Affecting Asparagus officinalis Shoot and Root Growth Characteristics with CPPU Foliar Sprays and Soil Drench

摘要

The effect of foliar spray and soil drench applications of M-(2-chloro-4-pyridyl)-A^-phenylurea (CPPU) on shoot (fern) numbers, fern height, axillary bud break, root number and bud production were investigated. A soil drench with CPPU stimulated fernproduction, but applying CPPU (> 10 mg-L~(-1)) to foliage of 'Jersey Giant' seedlings reduced the numbers of ferns. Since CPPU is poorly transported these results suggest that CPPU may be stimulating the production in the fern of a mobile inhibitor of shoot production. In contrast, CPPU applied directly to the crown buds using a soil drench could act directly in stimulating bud outgrowth, as is typical of cytokinin-like substances. CPPU as a foliar spray or soil drench stimulated the height of initial ferns, but decreased the height of subsequent ferns. All CPPU treatments significantly enhanced axillary bud break of the fern compared to the control. Although CPPU, applied as a soil drench, was effective in promoting fern production, it did not influence root and crown bud numbers.