Escala diagramática e influência de sistemas de produção na ocorrência do crestamento gomoso da melancia

CHAPTER 1 - The gummy stem blight, caused by the fungus D. bryoniae, is a disease commonly found in watermelon cultivated in several countries. In Brazil, there are numerous studies related to the disease, but there are not uniform methods for quantifying of disease severity in the field. Thus, we developed a diagrammatic scale based on scanned photos of watermelon leaves infected with D. bryoniae. The scale developed showed levels of 0; 10; 20; 45; 65 and 90% of severity. The scale validation was divided into two parts: initially, 10 evaluators (half with experienced and other half without experience) estimated the disease severity based on the initial observation of 100 photos of watermelon leaves with symptoms of the disease at different severity levels. Before, the same evaluators estimated the disease severity with the support of the scale prepared from the Quant program. Data were analyzed using linear regression and were obtained angular, linear, and correlation coefficients. Based on these data, we determined the accuracy and precision of the evaluations. The correlation coefficients (R2) ranged from 0.88 - 0.97 for the experienced evaluators and from 0.55 - 0.95 for the inexperienced evaluators. The average angular coefficient (A) for inexperienced evaluators was 20.42 and 8.61 with and without the support of diagrammatic scale, respectively. Experienced evaluators showed values of average linear coefficient of 5.30 and 1.68 with and without the support of diagrammatic scale, respectively. The absolute errors analysis indicated that the use of diagrammatic scale contributed to minimize the flaws in the severity levels estimation. The diagrammatic scale proposed shown adequate for gummy stem blight severity evaluation in watermelon. CHAPTER 2 - The gummy stem blight (Didymella bryoniae) is a disease that affects the productivity of watermelon leading to losses over 40%. This study aimed to evaluate the efficiency of different production systems in control of gummy stem blight in watermelon for to establish efficient methods to combat the disease. There were applied the following treatments: conventional tillage (T1), integrated management (T2) and organic management (T3). In T1 and T2 were applied mineral fertilization and T3 was used bovine manure. There was application of fungicides and insecticides in commercial dose in T1 and T2, being after soil chemical analysis in T2. Disease severity was assessed by grading scale. The experimental design was randomized blocks. The severity of gummy stem blight has increased substantially during the fruit formation. Watermelon plants grown with integrated management (T2) showed lower levels of disease severity, while plants in organic management (T3) exhibited higher levels of severity. We conclude that management based on judicious accompaniments in field represents best way to achieve the phytosanitary aspect adequate for cultivation of watermelon in Tocantins.

Influência das alturas iniciais de pasto diferido na recria de cordeiros sobre o desempenho na terminação em confinamento

The objective of this study was to evaluate the productive performance, metabolic and feeding behavior of sheep after ninety days deferred pasture at different heights. The experiment was conducted at Capim Branco experimental farm of the Universidade Federal de Uberlândia. During the period of 90 days, from June to September 2013, forty-eight crossbred lambs Santa Inês x Dorper, divided into groups of four animals, occupied twelve pickets deferred pasture with four initial heights (15 cm, 25 cm, 35 cm and 45 cm). During this period we evaluated the structural characteristics of pasture. For confinement, from September to December 2013, 32 of these animals were used (16 males and 16 females), divided into four bays, separated as pasture were using. The consumption was assessed daily, while biometric measurements were made every 21 days. In relation to gender, there were differences in average daily gain weight. Reviews of feeding behavior occurred at the beginning, middle and end of the experiment for 24 hours. The rumination and leisure activities do not present statistical differences, both initial height of pasture and by period. The time spent on intake was higher during the daytime both treatments starting height as the experimental periods, however, rumination activity was more intense at night. Blood glucose was achieved in five periods of the day, while other metabolites have been obtained with a collection made fortnightly. The different initial heights not promoted effects on blood glucose. The harvesting times were not affected. However, there was a reduction of basal blood glucose of animals throughout the experimental period. There was a significant interaction between the initial pasture heights and periods of evaluation of basal glucose. Cholesterol and triglyceride levels were below recommended levels, however the final phase of confinement cholesterol level increased significantly. The values of VLDL and GGT were above the reference range. FA and AST showed average values within the recommended values. Total protein was influenced by different initial heights of pasture. The creatinine and albumin had values below the recommended range. Moreover, the albumin decreased during the confinement time. Uric acid showed close to the recommended maximum. There was stabilization of compensatory growth, with modification of consumption and weight gain at 45 days of experiment.