International Journal of Horticulture, 2017, Vol.7, No. 12, 95-105
95
Research Article
Open Access
Longitudinal Growth Curve of Elephant Foot Yam under Extreme Stress and
Plant Sensitivity
Ratan Dasgupta
Theoretical Statistics and Mathematics unit, Indian Statistical Institute, 203 B T Road, Kolkata, India
Corresponding email:
International Journal of Horticulture, 2017, Vol. 7, No. 12 doi:
Received: 25 Apr., 2017
Accepted: 5 May, 2017
Published: 15 Jun., 2017
Copyright
©2017 Dasgupta, This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Dasgupta R., 2017, Longitudinal growth curve of elephant foot yam under extreme stress and plant sensitivity, International Journal of Horticulture, 7(12):
95-105 (doi:
)
Abstract
Plant sensitivity under extreme stress in harsh agro-climatic environment for yam plants is studied to maximise yam
yield for different seed weights. Longitudinal growths of 60 Elephant-foot-yam, 20 for each seed weight 500 g, 650 g and 800 g are
examined in a field experiment conducted at Indian Statistical Institute Giridih, Jharkhand. Little manure and a few irrigations were
available during the experiment. In order to maximise total yield, we examine yam growth under stress of interim yam detachment
with two options: interim yam detachment towards the beginning of experiment, or at a later time from the middle of experiment; we
also examine undisturbed yam growth for comparison. Growth curve analysis indicates that uprooting plants for taking interim
readings and subsequent replantation has a favorable effect on inert growth of yam. For three different seed weights in either of three
categories of induced stress on yam plants as, detachment of yam at first interim reading, detachment at second interim reading, and
no interim detachment during experiment - only uprooting and replanting after taking growth readings; longitudinal growth curves
are constructed via four possible readings on yam. Detaching yam around four and half month from sprouting for seed weight 800 g,
and replanting the remaining stem structure with some roots attached to it and continue experiment till final harvest on maturity, has
significantly increasing effect on interim yield plus yield on maturity, in comparison with other strategies under extreme stress. Yam
growth becomes higher due to stress from interim yam detachment.
Keywords
Growth curve; Longitudinal analysis; Lowess regression; Plant sensitivity; Sustainable agriculture;
Amorphophallus
paeoniifolius
1 Introduction
Elephant foot yam (
Amorphophallus paeoniifolius
(Dennst.) Nicolson) is a tropical tuber crop commonly used as
a staple food. This cash crop can be cultivated in harsh agro-climatic environment with little plant care. We
consider yam plantation of
‘Bidhan Kusum’
, a non-irritant high yielding variety in extreme climatic environment
of high summer temperature with nominal plant care of sustainable agriculture in alluvial soil full of gravels as in
Giridih, Jharkhand (23.35
o
N, 85.33
o
E).
Sensitivity of plants under various stimuli is well studied. Electrical signalling in the wounded plants is
investigated e.g., in Wildon et al. (1992). Plant sensitivity under stress can suitably be utilized to increase crop
yield see e.g., Dasgupta (2016), and the references therein. Among other stimuli, plants are sensitive to the color
of light and touch. The affect of colored light on plants are studied e.g., in Zait et al. (2017). Touch sensitivity of
plants are investigated e.g., in Musah et al. (2015).
Plants usually respond to changes in temperature, chemicals, touches etc., by change in growth rate or its
direction of growth. Extreme climatic stress has in general a negative impact on crop yields. We consider a form
of stress that may suitably be utilised for higher growth of yam. With a modification in harvesting strategy, one
may substantially increase yam yield in two-stage harvesting from individual plants with interim harvest at
appropriate time
of growth, this plus the final yield at plant maturity; the total yield, sum of the two; is seen to be
higher compared to that for other strategies including usual single harvest from plants. In this study we select
appropriate seed weight and also investigate the choice of appropriate time for interim harvest of yam in order to
have high yield with nominal plant care in harsh agro-climatic condition as in Giridih, Jharkhand (India). Under
