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Item Exploring the genetic potential of locally adapted germplasm for drought tolerance : a case for cowpea (Vigna unguiculata (L.)) Walp) from Malawi : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Science, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand(Massey University, 2014) Pungulani, Lawrent Lino MichaelThe shortage of improved cowpea (Vigna unguiculata (L.) Walp) varieties and increased frequency of droughts in Malawi have created a need to identify drought tolerant genotypes with desirable agronomic and utility characteristics. This research evaluated local germplasm maintained by the Malawi Plant Genetic Resources Centre (MPGRC), as an initial step towards the identification of genotypes with drought tolerance. Eco-geographic characterisation revealed diverse ecologies among the different germplasm collected. These genotypes were subsequently assessed for drought tolerance in a glasshouse study. All genotypes which tolerated low moisture conditions in the glasshouse originated from areas with high rainfall and low temperatures suggesting that extreme environmental conditions and/or human mediated actions interfered with adaptation processes. Furthermore, the eco-geographic characterisation identified germplasm gaps which need to be filled by either collection or repatriation of germplasm from international genebanks. The establishment of on-farm conservation in areas with low rainfall and high temperature such as Chikwawa and Nsanje districts may enhance adaptation of cowpea to drought conditions. Genotypes 479, 601, 645, 2226 and 3254 fully recovered from moisture stress, while 2232 started wilting within one week of drought stress initiation in the first glasshouse experiment. The genotypes which recovered from moisture stress showed low scores for wilting scales, low leaf wilting index (LWI), high relative water content, high scores for stem greenness and high levels for re-growth. In addition, the first glasshouse experiment resulted in the development of a leaf wilting index, which has been identified as an easily used method for scoring wilting, compared to common wilting scales. In a subsequent glasshouse experiment, all the genotypes which fully recovered from moisture stress showed high relative water content during the period of stress, but showed differences in other physiological traits. For example, genotypes 479, 601, 645 and 2226 had reduced stomatal conductance, transpiration rate and net photosynthesis, while 3254 maintained high scores for the three traits from the initial stage of moisture stress. Although 2232 showed a high transpiration rate and stomatal conductance, its net photosynthesis was significantly reduced, compared to all the other genotypes, after the third week of stress. The differences in physiological traits among genotypes indicated that 3254 has drought tolerance; 479, 601, 645 and 2226 avoid drought while 2232 is drought susceptible. The field performance of these six genotypes and two released varieties (Sudan 1 and IT82E16) was assessed in field trials in Malawi at Baka, Bvumbwe, Chitala, Chitedze and Kasinthula. Results from field trials revealed significant variation for reproductive, yield and seed characteristics. Sudan 1, IT82E16, 409 and 601 matured in less than 65 days after planting; 3254 took 70 days and 645, 2226 and 2232 took more than 85 days. Genotype 3254 consistently gave high yields at sites with low rainfall and high temperatures compared to 2232 which yielded poorly at the same sites. The eight genotypes showed variation in seed size with genotype 2226 producing large seeds (>20g/100 seeds) at all sites. The seed size of 2232 was significantly lower than 2226 at sites with low rainfall and high temperatures. The field performance of these genotypes reflects the physiological responses observed in the glasshouse, confirming the drought response categories of the genotypes. The agreement between glasshouse experiments and the field trial suggests there is intrinsic value in the locally adapted germplasm maintained by the Malawi Plant Genetic Resources Centre. Among the genotypes tested in the field, farmers selected 479 for early maturity; 2226 and 2232 for high leaf biomass; 3254 for high pod load; 2226 and 2232 for large seeds; Sudan 1 for small seeds; and 601, IT82E16 and Sudan 1 for smooth seed texture. Genotype 3254 was ranked poorly at all the sites due to rough seed texture. Genotypes for potential use in improving production of cowpea in drought prone areas were identified. In the absence of released drought tolerant varieties, it is recommended that genotypes with drought avoidance characteristics be promoted in areas with mild droughts, while 3254 with its typical drought tolerance may be suitable for areas with intense droughts. However, the rough seed texture of 3254 may limit its usefulness due to its poor ranking by farmers at all sites. Priorities for future cowpea in Malawi include investigating inheritance of drought tolerance in cowpea.Item A system of meal planning for self-improvement of the diet of villagers in northeastern Thailand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University(Massey University, 1983) Ngarmsak, TipvannaA method for self-improvement of nutritional status was developed for the villagers in Northeastern Thailand using the raw materials already available in the villages with cowpeas as a protein supplement. A low cost and nutritionally balanced 7-Day menu was designed for a family unit; it was based on the foods and food dishes already eaten in the villages, the present eating pattern of the villagers and protein maximised dishes. It was designed and introduced using a three stage system - study of the present foods eaten, development of the cowpea dishes and the 7-Day menu and introduction of the 7-Day menu to the villages. A survey of eating habits was conducted in ten villages in Khon Kaen Province, to find information on the types of food raw materials available in the villages, the types of foods and food dishes eaten throughout the year, the legumes and legume foods eaten in the villages. Twenty five cowpea recipes were developed from the traditional dishes and protein maximised using linear programming. They were highly acceptable to a taste panel of villagers. The protein content of 22 commonly eaten food dishes were also maximised using linear programming. These protein maximised dishes together with the other foods eaten by the villagers were used to develop a 7-Day menu in the traditional village meal pattern. A system was developed using mixed integer programming to select an acceptable daily menu pattern which could supply an adequate quantity of food for a family of 7 persons and meet their requirements for 26 essential nutrients. The 7-Day menu consisted of 6 daily menus of 29 foods and food dishes including 11 cowpea dishes and steamed glutinous rice. The 7-Day menu was found highly acceptable by the villagers. Three Introduction Models fitting with the village life style were developed for introducing the 7-Day menu and the cowpeas to 6 villages in Khon Kaen Province. Each model was tested in two villages during a 21 week introduction period. The most successful introduction method was to firstly explain the whole menu to the village headman, and then with his help organise a party for the villagers to introduce the menu and the cowpeas and to give nutritional information. Video demonstrations were used to teach the cooking methods for the various dishes and a cooking competition encouraged the villagers to cook the dishes and to follow the menu. This method of introduction created a large increase in the number of villagers using cowpeas.