Growth performance of black pepper raised on Artocarpus heterophyllus planted at variable stand densities

Abstract

Black pepper (Piper nigrum L.) is the one of the prominent commercial spice crops grown for culinary and pharmaceutical value. It is trailed on large number of tree species traditionally grown in homegardens and farm lands of humid regions of Kerala. Artocarpus heterophyllus is one such promising support trees for cultivation of pepper. Despite the traditional knowledge of trailing pepper on staggered jack trees, such information on optimal tree spacing/density for enhancing the productivity of black pepper when cultivated in blocks in organized manner, is lacking. Considering the utility of Jack as a support for raising black pepper, the jack woodlot was established in 2020 to evaluate the growth performance of black pepper under jack trees managed at different planting spacing (3×3 m, 3×4 m, and 3×5 m). The experimental design followed was randomized block design (RBD) with four replications, at Suhasini hills, Kerala Agricultural University, Thrissur, Kerala. The black pepper was raised after 1 year of establishment of jack woodlot. The results from the study showed variable growth trends for black pepper under different tree spacing regimes, though many of such trends were non-significant. The closely spaced jack woodlots registered lower vine length (21.75 to 83.50 cm) while the trees at wider spacing (18.50 to 111.50 cm; 3×4 m and 20.25 to 92 cm; 3x5m) recorded fairly better vine length for trailed black pepper. The pepper vine collar diameter showed variable trend with better collar diameter associated with closely spaced jack trees (4.83 to 6.28 mm; 3×3 m and 4.67 to 6.22 mm; 3×4 m) while the corresponding range at wider spacing was less (4.84 to 5.54 mm; 3×5 m). Comparable leaf number (6.25 to 17.75 and 6.75 to 18.50) was recorded under 3×4 m and 3×5 m spacing respectively, while low leaf count was observed under 3×3 m spacing (6.50 to 15.50). Although, the best growth has been achieved under 3×4 m spacing, the future predictions cannot be made based on the early results. The present study underscores the need for further investigation to better understand the conditions that favour the growth and emphasize the consideration to other factors such as environmental conditions and management practices, along with tree spacing.