Investigation of harvest index linear increase and related parameters in filling grain period of chickpea (Cicer arietinum)

Quantitative information regarding biomass partitioning in chickpea (Cicer arietinum L.) is limited or inconclusive. The objective of this study was to predict biomass partitioning to seed based on harvest index in chickpea crops grown under well-watered conditions. A field experiments, with 3 sowing dates and 4 plant densities, was conducted in Gorgan during 2004-2005. Crop biomass and phenological stages were measured between emergence and maturity. Density increase and delay in sowing date led to each phonological stages period decrease. Harvest index increased in seed filling period linearly. The effect of density on harvest index linear increase was not significant but there was different between sowing date. The time of beginning harvest index linear increase, decreased from 26 to 8 days from first sowing date to third one, but there was any difference in plant density. therefore From obtained coefficient in this research we can use in chickpea growth simulation models.