Natural Pest and Disease Control:
The following information is all about Natural Pest and Disease Control Methods in Agriculture Crops.
Plants like any other living organism are susceptible to diseases. Occurrence of a disease in a plant is a condition when the natural structure and function is disturbed by external factors like pathogens and environmental conditions. Plant species are affected by numerous types of diseases and the factors responsible for these diseases are all different. Diseases may occur in any part of the plant such as root, stem, leaf, flower and fruit. While diseases grow within the plant, the external conditions like rain, wind, water, soil facilitate the spread of the disease to the neighbouring plant. Seasons and weather conditions are also responsible for the growth and spread of diseases in plants. Therefore care must be taken to control the occurrence of the disease or use of proper natural compounds should be made to arrest the spread of the disease. Apart from these factors there could also be pests such as microscopic insects which feed on the plant material and cause damage.
COMMON DISEASES IN PLANTS AND TREES:
Natural Pest and Disease Control – BLIGHTS: it is a condition in plants when the leaves and branches stop growing, die and wither off. Later the entire plant may rot. There are different types of blights affecting the plants.
- This is generally seen in plants/ trees like apple, pear, rose and fruit trees.
- Tips of the branches are affected first and then the disease moves to the stems.
- The soft young newly grown area is infected first. Leaves and branches turn brown and black, the bark of the tree develops water soaked lesions in red colour.
- The disease is spread by rain, insects and dew. Warm moist weather worsens the condition during plant bloom. The entire plant is destroyed slowly.
- Excess use of nitrogen fertilizer should be avoided. The infected branches or parts can be pruned and burnt.
- Baking soda and apple cider vinegar in diluted form when sprayed on the plants can control the spread of the disease.
EARLY BLIGHT (alternaria blight)
- Observed in plants like tomato, potato, peppers and other ornamental plants.
- Is recognised by the development of black and brown spots which enlarge into concentric rings.
- Lower leaves are affected first. This is spread by dust and air
- Disposing infected plants and doing crop rotation for 3 years is helpful.
- Compost tea and baking soda spray can help control the disease.
LATE BLIGHT (phytophthora blight)
- The plants infected are lilacs, rhododendrons, azaleas etc.
- Water soaked spots on lower leaves is a symptom of this disease. The tubers are penetrated by dark coloured blotches. The plants rot in the wet season.
- Planting in well drained soil is helpful. The spray of compost tea can prevent the disease.
- Baking soda and apple cider vinegar sprays are used to arrest the spread of the disease.
Natural Pest and Disease Control – CANKERS: it is condition where the wooden stem is affected by developing cracks or dead abnormal tissues. Some trees ooze and this can be clearly noticed. Treating the cut area with methylated spirit can prevent cankers.
- Cherry and plum trees are most affected.
- Gum like or water soaked lesions indicate the disease on the plants. The oozing area may smell sour. The bark or area affected becomes moist and turns reddish brown or black.
- The disease starts when there is cut or wound on the tree trunk. It is mostly developed in winter or early spring season and spreads with rain or water.
- Pruning should be avoided during spring. Organocide diluted in water can be sprayed on pruned and wounded areas to help prevent the disease.
- Poplars, spruces and stone fruits are mainly affected.
- They appear as discoloured circular areas on the bark of trees.
- The resistance of the tree is developed by removing the cankered area.
- Vines, shrubs and hardwood trees are affected.
- It can be detected by the presence of sunken areas on the bark with small spore structures pink in colour.
- Removing diseased branches is helpful in preventing the disease.
Natural Pest and Disease Control – ROTS: it is a condition where the parts of a plant or tree decay. It can be soft and moist or hard and dry. The bacteria and fungi which cause rotting remain active in fruits, tubers and bulbs.
BLOSSOM END ROT
- Caused due to uneven watering and calcium deficiency in plants. Appears as water-soaked area which develops into brown wide sunken area in the bottom of the fruit or vegetable.
- This disease doesn’t spread from plant to plant.
- Spraying kelp, applying organic foliar (seaweed extract), adding gypsum to soil before planting can help prevent the condition.
- The affected parts turn brown and soft in case of stone fruits and with grapes the infected with rot become black and hard.
- Removing infected area, pruning to make air movement easy can control the rot. Compost tea sprays can be effective.
- Horseradish spray can control the disease
- Observed by the presence of red spots on leaves and twigs.
