SEVERITY OF CONOPOMORPHA CRAMERELLA (SNELLEN) INFESTATION: OBSERVATION OF THE DAMAGE USING MALAYSIAN COCOA CLONES
Authors: Saripah, B.
Journal Issue: Malaysian Cocoa Journal, Volume 13(1)/2021
Keywords: Average Damage Severity Index (ADSI), Cocoa, Cocoa pod borer, Conopomorpha cramerella, screening
Published On: 1/11/2021
Abstract
Plant is generally considered resistant to an insect when the insect able to inflict greater damage to other plants of the same species under similar environmental conditions. Therefore, observation of the severity of 28 Malaysian Cocoa Clones from four different classes (I, II, III, and IV) towards Cocoa pod borer, Conopomorpha cramerella (Snellen) were evaluated at the Cocoa Research and Development Center (CRDC) Jengka, Pahang. One hundred mature cocoa pods were selected as a sample per clone, and the slicing technique was conducted to observe the entry hole, exit hole, and damage category. The best clones based on the lowest entry holes were observed at MCBC 8 (1.300), MCBC 1 (3.370), MCBC 10 (4.800), KKM 22 (6.360), and DESA 1 (6.470). Five best clones for observation on the exit holes were MCBC 8 (0.310), MCBC 10 (0.880), MCBC 1 (1.100), PBC 221 (1.170) and QH 22 (1.440). MCBC 8 was recorded as the top clone after assessing the ADSI (0.470), followed by MCBC 1 (0.910), PBC 221 (1.010), MCBC 10 (1.020) and KKM 22 (1.220). MCBC 8 and MCBC 1 were categorized into Healthy to Slight Infested category. Meanwhile, PBC 221, MCBC 10, and KKM 22 were categorized into Slight to Light Infested category. Based on the screening result, it can be summarized that four clones from Class I performed as the best clones in terms of lowest entry and exit holes, and ADSI (KKM 22, MCBC 1, MCBC 10 and MCBC 8). These clones suffered less from CPB infestation compared with the other 24 clones.