When tomato (Lycopersicon esculentum Mill.) fruit come in contact with water at the packing house dump tanks, they can infiltrate water through the stem scar. If the water is infested with Erwinia carotovora, the fruit can infiltrate the bacteria, which will later develop into bacterial soft rot. To determine the inheritance of low water infiltration and thus tolerance to soft rot, a complete diallel was produced using six parents that infiltrate different amounts of water. The parents and hybrids were grown in a completely randomized block design with three blocks and 10 plants per block. The amount of water infiltrated by the fruit was measured by the change in weight after the fruit were immersed in water in a pressure cooker for 2 min. Both general combining ability (GCA) and specific combining ability (SCA) were significant, with GCA having a higher significance than SCA. There appeared to be a cytoplasmic effect on water uptake, where less water was taken up when the low-uptake parent was used as a female. When orthogonal contrasts were performed on reciprocal hybrids from parents that were significantly different, 33% of them were significantly different.
Sarah M. Smith, John W. Scott, and Jerry A. Bartz
Carlene A. Chase, Odemari S. Mbuya, and Danielle D. Treadwell
The effect of living mulches (LM) on weed suppression, crop growth and yield, and soil hydraulic conductivity were evaluated in broccoli in North Central Florida at Citra and in North Florida at Live Oak, using organic production methods. `Florida 401' rye, `Wrens Abruzzi' rye, black oat, and annual ryegrass, were either mowed or left untreated and compared with weedy and weed-free controls. Cover crop biomass was highest with `Florida 401' at both locations, intermediate with black oat and `Wrens Abruzzi', and lowest with ryegrass. The greatest weed infestation occurred with the weedy control. In Citra, ryegrass decreased weed biomass by 21% compared with ≈45% by the other LM with no differences due to mowing. However, at Live Oak, mowed LM and the weedy control had similar amounts of weed biomass; whereas unmowed LM had 30% to 40% less weed biomass than the weedy control. At both locations, broccoli heights were greatest with the weed-free control, intermediate with the cover crops, and lowest with the weedy control. Total above-ground broccoli biomass and marketable weight of broccoli at Live Oak, and number of marketable heads at both locations, were unaffected by the LM. At Citra, total broccoli biomass with LM and the weedy control decreased in a similar manner, so that total broccoli biomass was highest with the weed-free control. Ryegrass and the weedy control suppressed marketable broccoli weight by 24%; however, greater decrease in marketable weight (39% to 43%) occurred with `Florida 401', `Wrens Abruzzi', and black oat. At both locations, mowing of LM had no effect on broccoli growth or yield. There was no difference in saturated hydraulic conductivity among treatments.
Christian M. Baldwin, Haibo Liu, Lambert B. McCarty, Hong Luo, Joe Toler, and Steven H. Long
#9840; Taylor), visual turfgrass quality (TQ), clipping yield, chlorophyll concentration, root total nonstructural carbohydrates (TNC), soil bulk density, and water infiltration rates. Canopy and soil (7.6 cm depth) temperatures were recorded after each
Tanachai Pankasemsuk, James O. Garner Jr., Frank B. Matta, and Juan L. Silva
Characteristics of mangosteen fruit with normal and translucent flesh were determined. Fruit exhibiting translucent flesh disorder had significantly higher rind (65%) and flesh (82%) water content than fruit with normal flesh (63% and 80% in the rind and flesh, respectively). Specific gravity of translucent flesh fruit was >1 and that of normal flesh fruit was <1. Fruit specific gravity and natural transverse rind cracking were used to separate translucent-fleshed fruit from normal fruit. Translucent-fleshed fruit had a lower soluble solids concentration and titratable acid percentage than normal fruit. Translucent flesh was induced in normal fruit following water infiltration at 39 kPa for 5 minutes.
