Highest Total Marketable Yield Research Articles

Optimizing anaerobic soil disinfestation for fresh market tomato production: Nematode and weed control, yield, and fruit quality

Anaerobic soil disinfestation (ASD) has potential as an alternative to chemical-fumigation for controlling soilborne pathogens and pests. Previously, control of nutsedge was sub-optimal and the quantity of inputs for commercial production was an impediment to adoption. Field studies were conducted in Citra and Immokalee, Florida to assess the effects of ASD with reduced amendments and inclusion of a pre-emergent herbicide on weed and nematode populations, tomato yield, and fruit quality. Pre-plant soil treatments included ASD with 6.9m3ha−1 of molasses and 11Mgha−1 of composted poultry litter (CPL) (ASD0.5), ASD with 13.9m3ha−1 of molasses and 22Mgha−1 of CPL (ASD1.0), and chemical soil fumigation using Pic-Clor 60 (CSF). Subplot treatments were halosulfuron-methyl (Sandea®) herbicide and no herbicide application. ASD0.5 reached high and equivalent accumulation of anaerobic conditions as ASD1.0 during the three-week soil treatment in both locations. Root galling and plant-parasitic nematode population at harvest in ASD treatments were similar in nematode suppression to CSF in both locations, while ASD1.0 resulted in higher non-parasitic nematode populations in soil compared to CSF in Citra. In Citra, ASD treatments did not differ from CSF in total marketable fruit yield; however, ASD0.5 resulted in higher total yield of extra-large fruit than CSF and ASD1.0. In Immokalee, no difference was observed in total marketable yield between ASD0.5 and CSF, whereas ASD1.0 produced 26.3% and 20.4% higher total marketable yield than that of CSF and ASD0.5, respectively. ASD treatments had no impact on fruit quality attributes including color, firmness, pH, total soluble solids, and dry matter content. Herbicide application improved nutsedge control and had no negative impact on the development of anaerobicity in ASD-treated plots, while total marketable yield and fruit quality were not impacted by herbicide treatment in either location. Despite some variations between the two locations, reduced application rates of CPL and molasses produced results similar to the full rates of amendment as well as the fumigation treatment. Overall, combining ASD with an herbicide had no negative impacts on crop production and resulted in improved weed control.

Effect of tree and branch thinning on growth, yield, and fruit quality of persimmon trees in a high-density orchard

ABSTRACTA study was conducted to evaluate the effect of branch and tree thinning on growth, yield and fruit quality in 8-year-old non-astringent persimmon (Diospyros kaki L.f.) trees in a high-density orchard over 6 years in Korea. Adjacent trees in the rows were removed in 2008 (first-year thinning) or in 2010 (gradual thinning). Trees in the second treatment also had 25% of the main scaffold branches removed in the first two seasons. Control plots were left unthinned. First-year thinning elevated leaf macro-nutrient concentrations, increased the production of short fruiting shoots (less than 20 cm) per tree, decreased water sprout development and weight of pruned biomass, and increased fruit set compared with values recorded on control trees and with gradual thinning. First-year thinning gave higher photosynthetic photon flux in the centre of the canopy and better fruit quality. There were generally only small differences in total yield across the three treatments in individual years, but much higher total marketable yield from 2010 to 2013 in the first-year thinning plots. First-year thinning improved overall tree productivity, and the gross returns were 80% higher than those of control from 2008 to 2013 when the extra cost of the thinning was taken into account.

The Effects of Anaerobic Soil Disinfestation on Weed and Nematode Control, Fruit Yield, and Quality of Florida Fresh-market Tomato

