lines. The results are discussed for identification of DNA sequences that may be responsible for better digestibility and higher survival is discussed.

The article discusses the silk industry and research on the development of bivoltine silkworm double hybrids that can tolerate disease and tropical environments with high ambient temperatures. The article indicates that a robust bivoltine hybrid named CSR18 x CSR19 had been developed to tolerate high-temperature summer conditions, but its low yield was not accepted by farmers.

A set of nine mulberry genotypes each having high or low photosynthetic efficiency were assembled from the gene banks at Central Sericultural Research and Training Institute (CSRTI), Mysore. The overall mean photosynthetic rate ranged from 23.74 to 16.65 μmol m-2s-1. Most of the varieties included in the study were diploids except, AR-12, Tr-10 and Tr-8, which are confirmed triploids. Sixteen informative decamer random amplified of polymorphic DNA (RAPD) primers were utilized for screening the genotypes. These primers amplified genomic DNA segments and generated 133 markers in the size range of 300 - 3500 bp. Only 18 markers were monomorphic and the rest 115 (86.47%) were polymorphic. The comparative analysis of RAPD profiles indicated two genotype specific markers, viz.,M. multicaulis (OPB-03550) and BR-4 (OPB-042200). As per Dice similarity, coefficient(s) were calculated based on RAPD marker data among mulberry genotypes belonging to the two contrasting groups, M multicaulis and English Black. They were genetically close with a similarity of 88.1% and K-2 and RFS-135 were genetically divergent with least similarity (52.5%). Unweighted Pair Group Method of Arithmetic average (UPGMA) clustering based on SHAN routine using marker similarity, coefficient resulted in 4 major clusters. Cluster-II, III and IV were represented by one genotype each viz., S-799, BR-1 and RFS-135 respectively, whereas the cluster I comprised of rest of the genotypes. On the basis of molecular genetic analysis, divergence of photosynthetic activity and reproductive behavior, the most suitable parental combinations were found to be RFS-135 as low photosynthetic male and either BR-2 (GD = 0.352) or S-1 (GD = 0.413) as high photosynthetic female for crossing programme and development of mapping population for linkage analysis and identification of QTLs for the trait. [ABSTRACT FROM AUTHOR]

A close examination of the morphological features of the germplasm assembled for their contrasting response (resistance and susceptibility) to powdery mildew, root knot nematode and mealy bug infestation in mulberry indicated the presence of 10 groups of redundant collections. DNA marker profiling of germplasm was carried out using 16 informative random primers which amplified a total of 209 markers with 87% polymorphism. DNA marker similarity coefficient (s) ranged from a maximum of 1.000 to a minimum of 0.564. Unweighted Pair Group Method of Arithmetic Average (UPGMA) clustering of germplasm using marker similarity matrix confirmed duplicate status of collections in the groups I, III, V, VI, VII, and MIL However, in suspected redundant group II, the germplasm collection namely, Calabrassa had a unique profile and separated from the rest two with a genetic distance (1-s) of 0.267. The largest suspected redundant group IV comprised of 10 germplasm of which 4 collections had unique banding patterns and thus discriminated. Rest of the collections in the group was redundant. In the suspected group IX, Jatinuni had distinct banding pattern and separated from the other two accessions in the group. The other redundant collections viz., Viswa and Araku Local formed one cluster with 100% similarity. The two collections of the last suspected redundant group X were distinct. Minimum genetic redundancy is the key to the success of crop evaluation and biodiversity management by cutting down the physical and financial resources [ABSTRACT FROM AUTHOR]

Mulberry (Morus sp.) is extensively cultivated for rearing silkworms (Bombyx mori L.) for production of silk. As the mulberry leaf is rich in nutritive value with 22-24% protein, the studies on its use other than silkworm rearing are gaining importance in recent years. To utilize the mulberry leaf for alternative purposes other than silkworm rearing, a study for utilizing mulberry as a poultry feed supplement was conducted at CSRTI, Mysore. Broiler chicks (Breed: COB-400) were raised on four different test rations supplemented with different levels of mulberry leaf powder viz., 0 (control), 5, 10, 15 and 20% and data on initial body weight, final body weight, feed consumption, etc., were recorded. The results revealed that the highest mean body weight after the growth period of six weeks was recorded in 10% supplementation. The highest feed consumption per bird was in control followed by 5, 10, 15 and 20%. The maximum feed conversion ratio at six weeks of growth was in 10%, suggesting that the mulberry leaf powder supplementation at 10% would cut down the cost of poultry feed. This is the first report on this aspect in India, which would benefit the poultry farmer in economizing the cost of meat production. [ABSTRACT FROM AUTHOR]

The pre-penetration and infection process of Colletotrichum dematium on mulberry leaf was investigated by scanning electron microscope. Conidia produced on germination appressoria directly or at the end of short germ tubes. Appressoria were formed mostly over cuticle, but sometimes over stomata also. At 72 h post-inoculation, an extensive network of sub-cuticular runner hyphae (RH) was produced. The RH were traceable by the cuticular bulgings on leaf surface. The RH emerged to leaf surface through ruptured cuticle to form secondary infection hyphae (SIH). The SIH re-entered the leaf tissue by sending penetration branches through stomata. Conidia were formed singly on short conidiophores from the RH and SIH, at short intervals. The conidia developed on RH were exposed to leaf surface through ruptured cuticle. Some times conidia were released through stomata also. The RH and SIH had thick knots from which hyphal branches and conidia were developed. Definite acervuli were not developed. [ABSTRACT FROM AUTHOR]

Silkworms show high variability in silk quality and disease resistance. Attempts are on to combine the disease tolerance of multivoltine races and the silk quality of bivoltine races to generate new races with desirable phenotypic traits. We report the identification of a 26.5-kDa protein that is overexpressed in the gut juice of disease-resistant multivoltine races and that has anti-BmNPV activity. We have characterized this protein as a soluble NADH-oxidoreductase-like protein (BmNOX). Treatment of live BmNPV particles with BmNOX inhibited the capability of the viral particles to infect BmN cells in vitro.