Corky root (CR) of lettuce (Lactuca sativa L.) is caused by the bacterium Rhizomonas suberifaciens. Current management strategies involve the use of resistant cultivars and crop rotation. The use of transplants as a method to grow CR-susceptible cultivars in CR-infested fields was recently demonstrated. The objective of this study was to evaluate corky root destruction of root systems of direct-seeded and transplanted lettuce. Direct seeded, and three and five week old transplants of CR susceptible `Shawnee' and CR resistant `South Bay' crisphead lettuce were grown in a naturally CR-infested field. Root systems were evaluated at head harvest maturity. When direct seeded, South Bay developed 104% more total lateral root length than did Shawnee. When transplanted at three and five weeks, South Bay developed 50% and 61% more total lateral root length than Shawnee, respectively. Total lateral root length for Shawnee transplanted at five weeks was 100% greater than direct seeded Shawnee. Comparatively, total lateral root length for South Bay transplanted at five weeks was 58% greater than direct seeded South Bay. Tap root lengths and dry weights were not different among planting systems. Transplanting is a possible method for reducing the impact of CR on lettuce lateral root development.
Frank J. Coale, Russell T. Naqata, and Lawrence E. Datnoff
Matthew T. Rulevich, Francis X. Mangan, and Anne K. Carter
Field studies were conducted in 1998 and 1999 in Massachusetts to assess the effects of transplants, black polyethylene mulch, and polyester spun-bonded row cover on early fruit set and total yield of two squash (Cucurbita moschata Duchesne) cultivars: `C42 × La Segunda' calabaza and `Waltham' butternut. Treatment comparisons included direct-seeded or transplanted squash, with or without black polyethylene mulch, and with or without the addition of a row cover in all combinations. The use of transplants was more effective at stimulating early fruit set and highest total yield than the use of mulch and row cover. The initiation of fruit set using transplants was advanced 9 days relative to direct-seeding. Mulch and row cover treatments significantly advanced early fruit set by 7 and 5 days, respectively, but only in 1998. Yields for both winter squash were 45% higher using transplants compared to direct seeding, 19% higher using mulch compared to bare soil, and 16% higher using row cover compared to no row cover. Total yields were higher for both cultivars in 1999 (warm, dry season) than in 1998 (cool, wet season). Use of transplants with plastic and row cover compared to the use of direct seed with neither plastic nor row cover increased yield of calabaza by 100% in both 1998 and 1999. Only the direct seeded plus plastic plus row cover treatment had yields that were similar to any of the transplanted treatments. Transplant treatments also increased number of fruit per plant and fruit size for both calabaza and butternut.
Natalie R. Bumgarner, Mark A. Bennett, Peter P. Ling, Robert W. Mullen, and Matthew D. Kleinhenz
viable approach for producing a direct-seeded baby leaf lettuce crop outdoors under conditions experienced in this study. The separate and combined value of passive aerial and active root-zone heating should be investigated in high tunnels, especially
A. Carter and M. Rulevich
The population of Puerto Ricans and Dominicans in Massachusetts is ≈6% of the total state population. Latinos have begun to request certain commodities native to their culture at Farmers' Markets and retail stores. One of these commodities is a winter squash [Cucurbita moschata (Duchene Poir)] called calabaza in Puerto Rico and auyama in the Dominican Republic. Calabaza has also been found in Asian markets. In order to have the crop ready for market by August in the Northeast, cultural practices which hasten maturity would need to be used. Eight treatments were tested: 1) direct seeded in bare ground, 2) direct seeded in black plastic, 3) direct seeded in bare ground with rowcover, 4) direct seeded in black plastic with rowcover, 5) transplanted in bare ground, 6) transplanted in black plastic, 7) transplanted in bare ground with rowcover, 8) transplanted in black plastic with rowcover. Calabaza was compared to butternut squash. Three weeks after seeding or transplanting, the transplants on black plastic were just beginning to vine and those transplants on black plastic and covered with rowcover were vining and in flower. Direct-seeded plants were in the second- or third-leaf stage. Treatment effects on early growth in the spring translated to differences in earliness and yield at the end of the season. Overall, the use of transplants improved yield by 30%, black plastic improved yield 15%, and the use of rowcover improved yields by 12%. There were no significant differences among the treatments where transplants were used along with plastic, rowcover or both. Significant differences were found in the number of fruit available for harvest in August. Direct-seeded plants on bare ground or on plastic did not have any harvestable fruit in August. The transplant, plastic and rowcover treatment had 300 to 500 boxes/acre depending on the year. Even the use of transplants on bare ground yielded an August-harvested crop.