- Caused due to less photosynthetic activity and defoliation which starts at the lower parts of the plant or tree.
ROOT AND STEM ROT
- Providing proper drainage and air circulation, soil drenching with beneficial bacteria and fungi, disposing all infected plant material and sterilizing the cut parts have to be practices to overcome this problem.
Natural Pest and Disease Control – RUSTS: these are fungal diseases. It can be identified as powdery tan or rust coloured coating. Mostly the disease needs two plant species to complete the cycle.
- Brown and red colour of the small twigs and needles indicate the disease. The rust that develops is spread by wind to other plants.
- Allowing air circulation, planting resistant cultivars, removing and burning the infected parts can help solve the problem.
- Garlic and corn spray can stop the infections.
Other forms of rust are apple cedar rust, white pine blister and wheat rust. The secondary host plant can be removed to control the disease.
Natural Pest and Disease Control- WILTS: lack of water is main reason for plants to wilt. Permanent wilting occurs when the bacteria blocks the water conducting system of the plant. It resembles blights.
- Occurs mainly in sweet corn plants. Bacterial slime oozes out when the leaves or stalks are cut. Plant growth is stunted or plants die.
- Resistant cultivars can be used to eradicate the problem.
FUSARIUM WILT AND VERTICILLIUM WILT
- Flowers, fruits, vegetables etc are affected by the fungi. Plants turn yellow and wilt.
- Crop rotation and destroying the infected parts can eliminate the problem.
- Spraying hydrogen peroxide can control the disease.
Natural Pest and Disease Control – OTHER DISEASES:
- Infection is indicated by the dark water soaked lesions on stems and leaves. Pink gelatinous mass of spores is found in the center of the lesions.
- It spreads very fast by the help of wind, rain, insects and garden tools. Moisture can worsen the situation.
- Spraying neem oil for killing the insects and fungus is a preventive measure to stop the disease.
- Disinfecting the garden tools can also serve as an option.
- Occurs in apples and crab apples affecting both leaves and fruits.
- Disease is indicated by pale yellow or olive green spots over the leaves and dark velvety spots under the leaf. The leaves sometimes get twisted. Sunken tan spots with velvety spores in the center become wider and turn brown which indicates the severity of the infection.
- Fruits get distorted or may drop when young.
- Disease spreads in cool wet weather by wind, rain, soil etc. The tender leaves of the tree during winter are more susceptible to the infection.
- Spreading the compost under the trees and preventing splash dispersal of the fungus is effective to control the disease.
- Irrigating the plant in the morning or early hours helps the leaves to dry, so that infection occurrence is lower.
- Destroying the infected leaves reduces fungal spores thereby reducing the spread of disease.
- Chive spray can also prevent the disease.
- Crops like cabbage, broccoli, cauliflower etc. are most affected.
- This soil fungus infects the root hair by damaging the roots and causing them to swell, crack, deform and finally rot. Due to this condition the plants cannot absorb water and nutrients.
- Growth is slow in plants and they turn yellow, purple or brown.
- Wind, water and gardening tools can help in spreading the disease. The fungal spores remain in the soil for approximately 10 years.
- Infected plants can be removed, garden can be maintained clean and crop rotation can be practiced to control the disease.
- Soil solarisatione. covering the soil with a plastic tarp and allowing it to get exposed to sun for 4 to 6 weeks during hottest days can eliminate all the infections in the soil.
- Adjusting the soil pH to 6.8 can also be a solution to this problem.
- Occurs in seeds and new seedlings. The stem and the root tissues rot at the soil surface.
- Deep planting, high humidity, planting seeds in cold wet soil with poor drainage can all cause damping off.
- Fungal spores remain in the soil and get carried by the gardening tools.
- Seedlings should be planted so that there is proper air circulation. Overcrowding of the seeds should be avoided.
- Adding compost to the soil also helps reduce the problem.
- Chamomile oil spray is a good preventive measure.
- Sprinkling cinnamon can prevent damping off.
- Indicated by the yellow and white patches on the surface of the older leaves. The inner side of the leaf is white with cotton like fungi.
- The leaves eventually turn brown and crisp and wither off. Occurs in cold moist weather and is spread by insects, wind, rain and garden equipment.
- Pruning, watering the plants in the morning, destroying the infected plants and maintaining the infected plant area clean can all help to reduce the problem.
- Milk spray can control mildew problems.
