Nutrient Sprays Research Articles

Effects of Foliar-applied Boron on Fruit Retention, Fruit Quality, and Tissue Boron Concentration of Pecan

Previous studies with a variety of tree species have demonstrated enhanced flowering, fruit set, and yield with foliar boron (B) applications. The effects of foliar-applied B on pecan [Carya illinoinensis (Wangenh.) K. Koch] in the southeastern United States are poorly understood. This study was undertaken to investigate the effect of foliar B application on leaf tissue B concentration, fruit retention, and kernel quality of pecan. Controlled pollination studies showed no effect of B on fruit retention of ‘Stuart’ pecan. Tissue B concentration, fruit retention, and percent kernel of ‘Desirable’ pecan were occasionally enhanced by both two and five B applications made before and through the pollination window in multiple studies over 3 years. As long as leaf B is within the recommended sufficiency range, timing of foliar B application during the critical prepollination period appears to be more valuable for pecan production than are increasing leaf B levels. Given the production enhancements observed here, and the low cost of B fertilizers, the practice of foliar B application merits consideration as a component of pecan orchard management when tank-mixed with normal prepollination pesticide or nutrient sprays.

Changes of coastal dune landscapes in Estonia

Changes of coastal dune landscapes in Estonia Coastal landscapes are strongly affected by their geomorphology, based on the character of deposits and moisture conditions. The main influences on the aeolian ecosystems of coastal areas are heavy winds, salt spray and lack of nutrients. An increase in the frequency of storms in coastal waters may result in the erosion of beaches that were previously stable or prograding. Coastal dune ecosystems are in different stages of vegetation succession and soil development. At present coastal dune landscapes are being rapidly changed by waves and human impact. In the last decade, research on the geomorphologic changes of the coast in Estonia has been quite noteworthy, but the associated changes in ecosystems have been little considered. The main problem for coastal dunes landscape is the decrease of natural habitats due to afforestation, recreation and building. In this paper our attention is focused on changes of Estonian coastal dune landscapes during the last one hundred years.

Amelioration of detrimental effects of waterlogging by foliar nutrient sprays in barley.

Six barley (Hordeum vulgare L.) cultivars contrasting in their waterlogging tolerance were subjected to waterlogging for 2 weeks under glasshouse conditions. The adverse effects of waterlogging were significantly alleviated by the foliar spray of nutrients (quarter- or full-strength Hoagland solution) in all cultivars. Beneficial effects of nutrient sprays included improved shoot and root growth and reduced leaf senescence. Chlorophyll content was increased, as was net CO2 assimilation, photochemical efficiency of PSII, and adventitious root production compared with waterlogged plants with no added foliar nutrients. Auxin was found accumulated at the shoot base in waterlogged plants, and the spray of foliar nutrients significantly increased this accumulation in waterlogged plants after 14 days of treatment. Foliar application of 1-NAA also promoted the production of adventitious roots. The highest concentration of auxin was measured in the stem region between 1.2 and 1.6 cm above the shoot-root junction. Foliar nutrient application also improved nitrogen and potassium content in both shoot and root, but calcium content was hardly affected. It is concluded that the improvement of waterlogged plant growth by foliar nutrient sprays could be related to both the improved plant nutrition and increased auxin accumulation in the shoot base, responsible for development of adventitious roots.

(100) Effect of Cropload, Irrigation, and Fertilization on Yield and Postharvest Bitter Pit Incidence of `Honeycrisp' Apple

