Results showed that different tillage methods significantly (P [?] 0.05) influenced RNPH, but there was no significant difference in other studied traits (Table II).
NS = Non-significant; = Significant at 0.05 probability level; (RNPH: root number per hectare; RODM: root dry matter)
In this study, root yield, yield components (RNPH, sugar yield, RODM, root length and rim diameter) and some quality characteristics (sugar content, K, Na, ALAN and molasses) of sugar beet were studied to investigate the influence of different tillage methods on yield and quality of sugar beet.
Root yield and yield components: The highest value of RNPH (135412 roots ha-1) was recorded in the MR treatment, while the lowest value of RNPH (115000 roots ha-1) was recorded in the NT treatment (Table III).
(2008), Rashidi and Khabbaz (2009) that tillage practices can be associated with improved soil physical and mechanical properties (increased pore space, decreased bulk density, increased moisture preservation and decreased penetration resistance), enhanced soil structure, better seed- soil/root-soil contact and superior weed control, which positively influence RNPH and consequently root yield and sugar yield of sugar beet.
soil physical and mechanical properties (decreased pore space, increased bulk density, decreased moisture preservation and increased penetration resistance), inferior seed/root-soil contact and raised diversity of weed species and population, which negatively influence RNPH and as a results root yield and sugar yield of sugar beet.
(1992), Borresen (1993), Carter & Ivany (2006) and Ozpinar (2006) that conservation tillage methods may be associated with worse soil physical and mechanical properties (decreased pore space, increased bulk density, decreased moisture preservation and increased penetration resistance), poorer seed/root-soil contact and raised diversity of weed species and population which negatively influence RNPH, resulting in decreased RY and as a result SUGY of sugar beet.
Different tillage methods significantly (P # 0.05) affected RNPH, but there was no significant difference in RY, SUGY, RODM, ROTL and RIMD.
Table 1: Soil physical and chemical properties of the experimental site (0-30 cm depth), 2008 & 2009 Date pH EC OC(%) N(%) P(ppm) (dS[m.sup.-1] 2008 7.9 0.72 0.92 0.09 10.5 2009 8.3 0.55 0.36 0.04 25.6 Date K(ppm) Fe(ppm) Zn(ppm) Cu(ppm) Mn(ppm) 2008 280 6.2 0.8 2.3 16.2 2009 310 6.4 1.0 2.4 14.4 Date B(ppm) Soil texture 2008 0.7 Loam 2009 0.7 Loam Table 2: Analysis of variance for root yield and yield components of sugar beet under different tillage methods (mean of 2008 & 2009) Mean square Source of variation Df RY RNPH SUGY Replication 3 257.9 (NS) 127777616 (NS) 6.10 (NS) Treatment 6 72.36 (NS) 184223872 * 3.27 (NS) Error 18 390.7 62268312 10.5 C.V.