Integrated Pest Management ( IPM) on Mango

Transcription

1 Integrated Pest Management ( IPM) on Mango Introduction Agricultural production in India increased dramatically during the last four decades, leading to an era of food selfsufficiency. The remarkable growth was achieved through the uptake of newer technologies in the form of high yielding crop varieties, chemical fertilizers and pesticides, as well as from the expansion of cropped area. Nevertheless, the growth in agricultural production needs to be sustained to meet the food demand of ever increasing population to supply quality and safe food. Insect pests, diseases and weeds inflict enormous losses to the potential agricultural production. At the same time, there is a rising public concern about the potential adverse effects of chemical pesticides on the human health, environment and biodiversity. These negative externalities, though, cannot be eliminated altogether, their intensity can be minimized through development, dissemination and promotion of alternative technologies such as biopesticides and bioagents as well as good agronomic practices (GAP) rather relying solely on chemical pesticides. Chittoor district has a vast flora and fauna that have the potential for developing into commercial technologies. Plant protection research has generated many technologies using flora and fauna. A few have been standardized for commercial application, and are claimed to provide better pest control and crop economics than the conventional chemical control, when used in conjunction with other pest control measures. The strategy is often referred to as Integrated Pest Management. Nevertheless, the adoption of biopesticides and bioagents remains extremely low owing to a number of factors relating to technology, socio-economic, institutional and policy. Mangoes are prone to insect infestation and disease infection at any stage of their development. Without proper pest management program, quality fruits may not be produced. The current control measures for pests attacking mango still relies on the use of pesticides. Most insecticides and fungicides are applied as calendar spray in an excessive manner resulting to pest resistance, elevation of minor pests to major ones, destruction of natural enemies and contamination of environment. In addition, pesticides are expensive and have caused in increased production inputs. Many of these problems can be minimized though Integrated Pest Management (IPM). This involves these of alternative measures in combination, to minimize pests. The IPM strategies make use of cultural management (pruning, cultivation, sanitation, proper nutrition to enhance vigor and fruit bagging) conservation of beneficial insects (pollinators and bio-con agents) and proper pesticide management. This brochure on IPM for mango production emphasizes prevention of pests through destruction of source and prevention of its spread. The major pests and diseases and their management and control measures are herewith furnished. In brief the calendar of operations to be followed by the farmers as ready reconary. Page 1 of 12

2 Calendar for IPM Target pest Activities Months January Inflorescence midge, Mealy bug, powdery Mildew, frost, Malformation, Stone weevil IPM activities Cleaning the alkathene bands at regular interval. Spray of 0.05% or dimethoate (0.045%) or some safer insecticide at bud burst stage. Removal of weeds and infected young leaves for powdery mildew. Delossoming of emerging floral buds. Cover young plant with thatch and irrigate the orchard. Remove infected leaves / malformed panicle infected by mildew. February Hopper, midge, Powdery mildew, Mealy bug, Blossom blight, Spraying with neem seed kernel extract (5%) or imidacloprid (0.05%) or thiamethoxam (0.05%) or propanophos (0.05%) for hoppers with 0.2%, or tridemorph (0.1%) for mildew. Cleaning of polythene band at regular interval. Sprays of mancozeb (0.2%). Pruning and destruction of inflorescence infested with midge. March Powdery mildew, hopper, Stone weevil Need base spray of insecticide + fungicide + NAA (20 ppm) for control of hopper, mildew and fruit drop at pea stage. Spray fenthion (1 ml/l ) or deltamethrin (1 ml/l ) at the time of egg laying when fruits are of lime size (2.5-4 cm diameter) for stone weevil. April May Hopper, Powdery mildew, Sooty mould, Fruit fly, Leaf cutting weevils, Black Tip, Internal Necrosis, Fruit fly, Third spraying of dinocap / tridemorph (0.1%) after fruit setting (Need base). Removal of powdery mildew infected leaves and malformed panicles. Spray wettable sulphur + monocrotophos + Gum Acacia ( %) or Indian oil formulation (3%) or 2% for sooty mould. To look after the grafted seedlings and if requ ired spraying of carbaryl (0.2%) or Dimethoate (0.05%) for control of leaf cutting weevils. Hanging of methyl engenol bottle traps (Methyle eugenol 0.1% + malathion 0.1% solution) for monitoring of fruit fly. Spray of borax (1%) at 15 days interval. Hanging of methyl eugenol traps (0.1%) + Page 2 of 12

