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  • Author or Editor: Joseph Kemble x
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The heritability of shortened fruit maturation (SFM) period in Cornell 871213-1, an inbred cherry tomato [Lycopersicon esculentum var. cerasiforme (Dunal.) A. Gray] line, was estimated from a greenhouse experiment. Cornell 871213-1 was crossed with the cherry tomato line NC 21C-1. Mean fruit maturation period (FMP) (days from anthesis to the breaker stage of fruit color) was 40.8 days for NC 21C-1 and 32.0 days for Cornell 871213-1. Parental, F1, F2, and backcross generations all differed in mean FMP and yielded, estimates of broad- and narrow-sense SFM heritabilities of 72% and 40%, respectively, on a single-plant basis. A test for midparent heterosis showed significance. Genetic control of SFM was quantitative in nature and highly dominant. A field study of an F2 population developed from the cross Cornell 871213-1 × NC 84173, the latter a large-fruited tomato line (Lycopersicon esculentum Mill.), gave a mean FMP of 48.4 and 31.2 days for NC 84173 and Cornell 871213-1, respectively. The F1 and F2 generations had FMP of 33.1 and 34.7 days, respectively. The parents, F1, and F2 generations all differed in FMP. Parental, F1, and F2 generations yielded an estimate of broad-sense SFM heritability of 64% on a single-plant basis. F3 progenies from selected F2 s were grown in a greenhouse, and F3-F2 regression analysis gave a narrow-sense SFM heritability of 39%. Parental means differed from each other and from the F1 and F2 means for period from sowing to anthesis, fruit weight, and locule number. F1 and F2 means did not differ for any trait and were far below the midparent values, approaching Cornell 871213-1 for each trait except for the number of days from sowing to anthesis. Significant correlations existed in the F2 generation between FMP and fruit weight (0.61) and between fruit weight and locule number (0.69). Significant correlations existed between selected F2s and their F3 progeny for FMP (0.53), fruit weight (0.78), and days from sowing to anthesis (0.78). In the F3 generation, a significant correlation occurred between FMP and fruit weight (0.48). F3-F2 regression and realized heritabilities were used as two estimates of narrow-sense heritability (29% and 31%, respectively) for days from sowing to anthesis.

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Experiments were conducted in 1989 to determine the heritability of shortened fruit maturation (SFM) period in 871213-1, an inbred cherry tomato line (Lycopersicon esculentum var. cerasiforme (Dunal.) A. Gray), and to determine the relationship between this trait and fruit size. In the first study, a cross was made between 871213-1 and NC 21C-1, an inbred cherry line. NC 21C-1 had a mean maturation period of 40.8 days compared to 32.0 days for 871213-1. A mean maturation period for the F1 hybrid of 32.9 days and 32.2 days was found using 871213-1 as the female and male parent, respectively. Analysis of the data from parental, F1, F2 and backcross generations yielded estimates of broad-sense and narrow-sense heritabilities for SFM as 0.72 and 0.56, respectively. Further analysis indicated that genetic control of SFM was quantitative in nature and highly dominant. A test for epistatic interaction showed significance. In the second study, an F2 population from the cross 871213-1 x NC 309-1, a large-fruited tomato line (Lycopersicon esculentum Mill.), was evaluated to determine if any correlations existed between fruit size and SFM. Two fruit characteristics, locule number and fruit weight, were used as estimates of fruit size. Correlations between SFM and these two characteristics were +0.28 and +0.61, respectively. Broad-sense heritability of SFM was estimated as 0.64.

