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George E. Fitzpatrick, Edwin R. Duke and Kimberly A. Klock-Moore

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Janet C. Cole, Roger Kjelgren and David L. Hensley

Nursery crops have traditionally been grown in the field and harvested as balled and burlapped or bareroot plants or grown in above-ground containers. A relatively recent product, the in-ground fabric container, has allowed producers to combine advantages of field production with those of container production. The effect of these containers on plant growth, transplant establishment, plant chemical composition, and water relations appears to be species and site specific.

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Monica Ozores-Hampton, K.E. Cushman, F. Roka and R.D. French-Monar

Several experiments were conducted in commercial tomato (Solanum lycopersicum) plantings during the 2004–05 and 2005–06 seasons in Immokalee, FL, to understand types of plant damage and potential yield reductions caused by hurricanes. Expt. 1 involved ‘Florida 91’ tomato seedlings damaged during 2004 by hurricane Frances, 15 days after transplanting (DAT). Individual plants were rated and categorized as best, good, or fair, 34 DAT according to plant size and vigor/severity of injury. Ten plants from each category were removed with roots intact, and dry weights were recorded. During 2005, 23 DAT or 8 days after hurricane Wilma, Expt. 2 was conducted to compare rescued and replanted ‘Soraya’ tomato seedlings. Rescued seedlings were left in place after the hurricane and others were removed and replaced with new transplants of the same variety. Expt. 3 (‘Florida 47’) and 4 (‘BHN 586’) involved the contrast of two yield seasons without a hurricane (2004–05) and with hurricane Wilma (2005–06) to estimate the effect of the hurricane damage on tomato 65 and 45 DAT. Fruit was counted, graded by size, and weighed for each experiment from 10 plants/plot. Injury caused by hurricane winds was most evident in Expt. 1 mostly in stem damage below the soil surface showed callous tissue at the site of injury due to plants being whipped around in the planting hole. Plants rated “best” showed greater plant and root dry weight, stem diameter below the injury point, and higher yield of extra large and total marketable fruit at first harvest than plants rated good or fair. Total marketable yields from rescued plants in Expt. 2 were double than that from replanted plants, and fruit matured 20 days earlier for rescued plants indicating that plants injured by Wilma recovered quickly. Hurricane-damaged crops during 2005–06 in Expts. 3 and 4 yielded 60% lower than that of undamaged crops during 2004–05. In the extra large size category, the yields were reduced between 34% and 12% from the previous season. However, hurricane-damaged loss of yield in the extra large category was offset by increased yield in the medium category. It appears that hurricane-damaged plants, when young, were capable of full recovery and normal yields, whereas hurricane-damaged plants, when older at the time injury occurred, were not able to fully recover and eventually produced only half the normal yield.

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J.P. Mitchell, P.B. Goodell, R. Bader, R. Cifuentes, T.S. Prather, R.L. Coviello and D.M. May

A participatory, on-farm research and extension program has been established around 16 demonstration comparisons of biologically integrated soil building–pest management systems and conventionally managed systems within the West Side row crop area of California's San Joaquin Valley. In each of the biologically integrated parcels, cover crops and composted organic materials are integrated into rotations wherever appropriate, whereas in the conventionally managed parcels, mineral fertilizer applications are made. Pest management practices are evaluated and biologically and informationally intensive alternatives are developed through a participatory process. Indices of soil quality including nutrient status, water stable aggregates, organic matter content, and phospholipid fatty acids are routinely monitored. Information related to the objectives, structure and monitoring activities of this project during the establishment phase will be discussed.

