Showing papers in "Njas-wageningen Journal of Life Sciences in 2015"

Cocoa production in West Africa, a review and analysis of recent developments

Abstract: This paper reviews the present condition of cocoa growing in West Africa where some six million ha are planted with cocoa which provide about 70 percent of the total world production. Cote d’Ivoire and Ghana are the largest producers, followed by Nigeria and Cameroon. In the beginning of the 21st century the cocoa production increased from about 2,000,000 tons to about 3,000,000 tons in 2010 and subsequent years. While in this period expansion of the cocoa area (at the expense of forest land) contributed to increased production, nowadays more cocoa has to come from higher yield per ha which is very low at present. This paper highlights at first cocoa growing in each of the cocoa producing countries and then deals with the common constraints and options to higher yields, especially those in Cote d’Ivoire and Ghana. The major causes of low yield are a high incidence of pests and diseases, the old age of cocoa farms and lack of soil nutrients. Concerns about declining output due to aging and diseased trees have urged the government of Cote d’Ivoire and Ghana to launch large rehabilitation and replanting schemes which provide farmers with improved planting materials, plant protection chemicals and fertilizers. As owners of small farms do not earn enough income from their cocoa to purchase external inputs, the traditional mixed planting of cocoa and forest and fruit trees and some oil palms is discussed as an alternative to a high input approach. This low input low output system is sustainable but not the way forward to higher yields. It is thought that in the short run higher cocoa prices and improved management including pest and disease control and to a certain extent fertilizer use offer scope for a larger cocoa output. In the more distant future the predicted climatic change and increased land use for food production will reduce the size of the cocoa area and affect the leading position of West Africa on the world cocoa market. This review shows that at present the conditions for sustainable production are not met and concludes that important structural changes in the cocoa sector are needed to reach this goal. These changes concern the economic viability of cocoa on small farms, extensive land use and the ecological impact of the current cocoa growing practice. The implementation of these changes requires area specific programs with as their common goal increased economic and environmentally sustainable cocoa production on less land.

Information, trust and pesticide overuse: Interactions between retailers and cotton farmers in China

Abstract: In the absence of adequate extension services, retailers have become the major information source for farmers’ pesticide use in rural China. Pesticide application for smallholders is rather complex, and mistakes can lead to significant crop losses. Farmers, therefore, seek sources of information regarding pesticide use. This paper first explores how different kinds of retailers may employ different strategies of providing information to farmers. We find that for village, town, and county retailers, the more familiar they are with farmers, the more likely they are to amplify the recommended dosage of pesticide use. In cooperatives, who buy pesticides from an extension station, the information is directly transferred to member farmers without information distortion. Apart from examining retailers’ different strategies of information provision, this paper also asks in how far farmers’ trust in retailers may affect pesticide use. It finds that trust in different kinds of retailers indeed varies and plays a critical role in converting information into farming behavior. Members of the cooperative show rather high levels of trust in their retailer, while farmers who are not members of a cooperative show low levels of trust in retailers. Pesticide use is a joint result of retailers’ information provision strategies and farmers’ trust. The lowest pesticide use occurs when accurate information is provided and when farmers highly trust the information provider. Overuse occurs with either information distortion or low levels of trust. Cooperatives have advantages both in terms of information provision and trust, thereby leading to the lowest use of pesticides.

Exploring the roles of women in the development of multifunctional entrepreneurship on family farms: an entrepreneurial learning approach

Abstract: This paper analyses women's roles in the learning process that accompanies the switch towards multifunctionality and multifunctional entrepreneurship: the process by which farmers gain the necessary knowledge and skills ‘to do multifunctionality’, develop and adapt their identity as ‘multifunctional entrepreneurs’, and re-establish the identity of the farm as a multifunctional one. Detailed inspection of men's and women's positions and functions in the learning process reveals women's leading roles in: 1) introducing new identities and practices onto the farm, 2) providing access to new networks and learning environments, and 3) initiating negotiation within the farming family regarding the farm's (future) orientation towards primary production or multifunctionality. All three aspects of learning are essential building blocks for the development of multifunctional entrepreneurship on family farms. The paper is based on a study of 120 Dutch multifunctional farms, with a detailed analysis of the genderedness of the entrepreneurial learning process in three specific farm cases.

Nutritional qualities and antioxidant activity of three edible oyster mushrooms (Pleurotus spp.)

