OBJECTIVES:

   1.  To discuss the types of bramble fruits successfully grown in Colorado.
   2.  To explain the cultural requirements of bramble fruit.

MOTIVATION:

   1.  Bring in red, yellow, and black raspberries if possible. Show the students the differences in red and black raspberries.
   2.  Relate this lesson to the specific growing conditions in your county.

STUDY GUIDES:

   1.  What are brambles?
   2.  What varieties are best for Colorado culture?
   3.  What are the 2 types of red raspberries and some appropriate cultivars?
   4.  What are the site selection and cultural requirements?
   5.  How are brambles propagated?
   6.  How are raspberries protected in the winter?
   7.  What are the different trellis systems used?
   8.  How are the canes pruned?
   9.  How is the fruit harvested?
  10. List and explain some of the common raspberry problems.

ANALYSIS:

   1.  What are brambles?

     Brambles is a term given to raspberries, blackberries, boysenberries, loganberries and dewberries which are all members of the Rose family.
     These perennial plants have aggregate fruits and (generally) spiny canes (suckers.) With raspberries the fruit is hollow because the receptacle
     remains on the plant. Blackberries are solid, because the receptacle remains with the fruit.

   2.  What varieties are best for Colorado culture?

     Red and yellow raspberries (Rubus idaeus) are recommended for Colorado because they are hardier than the more tender blackberries.
     Purple raspberries, dewberries, boysenberries, and loganberries are not recommended.

   3.  What are the 2 types of red raspberries and some appropriate cultivars?

   a.Summer-bearers- biennial plants that develop vegetative canes the first year (primocanes) and fruit on lateral branches of canes the second
     year (floricanes). They fruit typically in mid- summer. The canes require winter protection. Latham, Boyne, Newburgh, Canby and Titan are
     examples.
   b.Fall-bearers- the canes bear fruit in August or September of the first year, and again the next summer, although a smaller yield. Redwing,
     August Red, Heritage, Fall Red, Fall Gold (yellow), and September are examples. The fall-bearers are easier to manage than
     summer-bearers.

   4.  What are the site selection and cultural requirements?

     - deep, well drained, slightly acidic soils (will tolerate up to 7.5 pH)
     - wind protection
     - light, frequent watering of approximately 1-3 inches/week
     - do not plant after tomatoes, potatoes, peppers due to Verticillium wilt
     - full sun
     - important to remove perennial weeds, sod or mulch between rows

   5.  How are brambles propagated?

     By division of suckers, tip rooting, mound layering and tissue culture.

   6.  How are raspberries protected in the winter?

     Summer-bearing raspberries require protection of the first year primocane. After November 1, lay canes down and weight with soil. Cover
     with straw. The following year gently lift the canes. The floricane will fruit and die afterwards. Fall-bearing raspberries can be protected in the
     same manner. It is recommended, however, that first year canes be mowed down. Winter protection is no longer needed. The next year’s
     summer crop is sacrificed, but the yield is small anyway. New canes will develop and produce a good fall crop.

   7.  What are the different trellis systems used?

     Summer-bearers often require support. Two-wire, Cross arm or I, Lincoln, V shaped, and shift trellis systems are used.

   8.  How are the canes pruned?

     Cut out the dead floricanes of summer-bearers. Remove dead, weak, and small canes in the spring. Space 6 inches apart. Remove any
     winter killed tips. Mow down fall-bearers after harvest.

   9.  How is the fruit harvested?

     Mechanical harvesting is used in large commercial operations, but can cause bruising. Hand harvesting and sorting is used for fresh market.
     Remove fruit early in the day, after the dew has evaporated. Cool the fruit to 32 degrees F. Do not squeeze or pull fruit. It should easily roll
     off the receptacle.

   10.  List and explain some of the common raspberry problems.(see source #1 for in depth description and management practices)

a.White Druplet Disorder- caused by exposure to high temperatures and UV radiation; the fruit has pale or white areas within the fruit, although it still retains its moisture and flavor
b.Crown Borer- this insect is a clear winged moth, larvae feed on the roots, and crown of the plant causing wilting and dying; remove infected material
c.Cane Borer- adult cane borers lay eggs in the cane causing wounds that disrupt the vascular system; canes wilt, blacken, and abscise at the tip; larvae tunnel into the canes; remove infected material
d.Twospotted spider mite- caused reduced vigor, fruit size, and yield;
e.Verticillium wilt- a fungal wilt pathogen that is soil borne
f.Viruses- vectored by aphids and nematodes; there are five major diseases; use certified stock and destroy all infected material

SOURCES:

1.  Badertscher, Kerrie B. and Harrison G. Hughes; (1996) "Growing Small Fruit for the High Plains & Rocky Mountain West," Bulletin 561A, Colorado State University Cooperative Extension
2.  Hughes, Harrison and James E. Ells; (1994) "Raspberries for the home garden," Service in Action publication No. 7.001, Colorado State University Cooperative Extension