A factorial field experiment was conducted at the New York State Agricultural Experimental Station in Geneva, N.Y., during 2004 and 2005 with `Honeycrisp' apple trees on M.9 rootstock. The main plot factors were three levels of applied nitrogen (0 kg/ha, 50 k/ha, and 100 k/ha); three levels of applied K2O (0 k/ha, 100 kg/ha, and 200 kg/ha); ± foliar nutrient sprays containing N, B, Zn, and Mg, ± foliar sprays of CaCl2 and ± trickle irrigation. The subplot factor was cropload (3, 6, 9, 12, and 15 fruits/cm2 TCA). Trees receiving irrigation or potassium had higher yields and the effect was greater as cropload was increased. There was no effect of nitrogen fertilization, foliar Ca, and foliar N, B, Zn, and Mg on yield. Irrigation and increased potassium fertilization rate reduced fruit soluble solids at harvest. Foliar calcium applications, foliar N, B, Zn, and Mg applications, and nitrogen fertilization rate did not affect fruit soluble solids at harvest. No treatment factor had an effect on fruit firmness at harvest, but, after 4 months on cold storage, fruits from irrigated trees had greater firmness. Bitter pit incidence was lower on apples from trees that did not receive irrigation compared to irrigated trees. The difference was constant under all cropload levels. Foliar calcium applications, foliar N, B, Zn, and Mg applications, nitrogen fertilization rate and potassium fertilization rate did not affect bitter pit incidence.

Effect of foliar spray of nutrients and plant growth regulators (PGRs) for yield maximization in blackgram

An experiment was conducted during 2002 to study the morphological physiological and biochemical effects of foliar spray of nutrients and plant growth regulators on yield and productivity of blackgram. The treatments include foliar spray of 2% DAP, 0.2% Boric acid, 0.5% FeSO,, 0.5% ZnSO, 0.5% sodium molybdate, 2% urea, 0.1% humic acid, 1% KC1, Salicylic acid 100 ppm, Brassinolide 0.1 ppm and humic acid 20 kg basal application. Among these treatments, foliar spray of 2% urea recorded the highest yield of 955.2 kg/ha followed by foliar spray of KC1 1% along with soil application of humic acid 20 kg/ha (926.2 kg/ha). The yield enhancement may be due to improved morphological, physiological and biochemical parameters. The tested chemicals particularly 2% urea were found effective towards yield maximization in black gram.

SPRAY APPLICATION PLAYS A DETERMINING ROLE IN PERFORMANCE OF SYSTEMIC COMPOUNDS APPLIED TO THE FOLIAGE OF FRUIT PLANTS

Spray application factors are discussed relative to effective delivery of foliar applied nutrients to fruit trees. The application process can be viewed as a series of complex interdependent events, including: formulation of the active ingredient; atomization of the spray liquid; transport of the spray cloud to the tree; spray droplet impaction; retention; and residue formation and penetration of the nutrient. Any significant change in one event has profound effects on others, and each may be affected by application parameters, plant factors and environmental conditions. Only limited data have been generated specifically on effects of application parameters on performance of nutrient sprays. Thus, we have drawn heavily on studies of application of aqueous solutions of pesticides. Nutrient sources are not extensively formulated, but since nutrients are commonly incorporated in programmed pesticide applications, the spray additives (mostly adjuvants) used in the pesticide sprays will impact on the performance of the applied nutrients. The lack of uniform deposition over the fruit tree is a critical limitation; the lower quadrant next to the spray lane is frequently overdosed while the top and center are under sprayed. Fruit tree surfaces, except for some fruit surfaces, are not difficult to wet, thus droplet reflection is not a limiting factor. Surfactants, when used, reduce reflection, increase spreading (coverage) and, at high volume spraying, reduce the total dose retained per unit surface area. Residues from previous pesticide sprays and the presence of natural products (e.g., extrafloral nectar) on some plant surfaces modify spreading and retention. Droplet reflection, spreading, retention and nature of droplet residues are determined primarily by the physico-chemical properties of the spray solution together with plant surface morphology, fine structure (microroughness) and chemistry. The nature and distribution of spray droplet residues are important factors in performance of systemic compounds because penetration not only takes place from the droplet, but also from the remaining residue.

