Copper requirement of wheat (Triticum aestivum L) cultivars

Abstract

Copper (Cu) is one of the most limiting micronutrients in wheat grain production (Triticum aestivum L.). The objectives of these studies were to (i) determine the response of eight Canadian spring wheat cultivars to Cu and to determine Cu concentration in the youngest fully emerged leaves (YFEL) in the field, and (ii) determine the Cu-efficiency of 5A/5RL wheat-rye translocated lines and nine wheat cultivars on Cu-deflcient soil in the greenhouse. A two year field study was conducted at Stony Plain, Central Alberta (53° 02' N - 114° 00' W). The soil at the experimental site had a pH of 5.4, and 0.48 (ig Cu g*1 soil. Eight cultivars were tested in two Cu treatments (12.2 kg ha-1 Cu applied, and no Cu applied). The YFEL were analysed for Cu using atomic absorption spectrophotometry. A dose response experiment with four wheat cultivars and nine levels of Cu were also conducted. Twelve genotypes were evaluated in the greenhouse in two Cu treatments (145 (ig kg*1 soil Cu applied, and no copper applied). In the field trial, results indicated significant differences (P <0.01) due to cultivars, copper and year for yield, and for some yield components. A significant (P < 0.05) cultivar x Cu interaction was observed for grain weight. Year x cultivar x Cu interactions were significant (P < 0.05) for floret fertility, and for number of grains spike*1 on the main stems. Copper treatment significantly (P < 0.05) increased grain weight, the number of grains spike*1, and grain yield on cv. Oslo, Park, Roblin, and Conway. Copper concentrations in YFEL ranged between 2.8 and 5.7 jig g*1 on cvs. Katepwa, Park and Roblin when symptoms first appeared. The level of Cu in the YFEL depend on cultivar, growth stage, year and Cu status in the soil. The cultivar Biggar increased grain yield by 81%, and cv. Oslo by 419% when Cu was supplied at 145 |ig kg*1 soil. Significant differences (P < 0.05) due to the 5A/5RL chromosome translocation were observed for grain yield and some yield components. Differential response to Cu supply was observed between 5A/5RL wheat-rye translocated lines compared to other wheat cultivars for grain yield and for number of grains spike*1 of tillers. The 5A/5RL wheat-rye translocated lines showed a Cu-efficiency range of 70-127%.