3 The detailed major pests and disease control measures with photographs are as follows: Termite Scientific name: Common names: Alternate hosts: Macrotermes gilvus (Hagen) White ants, termite Several fruit trees Destructive stage: Adults and immature Parts affected: Roots, trunks and branches Termite Termite damage Description: Similar to ants but have soft bodies and are whitish in color. Termites construct earthen tunnels visible near damaged plant parts. The barks may be partly or fully eaten. Termites multiply very fast and are capable of destroying the entire tree. After damaging the roots, termites go up the trunk through earthen tunnels. The workers feed on the bark and underlying tissues. Parts affected are partially or totally destroyed. Prevention/control Paint or brush the trunk with used diesel oil to discourage the movement of termites from soil to the upper parts of the tree. Prune crowded branches to allow light penetration. This will provide unfavorable environment for the multiplication of the insect. Termites have soft bodies and die upon exposure to sunlight. Insecticides can be sprayed to control termites. Be sure to destroy the earthen tunnels before applying insecticides. For termite mounds, make a hole on one side, deep enough to reach the nest and pour kerosene. Mango hopper Page 3 of 12

4 Scientific name: Common names: Parts affected: Idioscopus clypealis (Lethierry Blossom leafhopper, Mango leafhopper Leaves, flowers and young fruits Destructive stage: Nymphs and adults Description: Adults are brown to gray with wedge-shaped body. Head is distinct with protruding eyes on the side. Nymphs are smaller, light brown and have no wings. Nymphs and adults damage the flowers by piercing the tissues and sucking the plant sap which causes withering, drying and falling of individual flowers. Under severe infestation, no fruit develops. The insects excretes fluid called honey dew, an excellent medium for development of the fungus, sooty mold, which interferes with the photosynthetic activity of the leaves. It also disturbs flower fertilization and spoils the appearance of fruits. Under high insect population, the entire canopy is covered with sooty mold with the leaves and flowers turning black. Prevention/control : Since hopper population is expected to be high in summer, early induction of mango trees (September, October and November) will minimize hopper problems in the field. Use light traps during early stages of flower development to attract and kill adults which are ready to lay eggs. To install a light trap, hang the source of light (electric bulb or kerosene operated lamp) on the tree. Place a basin containing a mixture of soap and water (1:10) underneath the light. Hoppers which are attracted to the light are drowned in the solution. One light trap is required per hectare of mango plantation. Prune crowded branches to discourage hoppers from staying in the tree. Pruning allows good light penetration and makes the habitat unfavorable for hopper development. Spray insecticide directed to the nymphal stages rather than the adults, hence, detection of this stage is important. (Please see Annex for suggested control measures) Page 4 of 12

5 Mango fruit fly Scientific name: Bactrocera philippinensis sp. n. And Bactrocera accipitalis (Bezzi) Common names: Mango fruit fly Alternate hosts: Guava, Santol, Sineguelas, Starfruit, Guyabano, Chico, Papaya, Passion fruit, Macopa Parts affected: Fruits Destructive stage: Adults and larvae Fruit fly Fruit fly damage on mango fruit Description: Damage on fruits starts during egg-laying of adult that resembles colorful housefly. Fresh punctures may not be readily recognized until after 3 to 5 days when soft brownish spots appear on the skin and the underlying tissues start to spoil. The larvae cause the major problem since continuous feeding destroys large portions of the flesh. Breakdown of tissues makes the mango fruits unsuitable for consumption. In the field, infested fruits drop to the ground and decay. Under severe infestation, as much as 70 percent of the crop is damaged. Prevention/control : Collect and bury fruit droppings at least half a meter below the ground to prevent the development of the insect. Avoid bruising of fruits during spraying since damaged fruits are susceptible to fruit fly attack. Bag the fruits using newsprint at 55 to 60 days after induction (chicken egg size) to minimize damage from fruit fly. (Please see Annex for suggested control measures) Avoid planting papaya, guava, sineguelas or santol as intercrops for mango since these fruits are preferred hosts of the insect. On the other hand, cashew and calamansi are less preferred. Spray the insecticides at 90 to 105 days after induction since fruits at these stages are attractive for egg laying. Recommended insecticides to prevent fruit fly infestation are Baythroid (1 to 1 ½ tbsp per 16 L water), Karate (3/4 Page 5 of 12