The effects of a foliar spray containing phosphorus and zinc on the development, composition and yield of forage maize

Forage maize grown in areas where spring temperatures are low and accumulated heat is limited will be restricted in terms of maturity and thus nutritional value. A stagnant growth phase is commonly caused by low temperatures between germination and the five‐leaf stage, which could be caused by reduced mineral availability. The effects on maize plant development and harvest characteristics of supplying phosphorus and zinc to young plants in a foliar spray were investigated. Three different application dates, between the four‐leaf and the seven‐leaf stage, were compared. Applying the phosphorus and zinc foliar spray at the four‐leaf stage resulted in a significant (P < 0·05) increase in starch content at harvest. Cob index [proportion of plant dry matter (DM) in the cob] was increased (P < 0·05) by applying the nutrient spray at the four‐, five‐ and seven‐leaf stages. However, there was no effect on DM yield, suggesting some alteration in partitioning within the plant.

Recommended prebioom copper spray has no beneficial effect on ‘delicious’ apple tree copper status or fruit typiness

Three field experiments were conducted to evaluate a new commercial recommendation to add small amounts of a Cu(OH)2‐based fungicide, Kocide 101, to prebioom zinc (Zn) nutrient sprays in order to enhance ‘Delicious’ apple tree copper (Cu) status and improve fruit typiness. Treatments were (1) single prebioom spray of basic Zn sulfate in combination with varying rates of added Cu as Kocide; (2) single spray of Kocide alone at pink timing; and (3) single silver‐tip spray of Zn sulfate in combination with varying rates of Kocide or a more soluble Cu sulfate‐based product. The Cu sprays applied at silver‐tip had little or no effect on flower cluster Cu concentration at full bloom. Kocide applied at green‐tip and later increased flower cluster Cu. None of the Cu sprays influenced midsummer leaf Cu concentration. The Cu sprays had no beneficial effect on fruit mass or on any of five fruit typiness indices. The experimental results indicate that there are no detectable nutritional or fruit typiness benefits resulting from adding Kocide to Zn sprays at any prebioom timing, or from adding Cu sulfate to Zn sprays applied at silver‐tip bud stage.

Effects of nutrient spray applications on malic and tartaric acid levels in grapevine berry

Abstract The levels of tartaric and malic acids in grape berries sprayed with either CaCl2, KCl, KNO3, NH4Cl, or Ca(NO3)2 in order to increase potassium (K), calcium (Ca), ammonium (NH4), or nitrate (NO3) availability during the fruit set‐veraison period did not show a direct effect on the synthesis of malic and tartaric acids in the berries during the pre‐veraison period; however at veraison, a relationship was established between K and malic acid, a relationship that did not last until the ripening of the berry.

Nutrient sprays applied to the foliage of narrow-leafed lupins (Lupinus angustifolius L.) during flowering and podding do not increase seed yield

Nitrogen (N), phosphorus (P), potassium (K), sulfur (S), manganese (Mn), magnesium (Mg), and boron (B) were applied as foliar sprays to narrow-leafed lupins (Lupinus angustifolius L. cv. Gungunu) grown in Esperance in 1991 and 1992. Applied individually, no nutrient increased the seed yield of lupins. In 1992, the application of 15 kg N/ha at 2 growth stages [flowering and 2 weeks after flowering (2WAF)I and 4 kg S/ha at 2WAF reduced the seed yield by about 10% (300 kg/ha), despite no evidence of damage to the foliage of the lupins. Nutrient mixes of N, P, K, S, and B were applied in both years at 3 growth stages (flowering, 2WAF, 6WAF), and no combination at any time of application increased the seed yield. In 1992, one combination treatment of (kg/ha) 15 N, 8 P, 12 K, 4 S, and 1 Mn applied 2 weeks before the start of flowering reduced yield by 14%. Where no foliar nutrients were applied, seed yields (t/ha) were 2.6 in 1991 and 3.2 in 1992. Foliar-applied nutrients sprayed during flowering and podding, in addition to some fertilisers applied to soil at seeding, are unlikely to increase the seed yield of lupin crops in the south coastal districts of Western Australia.

