Phenological events and pest incidence on Ilocos white garlic as affected by weather conditions in Ilocos Norte, Philippines

Issue Date

10-2013

Abstract

The study on the phenology and pest incidence at different phenophases of Ilocos white garlic was conducted to determine the appropriate time for applying pest management strategies based on weather conditions and phenological stages of this crop. Results revealed that the higher the minimum air temperature, the faster the phenophases during the vegetative stage of garlic. Likewise, the lower the maximum air temperature, the faster the phenophases of this crop during the bolting stage. Purple blotch (Alternaria porii) and Cercospora leaf spot (Cercospora duddiae) began to cause slight damage as early as the development of the 10th leaf (later part of bolting stage) and the 11thleaf (early part of pre-harvest stage) respectively when there was an occurrence of rainfall or when relative humidity was ≥88%. These diseases spread rapidly causing a very high damage when the relative humidity was consistently higher than 90%, but did not progress rapidly when the relative humidity was below 85%. Likewise, these diseases occurred causing only slight damage during the development of the 15th leaf (later part of pre-harvest stage) when the relative humidity was consistently below 85%. There was no occurrence of these diseases during the vegetative and early bolting stages of the plants even if there was high relative humidity (>90%) and occurrence of rainfall. Mite damage called tangle top appeared as early as the development of the 4th leaf (vegetative stage) when there was a change (low to high) in air temperature of about 1°C or more.

Source or Periodical Title

The Philippine Entomologist

ISSN

0048-3753

Volume

27

Issue

2

Page

210

Document Type

Article

Frequency

semi-annually

Language

English

En – AGROVOC descriptors

GARLISC; PHENOLOGY; WEATHER; AIR TEMPERATURE; BOLTING; PLANT DEVELOPMENTAL STAGES; PEST MANAGEMENT; PHILIPPINES

This document is currently not available here.

Share

COinS