Abstract:
Cowpea (Vigna unguiculata) is an important legume crop in dry zones of Sri Lanka.
As such study was to evaluate the physiological, morphological and yield characteristics of five
cowpea varieties namely Bombay, Dhawala, Waruni, ANKCP 01, and MICP 01 performed
under different moisture levels (100%, 75%, 50% and 25%) at FCRDI (Field Crops Research
and Development Institute), Mahailluppallama. The morphological, physiological, and yield
characteristics of the cowpea varieties were investigated in a field experiment, using a
Randomized Complete Block Design (RCBD) with three replicates. Analysis of Variance
(ANOVA) showed significant variations among the varieties and moisture levels for the traits
such as number of leaves after 6 weeks, number of branches 6WAP, leaflet width 6WAP, leaf
area, number of days to flowering, number of partially opened stomata, number of fully closed
stomata, pod length, seed length, seed width, seed thickness, and yield. The interaction effects
between varieties and moisture stress were significant for the trait, number of branches after six
weeks of planting, indicate the importance of considering these traits in the selection process of
new variety development. Dhawala (V2) was the most promising and it outperformed others in
terms of plant height, leaf size, number of branches, grain yield and root length under moisture
stress even under 50% moisture condition. ANKCP 01 showed least number of days to
germination (3 days) even in 25% moisture condition. At early stages (2WAP and 4WAP)
Bombay showed highest plant height among varieties and also Bombay showed good seed
characteristics and leaf characteristics above 50% moisture stress condition. Dhawala showed
highest number of leaves at all stages and concluded that the high rate of photosynthesis resulted
in a very important trait of highest average yield of 5.08g even in 50% moisture condition. At
25% moisture level only Dhawala produced flowers. Among five varieties MICP 01 showed
poor characterization for considered traits including lowest yield per plant (3.41g) under 25%
moisture condition. Waruni showed highest stomata activity with longest pod (12.33cm) even in
50% moisture condition. Results of this study revealed that Dhawala is more suitable for even
50% of moisture, will contribute to ensure sustainable cowpea production in water-scarce
environments, enhanced food security and agricultural sustainability.