Plant sampling: a review

The steps involved in collecting and handling samples for plant analysis are described under the following headings: purpose for which the sample is collected; sampling statistics; sampling strategies; choice of tissue; sample handling; special sampling techniques. In any application of plant tissue analysis close attention should be given to the approaches which are used to develop the critical values or ranges that are used. In diagnostic and prognostic use of plant analysis the statistics of the sampling procedure should be well understood, so that a sample which properly represents the crop or planting can be collected. When diagnosis is the primary objective the sampling unit may be as small as a single plant. It is important that contamination of the sample with nutrient sprays or other materials is understood and recorded. Washing may not be possible, particularly when samples are collected by unskilled people at a site distant from the analytical laboratory. Although washing with detergents or weak acids can remove contamination, there will remain some doubt as to the efficiency of the washing procedure. Samples which are to be used for sap tests immediately after collection for nitrate-nitrogen should be handled more carefully than those destined after drying for multi-element analysis at a remote laboratory. Ideally the respiratory loss of dry weight from samples should be minimised when the samples are destined for conventional multi-element analysis. Where certain aspects of sample handling are critical to the success of the test they should be emphasised to potential users. A wide range of plant tissues other than the commonly collected leaves and petioles has been used for assessment of mineral nutrient status, including juice, fruit, and shoot tips. Each of these presents different problems in sample collection handling and storage. Tests based on enzyme activity and other biochemical or physiological indicators probably present the most difficult sample handling problems, but these tests are not widely used. A number of sampling issues which arise from the author's experience with commercial tissue analysis services are raised. These include such matters as the extent of training of the personnel who do the sampling, contamination and transport to the laboratory. Although more attention to these issues is needed in practice, plant tissue analysis continues to be a most valuable tool in the hands of the informed manager.

PEACH TREE RESPONSES TO AMMONIUM AND CALCIUM SPRAYS

A field experiment was conducted to assess the effects of several foliar nutrient sprays on the vegetative growth of 'Jefferson' peach budded on 'Nemaguard' and 'Lovell' rootstocks planted on a site with a history of Peach Tree Short Life. The trees received foliar applications of 2 mN solutions of ammonium citrate, calcium citrate, calcium lactate, calcium phosphate, or a water control at 3 week intervals from April to August. Vegetative growth measurements were taken after one growing season. Trunk cross-sectional area (TCSA) was significantly increased by ammonium citrate (TCSA=20.35 cm2), calcium citrate (TCSA=20.03 cm2), and calcium lactate (TCSA=19.91 cm2) when compared to controls (TCSA=16.75 cm2). Trees on 'Nemaguard' responded more to treatments than those on 'Lovell'. All nutrient sprays increased TCSA, lateral growth, terminal growth, and total tree growth on 'Nemaguard' rootstock. Terminal growth increased 12-36%, and total tree growth increased 18-51 % compared to control trees, but only ammonium citrate applications were significantly greater. Lateral growth and TCSA of treated trees increased 65-168% and 17-28%, respectively.

STUDYING THE CAUSE AND CURE OF `ROME BEAUTY' APPLE RUSSETTING

Effects of several growth regulators and mineral nutrient sprays on `Rome Beauty' apple (Malus domestica Borkh.) russetting under climatic conditions of southwest Idaho were studied in the 1990 and 1991 growing seasons. Zinc (Zn-50), Calcium as a 12% liquid nutrient (Stopit-6), and fungicide (Polyram) sprays slightly increased, while GA (Provide) decreased fruit russetting. In 1991, GA and repeated Semperfresh (sucrose ester, carboxymethyl cellulose and mono and diglycerides) applications reduced russetting while Bayleton application increased russetting. Russetting varied from year to year. In 1991, a season of severe fruit russetting, trees which received a fungicide treatment for powdery mildew had generally higher incidence of fruit russetting regardless of treatments. It is believed that interaction between relative humidity, temperature, and systemic sprays used for powdery mildew control contribute to `Rome Beauty' russetting.

