Effect of Soil Warming by Electrically Heated Wire on Bolting and Growth in Welsh Onion (Allium fistulosum L.)

Abstract

Effect of soil warming by electrically heated wire (about 20°C) on bolting and growth in Welsh onion (Allium fistulosum L.) was investigated. Soil warming promoted the rate of leaf emergence to twice the control value. Soil warming increased dry weight of both above and under-ground parts, but did not influence the plant height or leaf length. Reduced bolting rate due to soil warming was observed. It was shown that soil warming using a heated wire was an effective treatment to suppress bolting and promote growth in Welsh onions harvested in early summer.