Cultural weed control

• Several cultural practices like tillage, planting, fertilizer application, irrigation etc., are employed for creating favourable condition for the crop.
• Methods like tillage, fertilizer application, and irrigation are important.
• In addition, aspects like selection of variety, time of sowing, cropping system, cleanliness of the farm etc., are also useful in controlling weeds.

Cultural method of weed control

a. Desiccation and Tillage:

• Drying propagules exposes them to sunlight, reducing viability.
• Subsequent tillage breaks clods and further exposes weeds to hot sun.

b. Maintenance of Optimum Plant Population:

• Adequate plant density suppresses weeds naturally.
• Practices include proper seed selection, correct sowing methods, appropriate seed rate, and protection from pests/diseases.

c. Crop Rotation:

• Growing the same crop repeatedly favors certain weed species.
• Rotating crops can reduce or eliminate difficult weeds (e.g., Cyperus rotundus controlled by lowland rice).

d. Intercropping:

• Intercrops suppress weeds more effectively than sole crops.
• Short-duration pulses like green gram and soybean smother weeds without reducing main crop yield.

e. Mulching:

• Covering soil with organic or plastic mulch blocks light, inhibiting weed photosynthesis.
• Effective against annual weeds and some perennials (Cynodon dactylon).

f. Soil Solarization:

• Pre-soaked soil covered with transparent plastic raises soil temperature by 5–10 °C.
• Inhibits weed growth by desiccation and prevents long-wave heat loss.

g. Stale Seedbed Technique:

• Initial flush of weeds allowed to germinate, then destroyed before crop sowing.
• Achieved via irrigation/rain followed by shallow tillage or non-residual herbicide (e.g., paraquat).
• Ensures crop emerges in near weed-free soil.

h. Blind Tillage:

• Tillage after sowing but before crop emergence to reduce weeds, especially in drill-sown crops.
• Helps overcome soil crusting after rain/irrigation.

i. Good Crop Management Practices:

• Use vigorous, fast-growing crop varieties to outcompete weeds.
• Proper fertilizer placement favors crops over weeds.
• Adequate irrigation ensures crops get a head start.
• Higher plant population smothers weeds.
• Well-planned crop rotation programs reduce weed pressure.