Abstract:
Weed infestation is one of the limiting factors in the production of chilli (Capsicum annuum L.). Weeds reduce the
availability of nutrients and water for the main crop reducing the fruit yield. The application of herbicides is not
an environmentally friendly method. Therefore, there is a movement to use alternative methods for weed
management. Polythene mulches have many benefits such as soil temperature modification, soil conservation by
preventing runoff, nutrient addition, and improvement in soil structure in addition to minimizing weed
infestation. Therefore polythene mulches are a popular method to reduce weed infestation in various crops. UV
treated silver on black polythene mulch is one such polythene mulch introduced to the Sri Lankan market
recently. Therefore, this research was conducted with the objectives to study the effect of UV treated silver on
black polythene mulch on growth and yield parameters and weed infestation of chilli. The possibility of the
reduction of the amount of recommended fertilizer with the application of UV treated silver on black polythene
soil cover was also tested. The experiment was laid out in a Randomized Complete Block design with four
replications. Two local chilli varieties (MI2 and MI3) popular among farmers were used for the study. The four
treatments comprised UV treated polythene mulch with different percentages of the recommended fertilizer
dosage (100%, 75%, and 50%) for chilli. Recommended fertilizer mixture without polythene mulch was the
control treatment. Yield and weed parameters such as time taken to 50% of flowering, time taken to first picking,
fruiting span, and yield per plant, number of weeds per unit area and fresh weight of weeds per unit area were
evaluated. Plants in the treatments with UV treated polythene mulch exhibited a significantly higher growth and
yield in both chilli varieties along with a significantly lower weed infestation. The plants grown with 100% and
75% fertilizer levels with polythene mulch did not show a significant difference in total yield, indicating the
possibility of reducing 25% of recommended fertilizers. Therefore, the UV treated biodegradable silver on black
polythene mulch can be recommended to obtain high production with less fertilizer and zero levels of herbicides.
