Abstract:
The issue of cashew tree allelopathy and in particular the association with annual crops often
comes up in the agronomy debate. The aim of this study is to test the agricultural suitability of
cashew nut substrate on sorghum and groundnut crops. For this purpose, three types of substrates
were sampled at a distance from the crown of the cashew tree (R/2), at the edge of the crown (R)
and at a distance equivalent to twice the crown radius (2R). These substrates are then placed in
trays for the cultivation of these two species under semi-controlled conditions. The experiment
was carried out in a site completely exposed to the sun and isolated from the trees in order to
avoid shading and competition with soil nutrients. A total randomized experimental design
consisting of three treatments (three types of substrate) in 5 replicates was used. Results showed
that the total biomass production of sorghum on the R/2 substrate was twice as high as that
obtained on R and 2R. It is estimated at 252g under R/2, 135g for R and 138g under 2R. As for
sorghum, total groundnut biomass (leaves, roots, pods and stems) total biomass is higher on R
(331g) and R/2 (294g) substrates compared to 2R (257g) with a significant difference (p =
0.0129). Most of the variables of the crops studied were more important on under cover than off
cover. These results would indicate that if allelopathy is present, it would not be related to the
substrate under the tree. A field experiment allowing the introduction of other parameters, such
as the shading effect, would allow a better understanding of the conditions under which crops are
associated with cashew nuts. This would be an alternative in improving crop yields and would
also contribute to a better security for producers |
