Vanilla is naturally distributed in Mexico and parts of Central America and the history of origin of cultivated vanilla suggests that the entire stock outside Mexico may be from a single genetic source. In the present study, RAPD polymorphism was used to estimate the level of genetic diversity and interrelationships among different collections of Vanilla planifolia Andr., and few related species, including both leafy and leafless types such as V. tahitensis J.W.Moore, V. andamanica, Rolfe, V. pilifera Holtt., and V. aphylla Blume. Studies revealed that there are very limited variation within collections of V. planifolia, indicative of its narrow genetic base, and of the related species we tested, V. tahitensis is nearest to V. planifolia. The species studied are diverse and have a similarity ranging from 1.2 to 57.3 %. Of the sampled taxa, V. andamanica is the most divergent and there is also reasonable variability within its collections, indicating the possibility of natural seed set. A total of 82 polymorphic bands expressed in the RAPD profiles were used to generate a genetic distance matrix, which was then used in cluster analysis. Specific groupings were revealed by the cluster analysis whereby the leafless forms (V. aphylla, V. pilifera and the new species) and V. andamanica formed separate clusters. This is the first report of species interrelationship studies, including both cultivated and wild vanilla species.

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The depletion/collapse and recovery of tropical marine fish stocks have been studied by deriving the time-series of stock status of commercially fished marine species in Karnataka. Majority of stocks (22 out of 47) showed wide fluctuations in catch whereas 15 stocks were dwindling. This analysis of catch trends (as a simple proxy for biomass estimates) shows that, in spite of consistently increasing efforts and absence of many regulatory measures, most species (66%) had fast recovery capacity within 1-5 years whereas 9% were slow to recover. The depleted and declining stocks need to be carefully monitored and conservation and rebuilding plans need to be made.

A field experiment was conducted to study the effects of weed management practices on cassava under irrigated conditions in Bhubaneswar (Odisha), India for consecutive three years (2010-11 to 2012-13). The results revealed that four rounds of manual weeding at 1, 2, 3 and 4 months after planting (MAP) and black polythene mulching resulted in taller plants, more number of nodes and leaves per plant, maximum number of storage roots per plant, maximum length and girth of storage roots as well as fresh storage roots yield per plant with lower weed biomass. Mean fresh root yield due to black polythene mulching was at par with four rounds of manual weeding (at 1, 2, 3 and 4 MAP). Black polythene mulching resulted in higher dry matter partitioning efficiency and soil microbial population. The root yield decreased by 9.6%, due to pre-emergence application of oxyfluorfen + two rounds of manual weeding (at 2 and 3 MAP) treatment and 10.1% in two rounds of manual weeding (at 1 and 2 MAP) + post-emergence application of glyphosate (at 3 MAP) compared to four rounds of manual weeding (at 1, 2, 3 and 4 MAP).