6 to 1 ½ tbsp per 16 L water) and Decis (1 to 5 tbsp per 16 L water). Last spraying should at least be 15 days from harvest. (See annex for recommended control measures) Hanging of methyl eugenol wooden block traps soaked in ethanol, methyl eugenol and malathion (6:4:1) during fruiting period from April to traps/ ha tie them tightly at 3-5 feet above ground level. To control adult flies during severe infestation placing poison bait viz Protein hydrolysate +malathion 50 ml +200 ml molasses in 2 litres of water be sprayed adding an additional 18 liters of water to bait poison. Commencing at pre oviposition period and repeat at 15 days interval. Addition of 10 ml methyl eugenol in place of molasses is also recommended. Mango seedborer Scientific name: Common names: Noorda albizonalis (Hampson) Red-ringed mango caterpillar, Red boring caterpillar, Fruit boring caterpillar, Mango fruit borer and Mango seed borer Parts affected: Fruits and seeds of mango Destructive stage of the pest: larvae Mango seed borer Damaged fruit Description: Unlike the fruit fly which feeds mainly on the flesh, the mango seed borer consumes both the flesh and seed. Damage starts when the newly-hatched larvae enter the fruit by boring holes through the apex or the narrow tip of the fruit. As the larvae develop, they feed on the tissues beneath the skin. The damaged area later collapses causing the apex to burst and the fruits eventually fall to the ground. Page 6 of 12

7 Serious damage is brought about by the destruction of the seed, since a single larva is capable of consuming the entire mango seed in a short period of time. Prevention/control: Pick the fruits showing damage. Otherwise, larvae will transfer and destroy adjacent healthy fruits. Collect and dispose infested fruits on the ground by burying them to prevent the insect from completing its life cycle. Bag the fruits with newsprints a 55 to 60 days after the induction will also minimize damage of the borer. Adults can be controlled by spray application of insecticide in the afternoon. (Please see Annex for suggested control measure) DISEASES Powdery mildew (Oidium mangiferae) Symptoms: Pathogen attacks the inflorescence, leaves, stalk of inflorescence and young fruits with white superficial powdery growth of fungus resulting in its shedding. The sepals are relatively more susceptible than petals. The affected flowers fail to open and may fall prematurely (Fig 28). Dropping of unfertilized infected flowers leads to serious crop loss. Initially young fruits are covered entirely by the mildew. When fruit grows further, epidermis of the infected fruits cracks and corky tissues are formed. Fruits may remain on the tree until they each up to marble size and then they drop prematurely. Mildew on flowers Mildew on fruits / pedicel Mildew on Lower Surface of Leaf Page 7 of 12

8 Infection is noticed on young leaves, when their colour changes from brown to light green. Young leaves are attacked on both the sides but it is more conspicuous on the grower surface. Often these patches coalesce and occupy larger areas turning into purplish brown in colour. The pathogen is restricted to the area of the central and lateral veins of the infected leaf and often twists, curl and get distorted. Reason for severity: High humidity, cludy weather & high wind velocity for 3-4 day. Minimum temperature ( C), maximum C and RH 82-91% are most conducive for disease severity. Third and fourth week of March attains maximum severity in UP plains Lack of timely fungicidal Schedule Close Planting without canopy management. Mode of Spread Spread is dependent on development of mildew pathogen persist on older leaves/ malformed panicles during off season. Disease spread through wind borne spores released between 1100 to 1600 hour, which takes 5-7 hours for infection after germination. Management Prune diseased leaves and malformed panicles harbouring the pathogen to reduce primary inoculum load. Spray wettable sulphur (0.2%) when panicles are 3-4 in size. Spray dinocap (0.1%) days after first spray. Spray tridemorph (0.1%) days after second spray. Spraying at full bloom needs to be avoided. Page 8 of 12

