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The costs associated with growing, harvesting and marketing strawberries (Fragaria × ananassa) using the plasticulture production system were estimated to be $13,540/acre ($33,457/ha). Net revenue analysis showed that growers would have to charge at least $0.85 and $1.40/lb ($1.87 to $3.09/kg) for pick-your-own (PYO) and prepicked fruit, respectively, and sell 12,000 lb of berries per acre (13,449.9 kg·ha-1) to cover this expense. Break-even analysis indicated that growers would have to charge a PYO price of $0.65/lb ($1.43/kg) and $1.20/lb ($2.64/kg) for prepick berries and sell a minimum of 15,041 lb/acre (16,858.4 kg·ha-1) to cover the projected expenses. However, if a grower received $0.95 and $1.50/lb ($2.09 and $3.31/kg) for the PYO and prepicked fruit, respectively, he/she would only have to sell 10,622 lb of berries per acre (11,905.4 kg·ha-1) to break even. It was assumed that an average of 11.6 lb (5.26 kg) of fruit would be sold to PYO customers and an average of 7.1 lb (3.22 kg) would be sold to customers who visited the fruit stand. Under these assumptions, the breakeven yield of 14,724 lb/acre translates into a requirement to sell fruit to at least 1,539 customers per acre (3,802.8 customers/ha) at the lowest combination of prices while a yield of 10,398 lb/acre converts to a minimum of 1,087 customers per acre (2,685.9 customers/ha) at the higher prices. Customers were also surveyed at direct market operations in Spring 1999 to gain insight into consumer demographic characteristics, why customers select a specific PYO or prepick direct market strawberry outlet, average expenditures per customer, typical driving distances to direct market strawberry operations, and the effectiveness of advertising. Middle age, middle-income customers living within 10 miles (16.1 km) of the farm comprised the largest percentage of customers surveyed at the PYO operations, while middle age, high-income individuals who also live within 10 miles of the fruit stand were the largest group of respondents at the fruit stands. PYO customers spent an average of $10.30, and prepick consumers spent an average of $9.40 per visit. Less than 23% of all the respondents said that advertising influenced their shopping decision while >77% indicated that any type of advertisement did not influence their decision. Overall, convenient location was easily the major reason that customers decided to patronize a specific direct market outlet while personal referrals were second.
Methods to evaluate soil water repellency (SWR) require extensive studies on field soils and are subject to the heterogeneity of SWR throughout the soil profile as well as plant/soil interactions. The objectives of this study were to develop a synthetic method to create hydrophobic sand, and to determine if that hydrophobic sand would affect the establishment of bermudagrass (Cynodon dactylon L. Pers. × C. transvaalensis Burtt-Davy, cv. Tifeagle) sprigs. Two techniques were developed to render sand hydrophobic: soap:sand method (hydrophobic sand; HSS) and sand:peat method (hydrophobic sand and read sedge peat; HSP). Both HSS and HSP remained severely hydrophobic at 0 cm depth for only 7 d, and at the 1- to 6-cm depth for 77 continuous days, as determined by water drop penetration time. Bermudagrass establishment, root growth, or shoot growth in two greenhouse experiments with four root zone substrates–HSS, HSP, WSAND (wettable sand), and WSP (wettable sand and reed sedge peat)—were not consistent. In conclusion, both HSS and HSP were shown to be safe and effective methods to synthetically produce hydrophobic sand for potential use in laboratory research, but further evaluation is needed to determine the feasibility of using HSS and HSP for turfgrass growth evaluations.
In 2017, five new cultivars specifically selected for Australian conditions were released. These were developed from an improvement program initiated by Commonwealth Scientific and Industrial Research Organisation in the early 1990s. Progeny seeds were produced by crossing industry standard cultivars with other cultivars with elite kernel production per unit projected canopy area. Seedlings were planted at two densities (2 m and 4 m along rows) in field trials at Bundaberg in 1997 and 1998, and Northern New South Wales in late 1997, along with replicated plants of parents grafted onto seedling rootstocks. Trials were assessed for commencement of flowering, growth, yield, kernel recovery, and components of kernel quality over 8 years. Best linear unbiased predictions of clonal values were obtained for each individual progeny using a pedigree-based mixed linear model. A bio-economic model was used to estimate economic weights for a selection index of clonal values to identify elite candidates. Final approval of 20 candidates for second-stage assessment was made by an industry committee using selection index rankings and observations of tree field performance and kernel quality.
Because sweetpotato [Ipomoea batatas (L.) Lam.] stem cuttings regenerate very easily and quickly, a study of their early growth and development in microgravity could be useful to an understanding of morphological changes that might occur under such conditions for crops that are propagated vegetatively. An experiment was conducted aboard a U.S. Space Shuttle to investigate the impact of microgravity on root growth, distribution of amyloplasts in the root cells, and on the concentration of soluble sugars and starch in the stems of sweetpotatoes. Twelve stem cuttings of ‘Whatley/Loretan’ sweetpotato (5 cm long) with three to four nodes were grown in each of two plant growth units filled with a nutrient agarose medium impregnated with a half-strength Hoagland solution. One plant growth unit was flown on Space Shuttle Columbia for 5 days, whereas the other remained on the ground as a control. The cuttings were received within 2 h postflight and, along with ground controls, processed in ≈45 min. Adventitious roots were counted, measured, and fixed for electron microscopy and stems frozen for starch and sugar assays. Air samples were collected from the headspace of each plant growth unit for postflight determination of carbon dioxide, oxygen, and ethylene levels. All stem cuttings produced adventitious roots and growth was quite vigorous in both ground-based and flight samples and, except for a slight browning of some root tips in the flight samples, all stem cuttings appeared normal. The roots on the flight cuttings tended to grow in random directions. Also, stem cuttings grown in microgravity had more roots and greater total root length than ground-based controls. Amyloplasts in root cap cells of ground-based controls were evenly sedimented toward one end compared with a more random distribution in the flight samples. The concentration of soluble sugars, glucose, fructose, and sucrose and total starch concentration were all substantially greater in the stems of flight samples than those found in the ground-based samples. Carbon dioxide levels were 50% greater and oxygen marginally lower in the flight plants, whereas ethylene levels were similar and averaged less than 10 nL·L−1. Despite the greater accumulation of carbohydrates in the stems, and greater root growth in the flight cuttings, overall results showed minimal differences in cell development between space flight and ground-based tissues. This suggests that the space flight environment did not adversely impact sweetpotato metabolism and that vegetative cuttings should be an acceptable approach for propagating sweetpotato plants for space applications.
