Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Yahya K. Al-Hinai x
Clear All Modify Search

This experiment was conducted to determine temporal weed management parameters for tart cherry (Prunus cerasus L.) orchards. Annual ryegrass (Lolium multiflorum L.) and lambsquarter (Chenopodium album L.) were planted in tree rows of a 4-year-old tart cherry orchard. Weeds either were not controlled or controlled with nonresidual herbicides during the following intervals: all-summer; May, June, July, or August; preharvest (April-July); or postharvest (late July to frost). Trees in all-summer, June, and preharvest weed-free plots had more shoot growth, more nodes, longer internodes, greater leaf area, and higher concentrations of leaf nitrogen than did those in the weedy control and postharvest, July, or August treatments. A larger increase in trunk circumference was observed in all-summer and preharvest weed-free plots than in postharvest and weedy plots. Early-summer weed control was important for tree vegetative growth. Tree yield (fruit weight and number) was greater on trees without weed competition postharvest than in those treated in May, June, July, or in weedy controls. Late-season (after late July) weed control is therefore important for fruit yield.

Free access

This experiment was conducted to determine temporal and spatial weed management characteristics for tart cherry orchards. Annual ryegrass and lambsquarter were planted in tree rows of a 14-year-old tart cherry orchard. Vegetation was controlled with nonresidual herbicides (Gramoxone + B-1956) either all season, May, June, July, August, before harvest, after harvest, or not controlled. Shoot growth measurements showed significantly more growth by trees without weed competition during the entire season, May, June, and before harvest compared to the weedy control and postharvest, July, or August treatments. Weedy early season plots reduced the shoot growth by half. All season, before harvest, May, and June weed-free plots showed higher amounts of leaf N compared with weedy controls or late-season treatments. Early season weed control is more important than late season. Vegetation-free areas of 0, 2, 3, and 4 m2 were maintained during 1998 by postemergence herbicides. Tissue analysis showed higher N concentration in leaves with vegetation controlled to 2 m2 or more compared to the weedy control. The critical vegetation free area for young cherry trees is between 0 and 2 m2.

Free access

The effect of rootstock on apple size is not clear due to inconsistent results of published studies. This study was conducted over 3 years at the Peninsular Agricultural Research Station near Sturgeon Bay, WI on 6-year-old `Gala' apple trees (Malus domestica Borkh) grafted on Malling 26 (M.26), Ottawa 3, M.9 Pajam 1, and Vineland (V)-605 rootstocks. Fruit diameter was measured weekly. Fruit weight and volume were estimated by a quadratic regression of weekly measurements. Fruit weight was positively correlated with fruit volume. Rootstock had no effect on fruit growth and final size even with the removal of crop load effects. Crop load was a highly significant covariate for fruit size, but canopy light interception and seed count were not. Trees on M.26 EMLA had slightly higher yield in 2000 but rootstock did not affect yield efficiency any year. Rootstock had no influence on fruit quality attributes during 2001; however, in 2002, fruit obtained from trees on Pajam-1 tended to be less firm. Generally, apple fruit size was influenced by crop load and other factors, but not by rootstock.

Free access

The effects of rootstock on growth of fruit cell number and size of `Gala' apple trees (Malus domestica Borkh) were investigated over three consecutive seasons (2000-02) growing on Malling 26 (M.26), Ottawa-3, Pajam-1, and Vineland (V)-605 rootstocks at the Peninsular Agricultural Research Station near Sturgeon Bay, WI. Fruit growth as a function of cell division and expansion was monitored from full bloom until harvest using scanning electron microscopy (SEM). Cell count and cell size measurements showed that rootstock had no affect on fruit growth and final size even when crop load effects were removed. Cell division ceased about 5 to 6 weeks after full bloom (WAFB) followed by cell expansion. Fruit size was positively correlated (r 2 = 0.85) with cell size, suggesting that differences in fruit size were primarily a result of changes in cell size rather than cell number or intercellular space (IS).

Free access

Nitrogen (N) uptake was compared on 10 dwarf apple rootstocks (M.9 EMLA, M.26 EMLA, M.27 EMLA, M.9 RN29, Pajam 1, Pajam 2, B.9, Mark, B.469, and M.9 T337) grafted with the same scion (`Gala') in a four year-old orchard. Trees were treated in either Spring or Fall 1998 with 40 g of soil applied actual N per tree using ammonium nitrate enriched to 1% 15N. Both percentage of N (%N) and N from fertilizer (NFF) in leaf tissue were highly affected by the rootstock and the season of N application. Generally, higher %N and NFF were observed for spring than fall applications, except for leaves collected during early June 1998. Generally, M.26 EMLA, M.27 EMLA, and M.9 RN29 were the most efficient rootstocks in N uptake for spring applied nitrogen. M.9 EMLA was most efficient late in the season following fall application. Mark was more efficient early in the season for fall applied N than spring application. However, trees on Mark rootstock had the lowest %N throughout the season regardless of the time of N application. Pajam 1 and Pajam 2 were the least efficient rootstocks in N uptake following fall N application. Rootstock also significantly affected %N and NFF of wood tissue. Generally, trees on B.469 had the highest %N in their wood regardless of the season of application. No single rootstock had consistently higher N from fertilizer in their wood tissue after spring application. At the May 1999 sampling date, M.26 EMLA had higher NFF than M.27 EMLA, Pajam 1, Pajam 2, and B.9 with a fall application. Other rootstocks were intermediate. Samples collected in August showed that Pajam 1 was the least efficient rootstock in N uptake for fall applied N compared to other rootstocks, except for Pajam 2 and B.9 that were intermediate. Leaf and wood tissue analysis showed that different rootstocks had different N uptake efficiencies throughout the season. Generally, M.26 EMLA, M.27 EMLA, M.9 RN29 and M.9 EMLA were more efficient at N uptake regardless the season of N application. Pajam 1 and Pajam 2 were the least efficient.

Free access