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  • Author or Editor: Luther Waters Jr. x
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Okra (Abelmoschus esculentus L. Moench) pods stored In a controlled atmosphere (CA) of 5% O2 and 10% CO2 at 11 ± 1C and in air at the same temperature (RA) were compared to determine the effects of the two storage environments on changes in sugars, organic acids, proteins and amino acids, and ascorbic acid contents within the tissue. Pods were sampled at 3-day intervals for 12 days. CA-stored pods generally had greater retention of sugars, soluble proteins, and amino acids than RA-stored pods. Citric, malic, and ascorbic acids contents of CA pods also declined more slowly than those of RA pods.

Free access

Abstract

This research examines the potential of seed hydration for improving sweet corn (Zea mays L.) seed performance, especially for plantings in cool (10°–15°C) soils. In addition to the effect of hydration treatments, the influence of seed quality and cultivar was evaluated using electrolyte leakage tests and seedling growth cold tests. Seed hydration treatments included seed hardening (a wetting/drying cycle), seed moisturizing (placing seed in moist vermiculite), and osmoconditioning, which were compared to a dry seed control. Hardening and moisturizing treatments improved early emergence by as much as 20%, while osmoconditioning significantly lowered field emergence. Seed moisturizing and hardening also improved uniformity of emergence, and reduced the number of days required to attain 50% or 75% emergence. Seed hydration treatments were effective with the three levels (high, medium, and low) of seed quality and the three cultivars (‘Jubilee’, ‘Midway’, and ‘Reward’) studied.

Open Access

Abstract

Field-emergence trials and laboratory seed-quality tests were conducted on 45 seed lots of 13 sweet corn (Zea mays L.) hybrids. Results from standard laboratory germination tests were not correlated with field emergence in 4 field trials. Cold tests conducted in sterile sand and on rolled towels were correlated highly with field emergence. Electrolyte leakage tests conducted on individual seeds with the ASA-610 Automatic Seed Analyzer were superior to bulk-seed measurements with a conductivity meter. By combining the seedling-growth cold test (total seedling dry weight) with the Automatic Seed Analyzer test, multiple correlation values with field emergence ranged from 0.70 to 0.80.

Open Access

Abstract

Field studies were conducted to examine the effect of increasing the moisture content of lima bean (Phaseolus lunatus ‘Kingston 098’) seed prior to planting. Seed moisture was adjusted by combining seed, vermiculite, and varying amounts of water in plastic packets which were then sealed and incubated at 22°C for 3 days. Initial seed moisture ranged from 8% to 56%. Trials were planted at 2 locations in 1981 (Becker and Rochester, Minn.), and at 3 locations in 1982 (Becker, St. Paul and Waseca, Minn.). Seed moisture above the normal 8% to 10% range increased emergence and stand establishment at all locations. As a general trend, increased seed moisture up to about 40% improved percentage of emergence and stand establishment. Harvest data varied between locations. Results from one location in both years showed elevated seed moisture to increase pods per plant, total pod dry weight, and total plant dry weight. Results from harvest (yield) data did not show consistent increases in the variables measured.

Open Access

Abstract

Studies were undertaken to determine the critical Zn levels for cowpea [Vigna unguiculata (L.) Walp] grown in low N medium and inoculated with Rhizobium. Cowpea ‘California Blackeye No. 5’ was grown for 40 days in a sand culture using Zn application rates of 0, 0.06, 0.5, 1.0, 1.5, 2.0, 2.5, 2.8, 3.0, 3.1, 3.4, 3.7, 4.0, and 4.5 ppm Zn as ZnSO4. N2 fixation was estimated by acetylene reduction. Critical Zn deficiency levels were determined as 12.5, 20, 30, and 50 ppm for upper leaf petioles, upper leaf blades, lower leaf petioles and lower leaf blades, respectively, Critical Zn toxicity levels for these tissues was determined as 145, 273, 300, and 440 ppm, respectively. It was concluded that upper, recently matured, leaf petiole tissue should be used to assess plant Zn status. The percentage of reduction of N2 fixation was greater than the percentage of reduction in dry-matter accumulation under Zn-deficient conditions. N2 fixation increased linearly with increased Zn content of nodules and roots. At Zn levels above 150 ppm for both tissues, however, N2 fixation declined significantly. Applied Zn did not affect the growth and development of the root system and had little effect on reproductive development.

Open Access

Abstract

Zinc concentration, nitrogen fixation (C2H2 reduction), nodulation and dry-matter distribution in the early maturing cowpea [Vigna unguiculata (L.) Walp] line Mn 13 were examined at 5 levels of Zn (0.0, 0.6, 1.5, 2.5 and 5 ppm) under field and greenhouse conditions. Significant increases in nodule number, nodule dry weight, and acetylene reduction occurred when plants received the higher Zn levels. In all plant parts sampled, there was increased Zn accumulation with increased Zn application, with roots having the maximum accumulation. Seeds per pod and seed yield (kg/ha) were highest at the higher applied Zn levels. The yield response to added Zn was reflected primarily by an increase in the number of seeds per pod. Zinc nutrition is important to the nodulation and fixation processes, and it may affect both Rhizobium nutrition and dry-matter accumulation.

Open Access

Abstract

A laboratory experiment was conducted to determine the effect of the hydrophilic polymer Waterlock B100 on the imbibition, respiration, and germination of seeds of the sweet corn (Zea mays L. var. saccharum) hybrid ‘Mevak’ at soil water matric potentials of -0.01, -0.40, -1.0, and - 1.5 MPa. Coated seeds had a higher final percentage of imbibition, higher rates of respiration, and germination at -0.01 and -0.40 MPa than uncoated seeds, but as the water potential decreased, the seed coating had a deleterious effect on the physiological processes leading to germination.

Open Access

Abstract

Four levels (1.1, 2.3, 4.6, and 9.1 g/kg seed) of the hydrophilic polymer Waterlock B100 were used as seed coatings to enhance stand establishment and plant growth of sweet corn (Zea mays) and cowpea (Vigna Unguiculata) during the spring and summer of 1983 on 2 soil types in Minnesota. The level with the best overall response in 1983 was used in 1984 to observe the response of 4 sweet corn hybrids. The 2.3 and 4.6 g treatment were most beneficial in enhancing stand establishment in sweet corn. At all levels, however, Waterlock B100 had a deleterious effect on cowpea germination and seedling development. One sweet corn hybrid showed a significant positive response to the coating during 1984. This reponse was attributed to a uniform pericarp which allowed an even seed coating.

Open Access

Abstract

Grower tours, one of the most effective agricultural extension teaching methods (13), have been conducted for many years to production areas generally unfamiliar to participating growers and agribusiness people. Most consist simply of a sequence of visits to farms or agribusinesses where the owners (managers) of the visited businesses explain the operation observed as the tour proceeds through the facility.

Open Access