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- Author or Editor: S.J. Locascio x
- Journal of the American Society for Horticultural Science x
Abstract
In the paper, Growth and Tissue Composition of Sweet Corn as Affected by Nitrogen Source, Nitrapyrin, and Season by B.D. Rudert and S J. Locascio (J. Amer. Soc. Hort. Sci. 104(4):520-523. 1979), there is an error in Table 2. The last 4 columns of data for Spring 1977 should be moved over 1 column to the right. The dry weights column for Spring 1977 should be blank.
Abstract
Strawberries (Fragaria × ananassa Dutch.) were grown during 2 seasons to evaluate 5 N sources and 2 times of N and K application using trickle irrigation with N and K rates of 134 and 149 kg ha−1, respectively. Fruit yields were influenced by significant interactions between N-source and time of N and K application during both seasons. With 100% of the N and K applied preplant, marketable fruit number and weight were significantly greater with sulfur coated urea (SCU) or isobutylidene diurea (IBDU) than with urea, NH4NO3 or KNO3 + Ca(NO3)2 as the N sources. With 40% of the N from the above 5 sources applied preplant and 60% of the N and K supplied with the trickle irrigation from NH4NO3 + K2SO4 or KNO3 + Ca(NO3)2, production was similar with all N sources. Leaf tissue N and K concentrations were not influenced consistently by N source. During both seasons, leaf N concentrations were higher with the split than with the 100% preplant treatments.
Abstract
Sweet corn (Zea mays L.) was grown to evaluate the effect of N source, N rate, time of N application, and the nitrification inhibitor, 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin), on crop efficiency and movement of applied N on a Kanapaha fine sand. Sweet corn yield was not affected by nitrapyrin rates of 0, 0.56, and 1.12 kg/ha, during 2 seasons. During a wet 1976 summer season, total yield was 65% higher with N applied as (NH4)2 SO4 than as Ca(NO3)2. Total yield increased linearly from 6. 1 to 9.8 MT/ha with an increase in N rate from 56 to 224 kg/ha as (NH4)SO4. With Ca(NO3)2, total yield averaged 4.9 MT/ha and was not influenced by N rate. During the drier 1977 spring season, marketable yield was not influenced by N source. Total yield increased linearly from 9.1 to 14.6 MT/ha with an increase in N rate. In the wetter season, the application of N in split rather than single applications as Ca(NO3)2 increased yield. During the dry season, timing of N application had no effect on yield with either N source. The suppressing action of NH4-N absorption on the absorption of other cations was evident but was not consistent throughout the study. The application of (NH4)2SO4 as compared to Ca(NO3)2 resulted in higher plant dry weights at an early sampling stage in the wet season but not during the dry season. Higher soil N (NH4-N + NO3-N) levels were maintained above a 20-cm soil depth with (NH4)2SO4 than with Ca(NO3)2 during the wet season.
Squash (Cucurbita pepo L. var. melopepo) was grown at two locations with different soil types as a second crop in a succession cropping study that used previously cropped polyethylene-mulched beds. Squash was produced with drip or overhead irrigation and with concurrent N-K fertilization or residual fertilizer from the previous crop. Tissue mineral concentration responses to irrigation method were variable; in early fruit, N and K concentrations were higher with overhead than for drip, but leaf Ca and Mg concentrations were higher with drip than with overhead irrigation. Concentrations of N and K were higher with concurrent than with residual fertilization and increased with an increase in application rate. In contrast, concentrations of P, Ca, and Mg decreased with concurrent fertilization and an increase in application rate.
Broccoli (Brassica oleracea L. var. italica), followed by tomato (Lycopersicon esculentum Mill) or squash (Cucurbita pepo L. var. melopepo), and then broccoli were produced in succession re-using the same polyethylene-mulched beds at two locations with different soil types. First-crop broccoli yield was earlier and greater with drip than with overhead irrigation and increased as N-K rate increased from 135-202 to 270-404 kg·ha-1. On a tine sandy soil, yields of second and third crops produced with residual or concurrent fertilization increased with an increase in N-K rate. On a loamy fine sandy soil, yields also increased as the rate of residual N-K increased; yields of second and third crops did not respond to rate of concurrently applied N-K, but were higher with concurrent than with residual fertilization, except total tomato yields were similar with either application time. With drip irrigation and concurrent weekly fertigation, yields equalled or exceeded those obtained with preplant fertilization and overhead irrigation.
