Search Results
Abstract
Tomato plants selected for rapid (early) emergence in several germination environments revealed small but statistically significant gains in maturity and fruit size. Even more significant was the interaction of selection time with germination environment and with entry. It was concluded that while some genetic gain might result from seedling selection, the seeding treatments utilized in this trial would not enhance this gain. The interaction with entry indicated a lack of consistent directed response.
Abstract
The growth of several vegetable and field crops in the greenhouse was increased by applications of 1-triacontanol to the foliage, soil, or seed. Neither the seed nor soil treatments increased the yield of crops in the field. However, foliar sprays ranging from 5 to 500 mg/ha significantly increased the marketable yield of 7 of 10 crops tested. The average yield increase was based on comparisons of all the different rates and time of 1-triacontanol applications with untreated controls. The response of tomato, carrot and wheat seed treatments with 1-triacontanol was shown to be positively correlated with temperature at time of germination and early growth.
Abstract
Slow and inconsistent germination of cyclamen, Cyclamen persicum Mill., seed appeared to be more related to seed and seedling vigor than to any type of seed dormancy. Pregermination and germination seed treatments such as immersion in hot water, still and flowing water, cool moist storage, alternating temperatures and fungicide treatments were of little value. Treatment with gibberellin (GA) solutions accelerated germination but created an expelled embryo problem. The grower is advised to surface disinfest fully imbibed seed in 5% sodium hypochlorite for 20 sec to 1 min.
Abstract
Successive plantings were made from August through October in southeastern Florida to compare plant establishment methods and their effects on stand establishment, plant growth, and maturation (time to anthesis) of bell pepper (Capsicum annuum L.). Direct-seeding treatments were germinated seeds planted in potassium starch acrylamide (PSA) gel, magnesium silicate clay (MSC) gel, plug-mix, MSC gel mix, PSA gel mix. Nongerminated seeds were covered with soil or plug-mix. Three types of containerized transplants were used for comparison of earliness to flowering. Regardless of planting date, the PSA gel mix treatment generally led to earlier emergence and more uniform plant stands compared with the other direct-seeding techniques tested. Fluid drilling with PSA (without plug-mix) typically led to reduced plant stands, whereas all other direct-seeding methods did not differ in stands. Plant dry weights were increased as much as 100% when seeds were sown in PSA gel mix rather than with other seeding treatments. Plants established by transplanting began flowering at least 16 days earlier than plants established via direct seeding. Direct-seeding germinated seeds in PSA gel mix or plug-mix led to earlier, more uniform anthesis than sowing nongerminated seeds in soil.
Abstract
The effect of seed environment and stage of germination during vernalization on flower induction in globe artichoke was investigated. Soaking the seed in water for 48 hr at 70° F prior to vernalization at 35° to 45° for 15 days with adequate moisture and oxygen, resulted in a higher percentage of bolters. Air temperatures above 65° immediately after sowing the vernalized seed caused devernalization, while a week of 50° to 65° had no effect. Seed treatment with chloro-choline chloride inhibited vernalization. Gibberellic acid sprays substituted successfully for vernalization with a large percentage of plants. A minimum of 10 leaves were required for bud initiation with all effective vernalizing treatments. Through vernalization and by subsequently growing the plants at an optimum temperature and light environment, the normal biennial reproductive cycle of artichoke was reduced to 6.5 months.
Abstract
Salvia (Salvia spendens, F. Sellow ex Roem & Schult.) seeds imbibed in distilled water at 6C for 6 days germinated earlier and with fewer days to 50% of total germination (T50) than non-imbibed seeds. Drying imbibed seeds for 1 to 5 days at 5C and 45% RH before sowing signficiantly reduced seed viability. Priming seeds in a hypertonic osmotic solution of aerated polyethylene glycol 8000 (PEG) at —0.8 MPa for 10 days at 15C improved germination of the three cultivars tested. In laboratory and plant growth chamber trials, seeds primed with PEG 8000 and nonprimed seeds had similar total germination at 20 and 25C, but primed seeds had significantly higher germination at 10, 15, and 30C. At 35C, PEG-primed seeds had 44% to 65% germination, while nonprimed seeds failed to germinate. Alternating 10 and 20C or 20 and 30C diurnally at 12-hr cycles did not increase total germination regardless of seed treatment. Seeds primed with PEG had lower T50 than nonprimed seeds at 10, 15, 20, 25, and 30C, with the largest difference at the most unfavorable temperatures for germination. Primed seeds stored at 5C for 1 to 16 weeks reduced total germination and the potential capacity for rapid germination.
Abstract
A preplant acetone permeation of ‘Grand Rapids’ and ‘Mesa 659’ lettuce (Lactuca sativa L.) seeds with either cyclohexanecarboxamide 1-(3-chlorophthalimide) (phthalimide) or gibberellin A 4+7 (GA) in combination with kinetin (KIN) and/or (2-chloroethyl) phosphonic acid (ethephon) markedly relieved the adverse effect of high temperature (20°, 12 hr night/30°C day regime) on seedling emergence from soil. Permeation of GA in ‘Grand Rapids’ seeds increased seedling hypocotyl length by 121% compared to only 25% for phthalimide permeated seeds. In ‘Mesa 659’ seeds, the corresponding increases with GA and phthalimide permeation were 52% and 26%, respectively. Permeation of GA + ethephon + KIN and phthalimide + ethephon + KIN increased seedling hypocotyl elongation over the control by 126% and 60% in ‘Grand Rapids’ and 91% and 21% in ‘Mesa 659’, respectively. Seed permeation with phthalimide tended to increase the leaf chlorophyll content of emerging seedlings. Permeation of GA decreased leaf chlorophyll up to 28% in ‘Mesa 659’ and up to 13% in ‘Grand Rapids’. These findings indicate that phthalimide could be substituted for GA in seed treatments needed to alleviate the adverse effects of high temperatures on germination and seedling establishment and to improve growth characteristics of emerged seedlings.
Abstract
Fruit set and fruit development of seeded, naturally seedless, and growth-regulator-induced seedless tomatoes (Lycopersicon esculentum Mill. cv. Azes), were examined under 17°, 22° and 27°C day temperatures, all with natural daylight and constant 10° night temperature. The best seeded fruit set and development were at 22° day temperature. A high positive correlation (r = 0.9) was found between number of seeds per fruit and fruit size with a day temperature of 27°; there was a lower but still positive correlation with lower temperature. Seedless fruit developed, and attained marketable weight (above 40 g), only when the inflorescences had been sprayed with 20% β naphthoxyacetic acid (B-NOA). Day temperature also affected fruit shape. At 27° the fruit was almost globe-shaped, but at the lower temperatures the fruit became more oblate. Fruit puffiness was particularly related to lack of fertilization resulting from flower emasculation or to lower day temperature affecting set of seed-deficient fruits. “No-Seed” treatment led to green jelly production and pointed blossom-end in fruits, under all temperature regimes.
severe than that in the preceding experiment but serious enough to have had an economic impact if the cultivar had been grown on a farm without seed treatment. Although A b testas at the end of the trial were again softer than A B testas, emergence of
.M. 2008 Presowing seed treatment with melatonin protects red cabbage seedlings against toxic copper ion concentrations J. Pineal Res. 45 24 31 doi: 10.1111/j.1600-079X.2007.00552.x 10.1007/s11357-997-0020-2 Reiter, R.J. 1997 Aging and oxygen toxicity