scholarly journals SPUR PRUNING `DELICIOUS' APPLE TREES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1102c-1102
Author(s):  
Richard Marini

Twenty-eight-year-old `Starkrimson Delicious' trees were spur pruned in 1986 and 1987 and/or treated with BA + GA4+7 in 1986 in an attempt to improve spur growth and fruit weight. Yield, fruit weight, and spur quality characters were recorded for 1986-1989. All treatment combinations failed to improve yield or fruit weight. Although spur-pruning improved spur length, spur bud diameter, leaf area per spur and leaf dry weight per spur, fruit weight was not improved. BA + GA4+7 reduced yield and fruit weight, and increased the number of pygmy fruit in 1986, but had little effect on fruiting for the three years after treatment.

1991 ◽  
Vol 116 (3) ◽  
pp. 454-459 ◽  
Author(s):  
Richard P. Marini ◽  
Donald Sowers

Twenty-eight-year-old `Starkrimson Delicious' and 10-year-old `Fullred Delicious' apple (Malus domestics Borkh.) trees were spur-pruned in 1986 and 1987 and/or treated with 500 mg BA + GA4+7/liter in 1986 in an attempt to improve spur growth and increase fruit weight. All treatment combinations generally failed to improve yield or fruit size. BA + GA4+7 reduced yield and fruit weight and increased the number of pygmy fruit in 1986, but had little effect on fruiting or vegetative growth for 3 years after treatment. Spur-pruning reduced spur density in 1986 and 1987 and increased yield, but not fruit weight, in 1987. Although spur-pruning improved spur length, spur bud diameter, leaf area per spur, and leaf dry weight per spur, fruit weight was not improved. Chemical names used: N-(phenylmethyl)-1H -purine-6-amine [benzyladenine (BA)]; gibberellin (GA4+7).


Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6501
Author(s):  
Mohammad Ajlouni ◽  
Audrey Kruse ◽  
Jorge A. Condori-Apfata ◽  
Maria Valderrama Valencia ◽  
Chris Hoagland ◽  
...  

Crop growth analysis is used for the assessment of crop yield potential and stress tolerance. Capturing continuous plant growth has been a goal since the early 20th century; however, this requires a large number of replicates and multiple destructive measurements. The use of machine vision techniques holds promise as a fast, reliable, and non-destructive method to analyze crop growth based on surrogates for plant traits and growth parameters. We used machine vision to infer plant size along with destructive measurements at multiple time points to analyze growth parameters of spring wheat genotypes. We measured side-projected area by machine vision and RGB imaging. Three traits, i.e., biomass (BIO), leaf dry weight (LDW), and leaf area (LA), were measured using low-throughput techniques. However, RGB imaging was used to produce side projected area (SPA) as the high throughput trait. Significant effects of time point and genotype on BIO, LDW, LA, and SPA were observed. SPA was a robust predictor of leaf area, leaf dry weight, and biomass. Relative growth rate estimated using SPA was a robust predictor of the relative growth rate measured using biomass and leaf dry weight. Large numbers of entries can be assessed by this method for genetic mapping projects to produce a continuous growth curve with fewer replicates.


Pastura ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 33
Author(s):  
Roni N.G.K. ◽  
S.A. Lindawati

The productivity of forage depends on the availability of nutrients in the soil where it is grown, so fertilization to replace harvested produce is absolutely necessary. This study aims to study the response of gamal and indigofera forage on application of inorganic and organic fertilizers. Research using a completely randomized design factorial pattern of two factors, the first factor is the type of plant (G = Gamal; I = Indigofera) and the second factor is the type of fertilizer (T = without Fertilizer; A = Inorganic fertilizer NPK; K = commercial organic fertilizer; O = conventional organic fertilizer; B = bioorganic fertilizer), repeated 4 times so that it consists of 40 experimental units. The variables observed were plant height, number of leaves, stem diameter, leaf dry weight, stem dry weight, total dry weight of leaves, ratio of dry weight of leaves/stems and leaf area per pot. The results showed that there was no interaction between plant species and types of fertilizer in influencing the response of gamal and indigofera plants. Plant species have a significant effect on stem diameter, while fertilizer types have a significant effect on plant height, leaf dry weight, total dry weight of leaves and leaf area per pot. Based on the results of the study it can be concluded that the response of gamal plants is similar to indigofera, all types of fertilizers can improve the response of plants and organic fertilizers produce the same crop response with inorganic fertilizers. Keywords: gamal, indigofera, inorganic fertilizer, organic fertilizer


