THE EFFECTS OF Cuscuta campestris Yunck INVASION ON TEA GROWTH PARAMETERS, QUALITY AND SOIL NUTRIENT UPTAKE IN NANDI, KENYA

Abstract

Major agricultural crops around the word face problem of parasitic infestations. Almost everywhere in the world, there are about 200 species of parasitic plants of the genus Cuscuta, family of Cuscutaceae also known as dodder. It is one of the most damaging parasitic plants for the worldwide agricultural broad-leaved crops. Tea (Camellia sinensis) bushes in Nandi County have been under invasion by Cuscuta campestris since 2013 posing a major threat to the existing tea clones, human livelihood and ecosystems in general. Custuta spp. depletes nutrients and other soluble components thereby stressing tea plant growth finally resulting in yield losses. This study was conducted in Nandi County to assess the effect of Cuscuta campestris on tea clones’ number of leaves, leaf area, trunk diameter, dry weight and quality. Biophysical/ biochemical factors that enhance C. campestris invasion on tea were also assessed. Complete randomized design was used in the experiment. Tea clones in potted tea plants in a greenhouse were infected with C. campestris twigs collected from infected tea clones in Nandi tea estates. Data analysis was performed in SPSS version 21 where differences in mean between infected and control were done using t-test. Chi- square test was use to analyses the differences between observed and expected percentages frequencies. From the findings, Cuscuta campestris affected harvest biomass in all the 6 clones (TRFK 430/90, TRFK 306/1, TRFK 31/8, TRFK 301/4, TRFK 303/577 and EPKTN14-3 and their respective controls), trunk diameter of clone TRFK 306/1, leaf area of clones TRFK 31/8 and TRFK 301/4 compared with the control. Among the six clones tested, only TRFK 306/1 had a significant difference (between infected (1.04±0.15) and control (0.7±0.04) for trunk diameter. Mean leaf area for the infected TRFK 306/1 clone (40.33±6.50) was significantly different (t=-3.0110, p=0.03951) from its mean control (46.00±14.00). For the TRFK301/4 clone, mean leaf areas (29.33±2.08) was significantly different (t=-2.94174, p=0.0423) from the mean leaf control (34.33±2.08). Mean number of infected leaves of 303/577 clone was highest (73.00±5.29) followed by TN14-3 (61.66±4.72) with insignificant differences from mean control. Differences in mean control and mean infected of harvest biomass including above and below ground tissue were assessedAll the six clones showed a significant difference compared with their controls. Biochemical quality of tea clones was not affected by C. campestris, including GC (p>0.05), EGC(p>0.05), +C(p>0.05), EGCg (p>0.05), EC(p>0.05), GCg (p>0.05), ECg (p>0.05), Cg(p>0.05), GA(p>0.05), and Caffeine(p>0.05). Cuscuta campestris invasion had no effect on biochemical soil components. In conclusion, harvest biomass of all tea clones was affected by C. campestris infestation with infected clones having significantly higher biomass. In addition, C. campestris does not affect nutrients uptake by the host plant. Cross breeding of clones especially TRFK306/1 with other more resistant clones would probably make TRFK306/1 more resistance to attack.