Rice leaf folder attack reported in samba paddy in Tiruchi

With incidence of rice leaf folder pest attack being reported in samba paddy crop in certain pockets of Tiruchi district, the Agriculture Department has advised farmers to initiate control measures to limit damage.

The pest attack was noticed on the crop planted in early October in Musiri, Pullambadi, Tiruverumbur and other areas, officials said and attributed it to the intermittent rain and overcast conditions that prevailed during last two weeks. High humidity levels and excessive application of urea as top dressing could have also contributed to the attack. Normally rice leaf folder incidence would be seen in paddy between October and January.

Accordign to the officials, adult moths of leaf folder are smaller in size with dull yellowish brown wings with dark wavy lines the centre and black bands on the wing margins. Larvae are light greenish and translucent. Each adult moth lays 150 to 200 eggs in its life cycle and they lay the eggs in clusters of 15 to 20 under the leafs. Eggs hatches in five days and the larvae folds the leaves longitudinally and feeds on the tissues of the leaves. This leaves long white patches on the leafs, which later withers. During severe incidence the whole field bears a scorched look and the crop growth is stunted.

The economic threshold level (ETL) to commence control measure for this pest is 10% leaf damage during active tillering stage and five percent leaf damage during flowering stage of the crop.

Botanical insecticides such as azadiractin and neem seed kernel seed extract spraying is recommended during the initial stages of infestation. Excessive usage of urea should be avoided and application of urea with gyspum and neem cake in the ratio of 5:4:1 for top dressing during the active tillering stage is recommended. Foliar spraying of chlorantraniliprole, cartap hydrochloride or flubendiamide is effective for the control of rice leaf folder, the officials said.