scholarly journals Fall Foliar-applied Boron Increases Tissue Boron Concentration and Nut Set of Almond

1997 ◽  
Vol 122 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Agnes M.S. Nyomora ◽  
Patrick H. Brown ◽  
M. Freeman
Keyword(s):  
Recent Work ◽  
Boron Concentration ◽  
Fruit Set ◽  
Foliar Application ◽  
Prunus Dulcis ◽  
Commercial Product ◽  
Flower Buds ◽  
Fruit Tissue ◽  
Visual Symptoms ◽  
Early Fall

Fruit set is the major determinant of productivity in almond [Prunus dulcis (Mill D.A. Webb)] where seed is the commercial product. Boron influences flowering and fruit set in a number of crops, but little has been reported on this subject in almond. Here, we investigated the effect of a fall foliar application of B on fruit set and tissue B concentration in open pollinated `Butte' and `Mono' almond over a 2-year period. Early fall B application significantly increased the vegetative, floral, and fruit tissue B concentration in the subsequent year. The greatest increase in organ B concentration was observed in flower buds, flowers, and hulls. Recent work has demonstrated that B forms a B-sorbitol complex in Prunus species. This B-sorbitol complex is phloem mobile and is transported to sink organs. Here we demonstrate that fall-applied B is absorbed by the leaf and is subsequently transported (presumably as the B-sorbitol complex) to floral buds where it is available to flowers and, hence, influences fruit set and yield. It is concluded that fall foliar-applied B is a useful fertilization strategy that can be used to optimize tissue B concentration in species in which B is phloem mobile. Boron applied at 245 and/or 490 ppm significantly increased fruit set in `Butte' and `Mono' and increased yield of `Butte' in 1994 on open-pollinated trees (yield was not determined in 1993). The highest initial and second fruit set was associated with either the 245 or 490 ppm B treatments in both cultivars and both years. This increased fruit set resulted in yield increases of 53% and 4%, respectively, for `Butte' and `Mono'. Of the two cultivars, `Butte', which had lower tissue B concentration before B application, responded more significantly in yield to B application. Application of 735 ppm B was less effective than either 245 and 490 ppm B; however, no visual symptoms of excess B were observed.

scholarly journals 431 PB 174 EFFECTS OF FALL APPLIED BORON ON ALMOND FRUIT SET

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 493a-493
Author(s):  
Agnes M.S. Nvomora ◽  
Patrick H. Brown
Keyword(s):  
Significant Influence ◽  
Fruit Set ◽  
Foliar Application ◽  
Major Determinant ◽  
Commercial Product ◽  
Flower Buds

Fruit set is a major determinant of nut productivity. Boron has been shown to have a significant influence on flowering and fruit set in a number of crops but less is reported on almond. This paper presents results of foliar application of a B commercial product, Solubor(20.5% B) at a rate of 1,2,3lb/100 gallons to `Butte' and `Mono' almond cultivars Boron at 1 and 2lb increased fruit set in both open and hand pollinated trees by over 100% while 3lb was less effective. The resultant B concentration in flower buds was correlated to B concentration in flowers (R2=0.58) and immature fruits (R2=0.6) but not to summer and fall leaf, pistil, and pollen B concentration or fruit set.

scholarly journals Rate and Time of Boron Application Increase Almond Productivity and Tissue Boron Concentration

HortScience ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 242-245 ◽  
Author(s):  
Agnes M.S. Nyomora ◽  
Patrick H. Brown ◽  
Bill Krueger
Keyword(s):  
Tree Species ◽  
Boron Concentration ◽  
Fruit Set ◽  
Prunus Dulcis ◽  
Optimal Rate ◽  
Commercial Product ◽  
Optimum Time ◽  
Fresno County ◽  
Optimal Effect

Previous studies with tree species have demonstrated that foliar boron (B) promotes flowering, fruit set, and yield. However, for most species the optimum time for foliar B application has not been determined. This investigation was undertaken to study the effects of time and rate of B application on almond [Prunus dulcis (Mill D.A. Webb)] tissue B concentration, fruit set, and yield. Solubor (Na2B8O13.4H2O), a commercial product containing 20.5% B, was applied with a handgun sprayer either in September (3 weeks postharvest), December (dormancy), or February (budbreak) at rates of 0, 0.8, and 1.7 kg·ha-1 B to almond cv. Butte at one site (Parlier, Fresno County, Calif.), and of 0, 0.8, 1.25, 1.7, and 2.1 kg·ha-1 B on the same cultivar in August, September, or February at a second site (Orland, Glenn County, Calif.) using Borosol, a polyboronated commercial product containing 10% B. At site 1, September application was more effective in increasing tissue B concentration, fruit set, and yield than were December or February applications. The optimal rate was 0.8 to 1.7 kg·ha-1 B when applied in September. At site 2, application in 1996 and 1997 increased tissue B concentration almost linearly, especially when applied in August and February. Application at the highest rate (2.1 kg·ha-1 B) in September produced the greatest final fruit set and yield in 1996. February applications increased initial fruit set at both sites but were less effective than September applications in increasing yield. Application of B did not affect any yield variable in 1997. These results suggest that B should be applied immediately postharvest (September) for optimal effect on tissue B concentration, fruit set, and yield in almond.

scholarly journals Effect of Boron and Calcium on Lowbush Blueberry Fruit Set, Fruit Characteristics, and Yield

