Thesis (Ph. D.)--University of Wisconsin--Madison, 1942. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 104-106).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 78-80).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1928. / Typescript. With this is bound: The known predacious and parasitic enemies of the pea aphid in North America / C.L. Fluke. (Research bulletin / University of Wisconsin, Agricultural Experiment Station ; 93), 47 p. Includes bibliographical references (leaves 93-96).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. Includes tables. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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Pigeonpea (Cajanus cajan (L.) Millsp.) is cultivated by many farmers in the semi-arid areas of Kenya as a source of food and cash. However, the yields have remained low, ranging between 500 to 800 kg haˉ¹. Apart from drought, fusarium wilt is reported to affect yield. Breeding pigeonpea hybrids, using cytoplasmic male sterile (CMS) lines, hybridized with the local improved germplasm, have the potential for increasing yield and improve income for smallholder farmers. The objectives of the study were to: 1) examine the various stakeholders of the pigeonpea value chain and their core functions and identify characteristics of the pigeonpea varieties preferred by the market to be considered in the hybrid breeding programme, 2) evaluate cytoplasmic male sterile lines of Indian origin for stability across several environments in Kenya, 3) screen pigeonpea genotypes for general resistance to Fusarim udum Butler and 4) evaluate pigeonpea hybrids for grain yield and earliness across sites and seasons in Kenya. The stakeholder analysis established that the main players in the pigeonpea value chain were farmers, traders/processors, International Crops Research Institute for the Semi-Arid Tropics, Kenya Agricultural Research Institute, Kenya Plant Health Inspectorate Services, and Ministry of Agriculture. White seed, large seed size and medium maturity were the preferred traits by farmers and processors/exporters for both domestic and export markets. The unavailability of quality seed in sufficient quantities of high yielding varieties was cited as the main factor negatively affecting pigeonpea production. The stakeholder analysis approach, used for the first time in a breeding programme, demonstrated that it can be an important tool that can be used to diagnose crop production constraints, and define opportunities available for setting up a breeding programme that is highly client-oriented. Two CMS lines, ICPA2043 and ICPA2039 were the most stable across sites with 100% and 99% pollen sterility respectively. Screening for the presence of physiologic races of F. udum based on morphological and cultural characteristics on PDA identified three distinct isolate groups named ISO-A, ISO-B, and ISO-C. Studies under controlled conditions using the three isolates identified seven pigeonpea genotypes (ICPB2043, ICP12012, ICP13092, ICPA2039xICP13092, ICPA2043xICP12012, ICPA2043xICP13092, ICPA2043xICP9135) resistant to the three F. udum isolates. In the field evaluation, seven genotypes (ICPA2039xICP13092, ICPA2039xAsha, ICPA2043x12012, ICPA2043xICP13092, ICPA2043xICEAP557, ICPB2043 and Maruti) were found to be moderately resistant. The variances due to GCA and SCA were significant, showing that both additive and non-additive gene actions were important. The resistant hybrid, ICPA2043xICP12012 had the highest negative SCA that was highly significant for all the isolates and in the field indicating general resistance. The CMS (A) line ICPA2043 was found stable across environments and highly resistant to the three F. udum isolates. Therefore, it can be evaluated further for commercial hybrid seed production in Kenya. Evaluation of the pigeonpea genotypes across environments indicated that the highest yielding environment was Kiboko, with average and maximum yield of 2,249 kg haˉ¹ and 4,234 kg haˉ¹ respectively. Most hybrids were in the medium duration maturity group with days to maturity ranging from 147 to 186. Overall, the highest yielding hybrids were A2043xTZ26 and ICPA2039xTZ24 with mean yields 2,803 kg haˉ¹ and 2,527 kg haˉ¹ respectively. Mean yields for the best performing parents were 2,036 kg haˉ¹ for ICP12012 and 1,629 kg haˉ¹ for Asha. For specific sites, the highest yielding hybrids in Kabete, Kiboko and Leldet were A2039xTZ24 (2,057 kg haˉ¹), A2043xTZ26 (2,803 kg haˉ¹), and A2043xUG8 (1,708 kg haˉ¹) respectively. Mean heterosis for yield varied from -35% (A2039xA2043) to 50% (A2043xUG8). In Kenya, the potential for production and commercialization of hybrid pigeonpea is feasible due to high hybrid vigour recorded, and the stability of the CMS lines. Hybrids also have greater uniformity in grain size a factor which is important for the market. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Bibliography: leaves 74-80. This study shows techniques for reducing hyperhydricity in the micropropagation of Sturt's desert pea. The effects of support matrix, tube closure and cytokinin regime are examined and the anatomy of hyperhydric shoots is investigated.

Field pea is the most produced and exported pulse crop in Canada, and makes a major contribution to Western Canadian agricultural diversification programs. Canada is now the world largest exporter of pea, lentil and chickpea and is fourth in dry bean. The demand for Canadian pulse products is steadily rising and the export market would continue to rise with the expected increased in production. Field pea exported to countries with tropical climates is at particular risk due to rapid loss of quality. It is therefore important to develop practical strategies for safe storage of feed pea. Knowledge on the moisture adsorption and spoilage characteristics of pea stored in adverse storage conditions is important in the transportation and storage of this export commodity. <p> This study was initiated to examine the conditions that lead to quality losses in storage and transport of pea. Tropical and subtropical conditions were simulated in airtight chambers. Relative humidities (RH) of 60, 70, 80 and 90% were created by saturated salt solutions in airtight chambers at temperatures of 10, 20 and 30°C, while the same range of humidity was provided by dilute sulphuric acid in airtight chambers at 40°C in environmental cabinets. The four RH levels at each temperature for both whole and feed-grade pea were tested in duplicate. The samples were observed for changes in moisture content (MC), mold appearance and RH in specific time intervals. The amount of produced carbon dioxide (CO2) was measured in airtight chambers during storage to control the condition existing in sealed airtight chambers. Also, all components of feed-grade pea were exposed to RH of 90% and temperature of 40°C in separate airtight chambers to find the effect of each component on mold appearance. Molds were identified after appearance on the samples in order to pinpoint potential toxicity. <p> Both feed and whole sound peas became molded after a short time of storage at high temperatures and high RH, but those stored at 70% and below did not develop mold after 175 days at 30 and 40°C (experiment duration) and 216 days at 10 and 20°C (experiment duration). Molds were identified mostly as species of Aspergillus and Penicillium. The amount of CO2 in the airtight chambers showed almost no difference from the ambient CO2 except at high temperature and high RH when samples had gone molded. <p> Moisture adsorption equations were developed based on the moisture adsorption data in dynamic environment. Although the Page model showed to fit the data better, the exponential model was chosen to fit the data because its parameters can be better expressed as a function of temperature and RH of the storage environment. <p> The mold-free days for both feed pea and clean pea were modeled at temperatures of 10, 20, 30 and 40°C and RH of 80 and 90%.