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The proteins of different faction of cowpea [Vigna unguiculata (L.) Walp] were fractionated by capillary electrophoresis (CE). The extracting solvent system was one of the most critical factors in the optimization exercise. To improve reproducibility, seed samples needed to be defatted with chloroform/methanol (V∶V＝2∶1) as preferred prior to protein extraction. Proteins were extracted from seeds, leaves and flowers with 50% aqueous 1-propanol and separated on a 50 µm×20 cm fused silica capillary column using a UV detector at 200 nm. Separation was conducted at constant voltage (10 kV, 40 ℃), using iminodiacetic acid (pH 2.5) containing 0.05% hydroxypropylmethylcellulose (HPMC) and 20% acetonitile. The results showed that proteins extracted from all fraction of cowpea were successfully separated by CE in less than 20 min. Seed extracts provided the greatest number of eluted protein peaks, followed by flower and leaf, respectively. The seed-protein extracts provided unique CE patterns for different varieties; hence the seed was the tissue chosen as being most suitable for variety identification. As a result, an optimized procedure was developed to provide rapid identification of cowpea varieties, based on capillary electrophoregram patterns.

This investigation was carried out at the Experimental Farm, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand to evaluate intensity of infection of Pseudocercospora Leaf Spot disease of cowpea cultivars, grown under field conditions with the use of Yasothon soil series (Oxic Paleustults). The experimental design used was a strip split plot design with four replications. The experiment consisted of three factors, i.e., with and without infector rows (Factor A), with and without inoculation and inoculated dates, i.e. none inoculation, inoculated at days 15 and 30 after sowing of seeds in main plots (Factor B) and three cowpea cultivars of KVC7, KKU25 and IT81D-1228-14-1 (Factor C). The results showed that the use of infector rows of cowpea plants (KKU25) being sown at 15 days before sowing seeds of cowpea cultivars in main plots gave a similar intensity of disease as those infector rows being sown at 30 days before sowing seeds of cowpea cultivars in main plots but significantly higher than without infector rows. Pathogenic disease being inoculated to the cowpea plants at 15 days after the sowing of seeds in main plots gave significantly higher intensity of disease than none inoculation. The establishment of infector rows at 15 days ahead of the sowing of seeds in main plots together with an inoculation of the disease at 15 days after the sowing of seeds in main plots gave the best results in evaluating amount of the infected disease. Thus infector rows surrounded the main plots are required whenever trials on disease evaluation are taken place.

A B S T R A C TThis study aimed to examine the impacts of sugarcane farmland expansion towards food security among the sugarcane-farming households in Khon Kaen Province, Thailand. A quantitative methodological approach was implemented in the study. The population of the study consisted of 3,332 sugarcane-farming households in Khon Kaen Province, who were associated with the Association of Sugarcane Farmers in the central-northeastern region during the production year of 2012/13. An interview schedule was implemented for data collection in order to collect data from the 357 sample households. Data was analyzed by the proportion of households who cultivated both sugarcane and rice. Four groups of sugarcane farming households were identified, including households where the proportion between sugarcane and rice plantation was 100:0, 75:25, 50:50, and 25:75. The research results indicated that the impact of expanding the cultivated area on the food security of farming households in Khon Kaen province could be seen at different levels, depending on the proportion of the area for cultivation of sugarcane to rice. The sugarcane-farming households with the proportion between sugarcane and rice plantation of 25:75 had the highest food security ( =3.54) and the sugarcane-farming households with the proportion between sugarcane and rice plantation of 100:0 had the lowest food security ( =3.05). The study results suggested that the relevant agencies should support adequate food production in order to meet consumption requirements within the households. Promoting agricultural areas and resource management in farmland are considered to be necessary to enhance the food security of sugarcane farmers.

The experiment was carried out at the Experimental Farm, Department of Agricultural Technology, Mahasarakham University, Mahasarakham Province in the 2005 (February to April) for F1 offsprings and also at the Experimental Farm, Khon Kaen University, Khon Kaen Province, Northeast Thailand for F2 offsprings (July to October), i.e., four experiments were carried out, each location had two experiments. The research aimed to investigate inheritance characteristics of F1 and F2 offsprings derived from full diallele crosses of five cowpea cultivars (20 pairs of crosses) against a pathogenic disease of Pseudocercospora cruenta (Sacc,) Deighton. The first two experiments were carried out under field and glasshouse conditions at Mahasarakham University for F1 offsprings and the other two experiments were carried out at Khon Kaen University for F2 offsprings. A Chi square test method was used to justify dominant genes on the infection of the disease. The results showed that the cowpea plants of F1 and F2 offsprings gave only one pair of dominant gene that had its complete dominant effect over recessive gene of the cowpea offsprings.