Abstract: Three species of oyster mushrooms ( Pleurotus spp.) that are cultivated mostly throughout the year in the plains of India were studied for their nutritional value and their antioxidant properties. Highest protein content was found in Pleurotus florida (22–25% dw) followed by Pleurotus citrinopileatus (20–22% dw) and Pleurotus pulmonarius (15–18% dw). Cholesterol content was in the range of 0.6–0.8% dw, making them low-cholesterol, proteinaceous food. The antioxidant properties of the three species were of both enzymatical and non-enzymatical nature. Reducing power, chelating activity on Fe 2+ and total phenol contents were higher in P. florida than in P. pulmonarius and P. citrinopileatus . With regard to antioxidative enzymes, P. florida had the highest peroxidase and superoxide dismutase activity whereas maximum catalase activity was found in P. pulmonarius . P. florida had higher antioxidative activity than P. pulmonarius and P. citrinopileatus thereby highlighting its nutraceutical values along with nutritional qualities.

Organic food and health concerns: a dietary approach using observed data

Abstract: A number of studies based on stated behaviour suggest that consumption of organic food is part of a life style that involves healthy eating habits that go beyond shifting to organic varieties of the individual food products. However, so far no studies based on observed behaviour have addressed the relationship between organic purchases and diet composition. The aim of the present paper is to fill this gab using purchase data for a large sample of Danish households. Using a Tobit regression analysis, the diets of households with higher organic consumption were found to include more vegetables and fruits but less fat/confectionary and meat which is in accordance with the official Danish Dietary Recommendations. Moreover, higher organic budget shares were found among well-educated consumers in urban areas and clearly linked to a belief that organic products are healthier. No statistical relations were found between consumption of organic food and perceptions that organic production is more animal or environmentally friendly.

Peat Characteristics and its Impact on Oil Palm Yield

Abstract: The yield potential of oil palm planted on peat land has always been a controversial subject. Most past soil research on oil palm yield on peat land was mainly based on the depth and drainability. Little attention was given to the impact of peat characteristics on oil palm from a yield perspective. This study tests the hypothesis that physical soil properties such as peat maturity, presence of wood, depth and nature of underlying substratum affects oil palm yield. The initial study involved the evaluation of soil mapping units on estates in Sibu, Sarawak, East Malaysia and from this exercise of four organic soil mapping units which reflected the different characteristics of soils were selected. Data on peat depth, presence and absence of decomposed and undecomposed wood, nature of underlying substratum and peat maturity (fibric, sapric and hemic) were collected, analyzed and interpreted. Comparisons were also made on mineral soil found at the same location. Yield data were analyzed from primary sources from oil palm estates. Results show that different types of peat have significant effect on oil palm yield ranging between 9.47 - 22.92mt/ha. Peat maturity has the most significant effect on yield. Sapric peat showed a yield range of 19.48-22.92mt/ha as compared to hemic peat ranging between 9.47- 13.37mt/ha. Palms planted on soils with sandy substratum showed significant 18 -142% higher yields compared to those over marine clay as underlying material. No significant differences were observed in the yields due to the different depths and presence/absence of wood as a single factor. However, a combined factor of peat maturity and presence with nature of wood do have significant impact on yield. The study further confirms that sandy spodosol like Bako series perform 30 - 40.44% lower yields compared to peat soils such as Telong and Naman series. The results are important as peat areas with specific physical soil properties and showing poor yields can been left for conservation prior to development. Thus selective development based on semi detailed soil surveys producing maps giving peat characteristics and its impact to oil palm yield is possible. However, a more balanced view and future research should be emphasised to other issues such as cost of development of peatland compared to the price of crude palm oil in the world market, biodiversity, social issues, Green House Gas (GHG) emissions and potentials of improving productivity on existing organic and mineral soils need to be further explored. The study therefore challenges the existing believe that peat depth is very significant in determining oil palm yield. The study also enhances the need for soil surveys for land use decisions and wise use of peatlands. Further research is recommended to narrow the knowledge gaps and uncertainties on peatland.

The changes in physical, bio-chemical, physiological characteristics and enzyme activities of mango cv. Jinhwang during fruit growth and development

Abstract: The changes in the physical, bio-chemical and physiological characteristics, and enzyme activities of sucrose metabolism during growth and development in mango fruit cv Jinhwang were investigated Fruit was harvested at five stages ie, 50, 80, 110 and 140 days after anthesis (DAA) Several changes in the fruits were analyzed The physical parameters like the fruit weight, width and length increased throughout the growth In turn, fruit firmness, titratable acidity (TA) and starch accumulation increased during the initial growth stage and later then decreased during maturity Total soluble solids (TSS) tended to decrease throughout fruit development Respiration rate and ethylene production were higher at 50 DAA compared to other growth stages Sucrose accumulation occurred later in the fruit development, however fructose was the dominant of the soluble sugars Starch accumulation was related to the reduction of sucrose phosphate synthase (SPS), acid invertase (AI) and neutral invertase (NI) activities, whereas sucrose synthase activity was increased Moreover, the AI and NI are the dominate enzymes that plays a major role in sugar accumulation and quality of mango fruit Therefore, mango fruit should be harvested after physiological maturity at 110 DAA, when the fruit reach the optimum size, weight and starch content including maximum value of firmness, TSS, fructose content, minimum value of TA, low respiration rate and the lowest of ethylene production

