—Chili growths on Murashige and Skoog (MS) medium
amended with 20 ppm chitosan solution with low (80−100 kDa),
medium (200−300 kDa), and high (600−900 kDa) molecular weight
(MW), 0.5% acetic acid, or without chitosan (control) was studied.
Chili seedlings cultured on MS with chitosan solution presented light
green leaves and had a lower number of leaves and lower plant heights
than the control seedlings. The untreated chili seedlings that were
transplanted into soil mixed with 3 MWs of chitosan powder were
investigated in a greenhouse. Results showed that the seedlings grown
in the soil mixed with 1.0% (w/w) high MW presented the greatest
growth rate and chlorophyll content, and a higher number of dark
green leaves followed by medium and low MW at 30 days after
transplant (DAT). A comparison of chitosan concentrations at 0.5 and
1.0% (w/w) on the growth and seed productivity was also performed in
the green house. The chili seedlings cultured in soil with 1.0% high
MW of chitosan powder presented significantly higher plant heights,
canopy diameter, leaf numbers plant-1, leaf widths and lengths,
chlorophyll content and dark green leaf color as compared to the
control plants. As a result, the significantly greatest seed yield
indicated by fruit fresh weight plant-1, fruit numbers plant-1, seed
numbers fruit-1, and seed weight plant-1 was observed in the plants
grown in the soil mixed with 1.0% high MW of chitosan.