Technoguide for Ampalaya Production Part 3

XII. Pests and their Management

1.  Fruitfl y, Bactrocera cucurbitae (Coquillett), is the most damaging insect pest of ampalaya causing 17% damage on fruits during WS 2006 in Batac, Ilocos Norte. Farmers claimed more than 50% yield loss during the dry season despite weekly spraying of chemical insecticide.

adult Bactrocera cucurbitae

The fruitfly lays its eggs on young fruits which later hatch into small worms or larvae that number 10-35 individuals per fruit. They bore into the fruits and eat the fl esh and young seeds.

Symptoms of their presence include deformed fruits that turn orange or yellow prematurely.

The fruitfly is not easy to manage because the adult is a good flyer and can travel long distances.

unmarketable fruits infested with fru

larvae feeding on ampalaya fruits

Steps in Managing Fruitflys

a. The insect can be managed by removing regularly all damaged fruits every harvesting time and burying them under the ground or decomposing them in sealed plastic bags.

old and infested leaves and fruits decomposing in plastic bags

b. Wrap young fruits with old newspaper, plastic bags (ice bag), or used clothing to prevent fruitflies from laying eggs on the fruits.

fruits wrapped in paper

 

2.  Aphids, Aphis gossypii Glover, suck the sap of leaves. This results in curling and yellowing of leaves, stunted growth, and even death of the whole plant. More importantly, the aphid is a vector of the cucurbit aphid-borne yellow virus (CABYV) which is similar to the “namamarako” disease in ampalaya.

“namamarako” disease in ampalaya

The virus disease causes curling, thickening, and yellowing of leaves, signifi cantly decreasing in female fl owers and consequently fruits. The virus disease is managed by destroying infested plants to prevent further spread.

Monitor the plants regularly for the initial infestation of aphids. Remove the leaves or uproot the whole plant if necessary. Control aphids by spraying water or chilli-soap solution at high pressure that will dislodge the pests from the plant, disrupting their life cycle.

Control the ants that carry aphids to the plants by spraying them with any green-label insecticide like methomyl or carbaryl. Do not use pyrethroids that are purely contact insecticides with no fumigating effects, hence cannot reach the aphids underneath the leaves. Read the label and follow strictly the instructions to avoid contamination.

The growth of sooty molds is an indirect damage due to the honeydew secreted by the aphids. Such growth hampers photosynthesis that fi nally kills the plant.

3.  The leafroller, Diaphania indica (Saunders), rolls young leaves when the foliage is dense especially during the vegetative stage. Too much nitrogen fertilizer results in very dense and green foliage that favors the prevalence of the pest. Its larvae could feed on fruits, making them unmarketable. Removing rolled leaves and crushing the larvae can help control the pest, especially if the area planted is not too big. Apply only the needed nitrogen fertilizer. In wide-scale planting, a biological insecticide or stomach poison, “halt”, can be sprayed late in the afternoon to control up to 3rd instar larvae only. Bigger larvae cannot be killed. If no chemical spraying is done, wasps can kill up to 92% of the larvae.

XIII. Harvest and Post-harvest Handling

harvestable ampalaya

 

Harvesting starts within 30-40 days after transplanting, and can be done twice a week. Harvest fruits according to the demand of the market. Harvestable fruits are shiny, preferably 9-14 days from pollination. For the pinakbet of the Ilokanos, harvest younger fruits. Harvest fruits early in the morning and protect them from the sun, rain, and mechanical damage. Remove damaged fruits and sort according to market standards. Pack in plastic bags, carton or plastic crates. Fruits can be kept fresh for 3-4 days under this condition.

ampalaya for sorting and packing

ampalaya packed in plastic bags