Mediation and moderation in food-choice models: a study on the effects of consumer trust in logo on choice

Abstract: The paper introduces a way to analyse the influence of mediating and moderating variables on willingness to pay in a simple way. Using data on 427 Italian consumers regarding different organic logos, mediation and moderation analysis is applied for the first time in a discrete choice setting. We tested the hypothesis that trust in logo mediates the relationship between the logo and consumer choice for organic labelled food products. Results do not allow rejecting the hypothesis that trust in logo totally mediates the effect of the logo. Therefore, the willingness for organic products could be interpreted as “cost for trust”: the higher the trust the higher the perceived value-for-money. The mediation effect of trust in logo does not vary across points-of-purchase or regions. Our novel approach is susceptible of various applications when analysing choice data and can be extended further.

A conceptual approach for measuring farmers’ attitudes to integrated soil fertility management in Kenya

Abstract: A sustainable increase in agricultural productivity is essential in assuring food security in developing countries. Low soil fertility is a major contributing factor to the current vicious cycle of low agricultural productivity and inadequate livelihoods among smallholder farmers. Integrated soil fertility management (ISFM) is one way of achieving sustainable agricultural development, but improving soil fertility through ISFM requires interventions that match the behavioural inclinations of farmers and their decision making. Using survey data on 125 commercial peri-urban farmers growing kale (Brassica oleracea) around Nairobi, Kenya, this study examined two conceptual approaches for measuring ISFM attitudes. A Rasch model, where the odds ratio for engaging in an ISFM practice is given by the difference between farmers’ attitude and the difficulty of the practice in terms of behavioural cost, identified ISFM attitudes as a unidimensional concept. However, assessing attitudes based on a standard valence method raised problems of construct validity. Accounting for behavioural costs as determinants of ISFM, in addition to other pecuniary costs, may improve our understanding of how farmers deal with complex choices in the ISFM context. Our findings suggest that high behavioural costs in relation to use of human faeces as manure, use of crop residues and transport impede adoption of ISFM practices vital to increased productivity. These findings can be used to develop ISFM communications and improve the efficacy of different interventions intended to increase potential uptake of ISFM practices.

Food chain design using multi criteria decision making, an approach to complex design issues

Abstract: Designing a food supply chain for a completely new product involves many stakeholders and knowledge from disciplines in natural and social sciences. This paper describes how Multi Criteria Decision Making (MCDM) facilitated designing a food supply chain in a case of Novel Protein Foods. It made the procedure transparent and aided the evaluation of alternatives. Two models, namely the Multi Attribute Value Theory (MAVT) and the Analytic Hierarchy Process (AHP), were used, due to the ease with which they handle a mix of quantitative and qualitative information, quantify the qualitative information and generate an overall value for each alternative. The resulting preference order differed mainly due to the manner in which criteria weights were elicited, alternatives scored and the use of scales in MAVT versus the pairwise comparison in AHP. However, the preference order of the top criteria with both methods was the same and weights were similar.

The Sectoral Innovation System of the Dutch Vegetable Breeding Industry

Abstract: In a number of studies, the Dutch vegetable breeding industry has been described as a highly innovative sector, but the root causes for its innovativeness have not yet been analysed systematically. In order to understand the factors that affect innovation and business performance, the Sectoral Innovation System (SIS) framework was used to analyse the linkages and interactions among the different actors in the Dutch vegetable breeding industry. Within SIS, five interacting domains are recognized and analysed: the business domain, the research & education domain, the intermediate organizations, the market demand, and the infrastructure & framework conditions, resulting in an integrated picture of the innovation system. It was found that the business domain, the research & education domain and the intermediate organisations do not only show an outstanding individual performance, but more importantly, they closely collaborate via public-private partnerships (PPP), research consortia, etc. It is shown that especially the cluster characteristics of the Dutch vegetable breeding industry, i.e. the geographical proximity and the high level of intra- and interconnectivity within and between domains, induces an intensive knowledge flow, a key indicator for the innovation level of a sector.