How to control Pests and Diseases in Organic Home Garden

Organic Home Gardening is most relaxing and entertaining hobby that provides health, wealth and happiness to family members. Organic farming in home gardens is most preferred production management system involving active participation by the family members in the growing of plants.

It promotes and enhances biodiversity and soil biological activities that maintain, restore, and enhance harmony in the ecological system. It is gaining popularity due to increased health consciousness by consumers, support from the government and high income generation to family. Since it is labour-intensive and all family members joyfully work together, this hobby provides a good physical exercise, improves the emotional bonding between the family members and keeps their body and mind fit, healthy and happy.

Home gardening ranges from very specialized, growing with only one type of plant or involves multiple cropping, by planting different types of shrubs, trees, herbaceous plants, lawn grasses, mushrooms, container gardening, to graceful, fragrant and easy to grow fruit trees, ornamental plants, medicinal and vegetable crops. These selected crops are cultivated for flowers, fragrance, aesthetics, home remedies, or for consumption.

Among other production problems, several pests and diseases cause huge damage by directly reducing yields or by deteriorating the physical appearance, quality, nutritive and market value by sucking, chewing or boring into different plant parts causing holes, cracks, disease spots or rotting in ornamental plants, fruits or vegetables. Alternative bio-control inputs to synthetic chemicals for controlling crop pests and diseases are now available. The mechanisms of bio control mainly include antibiosis, competition, myco-parasitism, cell wall degrading enzymes, and induced resistance.Pest and disease management practices in organic home gardens consist of a range of long-term activities that support each other and aim at preventing pests and disease attack by keeping existing pest populations and diseases low. Control, on the other hand, is a short-term activity and focuses on killing pests and pathogens. Knowledge of what method to use, time of its use and how much to use to reduce pest and disease incidence without compromising the crop yield and quality is essential.

Management practices

Pests can be avoided by selecting a site that is ideal for the crop and natural enemies of the pest but unfavourable for the pest itself.

Using local varieties that are tolerant to local environmental conditions will ensure healthy growth.

Straw mulches applied to soil reduce soil temperature, improve water holding capacity and reduce aphid infestation and viral infection.

Practices like removal of dead branches, leaves and infected wood, fruit and other plant tissue can reduce the severity of pest problems.

Plant variety, density, canopy structure and extent of pruning in southern growing regions should be considered to avoid fungal attack.

Plants grown in overly wet conditions are constant source for new outbreaks pest or disease and reduce yields drastically.

A regular monitoring and timely intervention are important for effective pest and disease management.

Diseases like mildew, anthracnose and leaf spot diseases can be regulated with sulphur or copper preparations, which are permitted and must be adhered to in organic cultivation.

Ecological engineering approaches

Cowpea, carrot, buckwheat, French bean, cluster bean, dandelion, maize, mustard, anise, tansy, caraway, dill, yarrow, zinnia, clover, alfalfa, parsley, cosmos, sunflower, chrysanthemum and marigold are flowering crops that attract the native wasp populations and provide good habitats for them. Growing these crops as border crops or trap crops can help in reducing the pest incidence in home gardens.

Biodiversity by planting windbreaks and shelterbelts helps in increasing parasitoids and predators’ number due to availability of nectar, pollen and insects.

Avoid clean cultivation by removing all weeds such as Tridax procumbens, Ageratum sp, Alternanthera sp. etc as they act as nectar source for natural enemies.

Cover crops of Brassicaceae family possess large quantities of glucosinolates, a sulphur compound that inhibits the development of soil borne pests and diseases through bio-fumigation.

Planting turmeric, garlic, marigold, chrysanthemum as intercrops can help to reduce soil borne pests and diseases.

Physical methods

Light traps effectively and efficiently trap different moth species such as armyworms, cutworms, stem borers and other night flying insects particularly when these are planted before the egg laying stage. Use of solar energy to kindle light traps can reduce cost and add Eco practices in garden. Embedded sensors automatically protect from rain, control light, relative humidity and can automatically switch on the lights in the evening and turn off in the morning.

Water traps are useful for trapping thrips, leaf miners and aphids.
Sex pheromones effectively disrupt the mating behavior of various lepidopteran pests. Hanging pheromone traps containing methyl eugenol among mango and guava fruit trees help in catching fruit flies and other pests.
Fruit bags prevents fruit flies from laying insects on fruits and helps to minimize physical injuries like latex burns, fungal spots, scratching and scaring and improves quality and productivity of fruits from an organic home garden.
Wrapping a slippery plastic band around each tree in the lower trunk region will restrict the movement of the emerging mealy bugs from soil up the trunk to branches, floral parts and growing fruits.
Migration of weevils to branches for egg laying can be reduced by tying sticky band. Kaolin clay impedes insect movement, feeding and egg laying capacity and controls aphids and other sucking pests and diseases.

