Search Results
Abstract
Response of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai cv. Charleston Gray] to factorial combinations of trickle irrigation or no irrigation and black polyethylene mulch or no mulch was evaluated during 2 successive years on a southwestern Indiana Lyles fine sandy loam. Both trickle irrigation and polyethylene mulch, alone and in various combinations, increased stem growth and early and total yields of watermelon compared to untreated watermelons. Greatest stem growth and early and total yields were obtained from plants grown on polyethylene mulch in combination with trickle irrigation. Mean fruit weight did not vary with treatment. Trickle-irrigated watermelon plants produced shallow rooting near trickle emitters; nonirrigated plants produced relatively extended, deep, and diffuse roots. Petiole Zn concentration was greater in plants grown on polyethylene mulch than no mulch. Trickle irrigation resulted in a decreased concentration of petiole Mn.
Abstract
A 2-year field study was conducted on a fine sandy loam soil near Vincennes, Ind., to evaluate tomato (Lycopersicon esculentum Mill. cv. Sunny) response to trickle irrigation and black polyethylene mulch. Use of trickle irrigation resulted in higher petiole P and B and lower Zn concentrations than using no irrigation. Trickle-irrigated soils had lower soil NH4-N, NO3-N, and K and higher Mg concentrations than non-irrigated soils. Soil NH4-N, NO3-N, and Mg concentrations were higher in soils mulched with polyethylene than in soils without mulch. The use of trickle irrigation increased plant height, whereas polyethylene mulch increased plant spread and dry matter production. Early, late, and total yields were improved with all trickle irrigation and polyethylene mulch treatments. Total yields were 66%, 70%, and 123% greater for plants grown with polyethylene mulch, trickle irrigation, and polyethylene mulch plus trickle irrigation, respectively, than control plants.
Abstract
Responses of muskmelon (Cucumis melo L. ‘Classic’), with respect to root development, stem and leaf growth, petiole mineral concentration and yield, to trickle irrigation and planting method (direct-seeded vs. transplanted) were evaluted. Field studies were conducted on a southwestern Indiana Lyles silt loam or fine sandy loam soil during 2 successive years using black plastic mulch. Trickle irrigation decreased depth of penetration of muskmelon roots as compared with no irrigation. Trickle irrigation significantly increased the stem length and diameter, leaf area, mean fruit weight and yield, but decreased soluble solids in fruit. Direct-seeded muskmelon plants produced deep, taproots exhibiting positive geotropism, whereas transplants produced more extensive lateral, plagiotropic or geotropically insensitive roots. Direct-seeded muskmelons had significantly larger stem length and diameter, leaf area, soluble solids, and petiole Mn concentration, and lower petiole Fe and Na concentration than transplants. Significant correlations were established between various components of muskmelon growth and development.
Abstract
Response of hybrid summer squash (Cucurbita pepo L.) cvs. Seneca Zucchini and Zucchini Elite to trickle irrigation and black plastic mulch was evaluated in field studies conducted on a southwestern Indiana loamy sand soil during 1982 and 1983. Trickle irrigation and plastic mulch each increased plant growth, early bloom, and yield. Trickle irrigation reduced percentage of culls. Plant growth was correlated negatively with days to bloom after planting. Days to bloom were correlated negatively with yield; the early-blooming plants tending to yield more than the late-blooming plants. Significantly higher yields are possible with current cultivars using trickle irrigation and plastic mulch.
Abstract
Field experiments were conducted to determine N-use-efficiency of muskmelon (Cucumis melo L.) grown in a loamy sand under trickle irrigation and black plastic mulch. Nitrogen rates of 0, 67, or 100 kg N/ha preplant plus 0, 50, or 100 ppm trickle applied N (fertigation) were compared. Significant increases in stem growth, soil NO3-N, petiole NO3-N, and early and total yields generally were attained with increasing preplant N fertilization rates. Muskmelon yield response to increasing N fertigation response was increased in regimes that received no preplant N. Fertigation response was reduced in regimes that received 67 or 100 kg preplant N/ha. A significant curvilinear relationship was established between soil saturation extract NO3-N and petiole NO3-N.
Abstract
We determined origin and time required for development of callus and root initials in Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] stem cuttings from stained sections. Callus originated principally from the vascular cambium, but phloem and xylem parenchyma also contributed. Continuous cell division, elongation, and differentiation within callus gave rise to root primordia. Once formed, root primordia elongated within 15–30 days.
There was no apparent difference in tissue origin of adventitious roots in stem cuttings collected from sheared juvenile or sheared or non-sheared adult trees during pre-, true, and post-dormancy. Time required for callus formation and root initiation varied with degree of bud dormancy. Rooting was low during pre-, almost none during true, and highest during post-dormancy.
Abstract
A mutant seedling with retarded growth and interveinal chlorosis of leaves characteristic of iron deficiency was discovered in a group of ‘Edisto’ muskmelon transplants. The seedling responded to supplemental Fe, suggesting that the mutant affects Fe uptake or use. The F1 phenotypes from crosses of the mutant with ‘Edisto’ and ‘Mainstream’ were normal. F2, F3, and testcross data indicate that the chlorotic phenotype is controlled by a single recessive gene, which is not allelic or linked to virescent.
Abstract
An 18-hr photoperiod (LD) significantly increased cambial activity, rooting, bud respiration, and also hastened bud break of stem cuttings as compared with similar cuttings propagated under a 9-hr photoperiod (SD). Rooting response was modified by sampling date and temperature of the rooting medium. Rooting was least from August through November and greatest in December and January. Rooting temperatures of 18 and 26°C enhanced rooting without affecting bud activity.