Academic literature on the topic 'Improved varieties'

The International Potato Center (CIP) and Peruvian National Agricultural Research Institute (INIA) have invested a substantial amount of resources towards the development of improved potato varieties in Peru. These varieties are adaptable to the agro-ecologies of the Andes and have specific biotic and abiotic attributes. These efforts have led to the release of several prominent varieties including Canchan-INIA, Amarilis, Unica, Serranita and others. A 2013 household survey conducted by CIP was used to describe the diffusion of improved potato varieties in Peru. These data were also used to identify specific constraints to their adoption and dis-adoption. The assessment focused on a two-step adoption model, adoption and dis-adoption, by utilizing a Heckman Probit model to demonstrate two-steps of the adoption process. The Heckman Probit model was used to analyze variables affecting adoption and dis-adoption of improved varieties. Results suggest that adoption is region specific, time dependent, and in some cases relies on informal transmission methods. Risk to food insecurity and recurrent natural phenomena affect adoption and sometimes dis-adoption. Additionally, factors affecting a farmer's exposure to risk, such as information constraints and household head age, wealth, and social network were found to affect the adoption and dis-adoption of improved varieties.<br>Master of Science

Public agricultural research has been conducted in Africa for decades and has generated numerous crop technologies, while little is understood on how agricultural research affects the poor and vulnerable groups such as children, and how farmers' perceptions affect their adoption decisions. This dissertation helps fill this gap with three essays on adoption and impacts of improved maize varieties in rural Ethiopia. The first essay estimates poverty impacts. Field-level treatment effects on yield and cost changes with adoption are estimated using instrumental variable techniques, with treatment effect heterogeneity fully accounted for in marginal treatment effect estimation. A backward derivation procedure is then developed within an economic surplus framework to identify the counterfactual income distribution without improved maize varieties. Poverty impacts are estimated by exploiting the differences between the observed and counterfactual income distributions. Improved maize varieties have led to 0.8-1.3 percentage drop in poverty headcount ratio and relative reductions in poverty depth and severity. However, poor producers benefit the least from adoption due to their small land holdings. The second paper assesses the impacts on child nutrition outcomes. The conceptual linkage between maize adoption and child nutrition is first established using an agricultural household model. Instrumental variable (IV) estimation suggests the overall impacts to be positive and significant. Quantile IV regressions further reveal that such impacts are largest among the most severely malnourished. By combining a decomposition procedure with estimates from a system of equations, it is found that the increase in own-produced maize consumption is the major channel such impacts occur. The third paper explores how farmers' perceptions of crop traits affects their willingness to adopt improved maize varieties. Under a random utility framework, a mixed logit procedure is implemented to model farmer's adoption intention, where perceptions of key varietal traits are first identified, and then instrumented using a control function approach to account for potential endogeneity. Perceived yield is found to be the most important trait affecting farmers' adoption intention. Further, yield perceptions among previous adopters appear to be affected by within-village peer effects rather than the real crop performance.<br>Ph. D.

"Maize is the most important food crop in Mozambique. However, maize production is low and is cyclically impaired due to abiotic stresses such as recurrent droughts (particularly in the arid and semi-arid areas), soil infertility, floods, and cyclones events. Biotic stresses, such as pests and diseases, also affect food production. Altogether, these constraints lead to food insecurity and the need for humanitarian food aid from local and international communities. (...)"<br>N/A

Cassava is the main staple crop in Nigeria. Using primary data from four south eastern states in Nigeria, the study assessed the gender impacts of improved cassava varieties. Comparative statistical analysis reveals that total female labor is higher than total male in cassava production, processing and marketing. Women spend more labor days than males for planting, weeding, harvesting, marketing and processing. The total female family labor is higher for adopters of new improved cassava varieties. There is however lower family labor input for both male and female adopters for clearing and plowing which are normally done by men. Significant determinants of female labor supply are number of children in the household, percent of females in the household providing labor on the farm, area under improved cassava varieties and total land area. There is a positive unexpected relationship between total female labor supply and number of children. For each of the decision making variables, there is a significant association between the gender of the spouse and the decision made except for the decision on family labor allocation. Probit results show a significant decrease in the probability that the wife makes the decision for family labor allocation, what inputs to buy and borrowing and traditional cassava income control with adoption. Results indicate that both men and women spend their income on services directly linked to the householdâ s welfare. More than half of the women ranked food as number one.<br>Master of Science

