Effects Of Mineral Nutrients Research Articles

The Rise of Biological Products in the Crop Protection and Plant Nutrition Markets

Biological control agents and biostimulants are niche sectors within the Crop Protection and Plant Nutrition sectors which are experiencing rapid growth, driven by an increasingly favourable regulatory environment, growing pest resistance to conventional products, the pull for sustainable agriculture and technological advances. Whilst there are now more BCAs registered than conventional CP products the products also have some limitations compared with conventional products and the sector remains confined mainly to fruit and vegetables, both indoors (protected crops) and outdoors. Their future growth will be determined by the extent to which their use can be expanded into broad-acre crops. The markets for crop protection (CP) products (such as herbicides, insecticides and fungicides) and fertilizers (including nitrogen, phosphorus pentoxide, and water-soluble potash) are generally considered to be mature. In most significant agricultural economies, these markets show single-digit growth at best. Within these markets, however, are two faster-growing sectors: those based on naturally-derived products. Biological control agents (BCAs) and biostimulants are growing at over 10% a year, according to some estimates BCAs include products such as plant extracts (for control of pests and diseases), insect pheromones (used primarily for mating disruption), predatory insects, and microbial products (often the output of fermentation processes). BCAs also address biotic stresses on crops, such as pests, diseases, and weeds. Biostimulants include amino acids, seaweed-based products, and humic and fulvic acids. These products trigger the processes that enhance nutrient use, increase tolerance to abiotic stress such drought and temperature extremes, enhance availability of confined nutrients in soil, and address quality traits beyond the effects of mineral nutrients. The distinction between BCAs and biostimulants is not always clear. Specific products can exhibit the properties of both categories, as with some plant oils. For regulatory purposes, classification depends on which properties companies claim. Both markets are still relatively niche, with $2 to $3 billion in 2018 sales at the ex-manufacturer level. With hundreds of products, these markets are also complex and fragmented. In comparison, the total CP market is valued at $57 billion and the total chemical fertilizer market has a value of over $100 billion for primary nutrients. BCAs and biostimulants are not new. In the BCA category, commercial Bacillus thuringiensis (Bt)-based products have been around since the 1960s and pheromones were introduced in the 1970s. Only recently, however, has their popularity increased.

Influence of mineral nutrients and freezing-thawing on peach susceptibility to bacterial canker caused byPseudomonas syringaepv.syringae

Introduction. Bacterial canker, caused by Pseudomonas syringae pv. syringae ,i s a devastating disease of stone fruit worldwide. The effects of mineral nutrients and freezing-thawing on bacterial canker susceptibility were evaluated using potted peach trees in an attempt to understand predisposing factors in bacterial canker of stone fruit. Materials and methods. A split-plot experi- mental design with randomized complete block main plots (i.e.,inoculations associated with freezing- thawing or nonfrozen pretreatments) and subplots of trees with the seven treatments (i.e., solutions deficient in N, P, K, Ca, Mg or Fe, respectively, and a full nutrient control) was adopted to study the effect of mineral deficiency and freezing-thawing on peach susceptibility to bacterial canker. Results anddiscussion. Phosphorus deficiency was the only treatment to significantly decrease lesion length that developed after inoculation with P. syringae pv. syringae, compared with the control trees that received full nutrients. Nitrogen and potassium deficiency treatments significantly decreased bark nitrogenandpotassiumconcentrationsaccordingly,buthadnocleareffectonlesionsizes.Inoculation during freezing-thawing cycles significantly increased lesion length. In another independent expe- riment, nitrogen deficiency significantly increased the number of P. syringae pv. syringae leaf scar infections, but the subsequent infection was limited to a few millimeters. Nitrogen-deficient trees, which had higher (carbon / nitrogen) ratios, developed lesion sizes equivalent to trees provided with full nutrients. Collectively, these data suggest that, in the absence of other major predisposing factors (i.e., low soil pH or ring nematodes), mineral nutrients may play a minor role in the susceptibility of peach to bacterial canker.

Protein accumulation and composition in wheat grains: Effects of mineral nutrients and high temperature

Effects of mineral nutrition and temperature on accumulation and composition of protein in wheat grains and on baking quality were studied under controlled environments. Under a moderate temperature regimen of 24 °C days and 17 °C nights (24/17 °C), post-anthesis N:P:K 20:20:20 (NPK) supplied by continuous drip irrigation increased the rate of protein accumulation, doubled flour protein percentage and slightly increased final single kernel weight. In contrast, post-anthesis NPK had almost no effect on rate or duration of protein accumulation or flour protein percentage under a high temperature regimen of 37 °C days and 28 °C nights (37/28 °C). The 37/28 °C regimen shortened and compressed the stages of grain fill, reduced the duration of dry matter accumulation, and reduced single kernel weight by 50%. Rate and duration of protein accumulation in thermal time and total protein per grain at 37/28 °C with or without NPK were similar to that at 24/17 °C in the absence of post-anthesis NPK. Protein percentage was higher for flour from grain produced at 37/28 °C with or without NPK than at 24/17 °C in the presence of post-anthesis NPK. Transcript and protein profiling studies confirmed that the 37/28 °C regimen compressed development without disrupting coordinate synthesis of gliadins and glutenin subunits, although some specific effects of NPK and temperature on relative amounts of individual gliadins and glutenins were observed. Transcript levels for ω-gliadins, α-gliadins and high molecular weight glutenin subunits (HMW-GS) declined at 24/17 °C in the absence of post-anthesis NPK, whereas transcript levels for low molecular weight glutenin subunits (LMW-GS) and γ-gliadins showed little change. Two-dimensional gel electrophoresis (2DE) demonstrated that relative spot volumes for several ω-gliadins, α-gliadins and HMW-GS were lower at 24/17 °C in the absence than in the presence of post-anthesis NPK, whereas the relative spot volume for a major LMW-GS was lower in the presence of NPK. Effects of temperature on relative spot volume were generally smaller than effects of NPK. Compared to the 24/17 °C regimen in the absence of post-anthesis NPK, relative spot volume for some α-gliadins and HMW-GS were higher at 37/28 °C, with or without NPK, and relative spot volume for a major LMW-GS decreased at 37/28 °C. Loaf volume was correlated with flour protein percentage regardless of temperature regimen but mixing tolerance was highest for flour from grain produced under the 24/17 °C regimens with NPK.