Anaerobic soil disinfestation (ASD) is considered a promising sustainable alternative to chemical soil fumigation (CSF), and has been shown to be effective against soilborne diseases, plant-parasitic nematodes, and weeds in several crop production systems. Nevertheless, limited information is available on the effects of ASD on crop yield and quality. Therefore, a field study was conducted on fresh-market tomato (Solanum lycopersicum L.) in two different locations in Florida (Immokalee and Citra), to evaluate and compare the ASD and CSF performances on weed and nematodes control, and on fruit yield and quality. In Immokalee, Pic-Clor 60 (1,3-dichloropropene + chloropicrin) was used as the CSF, whereas in Citra, the CSF was Paldin™ [dimethyl disulfide (DMDS) + chloropicrin]. Anaerobic soil disinfestation treatments were applied using a mix of composted poultry litter (CPL) at the rate of 22 Mg·ha−1, and two rates of molasses [13.9 (ASD1) and 27.7 m3·ha−1 (ASD2)] as a carbon (C) source. In both locations, soil subjected to ASD reached highly anaerobic conditions, and cumulative soil anaerobiosis was 167% and 116% higher in ASD2 plots than in ASD1 plots, in Immokalee and Citra, respectively. In Immokalee, the CSF provided the most significant weed control, but ASD treatments also suppressed weeds enough to prevent an impact on yield. In Citra, all treatments, including the CSF, provided poor weed control relative to the Immokalee site. In both locations, the application of ASD provided a level of root-knot nematode (Meloidogyne sp.) control equivalent to, or more effective than the CSF. In Immokalee, ASD2 and ASD1 plots provided 26.7% and 19.7% higher total marketable yield as compared with CSF plots, respectively. However, in Citra, total marketable yield was unaffected by soil treatments. Tomato fruit quality parameters were not influenced by soil treatments, except for fruit firmness in Immokalee, which was significantly higher in fruits from ASD treatments than in those from CSF soil. Fruit mineral content was similar or higher in ASD plots as compared with CSF. In fresh-market tomato, ASD applied using a mixture of CPL and molasses may be a sustainable alternative to CSF for maintaining or even improving marketable yield and fruit quality.

Increasing Plant Density in Eastern United States Broccoli Production Systems to Maximize Marketable Head Yields

Increased demand for fresh market crown-cut broccoli (Brassica oleracea var. italica) has led to increased production along the eastern seaboard of the United States. Maximizing broccoli yields is a primary concern for quickly expanding eastern markets. Thus, a plant density study was carried out in Fall 2012 and 2013 using the hybrid cultivar Emerald Crown on a commercial farm in Summerton, SC, and in Fall 2013 using ‘Emerald Crown’ and another hybrid, ‘Durapak 19’, on a research farm in Charleston, SC. The objective was to determine the effect of variable within-row spacings of 4, 6, and 8 inches (using a system with double rows spaced 12-inches apart) on marketable yields and quality in the three environments. Our results indicated that increasing plant density by reducing within-row spacing to 4 inches significantly increased overall yield per hectare over the 6- and 8-inch spacing treatments at two of three environments. Stem diameter and average head weight were unaffected by plant density; however, heads harvested from plots with the highest plant densities had significantly (P < 0.01) lower bead uniformity in the Summerton 2012 trial, and significantly (P < 0.05) larger bead size in the two trials conducted in 2013. In general, the highest total marketable yields were from the 4-inch within-row spacing, but increased competition at the highest density may increase the risk of plants producing heads with lower quality characteristics. With the increased risk of producing lower quality marketable heads along with the increased production costs associated with the 4-inch spacing, yield and head quality attributes may be optimized at the 6-inch within-row spacing.

Improving Growth and Productivity of Early-season High-tunnel Tomatoes with Targeted Temperature Additions

In northern climates where the growing season is shortened by cool spring conditions, high tunnels make it possible to plant and produce tomatoes (Solanum lycopersicum L.) at least 1 month earlier than in the field. However, limited high-tunnel research has been performed in arid high-elevation regions that experience extreme diurnal temperature fluctuations. High tunnels are designed to be passively heated; therefore, additional protection from frost may be warranted if growers wish to plant significantly earlier than normal. Low tunnels built within a high tunnel reduce the energy requirement by concentrating heat around the plants, particularly when a heat source is placed inside the low tunnel. ‘Sunbrite’ tomatoes were transplanted through black plastic mulch in four high tunnels in North Logan, UT (lat. 41.73° N, long. 111.83° W, 1382 m elevation) on 17 Mar., 30 Mar., and 7 Apr. in 2009 and on 19 Mar., 30 Mar., and 9 Apr. in 2010. Low tunnels were constructed over each row, and three supplemental heat treatments (unheated, soil-warming cables, and soil-warming cables plus 40-W incandescent lights) were tested to improve plant performance. The highest total marketable yield was achieved for earliest planting dates in both 2009 and 2010. In 2009, early-season yield was significantly greater when both the soil + air were heated, but only for the earliest planting date. In 2010, soil heat alone and in conjunction with air heat significantly improved early-season yield. Information gathered in this study on planting dates, yield, and energy costs provides valuable production and economic information to growers in arid high-elevation climates who desire the benefits of growing early-season tomatoes in high tunnels.

