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  • Author or Editor: George E. MacDonald x
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Abstract

Responses of sweet corn plants (Zea mays L. var. rugosa cv. Jubilee) to levels of residual P and K in a fine sandy loam soil from previous broadcast applications of concentrated superphosphate (CSP) and potassium chloride (KCI) and to band-applied monoammonium phosphate (MAP), potassium sulfate (K2SO4), and magnesium sulfate (MgSO4) at planting were studied. Fourteen years after no applications of broadcast CSP or KCI fertilizers, responses of sweet corn plants to levels of residual P were greater than to residual K in the soil. Increasing the level of residual P in the soil increased dry weight per seedling from 1.5 to 7.7 g, fresh weight per ear from 278 to 358 g, the concentration of P from 2.9 to 4.6 mg·g−1 dry weight, but decreased K, Ca, and Zn in the leaves. Increasing the level of residual K in the soil did not affect the dry weight of the seedlings or the fresh weight of the ears, but increased the concentration of K from 16.7 to 28.1 mg·g−1 dry weight and decreased Ca and Mg in the leaves. Banded MAP, especially at low levels of residual P in the soil, increased the dry weight of the seedlings and the fresh weight of the ears. Banded K2SO4 did not affect the weight of the seedlings or ears, but increased the concentration of K and decreased Ca and, especially, Mg in the leaves. Banded MgSO4, with or without high residual K in the soil and/or banded K2SO4, did not affect weight of the seedlings or ears, but decreased the concentration of K and increased Mg in the leaves of the sweet corn plants.

Open Access

Abstract

Cauliflower (Brassica oleracea var. botrytis L. ‘Imperial 10-6’), broccoli (Brassica oleracea var. italica Plenck ‘El Centro’), and brussels sprouts (Brassica oleracea var. gemmifera Zenk. ‘Jade Cross’) were grown at 0, 84, 336, and 1344 kg of concentrated superphosphate (CSP) (0, 17.5, 70, and 280 kg P) and 0, 67, 268, and 1072 kg of potassium chloride (KC1) (0, 35, 140, 560 kg K) fertilizers per hectare, per application in a long-term plant nutrition experiment. Increasing the rate of CSP increased the concentrations of P, Ca and Mg but decreased K and Zn in leaf blades at midseason. Increasing the rate of KC1 increased the concentrations of K and Zn but decreased Ca and Mg in leaf blades. Increasing the rates of CSP and KC1 hastened maturity and increased yields of cauliflower and broccoli in harvest sequences, whereas brussels sprouts were less responsive to CSP or KC1 at one harvest. High rates of CSP without KC1 reduced the yield of cauliflower compared to the lower rates. Increasing the rate of KC1 increased the incidence of hollow stem, a quality defect, in cauliflower and broccoli. Best production of uniform maturity and yield was obtained with a combination of the CSP at 336 kg·ha−1 and KC1 at 268 to 1072 kg·ha−1 per application in a long-term rotation.

Open Access

Abstract

Many different hydroponic systems and methods have been used for growing plants. This report describes an outdoor sand-nutrient culture system that has been used for more than 10 years to study the response of vegetables to inorganic nutrition under natural outdoor conditions and with controlled rooting conditions. The system is simple, dependable, and provides abundant aeration for plant roots.

Open Access

Effects of lateral movement of soil from tile lines based on soil and plant analysis, plus the effects of applications of ZnSO4 and MnSO4 on the concentrations of Zn, Mn, and other elements in the leaf blades of snap bean plants (Phaseolu vulgaris, var. humilis cv. Bush Blue Lake-47) and on the yield of snap bean pods at harvest were determined. Snap beans were grown across the tile lines and fertilized with five rates of ZnSO4 and MnSO4 fertilizers applied in a band at planting time. The soil decreased in pH and Ca and Mn content and increased in organic matter and Zn with distance from the tile lines. The leaf blades decreased in concentration of Ca and increased in concentrations of Mg, Zn, and Mn with distance from the tile lines. High rates of Zn and Mn fertilizers were required to obtain medium concentrations of Zn and Mn in plants grown over or near the tile lines. Concentrations of 24 to 30 μg of Zn per gram dry weight and 60 to 90 μg of Mn per gram dry weight in the leaf blades of the snap bean plants were adequate for highest yield of pods. Zinc sulfate at a rate of 0.5 to 0.7 g of Zn/m2 produced the highest yield of pods at a distance of 3 m from the tile lines. Applied together, ZnSO4 and MnSO4 produced a yield response similar to application of only ZnSO4. Twenty years after installation of the tile lines, the effects of the tile lines on soil and leaf analysis and yield of pods of snap beans plants extended 2 to 3 m in each direction from the tile lines, indicating that the soil moved laterally.

