PINEAPPLE RESEARCH STATION (KERALA AGRICULTURAL UNIVERSITY), VAZHAKULAM, MUVATTUPUZHA
Pests & Diseases
Plant Protection - Kew
No serious pests or diseases are noticed in the crop except for light incidence of leaf spot disease and of the mealy bugs.
Mealybugs (Dysmicoccus sp.) infest commercial pineapple plantings, affecting pineapple production in several ways. The rapid spread of this malady in the field is largely due to the feeding habit of bugs. Symptoms first appear on roots which cease to grow, eventually leading to collapse of tissues. Feeding of Dysmicoccus species on pineapple produces a toxic effect called mealybug stripe, expressed as green or black striped areas. The most predominant symptom is wilting of leaves, commencing from leaf tips. Reddish-yellow colour develops in the wilting areas. Finally the plants rot and develop decaying suckers. Fruits developed are undersized. Ants of several species act as carriers of mealy bugs.
For control of mealy bugs, adopt the following measures: Apply quinalphos at 0.025%, fenitrothion 0.05% or fenthion 0.05%. Destroy grasses and other monocot weeds, which serve as alternate hosts for the pest.
Leaf spot occurs frequently in moist and warm climate. Small water soaked areas developed on leaves, which gradually enlarge. The affected portions become pale yellow in colour and gradually dry up. This disease is caused by Phytophthora spp.
For control of leaf spot, spray with any one of the following fungicides
when symptoms of the disease are noticed:
Plant Protection - Mauritius
This anomaly occurs usually when the pineapple plant leans or falls over exposing one side of the fruit directly to the rays of the sun, thus resulting in long exposure of the peel, and flesh beneath it, to fairly high temperatures.
Affected fruits show a yellowish color in the area exposed to the sun. As the anomaly progresses the yellow area changes to brown and the flesh beneath it becomes more translucent. The peel may crack between the fruitlets, the flesh dries out and becomes spongy. The occurrence of sunburn during early stages of fruit development reduces the growth rate on the area exposed to the sun thus resulting in an asymmetric fruit.
During summer months protection from the scorching sun can be done by putting dried grasses, coconut or arecanut leaves.
Heart rot/root rot:
Heart rot disease of pineapples caused by Phytophthora spp. is characterised by yellow-red coloured leaves that are easily pulled from the plant and white leaf bases that bear a distinct water-soaked grey-brown transverse lesion. The lesion progresses slowly from the base of the leaf to the tip. Rotting pineapple fruit tissue may also smell badly. If the pineapple plants develop root rot, aboveground symptoms include stunting and low yield.
Heart rot caused by Psuedomonas spp. is characterized by yellowing, leaf tip dieback, and tipping of the plant caused by rotting of the growing point.
Pineapple leaf spot occurs frequently in moist and warm climate of parts of India. Initial symptoms are in the form of water soaked lesions on the leaves. The spots later on enlarge in size and gradually dries up.
Providing drainage is most essential for the management of heart rot. The water table should be at least 60 cm below the soil surface. Badly affected plants should be destroyed and the remaining plants should be drenched with 0.4% Hexaconasole in the soil. Leaf spot can be controlled by spraying 0.2% zineb / mancozeb / ziram.
Mealy bugs (Dysmicoccus brevipes / Pseudococcus bromeliae):
Mealybugs infest commercial pineapple plantings, affecting pineapple production in several ways. The rapid spread of this malady in the field is largely due to the feeding habit of bugs. Symptoms first appear on roots which cease to grow, eventually leading to collapse of tissues. Feeding of Dysmicoccus species on pineapple produces a toxic effect called mealybug stripe, expressed as green or black striped areas. The most predominant symptom is wilting of leaves, commencing from leaf tips. Reddish-yellow colour develops in the wilting areas. Finally the plants rot and develop decaying suckers. Fruits developed are undersized. Ants of several species act as carriers of mealy bugs.
Spray quinalphos 0.025-0.05% or fenitrothion 0.05% or fenthion 0.05% or chlorpyriphos 0.05% or dimethoate 0.05% or monocrotophos 0.05%. Care should be taken that the spray shall reach the base and also the sides of the plant. The plot should be kept weed free. For the control of mealy bugs, control of ants is a must. Hence apply carbaryl to control ants in its colonies in the farm.
The spraying of chemicals for the control of mealy bugs, mentioned above, will be sufficient for the control of scale insects.
KAU POP Recommendation for pest, disease and mosquito problems
To avoid any pest, disease and mosquito problems in pineapple, sufficient phytosanitory measures are to be adopted in the pineapple field.
Both Chlorpyriphos and Mancozeb can be mixed and applied simultaneously, if necessary.
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