- Occurs in rose, grape, floral and vegetative plants.
- It is indicated by the swelling in the mass of an abnormal tissue. It is caused by bacteria, fungi and insects. Galls have rough surface and corky tissue.
- Roots, stems, branches, graft union can all be affected.
- Removing the destroyed plants, disinfecting the tools, avoiding wounded stems can reduce the occurrence of the disease.
- Occurs in peach and nectarine trees.
- Red areas on tender growing leaves are a symptom of the disease. The leaves curl and distort which in turn reduces the fruit production.
- Wet and cold weather can cause the spores to infect new leaves and these spores can be carried from tree to tree by wind or rain.
- Organic compounds rich in nitrogen can be used as a solution to the problem.
- Destroy the infected plants and spraying dormant oil before bud growth can reduce the problem.
- This disease is indicated by black spots on leaves which are encircled by yellow ring of fungus. They wilt slowly and fall off.
- This disease commonly occurs in rose and mango plants.
- They spread by wind or water splash from leaf to leaf.
- Neem oil spray can be used for treating black spots. Another alternate solution to the problem is spraying baking soda diluted in water.
- This appears as gray colour soft mushy spots on different part of a plant. Fungal spores cover the spots.
- It is found at the soil surface or near the dense part of the plant canopy. The disease spread from wilted flowers to the rest of the plant parts.
- Stored fruits and vegetables can also be affected. Spores travel by wind or water and spread the disease during cool humid temperatures. Plant cuts are more susceptible to infection.
- Pruning the plants and allowing proper air circulation can a solution to the problem. Alternatively using a organic compost or mulch can prevent the splashing of spores. Watering the plants during day and keeping the plant area free from infected parts can also help eliminate the problem.
- This disease occurs due to low soil moisture and high humidity. Raised blisters with curling leaves are a symptom of this disease. A white powdery substance is developed on the infected leaves.
- Tender leaves are easily affected. Spores of the fungi spread through wind, water and insects.
- Mostly occurs in cucumbers, squash, pumpkins, tomatoes, roses etc.
- Pruning, using resistant cultivars, mulching or using organic compost, neem oil use at an interval of 7 days can help solve the problem.
- SNS 244 and zero tolerance herbal fungicide are two compounds made of food grade materials which fight against the fungi and resist the spread of infection.
- Brown pithy patches like warts are the symptom of the disease. Mainly occurs in potato.
- The bacteria spreads in alkaline soil conditions is transmitted through tubers, wind and water.
- Crop rotation, decreasing the soil pH levels, increasing the calcium content of soil and providing adequate irrigation without over watering can help treat the problem.
- Mostly seen in plants such as grasses, corn etc.
- This fungal infection is recognised by the enlarged galls which are soft, spongy and dark in colour. Powdery mass is formed as the disease ages.
- Spores travel through air, water and wind to infect new plants.
- Removing the infected area and destroying it can help solve the problem. Cuts and injured roots should be properly treated. Practicing crop rotation can also be a solution to the problem.
- This can be recognised as ringed spots on the leaves and stunts the growth of plants. May also appear as curled or wrinkled leaves, yellow veins, infected or warty fruit.
- Crops like bean, tobacco, tomato, potato, peppers etc. are affected.
- This is mainly spread by insects.
- Safer soap, Bon-neem and diatomaceous earth are some natural products which can treat the infection. And other general methods like destroying the affected areas, disinfecting the tools, proper weeding, use of resistant plant varieties can all solve the virus problem in plants.
Natural Pest and Disease Control – PLANT PESTS:
Natural Pest and Disease Control – APHIDS
- These soft bodied insects have different colours like green, yellow, brown, red or black. They are small and have two whip-like antennae.
- These insects can transmit diseases in plants and cause leaf curl, wilting and stunted growth. The sticky fluid produced by the insects attracts ants and produces a black soot mold on the leaves.
- Bug blasters, diatomaceous earth, safer soap, bon-neem and other horticulture oils can be used to get rid of the pests.
- High nitrogen content should be avoided to keep the pests away.
Natural Pest and Disease Control – CUTWORMS
- They are brown or grey in colour and fly at night. The caterpillars of this pest are found in few inches of the soil and may be green, yellow, brown or grey.
- Mostly tomatoes, broccoli, kale, cabbage etc are more susceptible to this pest.
- The worms feed on the seedling and chew the outer stem tissue.