Apple, Miticide Evaluations, 1991

Abstract Treatments were applied to 16 year old 'Triple Red Delicious' trees using single tree plots arranged in a randomized block design and replicated 4 times. Trees were sprayed to runoff using a Bean hydraulic sprayer operating at 400 psi. All plots were inoculated twice (29 May and 12 Jun) with mite infested water sprouts (10 per replicate) which were taped to existing foliage. Insecticides used during the season follow; fungicides, nutrient sprays, herbidices, etc. used are listed separately. All plots were oversprayed with Pounce 3.2 EC, 814 kg/ha (7.5 lb/A) on 9 Apr and 10 May; Dipel 3.36 kg/ha (3 lb/A) 1 May; and Sevin 50 W 3.36 kg/ha (3 lb/A) 25 Jul to reduce predator numbers in the mite plots. Morestan 25 W, 28.38 g/ 189.25 1 (1 oz/50 gal), was applied on 2 Apr (pink spray). All other miticide plots were sprayed on 2 Jul. Populations of mites did not reach levels requiring treatment after 2 Jul. One hundred apples per replicate were picked at random at harvest and graded on a scale from 0-5 for both stem end and side russetting where 0 = no russetting and 5 = completely russetted. These data were used to place each fruit in the appropriate USDA grade (extra fancy, fancy, No. 1, utility). Each fruit was also examined for injury by RBLR, TABM, CM, and miscellaneous Lepidoptera (LEP) (primarily gypsy moth). No significant differences between treatments were found.

Establishment of the Mistletoe Phoradendron macrophyllum: Phenology of Early Stages and Host Compatibility Studies

The timing and morphological characteristics of the early stages in the establishment of Phoradendron macrophyllum (Viscaceae) on Salix laevigata were observed and quantified using clonal host material in greenhouse conditions. Observed stages were seed germination; holdfast formation; renewed greening of mistletoe tissue; swelling of the underlying host branch; aerial shoot formation; and development of the endophytic system. Aerial shoot formation was influenced by local moisture availability, but other stages in establishment were independent of water or nutrient sprays. When seeds of P. macrophyllum were placed on cuttings of Eucalyptus (a host susceptible to certain loranthaceous mistletoes, but not susceptible to Phoradendron), seed germination and hypocotyl swelling took place, but no further stages in holdfast formation occurred. A corky layer, or wound periderm, formed locally beneath the mistletoe seeds. When viscin alone from Phoradendron seeds was placed on Eucalyptus stems, wound periderm formation was also triggered.

DISEASE CONTROL BY NUTRIENT SPRAYS IN VEGETABLE CROPS

Scientific literature contains several examples of disease development influenced by fertilization practices. A set of data collected by the «Scouting and Research Network, South of Montreal Area» and consisting of disease and tissue analysis data on carrot and onion crops was made available for principal component analysis. It was hypothesized from the analysis that high N tissue levels would reduce Cercospora carotae and Botrytis squamosa importance on carrot and onion leaves, respectively. In a controlled environment study, Cercospora spots were inversely related to urea levels sprayed on carrot leaves although urea had no influence on plant growth. In a field study with onion, however, urea sprayed at 10 kg/ha, alone or in combination with a fungicide, had no effect either on Botrytis or on maturation or yield. With these mixed results, more research seems needed to assess the potential of nutrient sprays in reducing pesticide use.

EFFECTS OF CHRONIC SHADE AND FOLIAR NUTRIENT SPRAYS ON APPLE SPUR VIGOR AND PERFORMANCE

Eleven year-old Empire/M.7 apple trees were shaded continously for 4 years with half-tree shading cages. Shading reduced primary spur leaf duration, bourse shoot leaf area, specific leaf weight, spur diameter and bud diameter. Over the four years, shaded spurs continued to increase in length but spur diameter increased very little resulting in long and brittle spurs. However, shaded spurs continued to flower and set fruit. Leaf area development was similar inside and outside the cages at one week after bloom but by 2 weeks after bloom, spurs inside the cages had significantly lower leaf area. Shading reduced fruit set, fruit size, fruit color, fruit soluble solids and fruit dry matter. Fruit growth rate was reduced by shading early in the season but was no different than the unshaded controls by 4 weeks after full bloom.In an attempt to reverse the negative effects of shading on spur vigor, foliar urea, zinc-EDTA and solubor were sprayed 3 times during the early growing season each year. Rather than increasing spur leaf area, foliar nutrient sprays significantly reduced bourse shoot leaf area and did not increase the duration of primary spur leaves. Although foliar nutrients reduced total spur leaf area, they improved fruit size, color and soluble solids slightly.

