Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Karen Pearson x
Clear All Modify Search

Production of broccoli in areas where summer temperatures exceed 30C is difficult because the head may not form properly. The high temperature causes an unevenness in the head due to widely differing sizes of buds. The sensitive stage of development was determined for the early maturing variety `Galaxy' by exposing it to 1-week at 36C at varying developmental stages, and subsequently analyzing the head structure. The injury is a cessation of bud enlargement during the high-temperature exposure. There is no corresponding cessation of bud initiation at the apex. The patter of injury is consistent with susceptibility over a relatively small range of bud development: even with a 1-week exposure, only about 1/3 of the buds will be affected. The plant's most developmental stage at this sensitive period still appears vegetative, but the youngest leaves are just beginning to reorient as a consequence of the reduced stem elongation rate. The meristem is less than 1 mm wide, and scanning electron micrographs show floral primordia just forming, still subtended by leaf primordia. The injury is fully expressed when the head is first exposed (≈10 mm wide), though it becomes more apparent as the head matures. The buds that were delayed in development by the high temperature developed into fertile flowers, albeit about a week late.

Free access


Effects of pine vole (Microtus pinetorum LeConte) damage on tree vigor and fruit yield, size, and grade were studied for ‘McIntosh’, ‘Delicious’, and ‘Rome Beauty’ apples (Malus domestica Borkh.). Pine vole damage reduced yield and fruit size and increased fruit color. The net effect was a significant reduction in the dollar value of the fruit for each of the 3 cultivars.

Open Access