Growth Responses, Pigment and Stomatal Behaviour of Maize to Foliar Application of NAA

Abstract

An investigation was conducted to find out the responses of two varieties of maize BHM- 7 (V₁) and BHM-9 (V₂) to Naphthalene acetic acid (NAA) on the growth, dry matter, pigment and stomatal behaviour. In case of V1, plant height was found to decrease due to all the treatments at all the ages except at 7 DAS due to T₃ treatment. In V₂, increase in plant height was recorded following T₁ and T₃ treatments at all the ages except at 21 DAS. In both the varieties at all the ages, maximum number of leaves per plant were obtained from T₃ treatment. In case of V₁ number of leaves per plant increased only due to T₃ treatment in comparison to control whereas, in V₂ number of leaves per plant increased following all the treatments. In case of V₁, dry weight of shoot increased due to T₃ treatment at 8 and 15 DAS. But in case of V₂, there was increasing tendency in dry weight of shoot due to all treatments at all ages except at 8 DAS due to T₂ treatment. In both the varieties dry weight of root increased due to T₃ treatment at all ages. Chl. a was more than chl. b at all the stages in both the varieties and both chl. a and chl. b were recorded lowest at the flowering stage. In case of V₁, amount of chl. b was remarkably higher at the tillering stage whereas, in case of V₂, amount of chl. a and carotenoid were remarkably higher at the grain filling stage. In both the varieties, the amount of chl. a was found to increase and decrease due to all the treatments at all the stages. Chlorophyll b both increased and decreased in V₁ and the maximum increase was due to T₃ at the tillering and grain filling stages. In case of V₂, chl. b increased at the tillering stage following all the treatments and maximum increase was also due to T₃. However, in V₁ carotenoid contents of leaf increased following all the treatments at the tillering stage and decreased following all the treatments at flowering and grain filling stages. Number of stomata increased except due to T₂ in V₁, whereas, number of epidermal cell decreased due to T₀ and T₂ in V₁. Stomatal density in V₂ was found relatively higher due to NAA application. It was also found that NAA increased the stomatal density with the increase of concentration except 50 ppm (T₂) in V₂. Stomatal index was found to decrease due to T₁ inV₁ and due to T₀ in V₂.

Journal of Bangladesh Academy of Sciences, Vol. 41, No. 1, 1-9 2017