Browsing by Subject "cassava"

The world population is growing and is expected to reach over 9 billion in about 30 years. Climate change is also widely expected to worsen famines in certain regions of the world. This will drastically increase global food demand. Food security efforts should be therefore be geared towards promoting food crops that can thrive in these regions and can withstand the condition likely to be brought about by changing climate. Cassava is a typical example of such a crop. This study investigated the use of digital images to estimate growth parameters of young cassava plants. Cassava was cultivated in pots at the University of Helsinki greenhouse at Viikki. The plants were given different water level (100%, 60% and 30% saturation) and potassium (0.1, 1.0, 4.0, 16.0 and 32.0mM) treatments. Digital red-green-blue (RGB) and multispectral images were taken every other week for 5 consecutive times. The images were processed to obtain leaf area, Normalized Difference Vegetation Index (NDVI), and Crop Senescence Index (CSI) and correlated with directly measured growth parameters of the young cassava crops. It was observed that leaf area that was computed from images, and NDVI which was computed from the multispectral images have significant positive correlations with the growth parameters, ie, actual leaf area, chlorophyll content, and plant biomass. CSI however showed weak a correlation between the growth parameters of the young cassava plants. Images leaf area and NDVI were then used to identify the changes in the effects of the water and potassium treatments.

Rice, cassava and eucalypts are important species for Thailand's economy and they are widely used in agroforestry systems in Thailand. In this research the studied agroforestry systems were boundary planting and alley cropping with rice, cassava and eucalypts, but there are also many other systems in use in Thailand. Rice is the most important crop in the world and also in Thailand and the demand of rice is increasing due to the population growth. Cassava has been an important plant in Thailand and also the demand of cassava is growing due the new potential industries. The amount of forests in Thailand has decreased from the 1960's while deforestation still continues due to that the planting of eucalypts is promoted for reforestation purposes. Also the demand of eucalypts is increasing because the consumption of paper is growing with the economic growth of Asian countries and due to the logging ban on natural forests in Thailand since 1989. Due to that contract farming of eucalypts is critical for pulp and paper industry and it has been increasing. The aim of this study was to find out the reasons why farmers have chosen agroforestry and what are the advantages and disadvantages of the used systems. The research was semi-structured interview and it was conducted with 25 farmers. Confirmative results on factors affecting farmer's adoption, continuation and experience on benefits of agroforestry did not emerge from the data. Farmers mentioned most often availability and suitability of the land, own experiences and knowledge as the reason for adoption. Farmers saw agroforestry as a way to increase their income, improve profitability and diversify their production. Most of the farmers were going to use agroforestry systems also in the future.