Keep the leaves
A banana plant fills its bunch from its functional leaf area. Sigatoka leaf spot works from the older leaves upward, and every leaf lost early is bunch weight that never arrives.
Sigatoka management is a routine, not a rescue:
- Remove and destroy affected lower leaves as they appear. This alone slows it considerably and is often skipped because it is labour.
- Adequate spacing and desuckering, so air moves and the canopy dries.
- Drainage, since humidity in a wet plantation is the whole requirement.
- Protectant sprays on a schedule in high-pressure areas, rotating the FRAC group. Sigatoka develops resistance readily where one group is used repeatedly.
- Cover the underside of the leaves. The spray that only wets the top surface is half a spray.
The pests that live where you cannot see
Rhizome weevil and pseudostem weevil bore into the corm and stem. Damage shows as wilting, weak growth and sometimes a plant that snaps.
- Use clean, treated suckers from a healthy plantation. This is where infestation usually arrives.
- Remove and destroy crop residue after harvest; the weevils breed in it.
- Split pseudostem traps to monitor and reduce the population.
- Treat at threshold rather than routinely.
Nematodes are a serious and under-diagnosed problem, causing root loss and toppling. Clean planting material, organic matter and rotation where possible.
Panama wilt
Fusarium wilt of banana is soil-borne, persistent and effectively incurable in an infected field. Management is variety choice, clean planting material, avoiding movement of soil and water from infected blocks, and not replanting susceptible types into a known infected field.
Take it seriously early. A single infected block that is ignored contaminates a plantation.
Propping and bunch care
A heavy bunch on a tall plant in wind goes down. Prop before it is needed, not after.
Bunch covering protects from sunburn, thrips scarring and dust, and improves finish. Removing the male bud after the last hand improves filling.
Nutrition
Banana is a very heavy feeder, above all of potassium. Split applications through the cycle, and fertigation if drip is available — this is one of the crops where fertigation clearly pays.
Removing diseased leaves weekly costs labour and saves fungicide. It is the cheapest thing in the plantation.
