International Journal of Horticulture, 2017,Vol.7, No. 23, 205-218
205
Research Article Open Access
Longitudinal Growth Curve of Elephant Foot Yam under Extreme Stress and
Plant Sensitivity III
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.23 doi
Received: 07 Aug., 2017
Accepted: 15 Aug., 2017
Published: 22 Sep., 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 III, International Journal of Horticulture, 7(23):
205-218 (doi
Abstract
We investigate yield of Elephant-foot-yam with seed weight, plant height, canopy radius and girth at the top of stem as
main variables in three dimensional studies on proliferation rate. Studies on plant sensitivity under extreme stress and minimal
survival environment in yam growth experiments to maximise yield were undertaken in Dasgupta (2017a). Detaching underground
yam around four and half month from sprouting for plants with seed weight 800 g, and replanting the remaining stem structure with
some roots attached to it and continue experiment till final harvest on maturity, was seen to have significantly increasing effect in
two stage harvest, when only a few irrigations were given in the peak summer temperature and little manure was administered at
start. We compute proliferation rates modifying a technique of Dasgupta (2015). We consider weighted average of raw rates on
proliferation, estimated at a time point with smooth weight function that down weights rates from distant points. Variations of
proliferation rates with seed weight in continuous scale over time indicates that plants with seed weight 500 g, if properly nourished
to have an extended lifetime, could have produced much higher yield than observed in the experiment, as the proliferation rate is
high towards the end of lifetime; in contrast to downward trend of rates towards zero over time in plants with higher seed weights.
Plant height, girth at the top of stem and canopy radius may also provide information on growth status in three dimensional figures,
in place of seed weight of yam.
Keywords
Elephant foot yam; Longitudinal analysis; Proliferation rate; Canopy radius; Brownian motion;
Amorphophallus
paeoniifolius
1 Introduction
Elephant foot yam (
Amorphophallus paeoniifolius
) is a tropical tuber crop that has production potential. This is
cultivated in different regions as a cash crop. Genetic background of yam across regions is studied e.g., in
Santosa et al. (2017). Sensitivity of Elephant-foot-yam plants under stress is analyzed in relation to yield to have
higher yield than usual. Plant stress may suitably be used to achieve higher yield of yam, e.g., see Dasgupta
(2017a), Dasgupta (2017b). Yam plants are found to be stress resistant when cultivated in a harsh agro-climatic
environment. Seed weight 800 g is seen to be appropriate for high yield in a study reported in Dasgupta (2017a).
When the stress is extreme for plant survival, higher seed weight supports the plant growth at initial stage and
800 g of seed weight produced more yam in an experiment conducted in Giridih, Jharkhand (India).
Harsh agro-climatic environment in the field experiment with a few irrigations given in peak of summer in the
beginning of the experiment acted as severe stress, the yam plants were further subjected to interim yam
detachment at either of the two time zones in growth experiment and remaining stem structure was replanted as
described in Dasgupta (2017a). The first interim yam detachment time was at two and half months after sprouting,
and the second interim detachment time was at four and half months from sprouting. Yams are detached only
once during the experiment from alive plants.
For seed weights 500 g, 650 g and 800 g; the second time period for interim yam detachment from plants is seen
to be superior to achieve high yield in total.
