Experts advise adopting integrated pest management for paddy crop

With rice and basmati crops covering over 31.79 lakh hectares in Punjab this kharif season, agricultural experts are sounding the alarm over increasing insect-pest infestations that threaten both yield and quality.

High humidity and warm conditions during the crop cycle have created a conducive environment for pests like stem borers, leaf folders, planthoppers and rice hispa to thrive—prompting calls for integrated pest management (IPM) and need-based chemical intervention.

Dr Preetinder Singh Sarao from the Department of Plant Breeding and Genetics, Punjab Agricultural University (PAU), emphasised the urgency of shifting away from blanket insecticide applications.

“Farmers often spray insecticides early in the season without assessing pest levels. This not only wastes resources but also disrupts ecological balance and increases pest resistance,” said Dr Sarao.

Stem borers: Persistent threat

Three species of stem borers—yellow, white and pink—are active from July to October. These pests bore into rice stems, causing ‘dead hearts’ in vegetative stages and ‘white ears’ in panicle-bearing plants, leading to seedless, erect gearheads.

“Avoid long-duration varieties like Pusa 44 and Peeli Pusa, which demand more water and additional pesticide sprays,” advised Dr Harpal Singh Randhawa from PAU’s Regional Research Station, Gurdaspur. “Instead, follow PAU’s sowing and transplanting schedule to reduce pest build-up,” he said.

Chemical control is recommended only when damage exceeds 5 per cent in rice and 2 per cent in basmati. Experts urge alternating insecticides and monitoring pest thresholds before spraying.

Leaf folder: Subtle but damaging

Leaf folders feed on green leaf tissue, reducing photosynthesis and weakening plant health. Females lay translucent eggs on leaf undersides and larvae fold leaves to feed internally.

“Mechanical control like rope dragging across the canopy can dislodge larvae effectively,” said Dr Rubaljot Kooner from PAU’s Department of Entomology. “This should be done before flowering and only when water is standing in the field.”

Chemical intervention is advised when leaf damage reaches 10 per cent with more than one-third of the leaf affected.

Planthoppers and emerging viral threats

White-backed and brown planthoppers suck sap from the base of tillers, causing ‘hopper burn’—dry patches that spread rapidly. Their honeydew excretion also leads to sooty mould, further hindering photosynthesis.

During kharif 2022, a new virus—southern rice black-streaked dwarf virus (SRBSDV)—was detected in early sown fields. The vector? White-backed planthopper nymphs and adults. “This virus causes stunted growth and poor yield. Farmers must monitor hopper populations using light traps and uproot infected plants immediately,” warned Dr Kooner.

Spraying is recommended only when hopper counts exceed five per hill. Spot treatment of affected patches and surrounding areas is crucial to contain spread.

Other pests and preventive measures

Grasshoppers and rice hispa also pose threats, especially in nurseries and waterlogged fields. Hispa beetles tunnel into leaves, leaving bold white streaks that impair photosynthesis.

Promoting eco-friendly practices

PAU scientists advocate for green chemistry solutions like Ecotin and PAU’s homemade neem extract. The neem extract, prepared by boiling 4 kg of neem parts in 10 litters of water, offers an effective, eco-safe alternative at pest initiation stages.

“Natural enemies like spiders, dragonflies and ladybird beetles thrive in rice ecosystems. Need-based spraying preserves these beneficial species,” said Dr Sarao.

Farmers are also cautioned against using banned insecticides such as acephate, buprofezin and chlorpyriphos on basmati, which can lead to chemical residue issues in the final produce.