The establishment of stands from directly sown seed may be a way to reduce the current high costs associated with guayule (Parthenium argentatum Gray) cultivation. These field studies were conducted to examine the combined effects of shade and fungicides on the survival of guayule seedlings established from directly sown seed. Soil in the experimental plot was a loam of pH 7.25. The following fungicides: a) Terraclor Super X, b) Ridomil 5G, c) Ridomil PC llG, d) Tilt 3.6E, e) Terracoat, and f) Vitavax + PCNB were tested alone and in combination with the nonwoven polyester shadecloth, Reemay, to identify treatments enhancing seed germination and seedling establishment. In all cases, seedling emergence in microplots covered with Reemay was significantly higher than in noncovered microplots. Terraclor Super X, Ridomil 5G, and Ridomil PC 1 lG were effective only when used in combination with the shadecloth. The long-term survival of guayule seedlings was strongly affected by severe climatic events. Since Reemay-protected seedlings were larger and more robust, they were more likely to survive the climatic extremes than unprotected seedlings. Two new guayule seedling pathogens were recorded -pythium dissotocum Drechsler and P. paroecandrum Drechsler. Chemical names used: 5-ethoxy-3-(trichloromethyl)-1,2,4-thiadiazole (Terrazole) + pen. tachloronitrobenzene (PCNB); N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-alamine methyl ester Ridomil + PCNB; 7. bromo-5-chloro-quinolin-8-yl-acrylate; Terrazole 5,6-dihydro-2-methyl-l,4 -oxathiin-3-carboxanilide + PCNB.
J.D. Mihail and S.M. Alcorn
David Granatstein, Joan R. Davenport, and Elizabeth Kirby
loss, increasing weed seed germination, and damaging surface tree roots. Direct seeding equipment has been developed for a variety of cropping systems and can be adapted for use in orchards, thus avoiding these problems. The objectives of the study were
Charlene M. Grahn, Barbara Hellier, Chris Benedict, and Carol Miles
emergence of seedlings has long been the goal of horticulturists as a means of optimizing stand uniformity and maturity in direct-seeded crops ( Fromme et al., 2014 ; Seale and Cantliffe, 1987 ). Low soil temperatures can increase the time to emergence
Dale N. Seale, Daniel J. Cantliffe, and Peter J. Stoffella
Primed, primed + BA, or nontreated lettuce (Lactuca sativa L.) seeds were sown with several soil amendment covers or a sandy soil cover (control) to assess stand establishment in three field experiments. Seeds covered with amendments Growsorb LVM 24/48, Growsorb 6/30, and plug-mix had a higher percent emergence than soil-covered seeds in warm soil. Primed seeds (with or without BA) had a higher percent emergence than nontreated seeds. Emergence was more rapid with plug-mix, LVM 24/48, and LVM 6/30 covers than with the sandy soil control. Primed seeds with or without BA also emerged more rapidly and produced heavier seedling shoots than nontreated seeds. Using primed lettuce seeds combined with specific soil amendments can improve lettuce stand establishment under various field conditions. Chemical name used: 6-benzyladenine (BA).
Gerald B. Odell, Daniel J. Cantliffe, Herbert H. Bryan, and Peter J. Stoffella
Primed, pregerminated, or nontreated `FloraDade' tomato (Lycopersicon esculentum Mill.) seeds in combination with several soil amendments were evaluated in three experiments for stand establishment characteristics and fresh-market fruit yields. Total percent emergence, seedling shoot weight, and marketable fruit yield were not consistently improved by GrowSorb, gel-mix, plug-mix covers, or mixtures with seeds as compared with a control (soil cover). However, rate of emergence was generally faster for plots containing primed or pregerminated seeds with soil amendments than for plots with a soil cover. Primed or pregerminated seeds emerged faster, and had higher total percent emergence and heavier seedling shoot weights than nontreated seeds, but there was little difference in response between primed and pregerminated seeds. Plants from the primed or pregerminated plots produced earlier (first harvest) marketable fruit than did plants from nontreated seed plots in one of three experiments. Priming or pregermination of tomato seeds resulted in a more consistently improved stand establishment than soil amendments.
