Effect of Ploughing Depth on the Growth and Yield of Heracleum candicans:a Threatened Medicinal Herb and a Less-explored Potential Crop of the Himalayan Region

This paper examines the effect of ploughing depths (A — 60 cm,B — 45 cm and C — 30 cm) on the growth and yield of Heracleum candicans Wall (Apiaceae),a threatened medicinal herb of the Himalayan region. This less-explored plant is being suggested as a potential crop for the mountain agriculture. The study was carried out in an orchard in Himachal Pradesh,India at 2500 m altitude,for two successive growth years. During the first year,all plants remained in juvenile state;in the second year,nearly 65 % plants produced flowers only under 60 cm ploughing depth. Among its morphological traits,plant height,collar diameter and aboveground fresh weight were found to be strongly correlated (P < 0.01) with the belowground biomass during the first year (r =0.968,0.925 and 0.973,respectively) and during the second year (r=0.945,0.928 and 0.775,respectively). Increase in the ploughing depth was significantly correlated (P<0.01) with all growth parameters,including the belowground dry weight,marketable portion of the produce. The belowground biomass (commercial yield;16.28 Qt/hec) at depth A was about 2.6 and 4.7 times higher than those recorded at depths B and C,respectively. The results clearly justify the importance of deep ploughing and this paper strongly recommends it for economically sustainable cropping.

This paper examines the effect of ploughing depths （A -- 60 cm, B -- 45 cm and C -- 30 cm） on the growth and yield of Heracleum candicans Wall （Apiaceae）, a threatened medicinal herb of the Himalayan region. This less-explored plant is being suggested as a potential crop for the mountain agriculture. The study was carried out in an orchard in Himachal Pradesh, India at 2500 m altitude, for two successive growth years. During the first year, all plants remained in juvenile state; in the second year, nearly 65 % plants produced flowers only under 60cm ploughing depth. Among its morphological traits, plant height, collar diameter and aboveground flesh weight were found to be strongly correlated （P 〈 0.01） with the belowground biomass during the first year （r =0.968, 0.925 and 0.973, respectively） and during the second year （r=0.945, 0.928 and 0.775, respectively）. Increase in the ploughing depth was significantly correlated （P〈0.01） with all growth parameters, including the belowground dry weight, marketable portion of the produce. The belowground biomass （commercial yield; 16.28 Qt/hec） at depth A was about 2.6 and 4.7 times higher than those recorded at depths B and C, respectively. The results clearly justify the importance of deep ploughing and this paper strongly recommends it for economically sustainable cropping.