The influence of land management and date of planting on physical properties of Safid e Pai-saye onion (Allium cepa L.)

Abstract

Onion botanically named Allium cepa L. is a major crop of Alliaceae family. It is one of the largest commercially grown vegetables in the world including Afghanistan. This crop originated from Afghanistan and large number of its wild varieties are observed in the country. Local variety named Safid e Paisaye was selected for this investigation due to its capacity of longer storage and higher demand in the market. Very less research efforts are made to improve its bulb quality and share in the market. This investigation is carried out at Kabul university agriculture research farm in coordination with Amity University Uttar Pradesh, to study the effect of land management and planting date on bulb physical properties of onion. The parameters studied in this investigation include bulb width (cm), length (cm), thickness (cm), geometric mean diameter, arithmetic mean diameter, shape index, sphericity, roundness, ellipsoid ratio, frontal surface, cross sectional area, total area, number of scales, equatorial firmness (Kg/cm2) and polar firmness (Kg/cm2). The data is collected using required tools and was analyzed using R statistical analysis software. The results showed significant effect of planting date on physical properties of onion bulb. The first planting date (10th May) recorded the largest bulb width (6.95 cm), length (4.42 cm), thickness (6.75 cm), geometric mean diameter (5.91 cm), arithmetic mean diameter (6.04 cm), frontal surface (24.26 cm2), cross sectional area (28.84 cm2) and total area (110.63 cm2). The same planting date recorded the lowest values for bulb shape index (0.64) and sphericity (0.85). Land management practices did not have significant effect on physical properties of onion bulb. None of the studied factors had significant effect on bulb roundness, ellipsoid ratio, number of scales, equatorial firmness and polar firmness. Conclusions: early planting of Safid e Paisaye onion seedlings can increase bulb size and improve bulb physical characteristics. This also helps to maintain the flat and round shape of onion bulb. Land preparation method and plough depth do not have significant influence on physical properties of onion bulb.