and Integrated Pest Management - part - usaid

22 PESTICDE MANAGENT AND IPM IN SOUTIEAST ASIA
TIE PEST SITUATION IN ESTATE CROPS
In the past, pests have always created serious problems on estate crops,
often resulting in huge losses and drastically affecting the welfare of the people
involved. One example is the Sexava problem on coconut in North Sulawesi,
which forced people to migrate from the Talaud iMands to other parts of
Indonesia and even to the Philippines in 1938 i'bi: copra yield in Talaud
dropped to 1.6 kg per tree compared to 7.3 kg in t,:v xeighboring islands where
there were less Sexava infestations. Another example is the -ust disease which
forced the government to have all Arabica coffee destroyed in the 1920s.
At present, pests remain a significint limiting factor in the intensification
of estate crop production. As a consequence of the development of estate crops,
minor pests have become major ones because of the sudden abundance of food,
especially in new areas which were previously forests. Table I shows the total
area affected by various pests from 1980 to 1984.
In 1980 alone, the Directorate of Estate Crop Prote-tion estimated the level
of infestation and annual value of crop losses on selected estate crops as follows:
insects at infestation levels from 5% to 70% (mean 25%) causing estimated
losses of Rp20 billion (USS32 million) mainly on coconut and coffee; diseases
with infection levels ranging from 15% to 62% (mean 27%) causing a loss of
Rpl I billion (USS18 million) mainly on cloves and rubber. and weed infestation
causing losses valued at RplOO billion (US$166 million) mainly on rubber,
coconut and coffee.
Insects are the most important group of pests on estate crops. They can
cause damage ranging from light to very severe, sometimes resulting in the death
of the crop. Some of the major insect pests of important estate crops are listed
in Table 2. Besides insects, vertebrate pests may also cause serious damage to
estate crops. These include rodents, wild pigs, and elephants. The intensity of
damage is usually more severe near fallow lands, uncultivated areas, and
secondary forests.
Although plant disease epidemics are not as widespread as insect
infestations, they cannot be ignored in the uevelopmnent of estate crops. A
number of diseases, previously of minor importance, have become major ones
causing damage over large areas. Examples are the Phyllosticta leaf disease on
cloves, Xylem Limited Bacteria (XLB) also on cloves, and the Vascular Streak
Dieback (VSD) o;a cocoa. Besides these pathogens, others which have been
Table I. Total area (inhectares) of estate crops damaged by pests during 1980­
1984.
Year
1980
1982
1983
1984
Insects
350,000
898,000
714,000
120,000
Pathogens
38,000
259,000
259,000
45,000
Wcedsa
884,000
134,000
NR
NR
Total
1,272,000
1,291,000
1,003,000
165,000
aNR = no report.