Stewartia pseudocamellia Maxim. (Japanese Stewartia), a member of Theaceae (tea family), is an excellent garden plant with ornamental features for all four seasons. Reproduction difficulty, however, limits its popularity. We conducted three experiments to ascertain the optimum conditions needed for rooting and subsequent overwintering of semihardwood Stewartia pseudocamellia cuttings. Cuttings were collected in July and prepared for rooting using two types of hormones (KIBA quick dip and Hormodin powder) and three media (Perlite + ProMix, Perlite + Perennial Mix, or Perlite + ProMix + Perennial Mix). Rooted cuttings were overwintered at four different temperatures. The best overwintering temperature was 5 °C, at which 65.6% of newly rooted cuttings survived. Temperatures lower than –12.2 °C were detrimental to the plants. Without cold treatment, only 21.9% of the rooted cuttings survived, which was three times lower than those that received 5 °C treatments. Plants rooted in Perlite + Perennial Mix had 61.8% overwintering survival, which is significantly higher than Perlite + ProMix. The quality of roots, indicated by total root length per cutting, was higher (104.3 cm) with Perlite + Perennial Mix, but not statistically significant. Cuttings treated with rooting hormones had higher rooting percentages (71.9% to 93.6%) as compared with the control (53%). For the same concentration (8000 mg·L−1), liquid (KIBA) and liquid + powder (KIBA + indole-3-butyric acid) rooting hormones resulted in better rooting percentages than powder (Hormodin) alone, although there was no statistical difference in rooting percentages among rooting hormone treatments. The best hormone for subsequent overwintering survival was the combination of quick dip (5000 mg·L−1 KIBA) and Hormodin #2 (0.3% a. i.; equivalent to 3000 mg·L−1). It resulted in 64.2% survival, significantly higher than for KIBA quick dip (8000 mg·L−1 a.i.) or Hormodin #3 (0.8% a. i.; equivalent to 8000 mg·L−1) alone. Our results suggest that reproduction (rooting and overwintering) of Stewartia was affected by many factors. We recommend rooting Stewartia in media that has good aeration and moderate water-holding capacity and overwintering them at ≈5 °C.
Ajay Nair, Donglin Zhang, John Smagula and Dongyan Hu
Jennifer Tillman, Ajay Nair, Mark Gleason and Jean Batzer
Increasing interest in using cover crops and reduced tillage to build soil health has created a demand for strategies to implement rolled cover crop systems. In northern areas of the United States, cool soil temperature in rolled cover crop systems can create a challenge when growing warm season vegetable crops. The use of rowcovers could mitigate the issue and facilitate adoption of rolled cover crop systems for both conventional and organic growers. This study investigated muskmelon (Cucumis melo) in two production systems, strip tillage (ST) into rolled cereal rye (Secale cereale) or conventional tillage with black plastic mulch (plasticulture), with or without the use of spunbonded polypropylene rowcovers. The trial was conducted in two fields, one in organic management and the other in conventional management. In general, ST led to cooler, moister soils than plasticulture, but rowcovers rarely affected soil temperature. Rowcovers increased mean and maximum daily air temperature by up to 4.2 and 11.7 °C, respectively, and decreased average daily light intensity by 33% to 37%. Rowcovers sometimes increased fruit size, but rarely affected marketable yield. Overall, ST reduced marketable yield compared with plasticulture by 6732 to 9900 lb/acre; however, ST with rowcovers often produced similar vegetative growth compared with plasticulture without rowcovers. Given the slow vining growth habit of muskmelon and the late planting inherent in a rolled cereal rye system, achieving high muskmelon yields, especially early yields, may be difficult.