Search Results
Tissue-cultured (TC) plantlets are gaining wide acceptance as the standard transplanting stock within both the fruit and nursery industry. However, research and grower experiences suggest that management practices used for conventionally propagated raspberry plants may need to be tailored for successful field establishment of the TC plantlet. The effects of weed control practices, rowcovers, and fertilizer placement on the performance of newly planted TC `Heritage' red raspberry were evaluated during two years. Weed control treatments included straw mulch (ST), black polyethylene mulch (B), white on black polyethylene mulch (WB), napropamide herbicide (N), simazine herbicide (S), hand-weeding (HW), and an untreated control (U). Rowcovers were used during the first six weeks of establishment on the mulched and hand-weeded treatments. Calcium nitrate was placed in the planting hole or on the soil surface around the plant. Second year yields were directly proportional to soil moisture levels during the summer of the planting year. Plants mulched with ST, B, or WB during the planting year produced greater early yields during the fruiting year. Primocane density was highest in the ST treatment. Rowcovers consistently increased both soil temperature and soil moisture, but tended to cause a reduction in cane length the first growing season. Fertilizer placement had no consistent effect on any measured variable.
Micropropagated (MP) raspberries (Rubus idaeus L. var. idaeus) are sensitive to moisture and temperature extremes and to certain preemergent herbicides used at transplanting. We examined fertilizer placement and row covers in conjunction with various weed management strategies to identify beneficial practices for newly planted, MP primocane-fruiting `Heritage' raspberries. Uncontrolled weed growth during plant establishment inhibited raspberry cane growth and production into the second and third growing seasons. Handweeding and herbicide treatments successfully controlled weeds, but soil moisture was apparently insufficient for optimum growth of the MP raspberries when these treatments were imposed, even with normal rainfall in early summer and drip irrigation in late summer. Polyethylene and straw mulches during the establishment year provided both weed control and adequate soil moisture, resulting in more cane growth in the first and 2nd year, and higher yields the 2nd year. Primocane density after the third growing season still was influenced by first-year weed management practices. Raspberry plants responded best to straw mulch without row covers as plant growth was better in both years. Canes were thicker, yields were higher, and a larger portion of the total crop was harvested early. Row covers were beneficial only in bare-soil treatments, and method of fertilizer placement had no effect on any measured variable. Mulching newly transplanted MP raspberries is an alternative to herbicide use that also provides physiological benefits to the plant through microclimate modification.