Nicolas C. Strange, John K. Moulton, Ernest C. Bernard, William E. Klingeman III, Blair J. Sampson, and Robert N. Trigiano
direct sunlight in the afternoon. This site was selected to examine potential pollinators of the sunflower found in a residential garden. The Oak Ridge location (semi-rural) at the University of Tennessee Arboretum in Oak Ridge, TN, has 250 acres of
Xiao-Juan Wei, Xiao-Jing Liang, Jin-Lin Ma, Kai-Xiang Li, and Haiying Liang
single flower was 4–8 d. Camellia ‘Maozi’ cuttings started to flower in 4–5 years, 1–2 years earlier than grafted plants. Some of the trees in the Nursery were more than 10 years old. None of them have produced seeds. Therefore, Camellia ‘Maozi’ seems
Melvin R. Hall
Primary vine lengths of `Crimson Sweet' watermelon direct-seeded on 25 March and 24 April 1992 were 62 and 58 cm within 7 and 5 weeks, respectively. Lengths of replacement vines direct-seeded on 20 April and 14 May in the respective plantings were 6% and 5%) while transplants were 46% and 52% of these lengths. Total number of marketable fruit and total tonnage yield from late March plantings (suboptimal soil temperatures) in 1992 and 1993 were enhanced when missing hills were replanted either by direct seeding or transplanting. However, these measurements from late April plantings (optimal soil temperatures) were not influenced by missing hills or replanting methods in either year. Distribution of fruit sizes varied for the two years and there was no consistent pattern to indicate how fruit size influenced total number of marketable fruit or total marketable tonnage yield.
Brian A. Kahn, James R. Cooksey, and James E. Motes
Raw seed, primed seed, and transplants were compared for effects on stand establishment, plant morphology, and yield of paprika pepper (Capsicum annuum L.) Raw seed seemed satisfactory for stand establishment, although primed seed had the potential to provide better initial stands. When populations were equalized, there were few differences in plant growth, plant morphology, or fruit yield attributed to seed treatment. Morphology of plants established by direct seeding generally was favorable for mechanical harvest. Use of transplants did not result in higher marketable fruit yields than direct seeding in two out of three years. When compared to plants established by direct seeding, three trends were consistent across all three years for plants established by transplanting: a) they were more massive: b) they had larger vertical fruiting planes: and c) they had more branches. These traits would increase the difficulty of mechanical harvest and would create the potential for more trash in the harvested product. Thus, transplanting is not recommended for stand establishment of paprika intended for mechanical harvest.
James R. Cooksey, Brian A. Kahn, and James E. Motes
Nontreated seed, primed seed, and transplants were compared for effects on stand establishment, plant morphology, and yield of paprika pepper (Capsicum annuum L.). Nontreated seed was satisfactory for stand establishment, although primed seed had the potential to provide greater initial stands. When populations were made equal by thinning, there were few differences in stem and leaf dry weight, fruit yield, or plant morphology attributed to seed treatment. Generally, morphology of plants established by direct seeding was favorable for mechanical harvest. Using transplants did not result in higher marketable fruit yields than direct seeding in 2 of 3 years. When compared to plants established by direct seeding, three trends were consistent across all 3 years for plants established by transplanting: 1) they were more massive, 2) they had larger vertical fruiting planes, and 3) they had more branches. These traits increase the difficulty of mechanical harvest and create the potential for more leaves and stems (trash) in the harvested product. Thus, transplanting is not recommended for stand establishment of paprika pepper intended for mechanical harvest.
Michael N. Dana and Ricky D. Kemery
133 POSTER SESSION 20 Seed Establishment/Cross-Commodity