Garlic Diseases and Problems

How to plant garlic profitably
Edilberto Santiago
Greenfields December 1992

Like other crops, garlic is attacked by a number of pests and disease.

Insect and their control.

1. Thrips (Thrips sp.) These are the most serious insect pests of garlic. Nymphs and adults suck plant sap, especially the young leaves and growing points. The leaves and growing points. The leaves turn yellow , curl slightly and become silvery-white or brown. Small black dots become visible. If the infestation is severe, the leaves wilt and die.

Thrips are small; adults measure 1 to 1.20 millimeters long. They are pale to light brown in colow with brown markings on the abdominal segments. The nymphs are pale yellowish or greenish and often dusky. The uniform white eggs are laid on the underside of leaves. The incubation period is three days. The life cycle of the insects is from three to five weeks.

Control: Nymphs usually hide in the angles of leaves, rendering their control difficult. Early planting is recommended in October to avoid heavy infestation which usually occurs in late January to March. Remove and burn badly infested leaves and bulbs.

For chemical control, use either Diazinon 20 EC, Malathion E 57, Lannate 20 EC or Mesurol R. Start treatment when the plants are 30 to 60 days old. For December planting, apply the insecticide 20 to 25 days after planting. Frequency of application is 5-10 day intervals, depending on degree of infestation. Continue reading “Garlic Diseases and Problems”