Recent advances in personal computer hardware and the rapid development of spatial analysis software that is user-friendly on PC's has provided remarkable new tools for the analysts of plant diseases, particularly ecologically complex virus diseases. Due to the complexity of the disease cycle of the animal-vectored plant virus, these diseases present the most interesting challenges for the application of spatial analysis technology. While traditional quantitative analysis of plant diseases concentrated on within-field spatial analysis, often involving rather arcane mathematical descriptions of pattern, the new spatial analysis tools are most useful at the dimension where many disease epidemics occur, the regional level. The output of many of the programs used in spatial analysis is a highly visual picture of a disease epidemic which has a strong intuitive appeal to managers of agricultural enterprises. Applications by us, thus far, have included tomato, pepper and cotton virus diseases in Arizona. Mexico, California and Pakistan. In addition, this technology has been applied by us to Phytophthora infestans in potato and tomato. Aspergillus flavus in cotton, and regional insect problems of tomato and cotton.

In reduced tillage and no-tillage production systems, crop debris is left undisturbed on the surface of the ground. This debris often harbors plant pathogens that may incite plant diseases. This survey was conducted to identify fungi associated with intact senescent cotton (Gossypium hirsutum) root systems in no-tillage production systems. Root systems were collected from Burke (southeast), Floyd (northwest), and Tift (southwest) counties in Georgia over 2 yr. Tissue sections (1 cm) of primary and secondary roots were assayed to determine mycobiota diversity monthly from December through April of 1994-1995 and 1995-1996. Forty genera of fungi were isolated including Alternaria, Chaetomium, Curvularia, Melanospora, and Trichoderma. Among the fungi isolated were several common boll rot pathogens, including Lasiodiplodia, Pestalotia, and Phoma. Mean isolation frequency for total fungi identified in 1995 was 8.8% on the primary roots to 8.1% on the secondary roots. In 1996, mean isolation frequency for total fungi was 14.8% from primary roots and 14% from secondary roots. Isolation frequencies of the important cotton seedling disease fungi Rhizoctonia solani AG-4 and Pythium spp. were low throughout the study, but these fungi were present in the roots collected just prior to cotton planting in April of both years. Fusarium oxysporum, responsible for seedling disease and wilt of mature plants, was routinely isolated from the root tissues throughout the sampling period. Pathogenicity tests of 30 isolates of F. oxysporum collected from the roots in 1995 and 60 isolates from 1996 were conducted on cotton seedlings in the greenhouse. Of the F. oxysporum isolates tested, 91.0% were pathogenic, and 13.5% and 15.7% of the isolates caused seedling death in greenhouse trials conducted in 1995 and 1996, respectively. Injury caused by the F. oxysporum isolates included cotyledon or leaf lesions, root tissue necrosis, and tap root pruning. Isolation frequency of F. oxysporum for all sites was greater than those for any other fungi identified during both years of the study. These results demonstrate that seedling disease and boll rot pathogens overwinter on intact senescent roots.

As part of a public health campaign in Egypt, various chemical parameters of oil which are considered good indices in assessing the degree of thermal abuse, oxidation and overall quality (acid values, iodine values, peroxide values, etc.) were studied with respect to different frying oils. Ingestion of decomposition products formed as a results of thermal abuse and oxidation of frying oils are known to lead to a variety of symptoms and diseases (allergies, atherosclerosis, coronary heart disease). Results show that the oil most commonly used by street vendors in Egypt (blend of cotton seed and sunflower oil) is the least suitable for frying, while palm oil on the basis of the various chemical parameters studied, is the ideal choice. However, from the nutritional and public health stand point, the use of saturated oils is to be discouraged. Corn oil is therefore the next best choice from both the chemical and nutritional stand point, and is recommended for public use in a country in which deep-fried vegetable patties (‘fallafel’) forms the staple food item in the diet.

