Diseases fruit

Occurrence of Phytophthora palmivora on Diseased Fruits, Servicio Tec-nico Agricola de Nicaragua, September 1953. 

Remove damaged and diseased fruit shoots, and foliage. 

Pick off diseased fruit and foliage as seen. Powdery mildew symptoms on leaves are more likely in dry weather. Use a drip or soaker hose watering system to avoid wetting the foliage. 

What to do Prune out affected branches and remove fruit from the tree. Pick up windfalls. Do not compost any of this material. Take care not to damage fruit that is to be stored. Do not store any diseased fruit. Prune out cankers and diseased spurs. 

This fungal disease is spread by wind and rain-splash, and enters the plant through cracks in the bark, leaf scars or pruning cuts. Diseased fruit left on trees can also be a source of infection. 

Webb, A. D., in Phenolics in Normal and Diseased Fruits and Vegetables, ... 

Many disease and insect problems can be controlled or greatly reduced by simple sanitation. Clean up and dispose of branches after you prune, especially when removing diseased wood. Many insects pupate in the soil or in loose bark or dead plant debris. Fbr this reason, rake and remove fallen leaves in fall. Also remove dropped fruit during the season and dry, diseased fruit (known as mummies) clinging to the branches after harvest. Inspecting bark in the winter and removing and destroying egg masses is also effective. 

Corse, J. (1964). Enzymatic browning of fruits and vegetables. In Phenolics in Normal and Disease Fruits and Vegetables. (V.C. Runeckles, ed.). p.41. Pergamon Press, New York. 

Scurvy results from a dietary vitamin C deficiency and involves the inability to form collagen fibrils properly. This is the result of reduced activity of prolyl hydroxylase, which is vitamin C-dependent, as previously noted. Scurvy leads to lesions in the skin and blood vessels, and, in its advanced stages, it can lead to grotesque disfiguration and eventual death. Although rare in the modern world, it was a disease well known to sea-faring explorers in earlier times who did not appreciate the importance of fresh fruits and vegetables in the diet. 

The general recommendations on energy and fat intake are similar to those for the avoidance of heart disease. However, the recommendation to consume a variety of fruits and vegetables is based partly on the putative presence of diverse protective factors in plant foods. This concept does provide, at least in principle, a rationale for the functional health benefits of plant foods beyond the simple provision of nutrients at a level that prevents symptoms of deficiency. 

Vitamin C occurs as L-ascorbic acid and dihydroascorbic acid in fruits, vegetables and potatoes, as well as in processed foods to which it has been added as an antioxidant. The only wholly undisputed function of vitamin C is the prevention of scurvy. Although this is the physiological rationale for the currently recommended intake levels, there is growing evidence that vitamin C may provide additional protective effects against other diseases including cancer, and the recommended dietary allowance (RDA) may be increased in the near future. Scurvy develops in adults whose habitual intake of vitamin C falls below 1 mg/d, and under experimental conditions 10 mg/d is sufficient to prevent or alleviate symptoms (Bartley et al., 1953). The RDA is 60 mg per day in the USA, but plasma levels of ascorbate do not achieve saturation until daily intakes reach around 100 mg (Bates et al., 1979). Most of the ascorbate in human diets is derived from natural sources, and consumers who eat five portions, or about 400-500 g, of fruits and vegetables per day could obtain as much as 200 mg of ascorbate. 

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