Investigation of alternate herbicides for effective weed management in glyphosate-tolerant cotton

ABSTRACT

Glyphosate-resistant (GR) weeds are the biggest concern for all cotton stakeholders worldwide. Currently, 43 weeds species are resistant to glyphosate and the number is increasing at an alarming rate. Soil residual/pre-emergence (PRE) herbicides like Pendimethalin and S-metolachlor can be effectively used for the control of GR weeds; however, their use is very limited at farmer’s side due to the adoption of herbicide-tolerant technology with complete reliance on glyphosate. The present study was conducted to evaluate the performance of PRE and post-emergence (POST) herbicides in glyphosate-tolerant (GT) cotton. The herbicide treatments were pendimethalin and S-metolachlor as PRE-residual, and glyphosate was applied as POST at 20 days after sowing (DAS) either alone or in combination with other herbicides like S-metolachlor, pendimethalin, and haloxyfop. A second application of glyphosate was made at 35 DAS. Results revealed that pendimethalin and S-metolachlor treatments gave 100% suppression of all dominant weeds and increased lint yield by 310–350% as compared to weedy control. In contrast, glyphosate applied once and twice, gave weed biomass reduction of only 10–86%, and increased lint yield by 136–185% over weedy control. This research established that PRE application of pendimethalin and S-metolachlor can be included in the weed management program of GT cotton.     

Effect of Japanese mint (Mentha arvensis) oil as fumigant on nutritional quality of stored sorghum

Japanese mint (Mentha arvensis) oil (JMO) can be used effectively as fumigant againstSitophilus oryzae in stored sorghum. The effect of JMO at a dose of 166 µl/l of space on nutrient composition and protein quality was studied in infested and uninfested sorghum grains stored for 3 months. The results revealed non significant effect of JMO on gran moisture, total ash, crude fibre, crude fat, crude protein and fat acidity in infested and uninfested grains at the end of 3 months storage. The JMO treatment had small but significant effect on reducing and nonreducing sugars. The values of Protein Efficiency Ratio (PER) for uninfested JMO treated grains, infested JMO treated grains and for untreated control stored for 3 months were 1.11, 1.07 and 1.09, respectively against control casein diet for which it was 2.15.     

Longitudinal growth strains in five clones of Eucalyptus tereticornis Sm.

We studied the variability in longitudinal growth strains and wood basic density in five-year old trees from five clones (one tree per clone) of Eucalyptus tereticornis. Mean longitudinal growth strain in clones ranged from 466 to 876 μm. There was a significant difference between clones in growth strains and wood basic density. Clone 10 exhibited maximum growth strains and basic density, whereas clone 3 and clone 7 exhibited minimum growth strains and basic density, respectively. Within a tree, the growth strain variation with tree height was high but statistically insignificant while within tree variation in basic density was very small. There was no specific trend in variation in either strain or density within a tree. There was 5% 200% difference in growth strain on opposite sides of the logs. However two strains showed a strong positive correlation. There was a moderate positive association of wood basic density and mean growth strains in logs. The variation around the periphery emphasize the need to measure strain more than one, preferably on opposite sides at the same height, on a tree to know the mean strain level for the purpose of selection of clones.     

Occurrence of canine parvovirus type 2c in the dogs with haemorrhagic enteritis in India

Canine parvovirus 2 (CPV-2) causes a highly contagious and often fatal disease in dogs. Since its sudden emergence in the early 1970s, CPV-2 has been evolving through the generation of novel genetic and antigenic variants (CPV-2a/b/c) that are unevenly distributed throughout the world. In the present study we have examined 36 clinical cases of dogs suspected of CPV collected during year 2006. A fragment of the VP2 gene of the virus was analyzed using polymerase chain reaction (PCR), restriction endonuclease (RE) and DNA sequence analysis. Out of the 36 samples analyzed, 16 were found positive for CPV-2a/2b by conventional PCR. DNA sequencing was done for 6 PCR positive samples, out of which three were characterized as CPV-2c, indicating that this CPV type 2c is currently circulating in India.     

