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  • Author or Editor: G.H. Neilsen x
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Abstract

Zinc-deficiency symptoms and relatively low mid-terminal leaf Zn concentrations were observed in apple seedlings (Malus domestica Borkh. ‘McIntosh’) grown in a minus-Zn Long Ashton solution comprised of reagent grade but unpurified chemicals. Leaf Zn concentration increased as the initial concentration of added Zn increased through the range 0 to 4 μm. Zinc was highest in seedlings grown in solutions with both high Zn and high P concentrations. High leaf P concentrations were associated with inadequate Zn nutrition.

Open Access

A split-plot experimental design was imposed in the year of planting and maintained for the first five growing seasons in a high density apple orchard on M.9 rootstock planted at 1.5 m (within row) × 4 m (between row) in a loamy sand soil susceptible to K deficiency when drip-irrigated. Four N-K fertigation treatments involving low (N1) and high (N2) rates of N combined with 0 (K0) or 15 g K/tree per year (K1) were applied in five replicated and randomized main plot units. Subplots consisted of three-tree plots of each of the apple cultivars Gala, Fuji, Fiesta and Spartan. Soil solution monitoring indicated the maintenance of distinctly different soil solution N and K concentrations in the respective N-K treatments during the study. The most important plant response was prevention of the development of K deficiency by the K1-fertigation treatment. Fertigation of 15 g K/tree generally increased leaf K, fruit K and Mg concentrations, fruit size and yield and fruit titratable acidity and red coloration at harvest for all cultivars. K fertigation also decreased leaf Mg and B concentrations, fruit N, P and Ca concentration and fruit firmness. In addition to leaf K concentrations <1%, K deficiency was associated with fruit K concentrations <100 mg/100 g fresh weight and soil solution K concentration <5 mg·L-1. Increasing the rate of fertigated N when growth was constrained by K deficiency increased leaf N and Mn and decreased leaf P and B, but had no effect on tree vigor or fruit production and quality.

Free access

`Gala' apple (Malus domestica Borkh) on M.26 rootstock was subjected, in the first five growing seasons, to NP-fertigation and a factorial combination of treatments involving method and frequency of irrigation. Two types of emitters (drip or microjet) were used to apply the same quantity of water at high (daily), intermediate (about weekly) and low (about bi-weekly) irrigation frequencies. Although initial tree vigor and yield were higher for drip-fertigated trees, by the end of the study microjet fertigation produced larger trees of similar yield. These microjet fertigated trees had higher leaf P, K and Cu but lower leaf N, Mg, and Mn than drip-fertigated trees. Soil pH and extractable Mg and K concentrations were higher and extractable-P concentrations lower directly beneath microjet-emitters as a result of the larger fertigated soil volume relative to drip-emitters. High frequency irrigation improved tree growth but had less effect on leaf nutrient concentrations or soil chemical changes than lower frequency irrigation. Leaf N concentration was most affected by irrigation frequency, tending to decrease with daily irrigation.

Free access

Application of high rates of P in the year of planting increased the number of flower clusters and fruit set the subsequent year on newly planted `Macspur McIntosh', `Summerland Red McIntosh', `Jonagold', and `Jonamac' apple (Malus domestica Borkh.) on dwarfing rootstock (M.26 and M.9) in three separate experiments. The effect occurred whether P was applied at rates of 36 or 48 g P/tree as granular monoammonium phosphate (11 N-23.6 P-0K) uniformly mixed with 100 or 180 liter of soil in the planting hole or at rates of 17.5 and 35 g P applied as soluble ammonium polyphosphate (10N-14.6P-0K) with the irrigation water. A leaf P concentration range between 0.20% and 0.36% was associated with the acceleration of fruiting.

Free access

Abstract

Mature ‘Golden Delicious’ apple trees (Malus domestica Borkh.) were subjected for 3 years to factorial combinations of 3 rates of N fertilization applied in April and 3 degrees of orchard floor management. Tree N nutrition was affected more by vegetation management than by rate of N fertilizer applied. Significant reduction in leaf N and trunk diameter, and superior fruit skin color and firmness at commercial harvest occurred consistently when the orchard floor was sod. Increased leaf N and reduced fruit skin color and firmness at harvest were measured at the highest N (180 kg N ha-1) in only 1 year while tree growth was not increased by this rate of N. Increased fruit Ca associated with smaller fruit and increased leaf Mg and leaf K were measured under sod in 2 of 3 years. Leaf Mn was affected only by rate of N fertilization and was consistently high at 180 kg N ha-1.