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 881A-881
Author(s):  
Youzhi Chen ◽  
John M. Smagula
Keyword(s):  
Boron Concentration ◽  
Fruit Set ◽  
Positive Response ◽  
Lower Number ◽  
Water Control ◽  
Fruit Characteristics ◽  
Flower Buds ◽  
Vaccinium Angustifolium ◽  
Lowbush Blueberry ◽  
Fruit Characteristic

Foliar sprays of B (400 ppm), Ca (4000 ppm), B (400 ppm) + Ca (4000 ppm), or water (control) were applied in Sept. 1993 to treatment plots of 12 lowbush blueberry (Vaccinium angustifolium) clones having low leaf B concentrations (<20 ppm). Boron concentration was raised in stem and bud tissue 3 months after application, but Ca concentration was unaffected. Twenty randomly selected stems with four flower buds were tagged in each treatment plot in Apr. 1994 to determine treatment effects on fruit set and fruit characteristics. Blossoms on tagged stems were counted in late May and a count of initial fruit was taken in early July. Initial fruit set was reduced slightly by the Ca treatment, which also resulted in a lower number of flowers per bud. Tagged stems were cut before plot harvest and stored at –15C for final fruit set and fruit characteristic measurements (fruit number, diameter, weight, and firmness, and seed number and size). Treated plots were harvested and weighed in August. Boron and Ca treatments did not increase yields averaged across all clones, but some clones showed a positive response. Yield of Ca-treated plots was significantly lower than the plots without Ca treatment. Effect of treatments on final fruit set and fruit characteristics will be presented.

scholarly journals INFLUENCE OF GROWTH REGULATORS ON OVULES ABORTION, SEED SET AND ITS GERMENATION OF TWO ALFALFA CULTIVARS

2016 ◽  
Vol 47 (3) ◽  
Author(s):  
Khrbeet & Al-Beiruty
Keyword(s):  
Growth Regulators ◽  
Seed Set ◽  
Foliar Application ◽  
Control Treatment ◽  
Naphthalene Acetic Acid ◽  
Flower Buds ◽  
College Of Agriculture ◽  
Vegetation Growth ◽  
Main Plot ◽  
And Control

A field experiment was conducted at the experimental farm, College of Agriculture, Abu-Ghraib, Baghdad, Iraq during the period from mid. of March 2012 to mid. of July 2014 to investigate the effects of plant growth regulators and foliar application stages on ovules abortion, seed set and its germination of two alfalfa cultivars. Layout of the experiment was R.C.B.D. arranged in split-split plot with three replications. Cultivars (local and hamedan) were assigned as a main plot and foliar application stages (vegetative growth, flower buds emergence, 50% flowering and 80% flowering) were assigned as sub-plots, while growth regulators (Alar, Ethephon, Naphthalene acetic acid(NAA) and control treatment) were assigned in the sub-sub-plots. Result showed that there were no significant differences between cultivars in all traits. Foliar application of NAA increased No. of ovules per floret (9.11) compare with other treatments, but it was not significantly different compare with Alar. In 1st and 2nd seed crop, plants sprayed with Alar at flower buds emergence stage gave highest seed set (5.17, 6.93) respectively. Percentage of ovules abortion significantly influenced by growth regulaters, folair application stages and their interaction. Since, foliar application of Alar at beginning of flower buds emergence reduce % of ovules abortion (30.89). In general, plants sprayed at vegetation growth stage increased % of seed germination. It was clear from this study that more than 40% of ovules were aborted, this may be one of the reasons for reduction of seed yield in alfalfa, therefore, we recommended to do more researches in this field in order to know the causes of ovules abortion.

Self-pollination does not affect fruit set or fruit characteristics in almond (Prunus dulcis)

2010 ◽  
Vol 130 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Pedro J. Martínez-García ◽  
Encarnación Ortega ◽  
Federico Dicenta
Keyword(s):  
Fruit Set ◽  
Prunus Dulcis ◽  
Fruit Characteristics ◽  
Self Pollination

scholarly journals Foliar Application of Boron to Almond Trees Affects Pollen Quality

2000 ◽  
Vol 125 (2) ◽  
pp. 265-270 ◽  
Author(s):  
A.M.S. Nyomora ◽  
P.H. Brown ◽  
K. Pinney ◽  
V.S. Polito
Keyword(s):  
Pollen Germination ◽  
Foliar Application ◽  
Culture Media ◽  
Pollen Viability ◽  
Prunus Dulcis ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Mature Trees

The effect of boron (B) on in vivo and in vitro development of almond [Prunus dulcis (Mill.) D.A. Webb (syn. P. amygdalus Batsch)] pollen and pollen tubes and the resultant effect on fruit set was studied in mature trees. The cultivars Mono (pistil donor) and Butte (pollinizer) in an orchard with low soil B in Fresno, California were sprayed with B at 0, 0.8, 1.7, or 2.5 kg·ha-1 during Fall 1993. Pollen viability as indicated by the fluorescein diacetate method (FDA) was >85% and was not affected by field-applied B, however, in vivo pollen germination and tube growth were enhanced by foliar-applied B. More effect of applied B on in vivo growth appeared as pollen tubes progressed toward the ovary. For in vitro germination, foliar-applied B reduced bursting of tubes, and addition of B to the culture media significantly increased pollen germination and pollen tube growth.

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