EFFECT OF MULCHING TYPE AND DURATION ON THE PRODUCTIVITY AND WATER USE EFFICIENCY OF POTATO

Abstract

Field experiments were conducted during the winter season of 2014/2015 at EL- Tahrir Provence, Behera Governorate, west of Nile Delta of Egypt to study the effect of mulching type and duration on the productivity and water use efficiency of potato. Sixteen treatments comprising of four level of mulching (no- mulch (MO) - Rice straw mulch (RSM), Black polyethylene (BPM) and transparent polyethylene (TPM)) and four mulching time (T1-T4) were investigated. All treatments were repeated three times in complete randomized block design. Soil temperature, soil water content, seasonal water applied and seasonal crop evapotranspiration were monitored throughout the growing season, while the harvested potato tuber were weighted and sampled to determine some quality parameters. Results revealed that, mulching practices influenced the soil temperature. Applying Rice straw mulch moderates the soil temperature throughout the growing season and offered the most favorable potato growing condition. In contrast, polyethylene mulch materials increased the soil mean temperature by about 4-5 °C throughout the growing season which hampered tuber initiation, bulking and consequently the total potato tuber yield. Both mulching types and duration affects potato tuber yield, quality and water use efficiency. RSMT4 treatment had the maximum tuber number per plant, tuber mass, tuber yield, starch and total soluble solids (TSS) content of 8.14, 105.35 g, 17.45 Mg/fed., 14.68 and 5.63%, respectively as compared with the other mulched and non- mulched treatments. Retaining the polyethylene mulch materials up to the end of growing season negatively influenced the growth parameters, tuber yield and the measured quality parameters. Concerning the seasonal applied water (SAW) and crop evapotranspiration (ETC), MO treatment had the maximum SAW and ETC values of 522 and 438 mm, respectively. Mulching practices saved irrigation water by 14.08, 19.65 and 18.48% with RSM, BPM and TPM, respectively as compared with the control treatment. RSMT4 treatment had the maximum irrigation water use efficiency (IWUE) and water use efficiency (WUE) of 10.39 and 13.02 kg/m3,respectively. However, BPM and TPM mulch materials inhabited the maximum IWUE and WUE values of 10.03, 12.54 and 7.89 and 8.89 kg/m3, respectively when it was retained over the soil surface up to the end of the tuber formation stage (T3), suggesting that the PM should be removed early in order to avoid their negative effects on the tuber yield, quality and water use efficiencies.