Ludhiana, 1 September 2017
A survey of rice crop for leaf folder and stem borers infestation is being conducted by scientists of Punjab Agricultural University (PAU) in different districts of the Punjab, said Dr P.K. Chhuneja, Head, Department of Entomology, PAU. The survey has revealed that leaf folder and stem borers incidence is below the economic threshold level (10% damaged leaves for leaf folder; and 2 and 5 % dead hearts for stemborers on basmati and non-basmati, respectively). Referring to their symptoms, he explained, “The leaf folder larvae fold the leaves longitudinally by gluing the leaf margins together with silken threads and then feed on leaf tissues inside the folded leaves. The stem borers larvae damage the rice plant by boring into the central shoot near the base of the plant, which result in ‘dead heart’ that can be pulled out easily.”
He advised the farmers to monitor their rice fields regularly for leaf folder and stem borers attack. If the damage has not reached the ETL, the farmers should avoid blanket application of insecticides, he told. Instead, mechanical control of leaf folder, by passing a 20-30 m long coir/jute rope, forwards and then backwards, both ways while touching the crop canopy should be done before flowering, he suugested. While passing the rope, ensure that water must be standing in the crop, he added. Fields showing leaf folder and stem borers damage above ETL should be sprayed with any of the insecticides recommended by PAU viz. Fame 480 SC (flubendiamide) @ 20 ml/acre or Mortar 75 SG (cartap hydrochloride) @ 170 g/acre or Marktriazo/ Sutathion 40 EC (triazophos) @ 350 ml/acre or Coroban/Durmet/Force 20 EC (chlorpyriphos) @ 1 litre/acre, using 100 litres of water per acre, he said. In basmati, these insect pests can also be managed by spraying Coragen 20 SC (chlorantraniliprole) @ 60 ml/acre or broadcasting granular insecticides viz. Ferterra 0.4 GR (chlorantraniliprole) @ 4 kg/acre or Vibrant 4 GR (thiocyclam hydrogen oxalate) @ 4 kg/acre or Padan/Caldan/ Kritap/Sanvex/ Nidan/Marktap/Miftap/Katsu 4 G (cartap hydrochloride) @ 10 kg/acre or Regent/Mortel/Mifpro-G/ Mahaveer GR/Shinzen 0.3 G (fipronil) @ 6 kg/acre or Dursban 10 G (chlorpyriphos) @ 4 kg/acre in standing water, he added.
The synthetic pyrethroid insecticides alone or in combination with other insecticides, should not be used for leaf folder/stem borers management as this may increase the planthopper population at later stage of the crop growth, he warned. If leaf folder damage happens to be localized under shade of trees or other such places, then go for the spot treatment to control the damage, he advised.