Abstract
‘Jonafree’ is an attractive red apple (Malm domestia Borkh) with field immunity to apple scab incited by Venturia inaequalis (Cke) Wint. The fruit is of medium size and matures with ‘Jonathan’. It is released as a potential commercial cultivar with strong resemblance to ‘Jonathan’ in many major horticultural characters in addition to its similar maturity date.
Abstract
Apple scab, caused by the fungus Venturia inaequalis (Cke.) Wint. is one of the most economically important apple diseases, because of the annual loss of marketable fruit, tree debilitation as a result of foliage destruction, and the cost of chemicals, equipment, and labor for its control. Infection can occur at any time during the growing season in humid apple-producing areas of the world. Most scab control programs must be based on the application of 5 to 15 or more protective fungicide sprays from the beginning of bud break to harvest. Estimates of direct costs for scab control including fungicides, equipment costs, and labor range from 20 to 30¢ per bushel or some 10% of the annual cost of production. In addition, chemical control must be exacting with application of spray materials most efficacious in rainy spring weather it is oftne difficult to move equipment through the orchard.
Nicosulfuron and mesotrione are herbicides from different chemical families with different modes of action. An association between the sensitivity of sweet corn (Zea mays L.) to nicosulfuron and mesotrione was observed when hybrids, inbreds, and S1 families (S2 plants) were evaluated for herbicide sensitivity in field trials. In 2003 and 2004, 50% and 53% of mesotrione-sensitive hybrids were sensitive to nicosulfuron compared with only 6% and 1% of mesotrione-tolerant hybrids that were sensitive to nicosulfuron. In trials with inbreds in 2003 and 2004, 88% and 78% of nicosulfuron-sensitive inbreds had some injury from mesotrione but 0% and 5% of nicosulfuron-tolerant inbreds were injured by mesotrione. Among S1 families, 77% of the mesotrione-sensitive families were nicosulfuron-sensitive but only 5% of the mesotrione-tolerant families were sensitive to nicosulfuron. Segregation of S1 families for response to mesotrione was not significantly different from a 1:2:1 pattern of sensitive: segregating: tolerant families (chi square value = 2.25, P = 0.324) which would be expected if sensitivity was conditioned by a single recessive gene. Segregation of S1 families for response to nicosulfuron was 15:23:26 (sensitive: segregating: tolerant) which was slightly different from an expected 1:2:1 ratio (chi square value = 8.84, P = 0.012). Segregation of S1 families probably was affected by the relatively small number of S2 plants sampled from each family. Similar responses of the S1 families to nicosulfuron and mesotrione lead us to hypothesize that the same recessive gene is conditioning sensitivity to both herbicides. Possibly, this gene is common in the inbreds and hybrids that were sensitive in these trials. These hypotheses will be tested by examining segregation in S2 families and other segregating generations and by conducting tests of allelism among sensitive inbreds and inbred parents of sensitive hybrids. Chemical names: 2-(4-mesyl-2-nitrobenzoyl)-3-hydroxycyclohex-2-enone, (mesotrione); 2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-N,N-dimethyl-3-pyridinecarboxamide, (nicosulfuron).
Systemic acquired resistance is a broad spectrum inducible defense response that is associated with the expression of a set of genes (SAR genes). Expression of one of these genes (PR-1a from tobacco) in transgenic tobacco confers increased tolerance to two oomycete pathogens.
A direct role for salicylic acid (SA) in signaling SAR has been established in tobacco by analysis of transgenic tobacco expressing salicylate hydroxylase (SAH, an enzyme that inactivates SA by conversion to catechol). Tobacco plants that express SAH are blocked in the accumulation of SA and the development of SAR when responding lo TMV. Furthermore, both Arabidopsis and tobacco expressing SAH have altered pathogen induced lesion morphology, exemplified by larger spreading lesions.
Putative mutants in SAR gene expression were isolated by screening M2 Arabidopsis plants for altered expression of PR-1 and PR-2 or for sensitivity to pathogen infection following INA treatment. The putative mutants all into two major classes,constitutive (cim, constitutive immunity) and non-inducible (nim, non-inducible immunity). Several cim mutants exhibits a disease lesion phenotype in the absence of pathogen.
Abstract
‘Redfree’ is an attractive high finish red apple (Malus domestica Borkh.) with field immunity to the apple scab organism (Venturia inaequalis (Cke.) Wint). The fruit is medium size. It matures 2 to 3 weeks before ‘Prima’ and 1 week before ‘Paulared’. ‘Redfree’ is released as a potential commercial cultivar for use as a summer dessert apple.
Abstract
‘Sir Prize’ is a yellow, russet-free apple with immunity to apple scab caused by Venturia inaequalis (Cke.) Wint. The fruit is large and ripens along with ‘Golden Delicious’. It is released as a home garden cultivar.