EFFECT OF LAST IRRIGATION AND THINNING OF PLANTS WITHIN THE ROW ON SEED YIELD AND IT`S COMPONENTS OF ALFAFA (Medicago sativa L.)

Abstract

A study was conducted at experiment field of the college of Agriculture ، University of Baghdad for two seasons 2011- 2012 and 2012- 2013 to investigate the effect of last irrigation date applied at ( full bloom ، beginning of pods formation، 50% of the pods with green color and 20% of the pods with brown color ) and thinning treatments within the row using the ratio between reminder : removal stands as fellow ( 10 cm : 10 cm، 10 cm : 30 cm، 10 cm : 50 cm، 20 cm : 20 cm، 20 cm : 30 cm and 20 cm : 50 cm) on seed yield and Its components in a local cultivar of alfalfa. Layout of the experiment was in Randomize Complete Block Design (R.C.B.D.) in Nested – split plot arrangement with three replications. Last irrigation dates were used as main plot، while thinning treatments were used as sub- plot. Results showed that in both season، last irrigation had significant effect on number of stem/m2 ، racemes/ stem ، pods/ racemes، seeds/pod and seed yield. 1000 seed weight significantly influenced only in 1st season. In both seasons، Results has also indicated a significant effect of thinning treatments on all seed yield components and seed yield except number of seeds / pod and seed yield in 2nd season. As average for two seasons ، higher seed yield ( 578.35 Kg/ ha) can be obtained from stands thinning to 20 cm : 30 cm and last irrigation was applied at beginning of pods formation.