To control or minimize aphid population you can use yellow sticky traps or spray insecticides with active ingredient of: methomyl (ex. Lannate), methiocarb (ex. Actara) and acephate (ex. Compete). The dosage and frequency of application is usually indicated on the label of each insecticide. We recommend that you do the spraying early in the morning or late in the afternoon to prevent chemical damage.
Here are some insecticides that can be used against fruitfly - dimethoate, fenthion and diazinon (these are active ingredients, any available brands can be used).
These insecticides can be used in combination with the following control measures - monitor the area regularly, maintain good field sanitation, wrap the fruits with newspaper or polyethelene sleeve and use of attractants (pheromones) to suppress male population of the adult fruitfly.
No. A virus can be held in undecomposed plant residue but it is not a problem once the residues have dried and are not attractive to aphids
Most viruses are not carried in the seed but a very small percentage of zucchini yellow mosaic virus is seed-borne. Squash mosaic virus is carried in the seed.
Preventing viruses from getting into the crop is the most important means of control. Once a plant is infected, there is no cure. Until the vines grow over the plastic, super reflective mulch works very well to discourage the aphids that carry the virus from landing in the crop. Oil sprays, either alone or in combination with insecticides, can help. The oil reduces the aphid's ability to pick up the virus and to pass it on.
Insecticides used alone will prevent a build-up of aphids and can reduce the spread of virus in the crop. However, they will not prevent the initial infection because the plant is infected as soon as the aphid feeds on it. It may take 30 minutes for the aphid to die after spraying, during which time it could infect several plants.
Use protectant fungicides until fruit sets then alternate a protectant fungicide with a systemic chemical, or mix a systemic with a protectant. Alternate between at least three groups of systemic fungicides for controlling powdery mildew to delay development of resistance to these chemicals.
Plough in old plantings immediately after final harvest. You must correctly calibrate spray equipment, including nozzles.
To control nematodes, apply a registered nematicide before planting. Soil fumigants will also control nematodes. In badly affected areas, a bare fallow for 12 months will greatly reduce numbers. Nematode control depends largely on crop rotation and improvement in levels of organic matter in the soil. This encourages the build-up of antagonistic organisms, which reduces the number of nematodes affecting your crop.
There are three major blights that can attack your tomatoes: Septoria leaf spot, early blight and late blight. All are fungal diseases spread by spores, which require dew or rain to infect the plant. These are most severe in wet weather. Septoria leaf spot, sometimes called Septoria blight, is caused by the fungus Septoria lycopersici and usually appears on the lower leaves after the first fruits set. Fruits are rarely infected. All the leaf loss reduces fruit yield and quality, and exposed fruits are more susceptible to sunscald. The fungus is spread by splashing water and by working among the plants when they are wet. It overwinters on tomato and weed refuse. Early blight, caused by the fungus Alternaria solani, appears on the lower leaves, usually after a heavy fruit set. The spots are dark brown to black. Concentric rings develop in the spot forming a bull’s eye. The leaf area around each target spot turns yellow, and soon the entire leaf turns yellow and drops. Early blight fungus also infects stems and may produce stem cankers. It occasionally attacks the fruit, producing large sunken black target spots on the stem end of the fruit. Infected fruits often drop before they mature. This disease is most common late in the growing season. The fungus overwinters on old tomato vines and on weeds in the nightshade family. Late blight, caused by the fungal-like organism Phytophthora infestans, occurs in moist weather with cool nights and moderately warm days. Dark-green to nearly black wet-looking spots begin spreading in from the leaf edge. In wet weather, the spots may have a downy, white growth on the lower leaf surface near the outer portion of the spot. Spots also develop on the fruits. At first, the spots are gray-green and water-soaked, but they soon enlarge and turn dark brown and firm, with a rough surface. When conditions are favorable, the disease may progress very rapidly. Avoid these diseases by rotating crops. Plant tomatoes in the same place only once in three or four years. Remove and destroy tomato vines in the fall. Plow or rototill to bury the remaining crop refuse. Use healthy transplants. Remove badly diseased lower leaves, as these are a source of leaf spot fungus spores that help spread the disease. Water at the base of the plants to avoid splashing water, which spreads the spores. Avoid watering with overhead sprinklers in late afternoon or evening. If the plants stay wet all night, leaf spot inThere are three major blights that can attack your tomatoes: Septoria leaf spot, early blight and late blight. All are fungal diseases spread by spores, which require dew or rain to infect the plant. These are most severe in wet weather. Septoria leaf spot, sometimes called Septoria blight, is caused by the fungus Septoria lycopersici and usually appears on the lower leaves after the first fruits set. Fruits are rarely infected. All the leaf loss reduces fruit yield and quality, and exposed fruits are more susceptible to sunscald. The fungus is spread by splashing water and by working among the plants when they are wet. It overwinters on tomato and weed refuse.
