Indigenous knowledge is the unique knowledge confined to a particular culture or society. It is also known as local knowledge, folk knowledge, people's knowledge, traditional wisdom or traditional science. This knowledge is generated and transmitted by communities, over time, in an effort to cope with their own agroecological and socioeconomic environments (Fernandez, 1994). It is generated through a systematic process of observing local conditions, experimenting with solutions and readapting previously identified solutions to modified environmental, socioeconomic and technological situations (Brouwers, 1993). Indigenous knowledge is passed from generation to generation, usually by word of mouth and cultural rituals, and has been the basis for agriculture, food preparation and conservation, health care, education, and the wide range of other activities that sustain a society and its environment in many parts of the world for many centuries.

Weedy rice (Oryza sativa f. spontanea) is a notorious weed that infests paddy fields worldwide. Understanding the morphological variation pattern of this weed in a given rice‐planting region will facilitate its effective management and use. Here, 29 populations, covering nearly all the rice‐cultivation regions in Sri Lanka, were characterized in a common‐garden cultivation experiment that was based on 13 morphological traits. The variation level of the weedy rice populations was considerably high, as estimated by the Simpson and Shannon–Weaver indices. An ANOVA revealed a higher level of among‐population variation than within‐population variation. Seed shattering was the most variable trait and the seed length and width were the least variable traits, as indicated by their coefficient of variation. The results of the principal component analysis, in which the first two principal components represented 57.5% of the total variation, indicated the important role of such traits as plant height, seed weight and number of tillers and panicles in the divergence of the weedy rice populations. However, the variation was not associated with their geographical locality. Knowledge of such a morphological variation pattern provides opportunities to design strategic management methods for weedy rice control in Sri Lanka, in addition to the proper use of it as a genetic resource for rice improvement.

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Weedy rice is becoming common in most rice growing areas in Sri Lanka. It is variable in almost all the vegetative and reproductive characteristics and tends to have low tillering ability, easy shattering, long awns and higher dormancy in some variants. In addition, weedy rice may contain important genes which can be incorporated into the cultivated varieties. In order to ascertain the diversity for its possible utilization in rice crop improvement, morphological characters of weedy rice accessions were observed in three locations in Ampara district. Characters were observed from 50 individuals with at least 5m distance between plants. A significant difference was observed in weedy rice plants observed at Thottama for plant height while at Lahugala significant differences were observed for tiller number (3.22) and number of panicles (2.54). 58% of observed panicles had awns and purple colored long awns were the most prominent. In addition, white colored long awns, purple colored medium sized awns and white colored medium sized awns were present. The plants observed at Thottama showed higher number of panicles from relatively shorter plants. The existence of great diversity in the morphology indicates the presence of other related agronomic, physiological aspects for their selection and adoption.

This study was conducted to investigate the effects of explant source and hormone concentrations on the callogenesis, calli growth, plantlet regeneration and rooting of a local tomato variety (Lycopersicon esculentum mill. variety 'Thilina'). Different combinations of Benzyl Adenine (BAP) and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) were used with hypocotyl, leaf and root explants in a completely randomized design with five replicates to evaluate the success in plantlet regeneration. Regenerated healthy shoots sub cultured in to MS medium with various concentrations of Indole-3-butric acid (IBA) for rooting. After one month the weight of fresh callus, number of regenerated shoots and roots were evaluated. Anova (DMRT) test shows there were significant effects at p<0.05 level. Combination of BAP (0.1mgl-1) with 2.4-D (2.0mgl-1) and hypocotyl explant produced the best quality fresh callus in highest weight. The best hormonal combination for shoot regeneration (4 shoots/explant) was 0.1mgl-1 NAA and 0.5mgl-1 Kinetin from callus. Maximum direct regeneration was observed on MS medium containing 0.5mgl-1 Kinetin, 2.0mgl-1 BAP, 0.1mgl-1 1-Naphthaleneacetic acid (NAA) and 100mgl-1 my-inositol within 15-20 days (4 shoots/explant). Leaf bud revealed to be better explants for direct regeneration. Highest root number per plantlet was observed with 2.0mgl-1 IBA.