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  • Author or Editor: H. J. Mack x
  • Journal of the American Society for Horticultural Science x
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Abstract

Yield and size grades of table beets (Beta vulgaris L.) as affected by row spacings of 60, 45, 30, and 15 cm, fertilizer rates and harvest dates were determined in 4 field experiments. Total yields were significantly lower from 15 cm rows than from the conventional 60 cm row spacing. Highest yields of small roots, 25-51 mm diame-ter, were produced from narrow rows. Delaying harvest increased total and weighted yields. Fertilizer rates were varied in 3 experiments, and increasing the fertilizer rate increased total yields in 2 experiments. Concentration of N in leaves was decreased as row spacings were decreased in 2 experiments but P concentration in leaves was highest in 15 cm rows. Leaf concentration of N was highest at the highest fertilizer rate but K concentration was lowest. Concentrations of other elements in leaves were not consistently affected by row spacings or fertilizer rates.

Open Access
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Abstract

There were no significant fertilizer x plant-density interactions affecting yields or leaf nutrient concentrations of snap beans (Phaseolus vulgaris L.) in 5 field experiments. Higher rates of fertilizer application produced significantly higher yields of pods than did lower rates in 2 experiments. At higher plant densities (15.2- to 30.5-cm rows, 43 to 65 plants/m2) yields were 20% to 38% higher than at lower plant densities (91.4-cm rows, 22 to 29 plants/m2). Average yield increase at higher densities was 29%. Crop economic values followed similar trends. At higher plant densities, average N, K, Ca, and Mg concentrations in leaves at early bloom were lower than at lower densities. Higher fertilizer rates tended to increase N concentration in leaves but had no consistent effects on P, K, Ca, and Mg.

Open Access
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Abstract

Sweet corn yields increased 35 to 55% as plant population increased from about 4,900 to 21,000 plants per ha under irrigated conditions. Ear wt was 10 to 15% less at the higher populations. Greatest difference in yield usually occurred as row spacing was reduced from 90 to 30 cm. Row spacing affected yield less than population. Some of the highest yields were from 30 × 30 cm spacings in equilateral triangles. Triangular spacing as close as 20 × 20 cm (46,000 plants per ha) produced smaller ears, more culls and lower yields. There were no significant interactions of fertilizer rates and populations on yield; however, minimum fertilizer rates were as high or higher than most commercial applications. Yields of ‘Jubilee’ were more favorably affected by narrow row spacings and higher populations than ‘Golden Cross Bantam’.

Open Access
Authors: and

Abstract

The percentage set of blossoms and number and weight of pods of bush snap beans, Phaseolus vulgaris L. were reduced when plants were subjected to high maximum temperatures during bloom. Yields were reduced 0 to 65% in greenhouse and field tests. Perforated plastic-covered cages in the field produced maximum temperatures of 83 to 101°F while maximum temperatures for checks averaged 74 to 89°. High temperatures decreased carbohydrates in leaves, starch more than sugars, when compared to checks.

Open Access
Authors: and

Abstract

Broccoli cultivars differed greatly in their tendency for premature heading and total loss from this factor and from culls. Per cent premature heads was increased by the use of large transplant sizes in the 9 cultivars studied; total loss was generally, but less, affected in the same way. Significant interactions were found between varieties and plant size in both premature heading and total loss. Transplanting date affected premature heading and total loss in one of the 2 years it was considered. Nitrogen levels, included in one experiment, did not cause significant effects.

Open Access

Abstract

Calcium (Ca) level of leaves sampled in mid- or late summer was closely related to peel Ca levels of mature apples (Malus pumila Mill. cv. Baldwin). Ca content of fruit was directly related to fruit yield of the tree, cycling with biennial bearing. In 1971 bitter pit incidence could be predicted from either leaf or peel Ca; internal breakdown and decay were less predictable. In 1972 leaf Ca and peel Ca averaged, respectively, 27 and 17% higher than in 1971, accompanying increased yield. Little bitter pit, internal breakdown, or decay occurred, even at Ca levels correlated with high incidence rates the previous year. We concluded that Ca must be only 1 among several factors regulating these occurrences.