N.G. Krohn and D.C. Ferree
Greenhouse and field-grown `Seyval blanc' grapevines (Vitis sp.) were grown with low-growing, shallow-rooted, mat-forming, ornamental perennial groundcovers, and the effect of the groundcovers on the vegetative and fruiting growth of the grapevines was evaluated. The groundcovers used in this experiment were `Kentucky-31' tall fescue (Festuca arundinacea); white mazus (Mazus japoonicus albus); english pennyroyal (Mentha pulegium); dwarf creeping thyme (Thymus serpyllum minus); strawberry clover (Trifolium fragiferum); `Heavenly Blue' veronica (Veronica prostrata `Heavenly Blue'); and a companion grass mixture of 75% perennial ryegrass (Lolium perenne) and 25% red fescue (Festuca rubra). A control treatment grown without any groundcover was also used in both the greenhouse and field experiments. All of the groundcovers reduced `Seyval blanc' total shoot length from 22% to 85% in the vineyard. Cluster size was reduced in the field from 7% to 68% by the groundcovers compared to the herbicide control treatment, and from 9% to 66% in the greenhouse experiment, but none of the groundcovers in either the greenhouse or field experiments affected the pH, total acidity, or soluble solids concentrations of the `Seyval blanc' juice. English pennyroyal was the only groundcover that reduced in the leaf area of the grapevine. Single-leaf photosynthesis of the `Seyval blanc' grapevines in the field experiment was reduced by all groundcovers except mazus and creeping thyme. Water infiltration rates were 10 to 50 times higher in the groundcovers compared to the bare soil of the herbicide control treatment. Weed growth in the field caused reduction in shoot length similar to the most competitive groundcovers. Weed growth was reduced in the early season by the english pennyroyal and companion grass, and in the late season by all groundcovers. The reduction in growth of the grapevines caused by groundcovers in the greenhouse was a reasonable screen for the affect of groundcovers in the field. The mazus treatment was the only groundcover in our experiments that coupled fast growth with low competitive ability.
Christian M. Baldwin, Haibo Liu, and Philip J. Brown
Hollow tine cultivation is a routine practice on golf course putting greens, where the tine entry angle normally is 90°. Effects of various tine entry angles impacting putting green surfaces have not been investigated. The hypothesis was that different tine entry angles during cultivation would impact a greater area of the soil profile by enhancing water infiltration rates, reducing localized dry spots, and enhancing turf quality. Therefore, a 2-year field study in 2003 and 2004 was conducted to determine the impact of core cultivation tine entry angle on `Crenshaw' creeping bentgrass (Agrostis stoloniferous var. palustris). Treatments included three angles of hollow tine entry at 50°, 70°, and 90° and an untreated plot without cultivation. Manual cultivators consisted of four 1/4-inch- and 1/2-inch-diameter hollow tines 3 inches in length, spaced 2 inches apart. Treatment applications were in April, May, September, and October. Measurements included visual turfgrass quality (TQ), molarity ethanol droplet test (MED), and water infiltration. No treatment (control, 50°, 70°, 90°) effects in years I and II for TQ were noted. MED scores in May were 23% higher than in August and September. Tines of 1/2-inch diameter reduced soil hydrophobicity (MED) 6% compared to tines of 1/4-inch-diameter tines. Tines of 50°, 70°, and 90° had 129%, 163%, and 211% greater water infiltration than the untreated, respectively.
William V. Welker Jr. and D. Michael Glenn
Peach [Prunus persica (L.) Batsch] trees were planted in four soil management systems (cultivated, herbicide, mowed sod, and killed sod) in 1982 and grown through 1984. A companion study was established in 1984 with three systems (cultivated, herbicide, and killed sod). Tree growth and fruit yield were greatest when trees were planted and managed in a killed sod system. Establishing a living sod before planting the trees, and then killing the sod with herbicides, prevented the depletion of soil organic matter and increased water infiltration rates, aggregate stability, macroporosity, and microbial respiration rates compared to conventional systems. The changes in soil structure persisted for 2 to 3 years.
Robert K. Showalter
Serious, postharvest decay losses occurred in tomatoes when water in which they were submerged was cooler than the fruit. Tomatoes have extensive intercellular air spaces, a heavily cutinized epidermis, and no stomatal openings. When tomatoes with unbroken skins were submerged in packinghouse dump tank water of lower temperatures, the internal air contracted and water plus decay organisms were drawn into the fruits through the stem scar. Heating dump tank water has been successful in limiting this decay problem.
Jordan M. Craft, Christian M. Baldwin, Wayne H. Philley, James D. McCurdy, Barry R. Stewart, Maria Tomaso-Peterson, and Eugene K. Blythe
levels of thatch-mat organic matter causes many problems, including increased ball marks ( Vermeulen and Hartwiger, 2005 ), increased pathogen and insect populations ( Bevard, 2005 ; Christians, 1998 ), and reduced water infiltration rates ( Bevard, 2005
Huisen Zhu and Deying Li
Intl., Loveland, CO) at the 2.9- to 8.9-cm depth below the turf surface to avoid sampling the thatch and mat layer which was less compacted. Soil samples were oven-dried at 105 °C for 24 h before the determination of dry bulk density. Water infiltration