Effect of Photoselective Sheet and Grafting Technique on Growth, Yield, and Mineral Composition of Sweet Pepper Plants

ABSTRACT The effect of two thermal photoselective polyethylene sheets with or without solar heat reflection pigments (SHRP) combined with two transplant types (grafted or un-grafted) were analyzed in sweet pepper plants. The selective transmittance through the photoselective sheet increased the temperature inside the greenhouse compared with the standard sheet. Plants grown under SHRP sheet significantly increased total leaves fresh weight and total fruit yield. When plants were grafted, leaf and stem fresh weight were reduced compared with the ungrafted plants, but total fruit number was increased. Leaf nitrate (NO3 −) concentration was affected by both sheet and transplant type at early stage of crop development but not at later stages. Total-nitrogen (N) was found to be higher in grafted plants, but with a lower microelements concentration. Grafted plants had an increased the number of days to harvest at the second truss, reducing significantly its weight and size. But at the end of the crop cycle, these plants showed higher total marketable yield than the un-grafted plants. Plant grown under SHRP sheet showed higher yield than those plants under standard sheet. Results shows that new cultivation techniques such as use grafted plants and new thermal photoselective sheets should be take into account to increase yield of sweet pepper under semi-arid conditions.

A Ratoon Cropping System for Fall Bell Pepper Production

Studies were conducted to examine the effects of pruning treatments applied to spring-transplanted bell peppers (Capsicum annuum L.) on marketable fruit yield in late summer and fall. Control plants were set in the field in early May 1997 (Oklahoma) and Apr. 1998 (Oklahoma and Texas) and harvested weekly into October (Oklahoma) or periodically into December (Texas). In 1997, all four treatments (involving height and method of pruning) reduced total marketable fruit weight, but differences among treatments were nonsignificant. In Oklahoma in 1998, plants were mowed on 27 July at an average height of ≈24 cm. Mowed plants produced less total marketable fruit weight but more U.S. Fancy fruit than did control plants, while weight of U.S. No. 1 fruit was not affected. In Texas in 1998, plants mowed on 4 Sept. at a height of ≈20 cm produced more than twice the weight of U.S. No. 1 fruit and fewer cull fruit than did control plants. Nonpruned transplants set in the field in Summer 1998 (both Oklahoma and Texas) produced low marketable yields. Maintaining spring-transplanted bell peppers is a viable technique for fall pepper production, and the highest total marketable yields may be obtained if these plants are not mowed. However, mowing offers an opportunity for increased fall production of premium fruit, and mowed plants would be easier to manage than nonpruned plants.

278 A Ratoon Cropping System for Fall Bell Pepper Production

Studies were conducted to examine the effects of pruning treatments applied to spring-transplanted bell peppers (Capsicum annuum L.) on marketable fruit yield in late summer and fall. Control plants were set in the field in early May 1997 (Oklahoma) and Apr. 1998 (Oklahoma and Texas) and were harvested weekly into October (Oklahoma) or periodically into December (Texas). In 1997, there were no differences in total marketable fruit weight among four treatments involving height and method of pruning, but all reduced total marketable fruit weight relative to the control. In Oklahoma in 1998, the control was compared to plants mowed on 27 July at an average height of ≈24 cm. Mowed plants produced less total marketable fruit weight but more U.S. Fancy fruit than control plants. Also, control and mowed plants did not differ in weight of U.S. no. 1 fruit. In Texas in 1998, the control was compared to plants mowed on 4 Sept. at a height of ≈20 cm. Mowed plants produced more than double the weight of U.S. no. 1 fruit and fewer cull fruit than control plants. Nonpruned transplants set in the field in Summer 1998 (Oklahoma and Texas) gave low marketable yields. Maintaining spring-transplanted bell peppers is a viable technique for fall pepper production, and the highest total marketable yields may occur if these plants are not mowed. However, mowing offers an opportunity for increased fall production of premium fruit, and mowed plants would be easier to manage than unpruned plants.

METHYL BROMIDE ALTERNATIVES IN FRESH MARKET TOMATO PRODUCTION

Pest management is of primary importance to the vegetable industry in our nation. In recent years producers have undergone much scrutiny concerning their pest control strategies, which often include the use of chemical pesticides. Due to the detrimental effects of many fumigants, growers are being forced to incorporate more environmentally sound agricultural practices while still producing a healthy, marketable commodity. The effects of three different fumigants and reflective mulches on plant growth and development were studied in field-grown, staked tomatoes. Methyl bromide, Telone II, or Telone C-17 were used in fumigation of plots. The establishment of mulch color was done via applications of exterior enamel paint, white or red in color, to the surface of black polyethylene mulch. With the exception of total marketable yields, no interactions existed between mulch color and fumigant. Red mulch and Telone II treatments resulted in the highest total marketable yield. Telone II application increased early marketable yield. White mulch color increased preharvest yield and black mulch color decreased early marketable yield. Low initial populations of nematodes may be the cause for lack of response due to fumigation.