- They can be trapped with cornmeal or wheat bran sunken bowls.
- Adding beneficial nematodes mixed with water to the soil can control the cutworms.
Natural Pest and Disease Control – FLEA BEETLES
- These insects are 1/10” long and are either black or brown in colour. They move quickly and hop.
- These insects feed on plants like the radish, potato, tomato, corn and eggplants.
- They damage the crop by making holes in the foliage. The larvae of the insect feed on the roots of the plants.
- Crop rotation, use of yellow sticky cards can control the beetles.
- Beneficial nematodes control the larvae growth and substances like garlic oil, hot pepper wax, neem, kaolin clay control the adult beetles.
Natural Pest and Disease Control – SLUGS AND SNAILS
- They are not insects, they are molluscs found in different colours such as grey, brown, orange or black.
- They feed on seedlings leaving irregular holes in the leaves. They ruin the crop in the night or during the rainy season.
- Encouraging birds, frogs, toads etc can keep the snail and slugs away.
- Handpicking and dropping the slugs into the soapy water can be a preventive measure.
- Iron phosphate activated slug baits can help trap the pests.
Natural Pest and Disease Control – SQUASH VINE BORERS
- These insects are red or black in colour and look like wasps.
- The caterpillars are found at the base of the vines.
- The plants related to the cucumber family are mostly affected by this insect such as the pumpkins, squash, melons etc.
- Wrapping a strip of aluminium foil at the base of the plant can protect the plant from egg-laying females.
- Covering the plants with floating row cover, injecting bacillus thuringiensis into the infected area and spraying insecticidal soap on the stem can control the spread of borers.
Natural Pest and Disease Control – LEAFMINOR
- Larvae stage of an insect which feeds on the upper leaf surface. They are recognised as gray flies with yellow stripes and transparent wings.
- Plants such as lettuce, cabbage, peppers, citrus fruits etc. get affected.
- These pests tunnel through the leaves and damage them.
- Harvest guard, organic fertilizers, compost and safer bio neem and some soil amendments can help control the leaf minor.
Natural Pest and Disease Control – ROOT MAGGOT
- These pests are dark gray flies which tunnel through the soil and feed on the root of plants.
- Plants like cabbage, carrot, turnip etc are mostly affected.
- Covering seed beds with floating row cover, applying diatomaceous earth and placing heavy paper collars as the base of the transplant can help solve the problem.
Natural Pest and Disease Control – APPLE MAGGOT
- Fruit bearing trees are mostly affected such as plum, apricot, pear, cherry etc.
- This pest looks smaller than a house fly and has a black band W on its transparent wings.
- They develop in the soil and start feeding on the plants in spring. They lay eggs in under the fruit skin which tunnel through the fruit as they grow. A fully grown maggot leaves the fruit and enters the soil.
- Red sphere traps can be used to capture the pests and reduce the damage.
Natural Pest and Disease Control – SPIDER MITE
- They are oval shaped reddish brown in colour. Very tiny in size of about 1/50 of an inch.
- They live under the leaf and feed on the plant fluids. The sucking of sap from the leaves is seen as light dots which results in drying up of the leaf and eventually falls off. They are common during the dry hot season.
- Plants like the strawberry, melon, bean, tomato etc are all affected. They spread or travel through wind.
- Mixing neem oil with coco-wet and applying it every 3 to 5 days can keep the pest away. Nuke Em an organic compound can also be used for pest control. Pruning the leaves or the infected areas and destroying the can eliminate the problem.
Natural Pest and Disease Control – WHITEFLY
- It is a white powdery winged moth like insect with small antenna.
- Found on the top of plants or on the end of stems. The pest damages the plant by sucking the fluids from it thereby causing stunted growth and yellowing of the leaf. Sometimes leaves become sticky and develop a black sooty mold.
- Generally attacks plants like grape, cucumber, potato, hibiscus etc.
- Yellow sticky traps, bug blaster, safer soap, organic neem oil and other horticultural oils can help is destroying the pests.
Diagnosis is the first step in Disease management and pest control mechanism. Correct identification of the disease and pest is highly recommended. Preventing a disease from occurring is not always possible so the best way to handle a disease is to avoid it using different organic and natural methods so that there is no risk of health hazards associated with the consumption of the produce. The general and the most basic way to manage disease and pests in the garden or farm is to maintain proper sanitation.