Effect of irrigation water sources and sowing dates on pesticide residues and chemical composition of sugar beet

摘要

Investigation on the influence of irrigation water sources and sowing dates on pesticide residues, chemical composition and productivity of sugar beet revealed sowing date in August increased SPAD value and sugar %. The sowing date in October producedthe maximum values of length and diameter root growth, yield (ton/fed), sugar (ton/fed) and leaves (ton/fed) of sugar beet at harvest. Further sowing date and irrigation water sources affected pesticides dissipation in soil. The detected amounts of residues were high in October cultivation than August; also, pesticide residues more degradable in soil irrigated by drainage water. The detected pesticide residues in roots and leaves were below MRL, except chlorpyrifos in case of river and mix water treatments during October sowing date. Sugar beet leaves contained much higher concentration of heavy metals than roots; also, plants irrigated by drainage water contained high amounts of heavy metals than other treatments.