Production of discernible disease phenotypes in Canna by five plant viruses belonging to the genera Potyvirus,Cucumovirus and Badnavirus

Cannas are tropical and subtropical flowering perennial plants. The genus contains many species but most commercially grown cultivars are interspecific hybrids selected for their attractive foliage and flowers. Canna production is so lucrative that there are farmers and nurseries dedicated solely to its production. The specific issue that the canna industry faces is virus diseases. In this study, rhizomes of 24 canna cultivars were gathered and diagnostics conducted to detect Bean yellow mosaic virus (BYMV, Potyvirus), Canna yellow mottle virus (CaYMV, Badnavirus), Canna yellow streak virus (CaYSV, Potyvirus), Cucumber mosaic virus (CMV, Cucumovirus) and Tomato aspermy virus (TAV, Cucumovirus). Visual assessment of disease symptoms and diagnostic tests were carried out to identify the prevalent diseases and describe the symptoms that are associated with virus infection. BYMV, CaYMV and CaYSV caused severe mosaic and necrosis either in the leaf lamina or veins of infected leaves. Potyvirus infection suppressed red colouration in the foliage of some varieties. CaYMV and CaYSV often appeared in the same plant, suggesting they might represent a viral complex. CMV and TAV were rarely seen in these populations. Interestingly, CaYMV but not CaYSV could be mechanically inoculated to Phaseolus vulgaris plants.     

Production of nuclear transfer embryos by using somatic cells isolated from milk in buffalo (Bubalus bubalis)

Somatic cells in milk are a potential source of nuclei for nuclear transfer to produce genetically identical animals; this is especially important in animals that are susceptible to risks of bacterial infection on biopsy collection. In this study, a minimum of 10 milk samples were collected from each of the three buffaloes representing Murrah breed. All the samples were processed immediately and cell colonies were obtained. Cell colonies from one buffalo (MU-442) survived beyond 10 passages and were evaluated by fluorescence microscopy and used in nuclear transfer experiments. In culture, these cells expressed vimentin, indicating they were of fibroblast origin similar to ear cells. We compared the effectiveness of cloning using those milk-derived fibroblast (MDF) cells and fibroblast cells derived from the ear derived fibroblast (EDF). Fusion and cleavage rates of MDF-NT and EDF-NT embryos were found to be similar (92.43 ± 1.28% vs 94.98 ± 1.24%, and 80.27 ± 1.75% vs 84.56 ± 3.73%, respectively; p > 0.01); however, development to blastocyst stage and total cell number was higher for EDF-NT embryos (50.24 ± 2.54%, 227.14 ± 13.04, respectively, p < 0.01), than for MDF-NT embryos (16.44 ± 0.75%, 170.57 ± 4.50 respectively). We conclude that somatic cells from milk can be cultured effectively and used as nucleus donor to produce cloned blastocyst-stage embryos.     

Effect of conjoint application of indigenous PGPR and chemical fertilizers on productivity of maize (Zea mays L.) under mid hills of Himachal Pradesh

The present study was conducted to work out the conjoint application of indigenous PGPR (plant growth promoting rhizobacteria) and chemical fertilizers levels on the productivity of maize (Zea mays L.). Three best PGPR isolates (B1N1, MAT1 and DHK) having maximum PGP (plant growth promoting) traits were screened at different recommended doses (80%, 60% and 40%) of NP (Nitrogen and Phosphorous) under net house conditions, and finally two isolates (B1N1 and MAT1) along with optimum dose i.e. 80% of NP were selected for field experimentation, which was performed for two years consecutively i.e. 2013–2015 under random block design (RBD). Conjoint application of 80% recommended doses of NP with PGPR (B1N1) significantly increased maize yield (11.7%), plant height (12.9%) and biomass (17.9%), over control (100% recommend dose of fertilizer (RDF) of chemical fertilizer). Therefore, the results revealed the potential of indigenous PGPR isolates to supplement about 20% NP fertilizers without hampering the productivity of maize.