Botanicals

Several of the plant oils and their constituents like neem oil and essential oils exhibit remarkable toxicity both as contact or fumigant to a large number of economically important pathogenic fungi, insect pests and mites. Triterpenoid, steroid and saponins present in different parts like leaves, stems, roots, bark and flowers of many plants are non-volatile, surface-active compounds, well tested against several insect pests like aphids, beetles, weevils, leafhoppers, worms, moths and several pathogens for their antimicrobial, antioxidant, insecticidal, nematicidal and molluscicidal activities.

Steroid saponins present in eggplant, peppers, tomato, potato, oats, garlic, onion, leek, alfalfa, alliums, fenugreek, yam, yucca, ginseng, soybean, chickpea and asparagus, triterpenoid saponins common in legumes, chenopods, spinach, sugar beet, liquorice, sunflower, horse chestnut, soapbark tree, sarsaparilla, quinoa and tea and saponins stored in the roots act as phytoprotectant against soil-borne microbes.
Soil application of neem cake or datura, calotropis and neem plant extracts help in killing eggs and larval stages of soil borne pests, termites, nematodesand pathogens.
Foliar spray with pyrethrum solution, plant extracts like neem, garlic, chilli and tephrosia, spraying with 1% soap solution in 1% alcohol, and application of paraffin oil (white oil) as a 3% water emulsion can reduce the pest incidence. Spraying of 0.2% Nimbicidin or Azadirachtin 3000ppm @ 2m/L of water at initial stage of hopper population can control hopper attack. Datura stramonium, Calotropis gigantea, Azadirachta indica and cow manure helps in controlling several fungal pathogens and sucking pests like mealy buds.

Bioagents

Bio-pesticides such as Pseudomonas fluorescens, Verticillium lecanii, Beauveria bassiana as foliar sprays on the infected parts will knock off many pests and diseases. Soil application of bioagents like Trichoderma viride, Trichoderma harzianum, Bacillus subtilis ensnare and consume other fungi as well as nematodes that live in the soil.

Panchgavya is a good source of macro, micronutrients, beneficial fungi and bacteria, which induce growth and also repel risky pests. Similarly other organic formulations like dasagavya, AmrutJal 10% solution can be applied to soil and as foliar spray once in 15 -30 days, which act as protective cover for beneficial insects and pathogens.
Handi Khata controls all pests and diseases when sprayed @ 20ml/litre of water. Foliar spray with organic formulations like handikhata, panchagavya, dasagavya and bioagents like B. subtilis, Beauveria bassiana, Verticillium lecanii, Trichoderma viridae, Trichoderma harzianum are effective, economically viable approach to control several soil borne pests, diseases and nematodes etc.

Natural enemies

Natural enemies such as lady beetle larva, wasps, spiders, parasitic fungi, attack the maggots of fruit flies and predators such as rove beetles, weaver ants, spiders, birds and bats are very efficient in protecting trees from several pests, including fruit flies. Their presence and foraging activity hinders the fruit flies from laying eggs, resulting in reduced fruit fly damage. Sterile Insect Technique (SIT) limits the reproductive ability of natural population and brings down the insect population to a manageable level.

Conclusion

The challenge in organic home garden is timely control of several pests like hoppers, mealy bugs, stem bores, fruit flies, bugs, caterpillars, mites, moth and diseases like powdery mildew, anthracnose, sooty mould, stem rot, gummosis, etc. that drastically reduce crop yields. A large number of parasites, predator and pathogens by their presence and foraging activity hinders from laying eggs, resulting in reduced pest damage. Crop diversification and ecological engineering by selecting flowering plants that are available and suitable to the agro-climatic region, along with management practices adopting physical and biological control methods can reduce pests and disease incidence in organic home gardens without using any chemicals.

Author: K. Usha, ICAR- Indian Agricultural Research Institute, New Delhi-110012 (Kalidindi.usha3@gmail.com)

Editor: Subhrajyoti Mishra (BLOGGER, Ph.D in Horticulture, subhrajyoti.agro@gmail.com)

Technical Manager: Soumya Ranjan Biswal (M.Tech)