Early blight, caused by the fungus Alternaria solani, appears on the lower leaves, usually after a heavy fruit set. The spots are dark brown to black. Concentric rings develop in the spot forming a bull’s eye. The leaf area around each target spot turns yellow, and soon the entire leaf turns yellow and drops. Early blight fungus also infects stems and may produce stem cankers. It occasionally attacks the fruit, producing large sunken black target spots on the stem end of the fruit. Infected fruits often drop before they mature. This disease is most common late in the growing season. The fungus overwinters on old tomato vines and on weeds in the nightshade family.
Late blight, caused by the fungal-like organism Phytophthora infestans, occurs in moist weather with cool nights and moderately warm days. Dark-green to nearly black wet-looking spots begin spreading in from the leaf edge. In wet weather, the spots may have a downy, white growth on the lower leaf surface near the outer portion of the spot. Spots also develop on the fruits. At first, the spots are gray-green and water-soaked, but they soon enlarge and turn dark brown and firm, with a rough surface. When conditions are favorable, the disease may progress very rapidly.
Avoid these diseases by rotating crops. Plant tomatoes in the same place only once in three or four years. Remove and destroy tomato vines in the fall. Plow or rototill to bury the remaining crop refuse. Use healthy transplants. Remove badly diseased lower leaves, as these are a source of leaf spot fungus spores that help spread the disease.
Water at the base of the plants to avoid splashing water, which spreads the spores. Avoid watering with overhead sprinklers in late afternoon or evening. If the plants stay wet all night, leaf spot infections are likely to occur.
Use fungicides when needed. These diseases spread rapidly and are difficult to control once established. Fungicides must be applied before the disease first appears and reapplied throughout the growing season. Chlorothalonil fungicide, sold as Ortho Multi-Purpose Fungicide, can be applied up to the day of harvest. fections are likely to occur. Use fungicides when needed. These diseases spread rapidly and are difficult to control once established. Fungicides must be applied before the disease first appears and reapplied throughout the growing season. Chlorothalonil fungicide, sold as Ortho Multi-Purpose Fungicide, can be applied up to the day of harvest. -- Beverly Shaw, Advanced Master Gardener Purdue University
In most cases, the answer is no. The fungi, bacteria, viruses, and nematodes that cause disease in plants are very different from those that cause disease in humans and other animals. Eating or touching an infected plant would not infect us with the same pathogen that is making the plant sick.
However, produce from sick plants often has a flavor or texture very different from healthy produce, so eating it may not be desirable anyway. Unless the disease is merely a superficial spot (such as sooty blotch and flyspeck on an apple), it may be best to avoid diseased produce.
There are very few pathogens that can infect humans as well as plants, and those that do tend to be "opportunistic pathogens" of both, only able to infect weakened hosts. Perhaps the most notable of these pathogens is the bacterium Pseudomonas aeruginosa, which can cause a weak soft rot of plants such as lettuce. In people with compromised immune systems, this bacterium is known to infect the urinary tract, lungs, blood, and burns and other wounds. It is especially common in hospitalized patients whose immune systems are compromised by severe burns, cancer, AIDS, or cystic fibrosis. For most of us (and for most healthy plants), P. aeruginosa is not a concern.
Usually, the stems become very mushy, dark in colour and rotten. The lower leaves may also curl and wilt. Try touching the soil at the top of the pot, if it is constantly wet then you are definitely overwatering and would need to reduce watering.
