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  • Author or Editor: H. J. Mack x
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Abstract

Total root yields as well as roots <25 and 25-38 mm diameter, were increased in carrot (Daucus carota cv Red Cored Chantenay), as row spacings were decreased from 60 to 15 cm in 2 field experiments. Different within-row seeding rates did not have a significant impact on total yields, but affected yields of various size grades.

Open Access
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Field experiments were conducted in 1986 through 1988 to evaluate the effects of rates and timing of ethephon application on growth, yield, and lodging of `Jubilee' sweet corn (Zea mays L.). As a comparison, hand-topping was performed 10 days after early silking to simulate the commercial practice of mechanical topping to reduce lodging. Ethephon reduced plant height by 12% to 26%, with timing of application determining location of internode length reductions. There was greater reduction of ear height by ethephon applied at tassel elongation (TE) than at 1 and 2 weeks later. Effects of ethephon on husked yield varied from an 8% increase in yield to an 18% decrease, depending on rate, timing, and season. Topping reduced yield in one of the four experiments. Ear length was reduced by ethephon at 0.28 kg·ha-1 in two of the four experiments. A helicopter fly-over resulted in 66% of topped plants lodging, compared to 87% of untreated plants. Lodging of plants that received an ethephon application of 0.28 kg·ha-1 at TE averaged 51% for Expts. 2, 3, and 4. The amount of lodging tended to be least in those ethephon treatments with the largest reduction `in plant or ear height. Chemical names used: 2-chloroethyl phosphonic acid (ethephon).

Free access

Abstract

Anatomical and morphological studies were made on ‘Gallatin 50’ and ‘Oregon 58’ bush snap beans. The first leaf primordium was observed 3 to 4 days after planting. Four or 5 leaf primordia were formed in spiral phyllotaxy with plastochrons lasting 1 day or less. The first floral primordium occurred in the axil of the uppermost leaf 7 to 9 days after planting. Floral parts became discernible 5 days later.

Open Access
Authors: and

Abstract

Total husked ear yield of sweet corn, Zea mays L. cv Jubilee, increased 38% as plant density was increased from 4.39 to 15.85 plants/m2. At populations above 10.98 plants/m2, marketable yields, based on ≥ 220 g ear size, were reduced. Plant height, weight of leaves, stalk diameter, and total plant weight were significantly affected by both plant density and nitrogen (N) rates. Nitrogen rates of 56, 112, and 224 kg/ha significantly increased ear weight over the 0 kg/ha rate but there were no significant plant density-N interactions.

Open Access

Abstract

Wider spacing and fertilizer application increased the weight of both axillary heads (AH) and main heads in an open-pollinated cultivar and an inbred line. AH weight increased more than main head weight. The effect of spacing on AH was greater than that of fertilizer application. Transplanting greatly decreased the development of axillary heads when compared with direct-seeding.

Open Access

Abstract

Incidence of head smut caused by Sphacelotheca reiliana (Kuhn) Clinton in sweet corn (Zea mays L.) was decreased by frequent early irrigation (total of 15-20 cm of water during the first 18 to 21 days after planting), compared to no irrigation during the same period. The percentage of infection increased as planting depth increased from 2.5 cm to 7.6 cm. Large seed produced fewer infected plants than small seed, whereas the percentage of infected plants produced from medium-size seed was intermediate.

Open Access

Abstract

Globe artichokes (Cynara scolymus L.) were grown from seed in the greenhouse and transplanted to the field in 1978, 1979, and 1980. Percentage of flowering without artificial vernalization of the transplants was 75%, 92%, and 99% for the 3 years. Nitrogen sidedress applications above a base rate of 48 kg N/ha did not significantly increase weight or number of buds per plant or buds/ha. Plant spacing of 1 × 0.6 m generally increased total weight and number of buds/ha, but reduced number and weight of buds/plant compared to spacings of l × lmorl × 2m. Average weight/bud was unaffected by either nitrogen level or plant spacing. Total yield was similar to California production of clonally produced artichokes, but buds were smaller.

Open Access

Abstract

‘Jubilee’ sweet corn (Zea mays L.) was grown under conventional tillage, strip tillage, and no-till methods in 1983 with 5 irrigation levels imposed on each tillage treatment. The crop-water production functions for evapotranspiration vs. yield were different in scale but similar in slope for the 3 tillage treatments. At each level of seasonal applied water, the conventional tillage produced significantly higher yields of husked sweet corn than did strip tillage, and strip tillage yields were significantly higher than those of no-till.

Open Access

Abstract

Mulching ‘Puebla 152’ beans with rice hulls to a depth of 4 cm reduced afternoon soil temperature, soil temperature fluctuation, and slowed the loss of soil moisture. These effects were greatest prior to canopy closure. Fresh weight of nodules, roots, stems, leaves, and total plant increased 50%, 38%, 49%, 24%, and 38%, respectively, with mulching, but pod and final seed weight were unaffected. Mulching had little effect on the concentration of soluble and insoluble carbohydrates. N2 fixation rates (C2H2 reduction) were low (≤ 0.6 µmole/plant per hr) but were as much as 3 times higher in mulched than unmulched plants.

Open Access