Indian Journal of Science and Technology

Abstract

A field study was conducted at the experimental site of the Islamic Azad University of Kermanshah province, Iran during 2010 to find out the effects of pod and leaflet removal treatments during reproductive growth stages on leaf area index (LAI) and dry matter accumulation in different part of soybean plant. The experimental design was a split plot in randomized complete block with three replications. Main plot treatments consisted cultivars V1=Williams and V2=Clark, and Subplot included six treatments of defoliation and pod removal: removing none (T1), one lateral leaflet at R1-R3 (T2), two lateral leaflets at R1-R3 (T3), one lateral leaflet at R5-R6 (T4), two lateral leaflets at R5-R6 (T5) and pods removal 50% at R5 +10 days (T6). The results indicated that there are a compensatory responses by soybean to pod and leaf removals treatments, especially, when that leaflet removal occurred at the R1-R3 stages and sufficiently severe (T3). Removal of two lateral leaflets at R1-R3 was caused that LDW/TDW ratio from 26 % at the 82 DAE increased up to 29 % at the 97 DAE. We did not compensatory responses at the other treatments (T1, T2, T5 and T6). In addition, maximum value of plant dry weight was obtained about at 82 and 95 days after emergence for Williams and Clark cultivars, respectively. Also, the highest LAI at the end of growth stage belonged to T2 treatment and Clark cultivar.
Keywords: Compensatory responses, defoliation, leaf area index, reproductive stages, soybean Abbreviation: DAE: day after emergence, LAI: leaf area index, TDW, SDW, LDW, PDW and GDW: total, stem, leaf, pod and grain dry weight per plant, respectively.