EFFECT OF MID-SUMMER FOLIAR BORON SPRAYS ON QUALITY OF `DELICIOUS' APPLE FRUIT

Fruit growers and shippers have suggested that excessive rates of boron (B) in foliar nutrient sprays may reduce quality of stored apples. Foliar B sprays were applied by handgun in mid-July to bearing apple trees (Malus domestica Borkh. cv. Starking) at rates of 0, 11.3,22.6 g B/tree. Fruits of uniform size (220 g) were analyzed for B content at harvest and for quality indices at harvest, after 10 days ripening postharvest, after 3 months refrigerated air storage, and after 8 days ripening poststorage. Whole fruit B concentration was directly proportional to B application rate. At all sampling times fruit firmness, soluble solids, titratable acidity, and internal and external color parameters were independent of whole fruit B concentration. Fruit disorders were unrelated to treatment except for internal breakdown after 8 months refrigerated air storage, which was positively related to whole fruit B concentration. Increases in fruit B were relatively greater in the core tissue, suggesting that some of the applied B entered the fruit through the tree vascular system.

Cumulative Effects of Pre‐sowing Seed Treatment and Foliar Application of Salts in Improving Biomass and Grain Yield of Soybean in Moderate Saline/alkaline Soil

AbstractField trial studies were carried out to find out whether performance of soybean could be improved as a result of pre‐sowing soaking treatment of seeds. Comparatively pre‐sowing seed treatment with KNO3, NaNO3, NaCl, thiourea and di‐Ammonium phosphate (DAP) resulted in better development of the root and shoot system than the control. As a result of pre sowing seed treatment, there was an increase in dry matter production by 44, 27 and 32 % over the control in KNO3, NaNO3 and DAP treatments respectively. Similarly increase in seed yield was noticed in NaNO3 (45 %), KNO3 (40 %) and DAP (50 %) pretreated plants. The number of existing nodules was reduced both in the control and treated plants due to pH (8.4) of the soil.To investigate the cumulative effects of foliar spray on plants raised from pre‐sowing seed treatment, salt solutions (NaCl, KNO3, NaNO3, thiourea, DAP) at optimal level were sprayed separately three times at three different stages of development. As a result of foliar spray moderate increase in growth in KNO3 (20 %), thiourea (29 %) and DAP (25 %) treatment was observed over the control. Seed yield increased significantly (56–70 %) in all treatments except NaCl spray, due to increase in the number of pods (41–63 %) per plant. Foliar spray of nutrients increased protein yield without affecting the oil content. It is suggested that a considerable fertilizer economy may be effected by coupling pre‐sowing seed treatment with foliar fertilization.

INFLUENCE OF FOLIAR-APPLIED N-P-K FERTILIZERS ON PRODUCTIVITY AND NUTRITION OF JUNE-BEARING STRAWBERRIES

A 2-yr field experiment was conducted to determine the influence of supplemental N-P-K foliar fertilizers (9-8-7 or 16-2-3) applied during flowering, fruit enlargement and/or flower initiation on yield, quality, and nutrition of Earliglow strawberries (Fragaria × ananassa Duch.). All plots received soil applied fertilizer at planting and at renovation according to soil test recommendations. Foliar fertilizers did not significantly increase total yield at any of the rates or times of application employed. Average yields the first year were 1.5 times greater than those the second year, regardless of whether foliar fertilizers were applied. Treatments did not significantly affect mean berry weight or percent soluble solids. Concentrations of N and P in recently matured leaves sampled during harvest were not significantly affected by foliar treatments, but K level was increased in the second year of the study by some foliar treatments.Key words: Fragaria spp., foliar nutrient sprays, nitrogen, phosphorus, potassium, strawberry