The Effect of Molybdenum Fertilization on Arachis Glabrata Biomass and Nodule Number in Different Mowing Periods in Western Cameroon
The effect of molybdenum fertilization on biomass and the number of nodules of Arachis glabrata was assessed at the Teaching and Research Farm of the University of Dschang in 2011 at different periods of mowing. A factorial design comparing four doses of molybdenum as ammonium molybdate (0, 0.75, 1.5 and 2.25 kgMo / ha) and six (6) periods of mowing in tubs of 0.0346 sq.m each repeated three times, representing a total of 72 experimental tubs used. At each mowing period, the plants were cut into two: the visible part and nodulated roots. The nodules are then separated from roots by placing the tubs in a water basin. The water then slowly disolves the earth coming off the roots. The nodules were then collected and counted. The nodules in the three tubs per level of fertilization and visible parts were weighed and then dried in a 60 ° C ventilated oven to constant weight to determine biomass in kg MS/ha and tMS/ha for nodules and visible parts respectively. The results showed that molybdenum fertilization had little influence on leaf biomass from Arachis glabrata. The highest value (9.21 tMS / ha) was obtained at 180 days from mowing, with a fertilization level of 0 kgMo/ha, while the lowest value (1.07 tDM/ha) was obtained at 30 days from mowing, with a level of fertilization of 1.5 kgMo/ha. A highly significant (p<0.01) linear relationship (R2 = 0.88) was observed between leaf biomass and mowing periods. The data on nodular biomass and number of nodules variably changed according to the different levels of molybdenum fertilization. The highest values 91.62 kgMS/ha and 322.33 were noted at 180 days from mowing at a dose of 0 kgMo/ha for nodular biomass and nodule number respectively. The lowest values 1.25 kgMS/ha and 22.00 were obtained at 30 days from mowing at doses of 0.75 and 1.50 kgMo/ha respectively. In this study, highly significant (p <0.01) logarithmic relations (R2 = 0.8 and R2 = 0.64) between nodular biomass and mowing period on the one hand and between nodule biomass and leaf biomass on the other hand were observed. However, no relationship was observed between the number of nodules and the mowing period. Thus, the results show that under the conditions of this experiment, the parameters studied were more influenced by the age of the plant rather than by molybdenum fertilization. However, doses of 0.75; 1.5 and 0 kgMo/ha achieved the highest above-ground biomass, nodular biomass and number of nodules of Arachis glabrata respectively.
Keywords: Arachis glabrata, Molybdenum, mowing period, nodules and biomasse.