Effect of solarization on the occurrence and damage of flea beetle (Phyllotreta spp.) in leafy Brassica production under CLSU [Philippines] condition

Flea beetle Phyllotreta spp. infestation is one of the major pest problems of farmers growing leafy vegetables in Nueva Ecija and other parts of Luzon [Philippines]. To minimize the occurrence and infestation of this insect pest, a solarization study was conducted at the CLSU [Philippines]. Ten plots measuring 1 x 18 m were prepared. The plots were raised and prepared accordingly to represent the blocks and treatments. There were 5 replications and two treatments; solarization and non-solarization. A 0.5 m distance between blocks and plots were provided. Plots that were solarized was covered with black polyethylene plastic for two weeks. There after, the soil was tilled and pulverized. Application of organic and inorganic fertilizer at the rate of 3.5 tons and 120-30-30 kg NPK/ha respectively was applied. Line sowing of Pak-choi seed was done. After planting, tunnel type net structure was put up in all plots. Monitoring of insect pests other than flea beetle was done twice a week. First trial result showed that the number of damaged plants due to flea beetle was significantly lower (4.8/m) from the solarized plots compared to the non-solarized plots (17.8/sq m). Marketable weight obtained from the solarized plots was significantly higher (18.8 tons/ha) compared to the non-solarized plots (ton/ha). Number of damaged plants, insect damaged rating, number of damaged plants due to Rhizoctonia solani was not significantly different in both solarized and non-solarized plots. An insignificant result was obtained during the second trial. However, the same trend was noted. The number of damaged plant due to flea beetle was lower (2.8/sq m) in the solarized than in non-solarized plots (9.2/sq m). Marketable weight of plants in solarized plots was higher (20.85 tons/ha) compared to the non-solarized plots (14.4 tons/ha). Findings revealed that solarization can control flea beetle infestation on brassica specifically on pak-choi, besides, the yield increased from 2-18.8 tons/ha or about 57.45%