Free access

Abstract

The objective of this study was to determine the effects of sources and rates of N, P, and K fertilizers applied in a band at planting and at several planting dates on the rates of growth and concentrations of elements in sweet corn (Zea mays L. var rugosa) seedlings. Sweet corn seedlings were grown under field conditions at 10 planting dates in a fine silt loam soil. Ten sources and blends of N, P, and K fertilizers were applied at planting time at linear increasing rates of 0 to 20 g of element per meter of row in a band placed 5 cm below the seed depth and 5 cm to the side of the seed row. Seedlings grown with blends of N + P + K fertilizers at 5 to 9 g of N, P, and K elements per meter of row had the greatest rates of growth in dry weight per day. The optimum reference concentrations of elements in the sweet corn seedlings with the greatest rates of growth were: 5 mg nitrate-N, 45 mg total N, 4.2 mg P, 45 mg K, 7 mg Ca, 3 mg Mg, 30 μg Zn, 70 μg Mn, 300 μg Fe, and 8 μg Cu per gram of dry weight of the seedlings.

Open Access

Abstract

The objective of this study was to determine the responses of ‘Bush Blue Lake-47’ snap bean plants [Phaseolus vulgaris (L.) var. humilis] to urea, (NH4)2SO4, NH4NO3, and Ca(NO3)2 sources of N fertilizers at rates of 0, 4, 8, or 12 g of N/m2 and to KCl and K2SO4 fertilizers at 5 g K/m2. Dry weight of the plants was determined at the seedling, bloom, and harvest stages. Blades of recently fully expanded leaves at the bloom stage were analyzed for total N, NO3-N, Cl, S, B, P, K, Na, Ca, Mg, Zn, Mn, Fe, and Cu. Snap bean plants grown with (NH4)2SO4 had the highest dry weight per plant and the highest yield of pods, followed by plants grown with NH4NO3. Plants grown with Ca(NO3)2 or urea had the lowest dry weight per plant and the lowest yield of pods, especially at the highest rate of N fertilizers.

Open Access

Abstract

Sweet corn seedlings (Zea mays L. var. rugosa cv. Jubilee) were grown with urea, (NH4)2SO4, NH4NO3, and Ca(NO3)2 at linearly increasing increments from 0 to 18 g of N/m of row. The N fertilizers, with 5 g of P from concentrated superphosphate and 5 g of K from KCl per meter of row, were placed in a band 5 cm below seed depth to the side of the seed at planting time in a Honeoye fine sandy loam soil with pH 7.0. Seedlings were sampled ≈30 days after planting for fresh and dry weight and for nitrate N, total N, P, K, Na, Ca, Mg, Zn, Mn, Fe, and Cu. Sweet corn seedlings grown with (NH4)2SO4 or NH4NO3 grew more rapidly than seedlings grown with urea, especially at the high rates of N fertilizers, and much more rapidly than seedlings grown with Ca(NO3)2 at all rates and for two planting dates. Seedlings grown with ≈3 g of N/m of row had the highest fresh and dry weights per seedling. Seedlings grown with (NH4)2SO4 or NH4NO3 had a higher concentration of P than seedlings grown with urea or Ca(NO3)2. Seedlings grown with (NH4)2SO4 had lower concentrations of nitrate N and Ca than seedlings grown with the other sources of N fertilizers. Seedlings grown with Ca(NO3)2 had higher concentrations of Ca and Mg, but lower concentrations of Zn and Mn than seedlings grown with the other sources of N fertilizer.

Open Access

Abstract

The concentration of mineral elements from the outer peel to the core of five table beet (Beta vulgaris L.) cultivars was determined by separating roots into five fractions. Soil contamination was important only in affecting the concentration of Fe in the outer peel. Mineral element concentration was highest in the outer peel, decreasing by about one-half in the inner peel. Some mineral element differences are noted among cultivars.

Open Access

Abstract

The concentrations of elements in the portions of vegetable plants used for human consumption as well as the yield should be evaluated. Applications of NaCl and KCl to loam soils (Glossoboric Hapludalf, loamy, mixed mesic) have consistently increased the growth of table beet (Beta vulgaris L.) plants and the yield of the enlarged portion of the roots. The concentrations of Na, K, and Cl in the roots were also increased. The objective of this study was to develop a method of predicting the concentration of Na in canned table beet roots. Sodium, K, and Cl from the soils and from preplant soil applications of Na at 0, 250, and 500 kg·ha−1 and KCI at 300 kg·ha−1 were monitored systematically as continua through the soil tests and the chemical analyses of leaf blade and petioles at midseason, in the raw roots at harvest, and in the solid and liquid portions of the canned roots. Sodium from the soils and from increasing the rate of NaCl linearly increased the concentration of Na in all components. The concentrations of Na in the leaf blades and the leaf petioles at midseason were excellent predictors of the content of Na in the canned beet roots. Application of equivalent ionic rates of NaCl and KCI produced the same yields of roots.

Open Access