Citron watermelon characterisation and trait analysis in Kalahari sands

Abstract

Background: Citron watermelon, a drought-tolerant and nutrient-dense crop requiring low input, holds potential for enhancing food security under climate change conditions. However, it remains under-researched, with low productivity levels.

Aim: To agro-morphologically characterise citron watermelon accessions and identify trait relationships relevant for variety development.

Setting: The experiment was carried out at a Lupane State University Farm with Kalahari sands in Zimbabwe.

Methods: A randomised complete block design field experiment, with three replications, was conducted over two consecutive seasons.

Results: The accessions displayed wide diversity in fruit shape, skin colour and seed colour. Fruit yield ranged from 18.5 t/ha to 190.2 t/ha, exhibiting a strong positive correlation with the number of fruits per plant (R = 0.99) and individual fruit weight (R = 0.98). Path analysis confirmed that these traits exerted the highest direct effects on yield. Principal component analysis revealed that the first three components explained 89.85% of the total variation between accessions.

Conclusion: The significant variation and trait correlations observed offer opportunities for effective parental selection and early genetic gains in breeding programmes. There is scope to improve yield-determining traits, such as the number of fruits per plant and individual fruit weight, forming a strong basis for initiating a breeding programme for this crop.

Contribution: Promising accessions identified in this study can be utilised as parental lines for citron watermelon improvement.