Timely and multiple weedings using the cono-weeder have a major impact on both SRI and control field development.
Comparisons among the five SRI and five control plots in each village show how field management affects crop development, as the other factors -- such as soils, land use history of the irrigation perimeter, land preparation of the test fields, timing of nursery establishment, and transplanting -- are similar.
Picture: Farmer in Katoua hand weeding a control plot.
The weed Cyperus sp. infested both the SRI and control plots of one of the farmers in Douegoussou. These plots were not weeded in time. The cono-weeder can no longer be used once weeds exceed a certain height, thus the farmer had to spend many hours weeding the plot by hand.
In this case, plants in both the SRI and control plots suffered a great deal from competition with weeds (with 30% fewer tillers compared to the 15 farmer average: see figure in Tillering Blog Entry). Nevertheless, plant vigor at 60 days in the SRI plots was better (26.9 tillers/plant) compared to the control plot (16.2 tillers/plant) .
Two neighboring SRI fields in Kessou Koreye: on the left, the cono-weeder was used once, on the right, it was used three times. Other management interventions remained similar.
Crop development in the left field is irregular, showing patchiness (the dark green spot is excluded from this observation, as it refers to a location were manure was deposited as explained in Yellowing of Fields Blog Entry). The crop in the right field is more uniformly developed, which we attribute to the use of the cono-weeder (see Cono-weeder Blog Entry).
Notice the straight plant alignment across the diagonal in the right picture, an indication that a precise spacing of 25 cm x 25 cm was respected.
September 7, 2008
Impact of Weeding
SRI Timbuktu Blog
These two neighboring SRI fields in the village of Katoua show a clear difference in crop development. On the left, weeding was delayed and the farmer applied goat manure to the plot. On the right, the field was weeded in time and early on with the cono-weeder, and the farmer spread a well-decomposed cow manure (refers to manure quality as discussed in the Yellowing of Fields Blog Entry).
The weed-infested fields quickly turned yellow (field to the left), as compared to the neighboring greener field (field to the right) where weeding was done early on with the cono-weeder.
used cono-weeder once
used cono-weeder three times
weeded too late
weeded in time
weeded in time - cow manure
weeded late - goat manure
SRI
Control