Open Access

Abstract

Yields of snap bean pods were increased by irrigation and plant density in 4 field experiments. Highest yields were obtained with the −0.6 bar soil water potential regime which represented removal of 40-45 percent of the available soil water at 30 cm depth. Yields were lowest with the −2.5 bars soil water potential which represented 65-70 percent water removal. An average of 60 percent more water applied to the −0.6 bar than the −2.5 bars treatment increased yields approximately 54 percent. Yields were usually intermediate with the −1.0 bar soil water potential representing 50-55 percent available soil water removal. Two cultivars were used in 2 of the experiments and responded differently to irrigation. Yield of ‘Oregon 1604’ was higher than that of ‘Galamor’ with −0.6 bar soil water potential but was lower than ‘Galamor’ with −2.5 bars. Yield of ‘Oregon 1604’ averaged 27 percent higher in square arrangement than in 91 cm rows and the increase was greater for the high than for the low population density when compared in 1 experiment. Yield was 20 percent higher for high density of 43.0 plants/m2 than for low density of 21.5 plants/m2. Yields of 2 cultivars in 2 experiments averaged 67 percent higher in high density (40-57 plants/m2) than in low density (20-33 plants/m2) plantings. There were no consistent irrigation × density interactions. Usually there was a more rapid depletion of soil water for high density than for low density. Fiber in canned sieve size 5 pods was higher in ‘Oregon 1604’ at −2.5 bars soil water potential than for ‘Galamor’, but at the −0.6 bar soil water potential regime, the amount of fiber was similar in the 2 cultivars. Percent of pod weight attributed to seed and percent fiber were usually highest at −2.5 soil water potential.

Open Access

Abstract

The yield-plant density relationships of 5 bush snap bean cultivars and the effect of rate of N application on the yield-density relationship of a single cultivar were studied in 2 separate experiments. Responses were described by the equation W-θ = α + βρ where W is the pod weight per plant, ρ is the plant population density, and θ, α and β are constants. The θ, α and β values were tested for significant differences among the cultivars and levels of N. In experiment 1, θ = 0.836 was acceptable for all 5 cultivars and in experiment 2, θ = 0.897 was acceptable for the 3 rates of N. Values of θ were similar to those found for bush snap beans by other researchers. Significant differences existed among both α and β values of the cultivars. In the N experiment, α was constant but values of β differed significantly and were inversely related to the level of N. Optimum plant density was dependent on the cultivar and increased with the level of N.

Open Access

Abstract

Leaves at nodes 4 or 8 of greenhouse grown beans, Phaseolus vulgaris L., cv. Puelba 152, were briefly exposed to 14CO2 at 35, 48, 63, or 70 days after planting. Prior to flowering, over 85% of the recovered 14C-activity translocated in 24 hours from node 4 was in roots, nodules, and lower stem. At flowering, radioactivity translocated to the lower stem decreased but correspondingly increased in nodules. Roots sequestered 45% of translocated-14C throughout the life of the node-4 leaf. About 80% of the 14C-activity exported from node 8 at flowering was in middle and upper stem sections, but during pod-fill over 85% moved into the pods and less than 1% to the nodulated root system. Starch concentration in the lower stem increased continuously from flowering, but in other plant parts declined after early pod-fill. At mid pod-fill, the concentration of soluble sugars in nodules and roots declined and reached a common value in stem sections. Nitrogen (C2H2) fixation decreased rapidly after peaking at early pod-fill. This decline, which was accompanied by loss of lower leaves, occurred in the presence of a high concentration of starch in the stem.

Open Access

Abstract

Close plant spacing in bush snap beans (Phaseolus vulgaris L.), sweet corn (Zea mays L.), and onions (Allium cepa L.) resulted in less weed competition, as measured by crop plant reproductive parts, than wider row spacings. Early weed competition was important in all crops but weed competition at any time reduced onion yields significantly. Corn required 2 weeks and bush snap beans 3 weeks of cultivation after emergence to eliminate losses due to weed competition. Fresh weights of weed at harvest time were significantly less (0.8 kg) in plots of bush snap beans at the narrow row spacing than in plots with the medium and wide spacings (2.8 and 2.4 kg) in an 0.81 m2 area.

Open Access