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In 1994, a study was conducted in Crossville, Ala., to determine if differences in leaf P concentration and crop yield occurred when P was applied as either a broadcast or banded treatment. Phosphorus (0, 34, 67, 101, and 134 kg·ha–1) was banded (2 × 2) or broadcast applied and incorporated before planting. Other nutrients were applied based on current recommendations and soil testing. As level of P increased from 0 to 134 kg·ha–1, fresh weight of harvested ears increased quadratically. There was no difference in fresh weight of harvested ears between banding and broadcasting. Yields were not maximized within the range of applied P, although it seems that yield reaches a plateau near the highest rate of applied P. Percent of P in corn ear leaves did not differ among treatments. There was no difference in P leaf concentrations between the banded and broadcast treatments, indicating that response in yield occurred due to rate of P application, not method.

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Ten “mini” or personal size seedless watermelons were evaluated at three locations: north and central Mississippi and in central Alabama. `Betsy', `Bobbie', `Demi-Sweet', `Extazy', `Mini Yellow', `Petite Treat', `Solitaire', `Valdoria', `Vanessa', and `Wonder' were the cultivars trialed. Seedlings were started, in a greenhouse, four weeks before planting. All locations used drip irrigation and black plastic mulch and were fertilized according to soil testing lab recommendations. A personal size diploid (seeded) variety, `Jenny', was used as the pollinator. One pollinator was planted, and interspaced evenly, for every three triploid plants. Four harvests were made at each location on 7-day intervals. Yields reported are based on 2,074 triploid plants per acre and 1,037 pollinizer plants per acre. Only the triploid yield reported. Plant spacing was 14 ft2 per plant. For total yield (lb/acre) the cultivars `Petite Treat' (27,210), `Valdoria' (25,700), and `Demi-Sweet' (26,400) were among the top producers at each location. `Mini Yellow' was a top producer at all locations averaging 22,480 lb/acre. For total yield (fruit/acre) the cultivars `Valdoria' (3,380), `Petite Treat' (3,470), `Bobbie' (3,470), `Betsy' (3,380), and `Vanessa' (2,740), were among the top producers at each location. For total yield (lb/fruit) `Betsy' (6.9), `Wonder' (6.7), and `Vanessa' (6.1) had the overall lowest individual fruit weights. `Demi-Sweet' had the highest individual fruit weight in central Alabama (10.0) and north Mississippi (8.8). One problem observed was that a number of melons among cultivars were above or below size class. Also determining melon ripeness was a challenge. Melon quality was good. The soluble solids concentration (sweetness) of all melons was excellent. `Demi-Sweet' had the highest incidence of hollowheart. `Wonder' and `Extazy' had no incidences of hollowheart at any location. Rind thickness had no significant differences, however in both locations measured `Mini Yellow' had the thinnest rind. Rind necrosis was not encountered.

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Most potato (Solanum tuberosum L.) is produced as a non-irrigated crop in the southeastern United States. This practice makes potato yields dependent on rainfall pattern and amount. An irrigation scheduling method based on a water balance and class A pan evaporation data (Ep) was evaluated in Spring 1996 on a fine sandy loam soil with `LaSoda' potatoes. Planting date was 9 Apr. and standard production practices were followed. The model was (12.7 DAH + 191) * 0.5 ASW = D(DAH-1) + [Ep (0.12 + 0.023 DAH - 0.00019 DAH*DAH) - R(DAH) - I(DAH)], where DAH is days after hilling (DAH = 0 on 14 May), ASW is available soil water (0.13 mm/mm), D is soil water deficit (mm), R is rainfall (mm) and I is irrigation (mm). Root depth expanded at a rate of 13 mm/day to a maximum depth of 305 mm. Root depth at hilling was 191 mm. Controlled levels of water application ranging between 0% and 161% of the model rate were created with drip tapes. The model scheduled irrigations on 35, 39, 43 and 49 DAH. On 85 DAH, potatoes were harvested and graded. Irrigation influenced total yield, marketable yield, and combined US #1 grades (P < 0.01; R 2 > 0.85). Mean marketable yields were 19, 28, and 21 t/ha for the 0%, 100%, and 160% irrigation rates, respectively. These results suggest that supplementing rainfall with irrigation and controlling the amount of water applied by adjusting irrigation to actual weather conditions could increase potato yields. Excessive water, as well as limiting water, reduced potato yields.

