Nutrient Disorders of Sweet Potato

Crop Production/Industries,

Mapping the Future: Policy Applications of Climate Vulnerability Mapping in West Africa

We describe the development of climate vulnerability maps for three Sahelian countries – Mali, Burkina Faso, and Niger – and for coastal West Africa, with a focus on the way the maps were designed to meet decision-making needs and their ultimate influence and use in policy contexts. The paper provides a review of the literature on indicators and maps in the science-policy interface. We then assess the credibility, salience, and legitimacy of the maps as tools for decision-making. Results suggest that vulnerability maps are a useful boundary object for generating discussions among stakeholders with different objectives and technical backgrounds, and that they can provide useful input for targeting development assistance. We conclude with a discussion of the power of maps to capture policy maker attention, and how this increases the onus on map developers to communicate clearly uncertainties and limitations. The assessment of policy uptake in this paper is admittedly subjective; the article includes a discussion of ways to conduct more objective and rigorous assessments of policy impact so as to better evaluate the value and use of vulnerability mapping in decision-making processes

Acid soil infertility effects on peanut yields and yield components

The interpretation of soil amelioration experiments with peanuts is made difficult by the unpredictability of the crop and by the many factors altered when ameliorating acid soils. The present study was conducted to investigate the effects of lime and gypsum applications on peanut kernel yield via the three first order yield components, pods per ha, kernels per pod, and kernel mass. On an acid medium sandy loam soil (typic Plinthustult), liming resulted in a highly significant kernel yield increase of 117% whereas gypsum applications were of no significant benefit. As indicated by path coefficient analysis, an increase in the number of pods per ha was markedly more important in increasing yield than an increase in either the number of kernels per pod or kernel mass. Furthermore, exch. A1 was found to be particularly detrimental to pod number. It was postulated that poor peanut yields

Experimental control of plant nutrient status using programmed nutrient addition

In simple non-renewed water culture systems, large changes in plant nutrient status may occur during the course of an experiment due to depletion of the nutrient solution. These changes complicate the study of effects of nutrient status on physiological processes. Flowing solution culture techniques offer one solution to the problem, but these techniques tend to be laborious and require equipment not available at most laboratories. Programmed Nutrient Addition is a simple, low-cost technique for controlling plant nutrient status. In this technique frequent, small additions of all nutrients are made, including the test element. In this way, plant nutrient status is held approximately constant or is varied in a predetermined manner. Computer software has been developed for generating schedules of nutrient addition given information on the growth curve of the plant species being studied, approximate tissue concentrations needed for healthy growth, and the level of stress (if any) intended. The paper discusses the Programmed Nutrient Addition technique which has been applied successfully over the past 16 years in studies on several species including grain sorghum (Sorghum bicolor L.), sunflower(Helianthus annuusL.), cotton (Gossypium sp.), cassava (Manihotesculenta Crantz), kiwi fruit (Actinide TchinensisPIanch), and ginger (Zingiberofficinale Roscoe)

Effects of plant population density and cultivar on growth, yield and yield components in groundnut (Arachis hypogaea 1.)

An experiment was conducted at the University of Queensland Redland bay Farm (27°37′ S, 153°17′ E) in southeast Queensland, Australia to study response of groundnut cultivars [Improved Virginia Bunch, NC-7, Q18801 (Virginia types), TMV-2, McCubbin and Red Spanish (Spanish types)] to different plant population densities (6.3, 11.1, 25.0 and 100.0) arranged in square spacings. The objective was to study plant physiological and morphological characteristics associated with the optimum plant population density among groundnut cul- tivars. Leaf area index (LAI), interception of photosynthetically active radiation (PAR), total dry mass (TDM), dry mass (DM) partitioning, economic yield and yield components were measured. The results show that TDM and economic yield were both maximized at 25 plants m in all cultivars and so were the radiation use efficiency (E), crop growth rate (CGR) and DM partitioning'toTeproductive components (pods and kernels). Overall, variation in economic yield (kernel DM) was determined by pod harvest index (HI), kernel HI, ratio of pod to peg plus pod number, kernel number per pod and kernel size. Most of these components were maximized at the optimum plant population density