Pests and diseases

Downy mildew

బూజు తెగులు

Diseases

The advice below comes from each crop's guide — every item shows its source, region and date. It is pending expert review; ask your local officer whether it suits your area.

Maize

  • Chemical pesticides: ask before you spray

    The source lists insecticides and fungicides for shoot fly, stem borer, aphids, fall armyworm, leaf blights, rust and downy mildew. Many are hazardous, and some may be restricted. Choose a product only with your local Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Maize – Pest & disease management, pp. 113–114
    Region
    Tamil Nadu
    Last updated
    2026-11-04
  • Downy mildew

    Sow resistant hybrids, and rogue out (pull out and destroy) downy mildew–infected plants.

    Pending expert review
    Source
    Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Maize – Disease management (Downy mildew), p. 114
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Jowar

  • Disease prevention

    Adjust the sowing period to prevent flowering during the rainy and winter seasons (this helps against grain diseases such as ergot and head mould). Rogue out downy mildew–infected plants up to 45 days after sowing. Seed treatment with Pseudomonas fluorescens at 10 g/kg or Trichoderma viride at 4 g/kg of seed is also listed.

    Pending expert review
    Source
    Crop Production Guide – Agriculture 2020 (Directorate of Agriculture, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Sorghum – Disease management, p. 78
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Cabbage

  • Pests and diseases: ask before you spray

    The source lists many chemical sprays for aphids, leaf-eating caterpillars, diamondback moth, club root, leaf spots, leaf blight, ring spot, downy mildew and black rot. Choose any product only with your local Horticulture or Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Cabbage – Plant protection, pp. 121–123
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Bottle gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. Choose any product only with your local Horticulture or Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Bottle gourd – Plant protection, pp. 90–91
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Bitter gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. Choose any product only with your local Horticulture or Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Bitter gourd – Plant protection, pp. 93–94
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Ridge gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. Choose any product only with your local Horticulture or Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Ribbed gourd – Plant protection, p. 88
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Snake gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. Choose any product only with your local Horticulture or Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Snake gourd – Plant protection, pp. 85–86
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Pumpkin

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew, and lists red pumpkin beetle, leaf miner, thrips, whitefly and pumpkin caterpillar among the pests. Choose any product only with your local Horticulture or Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Pumpkin – Plant protection, p. 83
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Ash gourd

  • Pests and diseases: ask before you spray

    The source lists chemical sprays for aphids, jassids, fruit borers and caterpillars, red spider mite, powdery mildew and downy mildew. Choose any product only with your local Horticulture or Agriculture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Ash gourd – Plant protection, pp. 96–97
    Region
    Tamil Nadu
    Last updated
    2026-11-04

Grapes

  • Pests, diseases and hormones: ask before you spray

    Remove loose bark at pruning to stop pests laying eggs. The source lists chemical sprays for flea beetles, nematodes, powdery mildew, downy mildew, anthracnose, rust and bacterial leaf spot, and a schedule of growth hormones (GA3 and others) for berry size. Hormone timing and dose are critical — for example, the source warns against GA3 in cloudy weather and from full bloom to fruit set. Choose any product only with your local Horticulture Officer.

    Follow the instructions on the product label. Consult your local Agriculture Officer before use.

    Pending expert review
    Source
    Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Grapes – Plant protection; quality improvement, pp. 24–27
    Region
    Tamil Nadu
    Last updated
    2026-11-04