No abstract

No abstract

‘Rogers Red McIntosh’ (Malus domestica Borkh.) on Mailing Merton (MM)111, MM 106, Mailing (M) 26 and M 7a were planted within an old apple orchard site. The trees were trickle-irrigated and the sandy soil was treated with the nematicides Telone (C-17), Vorlex, or Nemacur 3. In 1984, data were collected from trees excavated at 50, 100, and 156 days after planting and from permanent trees in 1985 from plots treated with nematicides prior to planting. The numbers of Pratylenchus penetrans [(Cobb) Filipjev & Schuurmans-Stekhoven] in soil and rootstocks from nematicide treatments and controls were well below reported damage levels and not considered a problem on this test site. M 111 and MM 106 roots and ‘McIntosh’ scion growth were superior to M 26 and M 7a counterparts regardless of soil treatment in 1984, while only the scions on MM 111 were larger than those on M 26 in 1985. ‘McIntosh’ scions grew 36% larger on Telone C-17-treated soil and 19% larger on Vorlex-treated soil than on untreated soil. Leaf and soil analyses showed no interaction with rootstocks and minor differences between soil treatments in both years. A soil replant bioassay revealed disease factor(s), including P. penetrans, present in untreated soil.

A whole-tree foliar application of BA at a concentration of 1000 ppm increased lateral bud density on douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] but not on Colorado blue spruce (Picea pungens Englm.) when treated ≈6 weeks after budbreak. A single BA application made at the same time, but only to the terminal leader, was not effective in increasing overall lateral bud density on either the terminal or lateral branches of either species. Lammas shoots formed on all trees that received whole-tree applications of BA. Bud formation on lammas shoots appeared normal for douglas-fir but uncharacteristic for Colorado blue spruce. Chemical names used: N- (phenylmethyl)-lH-purin-6-amine (BA).

A randomized complete block study was initiated in 1991 in a fifteen year old `Rogers Red McIntosh'/9-106 interstem orchard to investigate the effect of three dormant pruning regimes- an unpruned control, selectively thinned, and heavily structured or “tiered”, on tree canopy light distribution and fruit and spur quality. Fruit quality parameters being measured for the 1991 and 1992 harvests include skin color (% red blush), weight (g.), flesh firmness (kg.), soluble solids concentration (% Brix), and packout (% fancy grade). Pruning treatment effect on fruit spur quality, in terms of spur bud diameter (mm.) and spur efficiency (leaf dry weight/spur), is also being evaluated at time of harvest. Light distribution is being measured (% PAR, umol/s/m2.) within the tree canopy from petal fall through harvest. Preliminary findings indicate there is a difference in tree canopy light distribution and some fruit quality measurements, including red skin color, between pruning regimes. Complete analysis of results from 1991 will be presented.