Management of rice production systems to increase productivity

submerging the 7‐day old seedlings and resulted in seedling mortality,
retarded growth, poor plant stand, and ultimate low yield. During the
tillering period there was a defoliator caseworm (Nymphula stagnalis Zell)
outbreak. Farmers’ plots were devastated, but not a single SRI‐managed plot
was infested. The semi‐aquatic larva of the defoliator caseworms strips plants
of their leaves, reducing their photosynthetic capacity. After completely
defoliating a plant, they swim in the flood waters to the next plant. The
absence of standing water in the SRI plots provided an effectively control
against the defoliator caseworm. This incident was noticed by farmers and
brought to the attention of the researcher. SRI water control method of
repeated wetting and drying also helps to control mosquito breeding and thus
helps to control against malaria.
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High returns associated with SRI management practices thus have been
demonstrated to irrigated rice farmers in The Gambia. The prospects are that
more and more farmers will adopt some if not all of the components of SRI
management practices in their production. The production cost associated
with SRI management is initially higher than conventional production cost,
but the higher net return compensates for the high production cost (Table 19).
Land preparation and putting in place an effective drainage mechanism were
identified as the most limiting factors to adoption of SRI management practice,
but these could be addressed in the long‐term.
It is possible to improve the drainage system in most of the rice fields,
and once this is done it will serve for a long period of time without major
labor and capital input. Land preparation is much easier and faster in the
second and subsequent years after major leveling has been done in the first
year of SRI management. This is due in part to improvement of soil physical