Tree age influences nutritional,pectin, and anatomical changes in developing ‘Kinnow’ mandarin (Citrus nobilis Lour × Citrus deliciosa Tenora) fruit

An understanding of variation in fruit quality in relation to tree age can help understand the issue of poor fruit quality in young orchards; however, limited information is available on the citrus fruit. In this study, the endogenous nutritional status in rind, rag, and leaves; pectin status in rind and rag; and anatomical fruit growth parameter in rind tissues were studied in ‘Kinnow’ mandarins fruit during their development on trees from three age (6-, 18-, and 35-year-old) groups. In older (35-year-old) trees, rind, rag, and leaf nitrogen (N), phosphorus (P), and potassium (K) concentrations were superior. In fruit from all tree age groups, total pectin and protopectin reduced; however water-soluble pectin (WSP) improved. In rind tissues harvested from young (6-year-old) trees, cell density was more while cell size was less. In all tree age groups, cell density in rind tissues correlated negatively with rind WSP.     

Nutrient Indexing in “‘Kinnow” Mandarin (Citrus deliciosia Lour.× Citrus nobilis Tanaka) Grown in Indogangetic Plains

Diagnosis and remediation of nutrient constraints in perennial fruit crop like citrus are the two important pillars of an effective nutrient management program. Efforts were made to develop nutrient indexing (NI) criteria based on generated leaf and soil analysis dataset for “Kinnow” mandarin (Citrus deliciosia Lour. × Citrus nobilis Tanaka) grown on illitic soils of Indogangetic plains (Entisol, Inceptisol, and Aridisol). NI through diagnosis and recommendation integrated system (DRIS) using leaf analysis data showed optimum value of leaf nutrient concentration as 2.22–2.32% nitrogen (N), 0.11–0.15% phosphorus (P), 1.10–1.41% potassium (K), 2.32–2.79% calcium (Ca), 0.38–0.61% magnesium (Mg), 22.4–58.3 ppm iron (Fe), 26.3–56.2 ppm manganese (Mn), 4.2–7.2 ppm copper (Cu), and 21.3–26.9 ppm zinc (Zn) vis-à-vis a fruit yield of 32.4–56.1 kg tree^?1. Using these NI criteria, Zn was observed as most deficient (64.7%) followed by Fe (61.5%), Mn (57.6%), N (96.1%), and P (38.5%) using percentage of orchards as basis. While, optimum NI (mg kg^?1) using soil analysis data was determined as 114.3–121.2 potassium permanganate (KMnO₄-N), 7.8–12.3 Olsen-P, 96.4–131.3 ammonium acetate (NH₄OAc)-K, 189.4–248.6 NH₄OAc-Ca, 72.3–89.9 NH₄OAc-Mg, 5.8–11.1, DTPA-Fe, 4.3–6.9 diethylenetriaminepentaacetic acid (DTPA)-Mn, 0.45–0.69 DTPA-Cu, and 21.3–26.9 DTPA-Zn for the optimum yield of 32.4–56.1 kg tree^?1. Soil analysis-based NIs displayed a good complementary with leaf analysis-based NIs evident from the diagnoses indicating Mn (52.2%) as most dominant constraint Zn (61.2%) followed by Mn (48.3%), N (41.2%), and P (35.6%). The recommended DRIS-based NIs would lay a scientific basis in formulating citrus fertilization program.     

Influence of Humic Substances and Nitrogen on Yield,Fruit Quality,and Leaf Mineral Elements of ‘Early Spur Rome’ Apple

The effects of humic substances (AgriPlus, Humi-Zyme, and Humic Acid 6%) and nitrogen (N) on growth, yield, quality, and leaf minerals in apple (Malus domestica Borkh.) were studied during 1997–2000. Trees receiving medium or high N tended to be larger than trees with other treatments in 2000. Trees receiving AgriPlus with high N had higher yield than untreated control trees in 1998. Trees receiving medium N had larger fruits than control trees. Fruits of trees receiving high N (alone) had less red color than the control. Soluble solids concentrations (SSC) in fruits of all treatments were higher than those of the control at harvest in 1999. Fruit from the untreated control and low Humi-Zyme tended to be firmer than that from other treatments. The untreated control and low Humi-Zyme trees had lower leaf N and manganese (Mn), but higher leaf potassium (K) than trees under most other treatments. Leaf iron (Fe) in trees receiving medium Humi-Zyme was higher than that in the untreated control in two years. AgriPlus-treated trees showed higher water retention in the root zone.     

