Comparison of Flower Bud Initiation in Peach Cultivars in Northern and Southern Hemispheres

Abstract

Abstract Buds of three peach clones (‘Diamante’, ‘Capdeboscq’, and Conserva 334) were sampled weekly during the summer in Clarksville, Ark. and Pelotas, RS, Brazil and classified according to their developmental stage. The percentage of buds at stage 3 (apex showing broadening and assuming a roundish shape) was calculated, and flower bud initiation was considered to be the date when at least 50% of the examined buds were at stage 3 or beyond. In Arkansas, flower bud initiation occurred in ‘Capdeboscq’ on 18 July and in ‘Diamante’ and Conserva 334 on 25 July. In Brazil, ‘Capdeboscq’ initiated flower buds on 30 Jan. and ‘Diamante’ and Conserva 334 on 23 Jan. By transforming dates to number of days from beginning of summer, a comparison was made between the two locations for three stages of flower bud development (broadening of the apex, onset of sepal formation, and sepal differentiation). No statistically significant difference was found between locations for time of occurrence of any of the developmental stages. The largest differences obtained were no greater than differences between years at the same location. Buds of ‘Diamante’ were notably variable in stage of development at the same collection date, with some in stages 3 and 4 and others in stage 6. The possible relationship between differential rate of flower bud development and avoidance of winter cold injury is discussed.