1984 ◽  
Vol 62 (5) ◽  
pp. 1062-1068 ◽  
Author(s):  
M. Krol ◽  
M. Griffith ◽  
N. P. A. Huner

The accurate interpretation of physiological and biochemical alterations observed in plants grown under contrasting environmental conditions requires knowledge of their relative physiological ages. For this purpose, we compared the growth kinetics of winter rye (Secale cereale L. cv. Puma) at nonhardening and cold-hardening temperatures. Growth at nonhardening temperatures was characterized by a 10-day lag phase with the attainment of maximum growth after about 28 days. Growth at cold-hardening temperatures resulted in an extension of the lag phase to about 21 days with maximum growth being attained after 56 days. The calculated growth coefficient at cold-hardening temperatures was 35–40% of that at nonhardening temperatures. This relationship was consistent with growth parameters such as leaf dry weight, fresh weight, and area, but not with plant height. Although total leaf dry weight and total number of leaves per plant did not differ between nonhardened and cold-hardened plants at maximum growth, total leaf area per plant and stretched plant height was 3- to 4-times greater in nonhardened than in cold-hardened plants. This resulted in a fourfold increase in leaf dry weight per leaf area during growth at low temperature in contrast to the maintenance of a constant ratio during growth at nonhardening conditions. The increase in this ratio during low temperature growth was, in part, accounted for by a decrease in water content and an increase in cytoplasmic content. These results were confirmed by the investigation of growth on an individual leaf basis. However, the growth response of leaves 1 and 2 differed from that of leaves 3 and 4 when the leaf dry weight: leaf area ratio was measured as a function of time at cold-hardening temperatures. This indicates that the stage of leaf development influences its growth response to an altered environment. The results of the development of leaf freezing tolerance indicated that maximum vegetative growth appeared to coincide with maximum freezing tolerance of leaves from cold-hardened plants (−22 °C) but not of leaves from unhardened plants (−11 °C).


2003 ◽  
Vol 81 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Gunnar Austrheim ◽  
Ove Eriksson

Recruitment is critical for the maintenance of plant populations and community diversity, but sexual regeneration is considered to be infrequent in climatically harsh habitats such as subalpine grasslands. This study examines the importance of regeneration through seed for 16 sparse herb species, and we asked whether their populations are limited by safe sites or the availability of seeds. Seedling recruitment and winter survival were recorded after sowing in an experimental split-plot design in (i) pasture grazed by livestock, and (ii) exclosed grassland cultivated for annual mowing. In addition we examined the effect of disturbance and local seedbank recruitment. All species were able to recruit and survive the first winter in at least some of the experimental plots, although none were initially present. Recruitment mainly occurred in disturbed plots, and disturbed pasture plots had a significantly higher recruitment than disturbed exclosures for all species except Silene dioica. We further examined whether specific plant traits were related to variation in recruitment. Lower recruitment in the disturbed exclosure was associated with higher specific leaf area, leaf dry weight, and seed number. In contrast, seeds sown in disturbed pasture recruited more independently of species traits. The exception was a negative correlation between recruitment and leaf dry weight, and an unexpected negative correlation with seed weight. We suggest that recruitment differences among habitats mainly reflect lower humidity in the exclosure. Consequently, small stature plants with small specific leaf area should have the highest recruiting probability when exposed to drought. The almost exclusive recruitment on disturbed plots indicates a strong competitive effect on the target species in vegetated plots, and suggests that safe sites for regeneration through seed are rare in subalpine grasslands.Key words: colonization, herbs, plant abundance and distribution, disturbance, pastures, cultivated exclosures, sowing experiment.