Impact of Postharvest Sprays of Nitrogen,Boron and Zinc on Nutrition,Reproductive Response and Fruit Quality of ‘Schattenmorelle’ Tart Cherries

The aim of the study was to examine effects of fall sprays of nitrogen (N), boron (B) and zinc (Zn) on nutrition, reproductive response, and fruit quality of tart cherry (Prunus cerasus L.). The experiment was conducted during 2008–2010 in Poland on mature ‘Schattenmorelle’ sour cherry trees, planted at a spacing of 4.0 × 1.5 m on a coarse-textured soil with low level of organic matter, and adequate reaction and availabilities of macro- and micronutrients. Tart cherries were sprayed with boric acid-B, ethylenediaminetetraacetic acid (EDTA)-Zn, and urea-N at 40–50 d prior to initiation of leaf fall according to following schema: (i) spray of N at a rate of 23 kg ha^?1; (ii) spray of B and Zn at doses of 1.1 kg ha^?1 and 0.5 kg ha^?1, respectively; and (iii) spray of N, B, and Zn at the same rates as in the above spray combinations. The trees sprayed with water were served as the control. The results showed that postharvest spray treatments had no effect on defoliation, cold damage of flower buds, fruit set, yielding, plant N status, mean fruit weight, and soluble solids concentration in fruit. Postharvest sprays of B and Zn with or without N enhanced status of Zn and B in fall leaves, and B in flowers but had no impact on levels of the above micronutrients in summer leaves. Leaf-absorbed B was withdrawn in the fall, whereas Zn was immobile. It is concluded that postharvest B sprays can be recommended to increase B status in flowers of tart cherry, whereas fall sprays of urea-N and Zn are not able to improve plant nutrition of those nutrients the following season.     

Impact of Animal Manure on Soil Chemistry,Mineral Nutrients,Yield, and Fruit Quality in ‘Golden Delicious’ Apple

ABSTRACT

Incorporating deep litter cow and deep litter poultry manures with the top 30-cm soil improved orchard soil chemistry, including nutrient availability, soil organic matter, electrical conductivity (EC), pH, cation exchange capacity (CEC) and biological activity in a ‘Golden Delicious’ apple (Malus domestica Bork) orchard in Zanjan, Iran. Application of deep litter cow manure at 30 t ha^?1 or deep litter poultry manure at 10 t ha^?1 resulted in a higher rate of nitrogen (N) release, and thus increased yield and fruit size, but decreased fruit color. The least leaf minerals were found in the untreated control trees. The control trees showed minor symptoms of N, iron (Fe), and magnesium (Mg) deficiencies during the following season. Positive correlation existed between the rate of manure applied and the content of soil organic matter (OM). The deep litter poultry manure at 10 t ha^?1 increased the soil K, Mg, calcium (Ca), ammonium-N, and EC levels.     

Nitrogen Fertilizer Influences Fruit Quality,Soil Nutrients and Cover Crops,Leaf Color and Nitrogen Content,Biennial Bearing and Cold Hardiness of ‘Golden Delicious’

Four rates of ammonium nitrate (NH₄NO₃) (0, 151, 454, and 908 g actual N/tree) were applied each spring for 6 years to ‘Golden Delicious’ (Malus domestica) apple trees. High rates of nitrogen (N) increased N concentration of Orchardgrass (Dactylis glomerata) blades and increased cover-grass growth whereas various legume species were prevalent at the low rates. Leaf N in spur or mid-terminal leaves increased yearly, and was related to leaf color by visual comparison and reflectance. Fruit from the higher N rates had greener peel and lower firmness, soluble solids content and titratable acidity. In vitro freeze tests indicated trees fertilized with lower rates of N were more cold hardy during the fall, winter and spring than those receiving the higher rates. In a similar long-term study on ‘Delicious,’ cold hardiness was related not only to seasonal temperature cycles and shoot dry matter, but to total sugars and sorbitol content in wood or sap.     

Nutritional Status,Yield, and Fruit Quality of “Encore” Mandarin Trees Grown in Two Sites of an Orchard with Different Soil Properties

Abstract

The nutrient status [annual fluctuation of leaf nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn)], yield and fruit quality [soluble solids concentration (SSC), titratable acids (TA), SSS/TA and juice content] of “Encore” mandarin trees cultivated in two sites of the same orchard were studied. The trees were grafted on Carrizo citrange rootstock and grown under identical conditions, apart from some soil properties. Soil B (site B of orchard) contained more K, Ca, Mg, and organic matter than soil A (site A of orchard). The patterns of annual variation of leaf nutrient concentrations were similar in both soils, although leaf concentrations of Ca, Mg, Mn, and Fe in soil A were significantly higher than those of soil boron (B), while leaf K concentrations were significantly lower. The mineral analyses of the leaves revealed some interesting antagonisms between K–Mg, K–Ca, and K–Mn. Manganese deficiency was especially limited in the trees grown in soil B. The average fruit yield per tree in soil A, on two-year basis, was significantly higher than this in soil B. The significantly higher water infiltration rate in soil B, in contrast to soil A, seemed to be the dominant factor responsible for the differences among the two sites in yielding and leaf mineral composition.