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John LeBoeuf

103 COLLOQUIUM 3 (Abstr. 643–649) Applications of Site-specific Management for Horticultural Crop Production

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Joseph P. Albano

Aminopolycarboxylic acid (APCA) complexones, commonly referred to as ligands or chelating agents, like ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), are commonly used in soluble fertilizers to supply copper (Cu), iron (Fe), manganese (Mn), and/or zinc (Zn) to plants. Offsite runoff and contamination of surface waters with these chelating agents is of increasing concern as a result of their reported ability to remobilize heavy metals in sediments and their low susceptibility to biodegradation. The APCA ethylenediaminedisuccinic acid (EDDS) is a structural isomer of EDTA with the [S,S′] stereoisomer of the complexone, a compound naturally produced by actinomycetes, and is biodegradable. Information on the use of [S,S′]-EDDS as a chelating agent in formulating soluble fertilizers for the production of horticultural crops is limited. Therefore, a series of studies were conducted with the objectives of evaluating Fe[S,S′]-EDDS as an Fe-chelate fertilizer agent in the production of marigold and [S,S′]-EDDS (free ligand) and/or Fe[S,S′]-EDDS spectral properties and vulnerability to photodegrdation. Marigold grown in peat-based media were fertilized with complete nutrient solution containing 1 mg·L−1 Fe from FeEDDS, FeEDTA, or FeDTPA. There was no significant difference in foliar Fe or Mn between Fe-chelate treatments, averaging 140 μg·g−1 and 88 μg·g−1, respectively, nor were there significant differences in leaf dry weight (2.30 g) between Fe treatments. Spectra of [S,S′]-EDDS and Fe[S,S′]-EDDS produced from ferrous or ferric sources of Fe absorbed maximally in the 210 to 230 nm and 238 to 240-nm range, respectively. The [S,S′]-EDDS complexone used in the current study, a 30% assay solution, had chromaphoric properties, appearing light yellow in color. When exposed to light, Fe[S,S′]-EDDS quickly degraded at a rate at least twice that of FeEDTA.

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James S. Owen Jr., Stuart L. Warren, Ted E. Bilderback and Joseph P. Albano

The physical and chemical properties of pine bark yield low water and nutrient efficiency; consequently, an engineered substrate altering the substrate properties may allow greater water and nutrient retention. Past research has focused on controlling the quantity and rate of water and nutrient inputs. In this study, pine bark was amended at 8% (by volume) with a Georgiana palygorksite-bentonite blended industrial mineral aggregate with a particle size of 850 μm-4.75 mm or 300 μm-710 μm to improve water and nutrient efficiency. Each particle size was pretreated at temperatures of ≈140 °C (pasteurized) or ≈390 °C (calcined). The study was a 2 (particle size) × 2 (heat pretreatment) factorial in a randomized complete-block design with four replications. The control was a pine bark substrate amended with 11% sand (by volume). Containers (14 L) were topdressed with 17–5–12 controlled release fertilizer. A 0.2 leaching fraction was maintained by biweekly monitoring container influent from spray stakes and effluent volume measured daily. An aliquot of the daily collected effluent was analyzed for phosphorus (P). After 112 days, tops and roots were harvested, dried, and weighed for dry weight comparisons. Compared to pine bark amended with sand the 300 μm-710 μm particle size mineral decreased mean daily water application by ≈0.4 L/day per container. The calcined mineral reduced P leaching by ≈10 mg of P per container or 60% over the course of the study compared to pine bark: sand. Top and root dry weights were unaffected. These results suggest 300 μm–710 μm calcined mineral provided the most significant decreases in water use and P leaching while growing an equivalent plant.

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M.H. Maletta, W.P. Cowgill Jr., T. Manning, W. Tietjen, S.A. Johnston and P. Nitzsche

148 POSTER SESSION 21 (Abstr. 238-269) Crop Production Saturday, 31 July, 1:00-2:00 p.m.

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J. Raymond Kessler Jr., Jeff L. Sibley, Bridget K. Behe, Darby M. Quinn and James S. Bannon

Fifty-seven herbaceous perennials were evaluated from July 1996 to October 1997 in USDA Hardiness Zone 8. Plants in this study generally performed better the first year after planting than the second year. Several selections did not reemerge the second year, though some natural reseeding occurred. Still other selections never fully recovered from the winter months or succumbed to stress in the summer. Plants that maintained an attractive foliage display while not in bloom and plants that had a high bloom rating during the bloom season are worth incorporating into a full sun perennial or mixed border in the southeastern United States. Performance of perennials in the landscape may vary from year to year as climatic conditions affect performance. Comparison of results from variety trials at other locations should help increase performance information reliability for perennial selection.