Search Results

You are looking at 1 - 10 of 919 items for :

  • apple seedlings x
Clear All
Author:

Abstract

An analysis of the initial fruiting in nearly 50,000 apple seedlings grown over a 29-year period showed that 12% had fruited by their 8th year from seed. For 18 carefully studied crosses, 82% of the seedlings had flowered by their 11th year. Parent cultivars producing the most precocious progenies were ‘Fyan’, ‘Haralson’, ‘Red Melba’, ‘Golden Delicious’, and ‘Idared’.

Early fruiting of seedlings was enhanced by large seedling size and wide spacing in the row, but season of transplanting had no significant effect.

Fruiting of apple seedlings was hastened by 2 methods of trunk ringing: scoring with a knife or saw and spraying trunks with 2-sec-butyl-4,6-dinitrophenol (Dow General). Ringing caused precocious bearing in 4-year-old seedlings but 3-year-old seedlings were too young to be stimulated by ringing and a large portion of 5-year-old seedlings bore without ringing.

Seedling fruiting was advanced about 1¼ years by grafting onto established 10-year-old trees having M.IX roots. This small advance was not enough to justify the considerable effort required to do the grafting. The presence of a fruiting branch of the stock tree did not hasten fruiting of seedling scions grafted onto the stock tree.

Open Access
Author:

Abstract

(2-Chloroethyl) phosphonic acid (ethephon) applied as a foliar spray at 1000 and 2000 ppm to 3-, 4-, and 5-yr old nonbearing seedlings of apple (Malus pumila Miller) significantly increased the percentage of trees flowering for the first time and the total number of flower clusters per tree.

Open Access

Seedling of “Cortland” and “Idared” apples (Malus domestica) were grown in hydroponics and the shoots and roots were evaluated for percent concentration of calcium. “Cortland” is reported to be efficient in calcium uptake in comparison to “Idared”, reputed to be less efficient in calcium uptake and utilization. The seedlings were grown in hydroponic solutions containing calcium ranging from 0.5 ppm to 3.0 ppm concentrations. The shoots and the roots of the seedlings were analyzed for calcium content after 45 days. “Idared” seedling roots and shoots had higher calcium content at 0.5 ppm. However, at 1.5 ppm and at 3.0 ppm “Cortland” seedlings appear to be more efficient at calcium uptake. Early screening may be a useful tool in helping apple breeders select future cultivars that are more efficient at calcium uptake

Free access

Abstract

Apple seedlings of two progenies whose parentage was predominantly cultivated apple (Malus spp.) were forced under optimum growing conditions in the greenhouse. Without chilling, flowering started on occasional plants 16 months after germination. Manual defoliation induced synchronous bud break very efficiently. By 20 months after germination 86% and 68% of surviving seedlings in the two progenies had flowered. The phase change from juvenile to adult occurred 10-14 months after germination or possibly earlier.

Open Access

Abstract

Mycorrhizal fungal inoculation of seedlings of apple (Malus domestica Borkh.) substituted for P application in soils deficient in P. Of 3 mycorrhizal species, Gigaspora margarita Becker & Hall was the least effective in promoting plant growth, Glomus fasciculatum (Thaxter sensu Gerdemann) Gerd. & Trappe was the most effective, and Glomus mosseae (Nicol. & Gerd.) Gerd. & Trappe was intermediate. Combining the 3 species was no more effective than G. fasciculatum alone. VA mycorrhizae increased leaf P concentration in apple leaves from 0.04% to 0.19% on Parkdale soil which had an exchangeable P content of 13 ppm.

Open Access

Abstract

Leaf explants excised from in vitro grown, open-pollinated seedlings of ‘Golden Delicious’ apple (Malus domestica Borkh.) and placed on Murashige and Skoog (MS) medium, containing B5 vitamins, 30 g/liter sucrose, and 8 g/liter agar supplemented with 10.0 mg/liter 6-benzylamino purine (BA) and 3.0 mg/liter naphthaleneacetic acid (NAA) produced low frequencies of globular to heart-shaped embryoids. The early embryonic states were observed after 3 to 4 weeks of incubation in the dark but not on cultures placed in the light. Upon excision and transfer to MS medium with or without 3.0 mg/liter BA plus 0.3 mg/liter NAA, most of the embryoids did not undergo further development; however, 6 did attain the cotyledonary stage. Two of these eventually developed into bipolar structures which gave rise to intact plants.

Open Access

The synthetic triazole derivative 14C-labeled BAS111 (14C-BAS111) was readily translocated throughout 8-week-old apple seedlings (Malus domestica Borkh.) within 3 days of application to roots in hydroponic nutrient solution. The majority of labeled BAS111 and total 14C activity was recovered from middle leaves and root tissues. Two metabolites of labeled BAS111 were found. Both 14C-BAS111 and metabolite 1 were recovered predominantly from leaf and root tissue and from nutrient solution. Metabolite 2, however, was found almost exclusively in root tissue. The rapid degradation of 14C-BAS111 accounts for its low efficacy in comparison with other triazole growth retardants. Chemical name used: [1-phenoxy-5,5-dimethyl-3-(1,2,4-triazol-1yl)-hexan-4-ol] (BAS111).

Free access

Abstract

Growth of seedlings of apple (Malus sp.) and pear (Pyrus sp.) was significantly greater in 14 out of 19 chloropicrin-fumigated-pear sous as compared to the nonfumigated check soils. Increase in seedling growth in the 14 soils varied from 50% to more than 400% with both apple and pear. The lack of response of pear and apple seedlings to soil fumigation in 5 soils may be due to low soil pH, high soil arsenic levels and high soil phosphorous fixing capacity. Counts of plant parasitic nematodes (primarily Pratylenchus spp.) were generally low in all but one soil.

Open Access

Abstract

Glomus mosseae (Nicol & Gerd.) Gerd. & Trappe, inoculation increased apple (Malus domestica Borkh.) seedling growth in 3 of 5 fumigated orchard soils without supplemental phosphorous. Mycorrhizae improved seedling growth in only one soil receiving additional P. Increasing P rates up to 100–200 mg/kg improved growth in only one soil receiving additional P. Increasing P rates up to 100–200 mg/kg improved growth of nonmycorrhizal-treated apple seedlings in 4 of 5 soils tested. The 5th soil had an adequate P content, 60 mg/kg soil prior to the addition of P. Mycorrhizal root infection of seedlings growing in soil that received G. mosseae inoculum decreased with increased P rates applied. Some infection was found in seedlings from all soils inoculated with mycorrhizae at P rates of 0–400 mg/kg, and seedlings from 2 of the mycorrhizal soils had infection at the P rate of 600 mg/kg.

Open Access

Abstract

Leaves from succinic acid-2,2-dimethylhydrazide (daminozide)-treated seedlings of ‘McIntosh’ apple (Malus domestica Borkh) accumulated significantly more 45Ca than those from 1-napthaleneacetic acid (NAA)-treated seedlings. Stem sections from daminozide-treated seedlings accumulated significantly more 45Ca than stems from control seedlings. Total 45Ca content in daminozide-treated seedlings was significantly greater than in either controls or NAA-treated seedlings. The expected reduction in total shoot length by treatment with daminozide, NAA + daminozide and NAA was noted. The increases in 45Ca content in all treatments appear to be due in part to the concentration effect of reduced shoot growth and in part to an effect of daminozide on rate of uptake.

Open Access