STUDIES ON DIFFERENTIAL RESPONSE OF SPRING CANOLA CULTIVARS TO BORON TOXICITY

Abstract

Although many states recommend boron (B) fertilizer for many field crops, information about B toxicity of canola is lacking. This experiment was carried out at Central Anatolia, Turkey from 2002 to 2003, to determine genotypic range in B efficiency of eight spring canola cultivars, to identify the B-inefficient cultivars and to identify specific responses. The cultivars were grown under B moderate deficiency (extractable B 0.56 mg kg⁻¹) and toxic B applied (15 kg B ha⁻¹) conditions. According to the results, seed yield varied significantly among the cultivars and B application decreased the seed yield by 31% on average. Also, toxic B application reduced protein and oil contents similar to seed yield, and increased leaf B concentration in all varieties. This study has shown that leaf B concentration has increased considerably when B is applied to Pactol and Star cultivars, but seed yield of +B and −B has not shown significantly a change. It is possible to say that Star and Pactol—which have not been affected by the toxic B application—are genotypes that are tolerant to B toxicity and may be cultivated at B toxic lands.

Keywords:

• boron toxicity
• interaction
• oil ratio
• protein ratio
• seed yield
• canola

ACKNOWLEDGMENTS

The financial support for this study was provided by the Turkish State Planning Organization (DPT) (Project No. 1999 K120560). The assistance of Dr. Fatma Gökmen in soil analysis, and Mr. Nesim Dursun and Mr. Ali Kahraman in the analysis of B by ICP is gratefully acknowledged.