Abstract
Tomatoes (Lycopersicon esculentum Mill.) were grown during two seasons at two locations on fine sands and fine sandy loam soils to study the influence of water quantity, frequency of water application, and timing of N and K application for polyethylene-mulched, trickle-irrigated fresh-market tomatoes. Water quantities were 0.50 and 1.0 times pan evaporation applied one or three times daily. Nitrogen and K were applied 100% preplant or 40% applied preplant and 60% applied with trickle irrigation. Higher tomato leaf tissue N and K concentrations in one of the two seasons and higher fruit yields were obtained with 0.5 than with 1.0 time pan water evaporation on a fine sand at Gainesville, Fla. On a fine sandy loam soil at Quincy, fruit yields were higher in a relatively dry season with the higher water quantity and not influenced by the water quantity applied in the second relatively wet season. The number of daily water applications (one vs. three) at both locations had no effect on N and K uptake or fruit yields. Time of N and K applications had no effect on early yields, but total yields were higher with split than all preplant-applied N and K on the fine sandy soil. Split applications of fertilizer resulted in greater yields of extra-large fruit at mid-season and of extra large and large fruit at late harvest than all preplant-applied fertilizer. On the fine sandy loam soil, time of fertilizer application had no effect on yield.
Abstract
Strawberry (Fragaria × ananassa Dutch.) response to trickle irrigation was compared with overhead and no irrigation. Fertilizer rates were 94-55-104 to 202-118-223 kg/ha N-P-K with 0, 50, and 100% of the N and K applied with trickle irrigation. The remaining fertilizer for trickle and all for overhead and non-irrigated treatments was applied preplant. Fruit yields were increased 34% with overhead irrigation and 37% with trickle irrigation above that for non-irrigated treatments. With 0 and 50% of the N and K applied in daily or weekly increments with trickle irrigation, fruit yields were 2 and 20% greater than with overhead irrigation, 30 and 58% greater than with no irrigation, respectively. The N levels of leaf tissue samples were not influenced by treatment. Leaf K levels were significantly higher with trickle irrigation than with overhead irrigation or check treatments. Soil value for total soluble salts, K and NO3 were significantly lower with trickle irrigation than with overhead or no irrigation treatments.
Abstract
Experiments were conducted to evaluate the response of carrots (Daucus carota L.) to target plant densities of 39, 59, and 79 plants per meter of band with various row arrangements (2 band/bed with 2, 3, or 4 seeded rows/band with 3.8 to 11.4 cm between rows) on a Landerhill muck soil. Marketable and total carrot yields increased linearly with increased plant density from 24 to 85 plants per square meter. In 2 of 3 experiments, row arrangement significantly influenced yield; greatest yields were obtained when spacing between rows in a band was greater than 3.8 cm, indicating some advantage to increasing the distance between rows. Mean length and diameter of marketable roots decreased linearly with increased plant density. Length and diameter of marketable carrots were influenced by row arrangement in one of the 3 experiments. Carrots grown in rows spaced more than 3.8 cm apart were longer and had a greater diameter than did carrots grown with 3.8 cm between rows.
Abstract
Plant growth and fruit yield were enhanced by broadcast as compared with band applications of either N-P-K fertilizer or micronutrients. Plant dry wt were similar with applications of either CuSO4-5H2O at 4 and 8 lb./acre Cu or complete micronutrient frit (FTE 503) at 30 and 60 lb./acre in 2 seasons. In 1 season, fruit yields were significantly higher where CUSO4 was used. Increases in rate of either micronutrient source resulted in increased fruit yields where applications were broadcast but a decrease where banded. These responses to increased micronutrient rates were related to an increase in micronutrient efficiency with the broadcast placement and to a toxicity with the band placement.
Abstract
Isobutylidene diurea (IBDU) and sulfur-coated urea (SCU) alone or in combinations with NH4NO3 were evaluated as N sources for potatoes (Solanum tuberosum L.) on 2 sandy soils. Nitrogen was applied either all preplant or in split application at 134 or 201 kg N/ha. Tuber yields were highest with NH4NO3 alone or with NH4NO3 combined with IBDU or SCU, and were lowest with 100% IBDU and SCU. Marketable yields obtained with NH4NO3 were 25% and 27% higher than with 100% IBDU and SCU, respectively. Marketable and total yields increased and tuber specific gravity decreased slightly with increased N. Split applications of N increased marketable and total yields at one location. Leaf N, Mg, and Ca concentrations were higher and K was lower with NH4NO3 alone or with NH4NO3 with IBDU or SCU than with IBDU and SCU. Nitrogen sources had no significant effect on soil total soluble salts, NO3-N, or NH4-N, 7 and 12 weeks after fertilization.