EFFECT OF BORON ON PEANUT GENOTYPES UNDER RAINFED CONDITIONS
Nazakat Nawaz*, Malik Shah Nawaz*, Mubashir Ahmad Khan*, Mirza M. Yasin*, Doulat Baig*, Nasir Mehmood Cheema**, Muhammad Amjad** and M. Altaf Sher**
A study was conducted during 2008 and 2009 to find out boron requirements and critical concentrations in diagnostic parts of three peanut genotypes, BARD-479, ICG-7326 and ICGV-92023. These genotypes were grown in boron deficient soil at National Agricultural Research -1 Centre, Islamabad, Pakistan. Five rates 0.0, 0.5, 1.0, 2.0 and 4.0 kg B ha as boric acid (H BO ) were applied. Boron fertilizer applications significantly 3 3 increased dry pod yield of all the tested genotypes over control. Dry pod yields of BARD-479, ICG-7326, and ICGV-92023 increased by 14- 20%, 21- 26% and 27- 34%, respectively. Genotype BARD-479 was the most boron efficient user, 83- 88% followed by ICG-7326, 79-83% and ICGV- 92023, 75- 79%. Critical boron concentrations in plant shoot terminals -1 recorded were 22-48, 23-50 and 25-54 mg kg during 2008 and 27-51, 30- -1 55 and 31-58 mg kg during 2009 in BARD-479, ICG-7326 and ICGV-92023, respectively. Critical boron concentrations observed in pods of BARD-479, -1 ICG-7326 and ICGV-92023 genotypes were 17-34, 20-38 and 22-40 mg kg -1 during 2008 and 21-36, 23-39 and 24-44 mg kg during 2009, respectively. Total uptake of boron both in pods and haulm noted were 85-177, 88-188 -1 -1 and 89-189 g ha during 2008 and 89-174, 93-183 and 89-190 g ha during 2009, in BARD-479, ICG-7326 and ICGV-92023, respectively. Critical boron concentrations in different plant tissues were higher in all genotypes as compared to control treatments during the two years. The boron using efficiency of peanut genotypes declined in the order of BARD-479 > ICG- 7326 > ICGV-92023. A boron fertilizer requirement observed for the -1 highest dry pods yields was 1.0 kg B ha for all genotypes and yield decreases gradually after certain level by increasing boron fertilizer rates.