2021 ◽  
Vol 4 (1) ◽  
pp. 6-13
Author(s):  
Baha Eldin. M. Idris ◽  
Wael. A. Marajan ◽  
Abubaker Haroun Mohamed Adam

Despite the existing several Sugar manufacturing companies in Sudan, there is an acute shortage in sugar supply, therefore the government imports Sugar to bridge the gap. One of the strategies to be followed is the introduction of Sugar beet (Beta vulgaris) crop, mainly for sugar production. This crop has several advantages over Sugarcane such as short duration, less water requirement, in addition to other uses like animal feed. Therefore it became necessary to have good understanding of agricultural operations, cultural practices and adaptation. However, the main objective of this study was to assess the effect of Nitrogen fertilizer and plant spacing on vegetative growth of Sugar beet. This study was conducted at the farm of the College of Agriculture, University of Bahri, Alkadro, Khartoum State-Sudan; during the season 2016/2017. The experiment was arranged in Split plot in Randomized Complete Block Design with six treatments and four replications. Two plant spacing (15 and 20 cm.) were used as main plot, referred as (S1, S2) along with three levels of Nitrogen fertilizer (40, 80 and 120 kg/ha.), as subplot; referred as (N1, N2 and N3) and the control (0). Data regarding leaf number, leaf area index (LAI), leaf dry weight (g) (LDW), root diameter (mm.) and root fresh weight were recorded and statistically analyzed. The results showed S2 (20 cm) increased all the studied plant characters, namely the leaf number (29.139), leaf area index by (7.54), leaf dry weight (g) to (89.870), root diameter (mm) (94,992), root fresh weight (g) (695.80) compared to S1(1015 cm). On the other hand; the application of N3 (120 kg/ha.) increased the lead number (30.956), leaf Area Index (8.841), Leaf dry weight (102.47), root diameter (97.955) and root fresh weight (851.77) compared to S2 and S1 as presented in (table 4, table 5 and table 6).


2001 ◽  
Vol 19 (2) ◽  
pp. 65-68
Author(s):  
Sandra B. Wilson ◽  
Nihal C. Rajapakse

Abstract Plant response to photoselective plastic films with varying spectral distribution properties was tested using three sub-tropical perennials: golden shrimp plant (Pachystachys lutea), Persian shield (Strobilanthes dyerianus), and cat whiskers (Orthosiphon stamineus). Films were designated YXE-10 [far-red (FR) light-absorbing film] and SXE-4 [red (R) light absorbing film]. Light transmitted through YXE-10 films reduced plant height (stem length) of golden shrimp plant and cat whiskers by 10 and 20%, respectively. Light transmitted through SXE-4 films increased plant height by 9% for golden shrimp plant but did not significantly increase stem length of Persian shield and cat whiskers species. Chlorophyll, leaf area, and mean days to flower generally were not affected by photoselective films, with the exception that cat whisker plants grown under YXE-10 films had reduced leaf area when compared to plants grown under SXE-4 or control films. As compared to the control film, light transmitted through YXE-10 films reduced leaf dry weight by 22–31% and stem dry weight by 19–28%, depending on the plant species. Root dry weight was not affected by spectral films.


HortScience ◽  
1990 ◽  
Vol 25 (12) ◽  
pp. 1578-1581 ◽  
Author(s):  
Curt R. Rom ◽  
Bruce Barritt

The role of spur leaves in bud and fruit development on two spur-type `Delicious' apple strains (Malus domestica Borkh.) and factors affecting spur development were studied. Reducing spur leaf area on vegetative spurs in August reduced the number of spurs that flowered the following year but did not affect flower size. On spurs that did flower, leaf area reduction the previous year did not influence leaf number or area, but the bourse shoot leaf area was reduced. Spur bud diameter, leaf area, size, specific leaf weight (SLW), and leaf dry weight were larger on 2-year-old vegetative spurs than on 1- or 3-year-old spurs. Within each age section of a limb, spur leaf number, area, size, SLW, and bud diameter decreased from the apical to basal positions on the limb. Flower number did not vary within a limb section, but fruit set was lower on the most apical and basal spurs compared to midshoot spurs. Fruit size was largest at the apical end of each limb section and was smallest at basal positions. These relationships were not affected by strain, tree age, or orchard location. Summer pruning at 30 days after bloom tended to increase leaf number, area, size, and spur length compared to unpruned trees or pruning later in the season but did not influence spur bud diameter.


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