Abstract:
A study was conducted to investigate the association of Vesicular Arbuscular Mycorrhiza
(VAM) with Commelina benghalensis (Girapala), which is an aggressive weed infesting
in tea cultivations. A field experiment was carried out at Wewessa estate, Badulla from
September to December 2019. Four treatments i.e. Tea infested with C.
benghalensis slashed at 3 weeks interval, Tea infested with C. benghalensis slashed at 6
weeks interval and Tea with no weeding for 3 months and tea alone (weed-free), were
included. VAM spore count and root colonization percentages were calculated at 6-week
intervals. Soil Phosphorus was analyzed and tea yield was measured. VAM spore count
and root colonization percentage were significantly (p<0.05) higher in two treatments
with C. benghalensis compared to those of no weeding treatment. Spore counts were
recorded as 190, 200 spores/100g of soil in the treatments of which C. benghalensis was
slashed at 3 and 6 weeks interval, against 120 in no weeding treatment. Root colonization
was also reported as 56.7%, 60%, 39.4% in tea infested with C. benghalensis slashed at 3
and 6 weeks interval, and no weeding treatments, respectively. Significantly higher levels
of soil Phosphorus (241 ppm and 237 ppm) were also reported from two treatments of C.
benghalensis slashed at 6 and 3 weeks intervals compared to no weeding (230 ppm)
treatment at the end of 3 months. There was no significant difference in tea yield between
treatments. The study concluded that there is an association of VAM with C.
benghalensis and P solubilization is taken place with VAM colonization in the
rhizosphere of C. benghalensis. VAM association with C. benghalensis weed has thus
been favorably affected on tea growth.
Keywords: Aeroponics, Growth, Yield, Potato mini-tubers, Quality, Root pruning