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The efficacy of garlic spray (GS; Garlic Barrier™) as an alternative to conventional chemical control of disease and insect pests was evaluated on bell pepper and lettuce. Treatments consisted of a recommended chemical spray as needed (Treat. 1), GS applied once (Treat. 2) or twice (Treat. 3) a week, and water spray applied twice a week (Treat. 4). Because of no pest pressure during the test, no chemical sprays were used in Treat. 1. Differences among bell pepper yields were not significant (P > 0.50). For lettuce, Treat. 2 resulted in significantly (P = 0.02) higher head yield. Differences among treatments were not visually detectable in the field. These results suggested that GB applied at the manufacturer's rate (Treat. 2) did not adversely affect bell pepper and lettuce growth and yield. Garlic smell was not detectable on either vegetables, even after Treat. 3. Due to a low pest pressure, this study failed to identify beneficial effects of the GS. Without more scientific reports, relying only on GS to control pests of bell pepper and lettuce may involve uncontrolled risks.

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The effect of irrigation scheduling method (variable crop factor, 1; constant crop factor, 2; empirical, 3), soil water tension (25, 50, 75kPa SWT), tillage (disc arrow, DA, moldboard plow, MP) and planting dates (PD) on total irrigation (TI), number of irrigations (NI), useful (UR) and lost rainfall (LR) was studied using a Pascal program that simulated water budgets of 720 crops of snap bean over 10 years. NI and TI were significantly (p<0.01) lower with met.1. Met.3 had the lowest LR and highest UR, but did not allow the complete calculation of the water balance. TI was significantly higher at 25kPa. MP tillage requested fewer NI and less TI, had lower LR and higher UR. Early PD requested fewer NI and TI, and had higher LR. Hence, when water supply was not limiting and weather data were available, a combination of Met.1, MP at any PD provided a continuous supply of water to the crop while controlling water deficit.

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A TurboPascal computer program was developed to calculate daily water budgets and schedule irrigations. Daily water use (di) is calculated as pan evaporation (Ep) times a crop factor (CFi), where i is crop age. The water balance uses a dynamic rooting depth, the soil water holding capacity (SWC) and rainfall data (Ri). di is added to the cumulative water use (Di-1) and Ri is subtracted from Di. An irrigation in the amount of Di is recommended when Di approximates allowable water use. The program cart be adapted to most crop and soil types, and can be used for on-time irrigation scheduling or for simulating water application using past or projected weather data. This program should increase the acceptance of modem scheduling irrigation techniques by farmers and consultants. Additionally, this program may have application in an overall water management programs for farms, watersheds or other areas where water management is required.

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Multidisciplinary integrated pest management (IPM) teams from seven states in the southeastern United States (Alabama, North Florida, Georgia, Kentucky, North Carolina, South Carolina, and Tennessee) met to develop standards for adopting IPM in fresh-market tomato (Lycopersicon esculentum L.) production. Teams were composed of growers, private consultants, extension personnel, and faculty. IPM practices available for use on tomatoes in the southeastern United States were identified and a survey to assess the current level of adoption of IPM practices was developed. The survey also allowed growers to identify insect, disease, and production problems; beneficial technology and research developments; and other information relevant to IPM adoption. In northern Florida, Georgia, Kentucky, North Carolina, and South Carolina, IPM adoption by tomato growers was classified as medium or high on >75% of the fresh-market tomato acreage surveyed. It appears these states may have met the federal mandate for IPM adoption. Tomato producers listed early blight, late blight, bacterial spot, bacterial speck, and bacterial wilt as the main disease problems; tomato fruit worm, thrips, and aphids as the primary insect problems; and poor weather conditions, government regulation, and labor as their primary production problems. Twenty-six percent of the producers throughout the region felt that the development of insect- and disease-resistant varieties would be most helpful to increase production.

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