Robert F. Bevacqua and Dawn M. VanLeeuwen
Chile pepper (Capsicum annuum L.) yields are highly variable and are strongly influenced by disease and weather. The goal of two field experiments was to evaluate crop management factors, especially planting date, that could contribute to improved and more consistent crop production. Current practice in New Mexico is to direct seed the crop from 13 to 27 Mar. In the first experiment, chile pepper was direct seeded on three planting dates, 13, 20, and 27 Mar. 2000, without or with a fungicide treatment of pentachloronitrobenzene and mefenoxam for the control of damping off. The results indicate planting date had no effect on stand establishment or yield. Fungicide treatment, significantly reduced stand, but had no effect on yield. In the second experiment, chile pepper was direct seeded on six planting dates, 13, 20, 27 Mar. and 3, 10, 17, Apr. 2001, with or without an application of phosphorus fertilizer, P at 29.4 kg·ha-1, banded beneath the seed row. During the growing season, this experimental planting suffered, as did commercial plantings in New Mexico, from high mortality and stunting due to beet curly top virus, a disease transmitted by the beet leafhopper. The results indicate planting date had a significant effect on crop performance. The best stand establishment and highest yield were associated with the earliest planting date, 13 Mar. This date also resulted in the least viral disease damage. Phosphorus fertilizer had no effect on stand establishment or yield. Chemical names used: pentachloronitrobenzene (PCNB); (R)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid methyl ester (mefenoxam).
Daniel S. Egel, Ray Martyn, and Chris Gunter
, 2007 ). It is not known how development (vine growth and root structure) and yield are affected by today's practices compared with direct seeding on nonfumigated bare ground. Although one study of triploid watermelon root systems found no aberrant
Michael D. Orzolek
Plasticulture enables growers to optimize establishment of vegetable and fruit crops under nonoptimum conditions and in locations with short growing seasons. Generally, warm-season crops such as muskmelon, pepper, and tomato, are established from transplants to decrease the time to maturity in the field. Directly seeding vegetables such as sweet corn, cucumber, and snap bean through plastic allows for optimum soil temperature and moisture to ensure maximum seed germination and subsequent seedling emergence. Mechanized transplanting or seeding of vegetables in plasticulture is available and successful if a firm, flat bed with plastic firmly stretched over the bed is formed and specific crop requirements are followed during establishment. Common mistakes made with plant establishment in plasticulture are discussed.
D.W. Heather and J.B. Sieczka
Greenhouse and field experiments were conducted in 1988 and 1989 to determine the effect of seed size and cultivar on seedling emergence through crusted soil for several hybrid broccoli cultivars (Brassica oleracea ssp. italica). Seed was separated into four sizes (2.0, 1.8, 1.6, and 1.4 mm in diameter) for the greenhouse investigations, and soil crusting was achieved using a crusting resin. In 1989, field experiments using three seed sizes (small = 1.4 to 1.6 mm, medium = 1.7 to 1.9 mm, and large = 2.0 to 2.2 mm in diameter) were planted at the Long Island Horticultural Research Laboratory in a Riverhead sandy loam that crusted readily following rainfall. Seedling emergence data from the greenhouse and field studies indicate that seed size and cultivar significantly affect emergence and stand establishment. Seedling stand, dry weight, and final yield significantly increased as seed size increased for both cultivars in the field experiments. The emergence of `Mariner' generally was significantly better than that of `Greenlady' for each seed size. Seed of `Greenlady' also weighed significantly less than that of `Mariner' within each seed size tested.
Charles L. Webber III, James W. Shrefler, and Merritt J. Taylor
.7%) broadleaf weed control through the first 46 d after planting (DAP) ( Webber et al., 2007a ), without reductions in yields from crop injury ( Webber et al., 2007b ). The impact of CGM applications on the plant safety of direct-seeded crops has been