Abstract:
Aloe vera had been used for numerous medical and cosmetic applications since ancient times. The
gel of A. vera possesses healing ability of skin burns and cutaneous injuries, prophylactic effect
against radiation leucopenia, antiulcer, anti-diabetic, anti-fungal, anti-bacterial, inflammationinhibiting
effect, anti-AIDS and anti-cancer. Unfortunately little attention was paid on different
aspects of this herb in Bangladesh. Two separate experiments were conducted sequentially in the
Department of Agricultural Chemistry, Bangladesh Agricultural University and Bangladesh Institute
of Nuclear Agriculture, Mymensingh to find out the most suitable soil for A. vera cultivation,
integrated effects of inorganic fertilizer (IF) and poultry manure (PM) on the growth, leaf biomass
yield, nutritional and pharmaceutical constituents of A. vera and post-harvest fertility of the soil. The
economics of A. vera cultivation and public perception regarding the medicinal and commercial
importance of this plant was also studied. Seedlings of 18 months old were collected from
Shomvogonj, Mymensingh and planted during last week of May, 2017 for soil screening experiment,
and 2
nd
week of October, 2017 for integrated experiment, respectively following CRD with three
replications. Based on the findings of soil screening data, acid soil was used for the integrated
experiment. Most of the soils were clay to clay loam in texture except non-calcareous and charland soil.
The soils were acidic to neutral and organic matter content was low to moderate except peat soil. Different
soil types significantly influenced the growth and leaf biomass yield of A. vera. Highest plant height,
leaf number, leaf area and fresh weight were recorded from the plant grown in non-calcareous soil
whereas maximum fresh gel weight, dry leaf weight and yield increase over acid sulphate soil were
from the plant grown in calcareous soil. The performance of the soils in relation to leaf biomass yield
was of the following order: calcareous ≥ acid ≥ non-calcareous > charland > saline 1 > saline 2 >
peat > acid sulphate soils. Different combinations of IF and PM also exerted significant influence on
the growth, leaf yield, nutritional and pharmaceutical contents of A. vera. The highest values of
growth parameters and yield were obtained from the plant treated with 25% IF and 75% PM (IF
25
) at
harvest. About 153% yield increase over control was obtained from this treatment. The concentration
and uptake of N, P, K and S were highest when the plants were treated with 100% IF whereas the
highest uptake of Ca, Mg, Fe, Mn and Zn was noticed from 25% IF and 75% PM. Aloin
concentration was increased with the increased application of PM. In contrast, highest chlorophyll,
phenolic and flavonoid concentrations were found in the plants receiving the treatment IF
25
.
Fresh gel weight were significantly and positively correlated with plant height, number of leaves, leaf
area and fresh leaf weight. Pharmaceutical compounds and mineral nutrients were also significantly
and positively correlated with each other. Fresh gel weight and mineral contents like NPK were also
strongly and positively correlated. The pH, organic matter, total N, exchangeable K, Ca, Mg and
available P, S, Zn, B contents of post-harvest soil were significantly increased with the increased
levels of PM. Based on BCR value (1.72), IF
25
PM
75
was the best profitable treatment. People’s
perception revealed that 61% respondents used A. vera for curing various ailments and 72%
respondents opined that the cultivation of this crop could be two to three times more profitable than
other crops. Considering the overall socio-economic conditions of the farmers, it might be advised to
cultivate A. vera in acid/calcareous soils applying 75% PM (5 t ha
-1
) along with 25% inorganic
fertilizer (N, P, K and S @150, 80, 120 and 30 kg ha
-1
, respectively) under the agro-climatic
conditions of the study area.