Grapes

• Grape Varieties for the Tri River Area - Western Colorado
  Vitis labrusca varieties are hardier than V. vinifera varieties, while the French hybrids (V. vinifera hybrids) are somewhere in between. This Web Page gives suggestions on varieties to plant in the Western Colorado based on cold hardiness.

• The home page of the Rocky Mountain Association of Vintners and Viticulturists is at www.rmavv.org

• Further information on grape production in Colorado can be found at http://www.coloradowine.com and the CSU Viticulture Home Page

Fruit Tree culture

Cold Climate Fruit Trees

This list is a compilation of tree fruit cultivars most likely to do well in cold locations in Colorado. This information is provided by Dr. Harold Larsen, CSU Western Colorado Research Center, Orchard Mesa.

Fertilizing Fruit Trees

Fruit trees are fertilized to guarantee continued growth and fruit production. The application of nitrogen in the spring prior to bud break helps maintain this productive status. The amount of nitrogen to apply depends on the growth the previous season. Specifics on the amount of nitrogen to apply are provided.

Frost Damage

Fruit buds are damaged when temperatures drop below a certain threshold for 30 minutes or longer. Each stage of bud development differs in its temperature threshold and each type of fruit differs. These pages provide photos of the various bud stages and the critical temperates that causes 10 and 90 percent bud kill.

Harvesting Apples and Pears

Knowing when to harvest apples and pears has always been a problem for the backyard growers. This page provides answers to this dilemma.

Japanese Beetle

An infestation of Japanese beetles Popillia japonica was identified in Palisade, Colorado (Mesa County) in the summer of 2002. The initial discovery was based on a single adult Japanese beetle taken to Bookcliff Gardens and forwarded to the Extension office on July 23. Action reports and additional information is provided at this site.

Preparation of Small Quantities of Pesticide Sprays

Pesticide labels often provide application rates on a per acre or 100 gallon basis. This web page provides conversions for mixing smaller quantities of sprays.

Pruning and Training Apples and Pears

Training and pruning are essential for growing fruit successfully. Fruit size, quality and pest management are influenced by training and pruning. Untrained and unpruned trees become entangled masses of shoots and branches that produce little or no fruit and harbor insects and diseases. A Clemson University Publication.

Pruning Peach and Other Stone Fruit Trees

Pruning is done to improve both the fruit crop and tree appearance, but is a practice frequently neglected and misunderstood. This publication is designed to assist the home orchardist by providing guidelines on the pruning and training of peach, apricot, almond, plum, and cherry trees from planting to maturity.

Thinning Fruit

A fruit tree commonly produces many more blossoms than should be permitted to set as fruit. Thinning is thus necessary to maintain production and tree health.

Twinning or Fruit Doubling

Fruit doubling is seen in apple, pear, peach, sweet and tart cherry, and plum. Even quadruple fruit have been observed in peach and sweet cherry. This problem is the result of stress the previous summer when fruit buds are developing.

• The Cost of Growing Peaches in Colorado

• Spray Guides for Backyard Orchards
  • Apples and Pears - fact sheet 2.800
  • Peaches, Apricots and other stone fruits - fact sheet 2.804
    • These guides provide the most up-to-date information on the control of insect and disease problems of fruit trees in Colorado

• Bacterial Spot

  Bacterial Spot, caused by the bacterium Xanthomonas campestris pv. pruni, is a disease of stone fruits. Apricots, peaches, nectarines, and plums are more severely affected than cherries. Cultivars vary greatly in susceptibility to damage for each of these crops. However, no cultivar is completely immune when environmental conditions are highly favorable to disease development.

• Apple trees, Blackheart Injury, and rootstocks

  Blackheart injury is a debilitating factor effected by both rootstock and apple cultivar. Blackheart, a form of winter injury kills and plugs xylem tissue. This physiological problem is so named due to the resulting oxidative brown or black discoloration of the xylem.

• Coryneum Blight

  (Coryneum blight also know as Shothole disease is caused by the fungus Stigmina carpophilum (= Coryneum beijerinckii). This stone fruit disease affects mainly peaches, apricots, and, to a lesser degree, sweet cherry. Both leaves and fruit may be attacked; severe leaf infections with extensive shot holing may weaken a tree, while infections on the fruit produce the most apparent damage and economic loss.

• The Grape Leafhopper and its control

  The white flecking seen on grape leaves is the result of the grape leafhopper puncturing the cells on the underside of the leaves and sucking out the sap.

• Peach Cytospora Canker

  Cytospora leucostoma is a serious problem of all stone fruit (peach, apricot, plum, nectarine, almond, and cherry) in Western Colorado. Specifics on identification, control and curative methods are provided.

• Peach Mosaic Virus in Western Colorado

  A quarantine was enacted in 1946 by the Colorado Commissioner of Agriculture prohibiting the importation and planting of nectarines and white-flesh, clingstone, and Rochester peaches in Mesa, Montrose and Delta counties. Known as Quarantine Order "G", this legislation has been updated several times to protect Western Colorado's peach industry from Peach Mosaic Virus (PMV).

• Peach and Nectarine Varieties & Peach Mosaic Virus

  This page lists nectarines and white-flesh peach cultivars approved for planting in Mesa County.

• Peach Tree Borer: Life History and Management Options for Western Colorado

  Peachtree borer (crown borer), Synanthedon exitosia, is a pest of peach, cherry, plum, prune, almond, and apricot. This discusses life history and provides management options for Western Colorado.

• Rusty Spot of Peach and Nectarine

  `Rusty Spot' is a term used to describe the dark reddish or rusty-brown spots which develop on peach and nectarine fruit. When the discolored fuzz is wiped off, a web-like russeting of the fruit can be seen.

• Western Cherry Fruit Fly

  The Western Cherry Fly (Rhagoletes indiferens) is established in Western Colorado in both backyard and commercial cherry orchards. If left uncontrolled, the fly maggots infest a high percentage of the fruit.

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