Open Access

Abstract

Three soil surface treatments were compared for grape production under irrigation. Plastic mulch was superior to glyphosate and to grass sod in producing yields during the first 2 years of production. By the 3rd year, the glyphosate treatment was equal to the plastic and both were superior to grass sod. Cluster weights and pruning weights were suppressed by grass sod, compared with plastic or herbicide, but were unaffected by nitrogen. Nitrogen fertilizer treatments had no measurable effects on the grapevines and showed no interaction with the soil surface treatments. None of the treatments (soil surface or fertilizer) had any effect on berry soluble solids. The use of plastic mulch is an effective cultural technique, the usefulness of which will depend mostly on cost and environmental comparisons with herbicides.

Open Access

Abstract

From 1981-83, 4 weekly sprays of 0.75% and 1% CaCl2 w/v, immediately prior to harvest, significantly increased fruit flesh Ca concentration of ‘Golden Delicious’ apple (Malus domestica Borkh.) without the leaf phytotoxicity associated with CaCl2 sprays above 1%. In contrast, chelated Ca sprays at concentrations 2 – to 16 × label recommendations, and direct trunk injection of 1.5 liters of 1% CaCl2, did not increase fruit Ca concentration.

Open Access

The effects of various nonfumigant planting-hole treatments on growth and yield of apple (Malus domestics Borkh.) trees were measured during the first 3 years after planting. Eight orchards diagnosed as having a replant problem were monitored. First-year shoot growth, the number of blossoms in the second year (inmost orchards), and first-year trunk cross-sectional area increment (TCAI) in 50% of test orchards were increased by monoammonium phosphate (MAP) fertilizer+ peat, MAP+ mancozeb, or MAP + peat + a bacterial antagonist. By the end of year 3, TCAI generally was not affected by treatments, but treatments resulted in more blossoms by the third season in two of seven orchards that blossomed in the second season. Cumulative yield after 3 years increased significantly in only three orchards, with the best treatment, MAP+ peat, resulting in cost recovery in only one orchard. Inadequate K or Cu nutrition may have reduced growth in some of the orchards, which were characterized by a wide range in yields, independent of planting-hole treatment.

Free access

A study was undertaken to identify key factors associated with storage disorders in three commercially important apple cultivars in British Columbia and to determine how early in the season associations could be measured. Fruit mass, density, and concentrations of N, P, K, Ca, Mg, and dry matter were determined for `McIntosh', `Spartan', and `Golden Delicious' apples (Malus ×domestica Borkh) from ≈30 commercial orchards 9, 6, 3, and 0 weeks before harvest. Storage samples were collected at commercial harvest and evaluated for the development of internal breakdown (`McIntosh' and `Spartan') or bitter pit (`Golden Delicious') after 4 and 6 months of 0 °C air storage. Mass and [Ca] and the mass/[Ca] and [K]/[Ca] ratios were the factors most often significantly correlated with storage disorders within each year for all three cultivars. Correlations were as frequently significant 6 and 3 weeks before harvest as they were at harvest. Mass of `McIntosh' and `Spartan' was the only variable consistently related with breakdown in all 3 years of the study. There were no variables with a consistent relationship to bitter pit in `Golden Delicious'. Fruit [Ca] was associated with the relative levels of disorders within years but could not be associated with specific levels of disorders across all years.

Free access

Abstract

Tomato (Lycopersicon esculentum L.), sweet pepper (Capsicum annuum L.), onion (Allium cepa L.), cucumber (Cucumis sativus L.), bush bean (Phaseolus vulgaris L.), and melon (Cucumis melo L.) were grown from 1983 through 1986 with trickle irrigation using either well water or secondary effluent. Yields with effluent irrigation were greater than or similar to yields obtained with well water. Effluent irrigation resulted in decreased Zn, increased P, and variable results for other nutrients in plant tissues. After 4 years of effluent irrigation, the exchangeable Na content of the 0.0 to 0.3-m depth increased, but soil chemical changes were of little practical significance. No major limitations were found for the production of high yields of vegetables irrigated with municipal wastewater on the loamy sand soil at the experimental site after 4 years.

Open Access