Influence of tree diameter and trunk distance on growth and yield of field crops in agroecosystems of North-Western Himalaya

In present study, trees of Toona ciliata of four different diameter classes viz., D₁ (20–30 cm), D₂ (30–40 cm), D₃ (40–50 cm) and D₄ (>50 cm) were selected on bunds in farmer's field to study crop production of Triticum aestivum, Hordeum vulgare, Pisum sativum and Coriandrum sativum in Darodeuriya area of Sirmour district of Himachal Pradesh. Crop production was studied under trees of different diameter classes at five distances (2, 3, 4, 5 m from tree trunk and outside tree canopy). Yield of T. aestivum increased significantly with increase in distance from the tree trunk and highest production (2309 kg ha⁻¹) was recorded outside tree canopy. Irrespective of distance from tree trunk, T. aestivum grown under 20–30 cm DBH class trees gave significantly higher economic yield (2130 kg ha⁻¹) and biological yield (3807 kg ha⁻¹). Economic yield of P. sativum increased with the increase in distance from tree trunk being maximum (11620 kg ha) outside tree canopy and minimum (8140 kg ha⁻¹) was registered at 2 m distance from tree trunk. Number of plants and production of all the crops enhanced with successive increase in distance; hence, the study recommends the mature trees in agricultural field bunds at least 4–5 m away from intercrop.