Other Phytophthora diseases in Hawaii / crops affected by other Phytophthora species. Plant-pathogenic species in the genus Phytophthora affect a wide range of important crops in Hawaii:

Integrated pest management practices (IPM):

• The most risky range of months to cultivate tomatoes in blight-prone areas in Hawaii is from November to April. Avoid winter plantings of tomato in areas where prolonged periods of cool, wet, humid weather tend to occur. The pathogen becomes inactive during dry periods. If one is unsure about the climate for a give area, one may check the "Hawaii climate summaries" link in the References to determine if the environment in a particular area tends to favor late blight disease development.
• Select a tomato variety that reaches maturity quickly (i.e., early-bearing or short-season types). This will allow the grower to get the crop harvested as soon as possible. "Early-season" tomato varieties require about 55-67 days to reach maturity; whereas "mid-season" and "late-season" varieties require from about 68-78 days and about 79-85+ days, respectively. 
• Grow tomatoes in glasshouses or in spaces where there is humidity control and the plants are covered and protected from rainfall.
• Ensure quick and vigorous tomato seedling growth though adequate and supplemental plant nutrition. Silicate-containing fertilizers may increase pest resistance, especially in the seedling stages.
• Early harvest. If your tomatoes are nearly full size (yet green) and there is a big storm coming and you can use green tomatoes, you might as well harvest them. 
• Stake up tomato plants, especially indeterminate types. Keep tomato stems and branches away from the ground. 
• Plant blight-resistant tomato varieties when they become available. Late blight-resistant tomatoes are difficult to breed and to find in seed catalogs, and they may not necessarily perform well at your location and may be very susceptible to other diseases. A search of seed company catalogs in February 2008 revealed only two tomato varieties with purported tolerance or resistance to late blight: 'Legend' (determinate, 65-68 days to harvest) and 'Juliet Hybrid' (indeterminate, 60 days to harvest).  
• Intercrop tomato with non-susceptible host plants, preferably non-solanaceous plants. 
• Disperse the tomato plants around the property and avoid planting them all together in one place. Use wide plant spacing to allow air ventilation of the tomato canopy, which allows wet plant surfaces to dry off most rapidly.
• Crop sanitation - inspect the plants regularly for late blight disease symptoms and promptly remove diseased material from the plot or garden (carefully detach diseased leaves, stems of fruits and destroy them).  
• Eliminate cull piles in the vicinity of tomato plantings.
• Use disease-free tomato transplants; inspect seedlings for symptoms and destroy diseased plants promptly.  Protect seedlings with fungicide sprays before transplanting. 
• Destroy volunteer tomato plants.
• Avoid moving through the tomato garden or field when plant foliage is wet. 
• Crop rotation - avoid successive crops of tomatoes in the same location. Avoid planting a new crop of tomatoes beside a diseased crop.
• Do not plant potatoes (S. tuberosum) near tomatoes, or if potatoes are planted, use a blight-resistant variety. 
• The plant row orientation should be parallel to the prevailing winds to allow breezes to move between plant rows, which allows more rapid drying of foliage and reduced relative humidity in the plant canopy. 
• Irrigation timing - water plants early in day, rather than late in the day. This allows foliage and soil to dry out before evening, lessening the duration of leaf wetness and lowering relative humidity. 
• Irrigation method - do not spray foliage with water; keep water off of leaves and stems (irrigate plants at ground level rather than overhead, except for foliar feeding).
• Weed control - control solanaceous weeds around the tomato garden.
• Where possible, apply fungicides on the basis of a weather-based disease forecasting system (see below) rather than on a calendar basis.
• Large growers may decide to use a preventive fungicide spray regime, applying products on a calendar basis. It is best to rotate different products to avoid fungicide resistance.
• Other growers may apply fungicides as soon as symptoms are observed.
• Do not purchase diseased tomato seedlings - inspect them for symptoms first.
• Protect seedlings from nutritional stress and other pests. Potassium silicate fertilizer can help to grow seedlings that are more resistant to fungal diseases and some insect pests.