Evaluation of Deficit Irrigation Effects on Sugarbeet Productivity and Control of Root- knot Nematode, Meloidogyne incognita Infection

Abstract

Water shortages have increased growers interest to investigate the effects of deficit irrigation (DI) levels, i.e. 25, 50 and 75% of irrigation water requirement (IWR) compared with the full irrigation level (100 % of IWR) on sugarbeet productivity and on final population size (p f) and reproduction factor (RF) of root-knot nematode, Meloidogyne incognita, as well as on water use efficiency (WUE) at the end of growing season, under greenhouse conditions. Results showed that DI at the levels of 25, 50, and 75% of IWR decreased significantly yield characters (root and gross sugar yields) and sugar percent of sugarbeet, and increased WUE compared to full irrigation level (100%) treatment, without significant difference between 75 and 100% DI levels in root yield. The yield characters were greatly reductions at DI levels of 25 and 50% of IWR. Among the irrigation levels treatments, WUE was lowest in the 100% irrigation level and highest in the 25% irrigation level. Also, the results indicated that the p f and RF were significantly lower at irrigation levels of 25, 50, and 75% than 100% level. The 75% irrigation level caused minor reductions in root yield, gross sugar yield and sugar percent, but significantly reduced nematode infection (p f and RF) compared to 100% irrigation level. Thus, deficit irrigation to level of 75% of IWR can be utilized to the management of root-knot nematode, M. incognita infection without significant reduction in sugarbeet yields.

Soil and Crop-Water Relations and Productivity of Two Sugar Beet Varieties as Affected by Irrigation Rates and Soil Amendments under Drip Irrigation System

“…Also, drip irrigation at 60% of IWR gave the best roots yield and good quality of sugarbeet crop (El-Darder et al, 2017). Also, Maareg et al (2018) found that the highest roots and sugar yields fed -1 . values were recorded with 75 and 100% of IWR rates, without significant difference between them, while irrigation rate of 75% of IWR significantly exceeded 100% of IWR rate, in water use efficiency (WUE).…”