9 2. Anthracnose Causal organism: Colletotrichum gloeosporioides Penz Parts affected: Leaves, flowers and Fruits Description: Considered as the most seriousfungal disease of mango in the Philippines, anthracnose occurs in all mango growing areas. It attacks the different parts of the tree, but major damage occurs at flowering and after harvest. It is serious during the wet seasons and usually occurs as a post harvest disease of mango fruits. The disease is characterized by the appearance of tiny spots on the leaves. These later enlarge to form discrete, rounded or angular spots which come together to form large, irregular shaped-patches with light brown to black spots. However, during advance stage of the disease, the spots give way and produce shot hole appearing in various shapes and sizes. This must be differentiated from the shot holes produced by the cecid fly which are small and circular. Anthracnose is the most devastating disease of mango flowers, especially when induction is done early in season (August to October). The presence of rain and high humidity favors the development of disease, thus, the flowers are easily infected. Common signs of the disease are black streaks on the main stalks and branches of the flower, which later become large, black patches. Under severe infection, entire flowers turn black and fail to develop. Young fruits are also affected and fall prematurely. Symptoms are, however, not visible since the fungus does not have proper condition for development (hard and acidic fruits). After harvest, when fruits start to ripen, the fungus is reactivated and spread over the surface (latent infection) Early symptoms of the disease are black, pin-pricked lesions. Later, the lesions form bigger black spots, until the whole fruit is covered. The disease is most serious during wet seasons and usually occurs as important post-harvest disease of mango fruits. Page 9 of 12

10 Prevention/control for leaves As a fungal disease, the development and spread of anthracnose are facilitated by high relative humidity within the tree canopy. Young leaves are susceptible to the disease. Prune crowded branches to allow light penetration and good air circulation that will create an environment unfavorable for disease development. Remove dead and diseased branches to reduce the source/reservoir of fungal spores. Ring cultivation can lessen humidity underneath the trees, which discourage germination of spores. Prevention/control for flowers Prune after harvest to increase ventilation and reduce humidity inside the canopy. Collect and burn trashes to reduce sources of disease inocula. Some farmers practice shaking of branches after blooming to remove morning dew deposited on the flowers. By doing so, the relative humidity is reduced and male flowers are eliminated, providing enough space for development of hermaphrodite flowers which produce fruits after pollination. Several chemicals such as Benlate (1 to 2 tbsp per 16 L water). Maneb (4 to 6 tbsp per 16 L water), Dithane (4 to 7 ½ tbsp per 16 L water), and Manzate (½ tbsp per 20 L water) have given varying degree of protection for flowers against anthracnose. These are applied singly or in combination in a sequential spray program. It is also suggested to incorporate any of these fungicides in the flower inducers, especially when flower induction is done early in season. (Please also see Annex for other suggested control measures) Page 10 of 12

11 Prevention/control for fruits Apply protectant fungicides such as Daconil (1/2 tbsp per 16 L water), Manzate (1/2 tbsp per 16 L water), Dithane (4 to 7 ½ tbsp per 16 L water), a week after bud break, at fruit set and 20 days before harvest. (Please also see Annex for other suggested control measures) Bagging of fruits at 60 days after flower induction can minimize the problem. Hot water treatment (HWT) by dipping newly harvested fruits in heated water (52 to 55 C) for 10 minutes, followed by hydro-cooling and air drying. 3. Stem end rot Causal organism: Dothiorella dominicana (Dd) Common names: Stem end rot, DSER Parts affected: Fruits Diseased stem Diseased fruit Description: of storage and transit rots of mango. The disease is considered next to anthracnose in importance and is responsible for about 2-6 percent The disease is characterized by appearance of dark discoloration near the fruit stalk (pedicel). Under warm and moist conditions, the infected area extends towards the end of the fruit. Later, the symptom turns from dark brown to purplishblack and the tissues become soft and watery. The disease produces soft rot in contrast to the hard rot produced by anthracnose. Page 11 of 12

12 Prevention/control Remove and burn primary sources of the disease such as dead twigs, barks and other trashes. Since high incidence of stem-end rot occurs on fruits without stalks, harvest the fruits with about 1.0 to 2.0 cm of the stalk attached. The pre-harvest sprays of fungicides recommended for anthracnose can also be used to prevent stem-end rot. Avoid the use of organic materials as liners for mango during packaging Spraying of 0.2% Nimbicidin or Azadirachtin 3000 at initial stage of hopper population. Spray Lambda cyhalothrin 5% 0.5 ml or imidacloprid ml/l or Thiamethaxam (0.05%) or propanophos (0.05%). First spray should be done at early stage of panicle formation if hopper population, is more than 5-10 panicle, second spray at full length stage of panicle and the third spray after fruit setting (at pea size). Chemical spray is to be minimized and should be need based. A rational rotation of insecticide is desirable to counteract the tendency of pest to develop field resistance Page 12 of 12