Este trabajo de tesis fue llevado a cabo en el ámbito de la Estación Experimental Agropecuaria "El Porvenir"; en el valle del Bajo Mayo. Provincia y Región San Martín (Perú), geográficamente caracterizada por presentar las coordenadas siguientes: longitud Oeste con 76º26", 06º34" de latitud Sur y 356 metros sobre el nivel del mar, con el objetivo de determinar uno o más variedades superiores en rendimiento y características adaptables a las condiciones de nuestra zona y realizar el análisis económico de los mejores tratamientos. El trabajo fue realizado en el mes de mayo de 1994 a enero de 1995. Se evaluaron días a la emergencia, aparición de la cuarta hoja verdadera, datos relativos a la planta forma de hoja, diámetro de copa y tallo, caracterización de producción y precocidad, fases de crecimiento y desarrollo, característica de fibra y semilla, rendimiento y reacción a plagas y enfermedades en algodones ásperos, empleando el diseño estadístico Bloque Completo Randomizado (BCR) con ocho tratamientos y cuatro repeticiones, cuyos resultados fueron analizados mediante el análisis de varianza y la prueba múltiple de Duncan. El suelo experimental fue de origen residual de superficie plana y mecanizada, con textura arcilla arenosa de reacción ligeramente básica (ph 7.3) contenido de materia orgánica (4.2%) nitrógeno total medio (0.18%), fósforo (5.4%) y potasio normal (206.7 ppm). El distanciamiento de siembra fue el 1.00 m entre golpes depositando de 5-8 semillas por golpe y 1.50 m entre surcos en terreno húmedo. El abonamiento no fue necesario por que anteriormente se sembró caupi en el terreno donde se sembró el algodón y recibiendo una precipitación promedio durante el período vegetativo de 106.4 mm y T° media de 254° C. De los resultados obtenidos de acuerdo al análisis estadístico se concluye que existió diferencias estadística con los tratamientos en el rendimiento de algodón en rama, debido a las diferencias que han interaccionado con el medio ecológico cuyos rendimientos fluctuaron entre 1461.39 y 822.78 kg/ha que corresponde a los tratamientos T8 (ASPERO FIBRA PARIO CLARO) y T6 (8852-2 AP) el mayor y menor respectivamente. Los tratamientos T8 (ASPERO FIBRA PARIO CLARO) T1 (PS-2 SUB PIMA-2) y T4 (FIBRA AMARILLENTA) generalmente por su mayor habilidad en rendimiento solamente el tratamiento T8 superó a los demás tratamientos. De acuerdo a la relación beneficio/costo se determinó valor deficitario para los cuatro mejores tratamientos debido al alto costo de producción. | This dissertation was carried out in the field of the Experimental Agricultural Station "El Porvenir"; In the valley of the Low May. Province and Region of San Martin (Peru), geographically characterized by the following coordinates: West length with 76º26 ", 06º34" south latitude and 356 meters above sea level, with the objective of determining one or more superior varieties in performance and Characteristics adaptable to the conditions of our area and perform the economic analysis of the best treatments. The work was carried out in the month of May of 1994 to January of 1995. The occurrence of the fourth true leaf, data on the plant leaf form, crown and stem diameter, production and precocity characterization, growth and development phases, fiber and seed characteristics, yield and reaction were evaluated. To pests and diseases in rough cottons, using the statistical design Complete Block Randomized (BCR) with eight treatments and four replicates, whose results were analyzed through the analysis of variance and the multiple test of Duncan. The experimental soil was of residual origin with a flat and mechanized surface, with texture clay slightly reactive sandy (pH 7.3) organic matter content (4.2%) average total nitrogen (0.18%), phosphorus (5.4%) and normal potassium 206.7 ppm). The sowing spacing was 1.00 m between shocks depositing 5-8 seeds per blow and 1.50 m between furrows in moist soil. The fertilization was not necessary because previously cowpeas were planted in the soil where the cotton was planted and receiving an average rainfall during the vegetative period of 106.4 mm and average t ° of 254 ° C. From the results obtained according to the statistical analysis it is concluded that there were statistical differences with the treatments in the yield of cotton in branch, due to the differences that have interacted with the ecological medium whose yields fluctuated between 1461.39 and 822.78 kg / ha corresponding to The treatments T8 (ASPERO FIBER PARIO CLEAR) and T6 (8852-2 AP) the major and minor respectively. The treatments T8 (ASPERO FIBER PARIO CLEAR) T1 (PS-2 SUB PIMA-2) and T4 (YELLOW FIBER) generally for their greater ability in performance only the treatment T8 surpassed to the other treatments. According to the benefit / cost ratio a deficit value was determined for the four best treatments due to the high cost of production.