2nd Week Of May Research Articles

Foliar-applied Boron Increases Fruit Set in ‘Barcelona’ Hazelnut

Abstract Boron (B) sprays applied to ‘Barcelona’ hazelnut orchards induced fruit set increases over controls, averaging 23% in 1984 and 17% in 1985. Leaves from B-sprayed trees had higher B contents than controls throughout the season. Amounts of B in young fruits increased two-fold with B sprays, but, unlike leaf values, differences between treated and control fruits disappeared by mid-summer. In the orchards studied, the B content of developing fruits from unsprayed trees was similar even though leaf B content varied widely. Because fruit set increases were obtained in both seasons with B sprays on trees whose leaf values currently are considered excessive, as well as those considered optimal or deficient, guidelines for B recommendation need revision. Boron content in May fruit from unsprayed trees might be universally low for optimum nut development, indicating that annual B sprays may be required. Foliar sprays in April damaged young leaves and shoot tips; thus, delaying sprays until the 2nd week of May is recommended.

Biological Studies of Ceutorhynchus punctiger (Coleoptera: Curculionidae) on Dandelion in Virginia

Development of Ceutorhynchus punctiger Gyllenhal, a weevil which feeds on dandelion seeds, was studied in relation to the phenology of dandelion in Virginia. Eggs were observed from when the flower bud rays were white (1st week of April) until the flower closed and the rays were dry and brown (2nd week of May). There were 3 instars; mean duration of the 1st, 2nd, and 3rd instars was 4.7, 3.7, and 29.2 days, respectively. First instars were initially detected when the bud's outer sepals were open (1st week of April), 2nd instars midway through the open flower stage (4th week of April), and 3rd instars at the beginning of the stage when the flower closed and rays were dry and brown (4th week of April). Pupation occurred in the soil; the pupal stage averaged 14.2 days. Seed consumption/larva was 19.0 ± 8.9 from a mean of 157.4 ± 40.1 seeds/dandelion flower. Adults fed on leaves and lived for an average of 96.5 weeks; there was no significant difference between sexes. Adult feeding had minimal impact on dandelion seed production.