Common beans are one of the most important food and cash crops for most Malawians. The insufficient production of the crop in the country coupled with low yields has made scientists give much interest to the crop so that they can address the constraints to the productivity problems. In this regard, breeders have been engaged in the development and release of improved varieties of common beans which in most cases are disease resistant, high yielding, drought resistant, and fast cooking. Therefore it is the interest of this study to find the reasons why productivity of the crop is still low despite the release of the improved varieties. The study adopted contingent valuation (CV), a method frequently used to assess willingnessto- pay of people for non-market goods or services and this was applied to assess farmer’s willingness-to-pay for the new improved bean seed varieties which are high yielding. Double bounded dichotomous choice with an open ended follow-up format was used to obtain the household’s willingness-to-pay. In addition; the study reviewed the existing dissemination channels of bean seed to make recommendations with regard to seed supply. Descriptive statistics from the 132 households interviewed shows that the structural constraints to seed acquisition are compounded by farmers’ poverty. Otherwise, most farmers are aware of the existence of improved varieties of common bean seed and perceive that with the use of this seed, productivity can improve hence willing to pay for the good. The study is 95% confident that mean price farmers are willing to pay for improved common bean seed is between MK 527.78 and MK 591.92. Three major existing informal dissemination channels of bean seed were discovered in the study areas. Therefore there is a need for government to work in collaboration with NGOs towards ensuring a formal supply system of bean seed characterised by vertically organised production and dissemination of tested and approved seed varieties, and using strict quality control rules, so that farmers can be assured of accessing improved seed varieties. This will increase the nation’s food security.<br>Dissertation (MSc Agric)--University of Pretoria, 2013.<br>gm2014<br>Agricultural Economics, Extension and Rural Development<br>unrestricted

Cooperation-88 (C88) is a late blight resistant potato variety that was formally released in China in 2001 and has become popular in China's Yunnan Province. The International Potato Center (CIP) and Yunnan Normal University collaborated to produce the variety, which is one of CIP's most successful varieties. C88 is popular due to its high quality and taste, and it is used commonly in China's expanding potato chip processing market. The purpose of this study is to examine adoption of C88 in the Yunnan Province, its value chain, and economic impacts. The analysis indicates that C88 is still popular with 16.8% of the potato area in Yunnan devoted to this variety in late spring 2015. To examine factors affecting household decisions to adopt and the intensity of their adoption, village adoption, household adoption, and household intensity of adoption were assessed. A village's proximity to a metropolitan county was the most important factor explaining adoption and intensity of adoption. Households in villages closer to a metropolitan county disadopted at higher rates than those farther away. To quantify the economic benefits of C88 adoption, an economic surplus analysis was conducted. Total surplus changes ranged from $2 to 3 billion indicating significant economic benefits to consumers and producers in Yunnan.<br>Master of Science

The current world population is over 7.4 billion and expected to exceed 9 billion in 2040, causing a 70% increase in food demand. Global environmental degradation, in the form of salinization, pollution and global warming, has also reduced the availability of suitable arable land and water sources, contributing to promote crop improvement in order to increase the potential yields. Rice (Oryza sativa) is the most widely consumed staple food for a large proportion of the world population. Classical rice breeding programs use its natural variability to create new allelic combinations which are screened for selecting those presenting superior agronomic traits such as improved yield. Those improved lines are stabilized through inbreeding to maintain the phenotype in their progeny. Certified seed producers systematically select and propagate registered varieties year by year in order to maintain their uniformity and the original registered cultivar traits, since natural mutations, spontaneous breeding between varieties and alien grain contamination can introduce undesirable variability at this stage. Nowadays biotechnology is used to drive the improvement of rice traits such as increased yield and grain quality. Moreover it helps to rapidly bestow tolerance to biotic (diseases and insects) and abiotic (drought, salinity, cold temperatures, nutrients deficiency) factors. Some of the available biotechnological techniques applied for crop improvement are i) the genetic engineering, which allows the addition of foreign genes in the rice genome although being controversial due to the social and environmental concerns, ii) the anther culture, which fasten and improves the selection of new breeding lines, and iii) the Targeting Induced Local Lesions IN Genomes (TILLING) which combines the production of large mutant populations with the detection of mutants in genes of interest through molecular screening. The main aim of the thesis is to study different biotechnological tools and their applications to the improvement of Mediterranean rice varieties. To achieve this biotechnology is used to study the pollen dispersion of a genetically engineered rice line, to accelerate the stabilization process through anther culture technique and to introduce new variability using a mutagenesis protocol followed by molecular detection of mutants. In this thesis we first studied the pollen-mediated gene flow between wild rice, conventional rice and an herbicide resistant transgenic rice line in order to determine gene flow rates in relation to the distance and the prevailing wind speed and direction. Results showed that pollen dispersal is dramatically effected by the distances between rice plants and the speed and direction of the prevailing wind. Furthermore, the enhanced pollen dispersal capability of weedy rice can also play an important role in transgenic pollen dispersal, which unfortunately had been underestimated. Then, we adapted an anther culture protocol in order to efficiently obtain commercial dihaploid lines from a Mediterranean japonica variety. Furthermore, we described the greenhouse and field trials used to select the best lines for registration which are now being successfully commercialized. Finally, we developed a fast protocol for obtaining mutants with agronomic interest. This protocol is based on ethyl methanesulfonate mutagenesis of seed-derived calli. The in vitro regenerated mutant population plants were directly screened for senescence-related genes, allowing to shorten in more than eight months the common seed mutagenesis protocol. The molecular screening protocol was also optimized and several potential delayed senescence mutants were identified and tested.