Growth, seed yield and economics of cowpea (Vigna unguiculata L.) as influenced by crop geometry and sulphur levels in Kandahar region of Afghanistan

Abstract

A field experiment was conducted during kharif season of 2020 at the research farm of Afghanistan National Agricultural Science and Technology University (ANASTU), Kandahar, Afghanistan. The experiment was laid out in split-plot design with three replications. The experiment consisted of 12 treatments viz., three plant spacing in main plot (30 cm ×10 cm, 40 cm ×10 cm and 50 cm ×10 cm) and four sulphur levels (0, 20, 40 and 60 kg S/ha) in sub-plots. The soil of the experimental field was sandy clay loam, and being low in organic matter levels. Thecowpea variety ‘Cheshm Bulbuli’ was sown using 60kg seed/ha. A positive effect of crop geometry was recorded on the growth parameters namely, plant height, shoot dry weight, root dry weight in cowpea crop. The highest values of these parameters were obtained at the crop geometry C (50 cm ×10 cm), followed by crop geometry 40 cm ×10 cm and 30 cm × 10cm. Yield attributes viz., number of branches /plant, leaf area (cm2/plant), number of nodules/plant,seed yield (kg/ha), stover yield (kg/ha), and biological yield (kg/ha)of cowpea were higher at crop geometry 50 cm ×10 cm compared to 40 cm ×10 cm and 30 cm ×10 cm. The highest seed yield (2164.51kg/ha) was recorded at crop geometry 50 cm ×10 cm. Application of 60 kgS /ha resulted in significantly higher values of the growth parameters and yield attributes as compared to the rest of the sulphur levels. Application of 60 kgS /haincreased the seed yield (1879.79 kg/ha) significantly over the no sulphur control. In general, higher values of different biometric observations and yield attributes were recorded at crop geometry 50 cm ×10 cm with application of 60 kg S /ha. Hence, the crop geometryof 50 cm ×10 cm with the application of adequate amount of sulphur (60 kg S /ha) fertilization is necessary.