G. W. Eaton

Strawberry yield response to fertilizer, paclobutrazol and chlormequat

Abstract Unadjusted vegetative and reproductive variates of strawberry ( Fragaria × ananassa Duch.) grown in a glasshouse were studied using analysis of variance. Two-dimensional partitioning was used to account for yield variation due to successive orthogonal variates, 20 N-8.7 P-16.6 K fertilizer at 45 or 180 mg/pot, paclobutrazol (PP333) at 0, 10, 46, 215 or 1000 mg l −1 and Chlormequat (CCC) at 0, 215 or 1000 mg l −1 . ‘Shuksan’ had more runner crowns than ‘Totem’, and the number of runner crowns was decreased more by PP333 than by CCC in both cultivars. PP333 severely stunted the plants at 215 mg l −1 . PP333 increased achenes per fruit but decreased yield by delaying fruit ripening. Adjusted variates revealed additional information on treatment effects not detected with unadjusted variates. Adjusted truss number was the most important contributor to yield variation. PP333-treated plants were less responsive to high NPK than controls. PP333 had no effect upon fruit set. High NPK increased the numbers of leaves and runners but not the ratio of runners to leaves. High NPK delayed fruit ripening and increased the number of achenes per fruit.

Productivity of individual cranberry uprights in Washington and British Columbia

Abstract Yield-component partitioning of the individual cranberry upright (fruiting shoot) was undertaken using a model which included upright length, number of leaves, flowers, berries and seeds, and fruit weight. Repeat cropping of the upright during the following year was also modelled and tested. Fruit set was a major component of yield, but its action was sometimes indirect. Less important components were the number of seeds per berry, berry enlargement per seed, and upright length. Measures of antagonism of “fruiting” to floral initiation were obtained which partially explain the biennial bearing habit of uprights.

Cranberry growth and yield response to fertilizer and paclobutrazol

Abstract In glasshouse studies with cranberry, paclobutrazol (PP333) ((2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-pentan-3-ol) applied twice as a foliar spray at 75, 150, 300, 600 or 1200 mg 1 −1 decreased shoot and root growth, and the shoot: root ratio. Paclobutrazol decreased shoot elongation within 3 weeks of application and increased the number of branches on primary shoots. Buds were formed within 7 weeks of treatment and some contained flowers. In a second experiment, flower-bud formation was greater when plants were treated with paclobutrazol at 1.25, 2.50 or 5.00 mg pot −1 as a soil drench and grown for a longer period. Plants grew more with high NPK than with low NPK but growth was diminished still by paclobutrazol. High NPK decreased floral induction. Paclobutrazol was still detected in the soil 50 weeks after application. In a cranberry field study, foliar sprays of paclobutrazol at 75 or 150 mg 1 −1 at full bloom and 2 weeks later decreased fruit set, fruit size and yield, but increassed bud set and flower-bud set on uprights. Shoot growth was decreased the following year but the number of flowers per upright was increased. Fruit set was the most important contributor to yield variation, followed by fruit size and flowers per upright. The effects of paclobutrazol upon adjusted yield components accounted for a substantial amount of yield variation. No effect of cultivar on yield was apparent as the higher proportion of adjusted number of uprights flowering in cultivar ‘McFarlin’ was offset by an increased adjusted number of flowers per upright in cultivar ‘Bergman’. Bud set and flower-bud set were greater in uprights that did not flower in the current season.

Yield component analysis of winter damage and flower buds in highbush blueberry

Abstract Potential components of winter damage and flower buds to cane tips of mowed high-bush blueberry plants ( Vaccinium corymbosum ) were analysed using multiple regression analysis. Thick, highly-branched canes were most conducive to high yields of flower buds and low incidence of winter injury. Winter damage may have influenced the yield of flower buds.

Effect of cotton-grass on the yield components of cranberry

Abstract Cranberry yield components were studied under weedy and control conditions. Most yield components and yield itself were reduced in weedy areas. Some variation in both fruit set and berry size could be accounted for by preceding variables in a sequential regression analysis, but only under weedy conditions. The major contributors to yield were generally floral induction, upright density, and fruit set. Fruit size was uniform regardless of conditions and did not contribute to yield variation. Flower initiation was an important yield component in control but not under weedy conditions.

Nitrogen fertilizer and fruit removal effects upon leaf mineral content in apple trees

Abstract In a preliminary study, stunted 7-year-old apple trees were treated with 2 levels of ammonium nitrate fertilizer in combination with fruit removal over a 2-year period. Leaf tissue analyses were used as an index of response to the treatments. Leaf N increased with higher ammonium nitrate application. Following fruit removal, leaf N, Ca, Mg, Mn, Zn and Cu decreased.

Thinning ‘McIntosh’ apple in British Columbia

Abstract Trials were conducted on 11-year-old trees of ‘McIntosh’ apple (Malus domestica, Borkh.) in Creston, British Columbia, to analyse the thinning effects of the blossom spray sodium 4,6-dinitro-ortho-cresylate (DNOC), and single and combination treatments of the post-bloom sprays naphthalene acetic acid (NAA), naphthaleneacetamide (NAD), and 1-naphthyl-(N-)methyl carbamate (carbaryl). DNOC was ineffective as a thinning agent when used alone. NAA did not significantly affect numbers of remaining fruit when used alone or with NAD or carbaryl. NAD showed significant thinning effects when applied alone or with carbaryl. Carbaryl was an effective thinning agent when used alone. The effects of carbaryl alone and carbaryl with NAD were found to persist after spacing the fruit on the branches by hand.