Effects of mineral nutrients on the growth of bacterioߚ and phytoplankton in two southern reservoirs

Nutrient limitation of bacterioߚ and phytoplankton was studied simultaneously in two warmߚwater lakes in the southern United StatesߞJoe Pool Lake (JPL) and Eagle Mountain Lake (EML). Lakes were sampled approximately biweekly between March 1998 and December 1999 from a single station. Nutrient limitation was assessed through dilution bioassays in which nitrogen (N, 50 µM above ambient), phosphorus (P, 10 µM above ambient), carbon (C, bacterioplankton only, 83 µM above ambient), and trace nutrients (Tm, phytoplankton only) were supplied. In both lakes, growth of bacterioߚ and phytoplankton was stimulated by nutrient additions. Multiple nutrient limitation was common. P alone and in combination with N and C or Tm most frequently limited growth of both bacterio and phytoplankton in JPL. N alone and in combination with P and C or Tm most frequently limited growth of both bacterioߚ and phytoplankton in EML. Comparison of in situ growth rates to growth rates under potentially nutrient saturating conditions revealed that both bacterioߚ and phytoplankton in both lakes were growing well below maximum potential during warm months but near maximum potential during cooler months. This result was due to a combined effect of low temperature in winter and restricted nutrient availability in summer. Phytoplankton was generally more strongly limited by nutrient availability than was bacterioplankton, but there were occasions when the intensity of limitation shifted between communities.

Effects of Mineral Nutrients on the Degradation of 2, 4-Dichlorophenol at Low Concentrations by Microbial Community and Bacterial Isolates

地下水の微生物群集は0.1μgC/mlの2,4-dichlorophenol (DCP) を分解しなかった. この試水にリン酸塩あるいは硝酸アンモニウム塩を添加するとDCPは分解された. 0.1μgC/mlのDCP分解菌は, DCPを含む無機 (MS) 培地を用いた最確数 (MPN) 法で求めると, これらの栄養塩類の添加の有無にかかわらず, 2～5週間で0.43cell/mlから104～105/mlに増加した. これらの結果はこの地下水ではリン酸塩あるいは硝酸アンモニウム塩は0.1μgC/mlのDCP分解菌の分解能の発現に必要であり, 増殖には不要であったことを示唆する. しかしながら, この地下水からの三つの単離細菌はDCP分解能の発現に際してさまざまな栄養塩類の要求性を示した. すなわち, 一つの単離細菌は濾過滅菌した地下水で純粋培養すると, 硝酸アンモニウム塩が添加されたときのみ0.1μgC/mlのDCPを分解した. 他の一つの単離細菌はリン酸塩が添加されたときのみDCPを分解した. そして, 残りの一つの単離細菌はこれらの塩類の添加の有無にかかわらずDCPを分解した. これらの単離細菌の密度は, これらの栄養塩類の添加の有無にかかわらず, 106～107/mlに増加した. DCP分解能の発現に際して, 微生物群集と単離細菌の塩類添加に対する反応の違いについて考察した.

Effects of mineral nutrients on senescence of the cortex of wheat roots and root pieces

Wheat seedlings were grown for up to 35 days in perlite moistened with mineral nutrient solutions of different N, P and K content. In parallel work, sterile 2 cm wheat root pieces were maintained for up to 12 days on agar with glucose and different mineral nutrient supplements. The effects of mineral nutrition on death of the root cortex (RCD) were assessed by nuclear staining with acridine orange. A reduced supply or omission of N [as Ca(NO 3); or (NH 4);SO 4] enhanced the rate of RCD, whereas P and K had lesser effects. Ammonium-N was less effective than nitrate-N in maintaining cortical viability, and this effect could not be explained by differences of pH. Effects of mineral nutrients on RCD were not closely correlated with effects on shoot or root growth. Also the effects were similar for whole roots or root pieces. So mineral nutrients apparently exerted direct, localised effects on root cell viability. In addition to the previously reported normal pattern of RCD, a further phase of cortical senescence is described in which nuclei are deleted from the innermost cortical cell layer. This was associated with root impedance when the root tips reached the bottoms of soil containers.

Effects of mineral nutrients, sludge application rate, and application frequency on biodegradation of two oily sludges

A continuous flow soil respirometer was used to evaluate the effect of nutrient addition, application rate, and application frequency on biodegradation of 2 complex oily sludges in soil. The most rapid biodegradation of the refinery sludge occurred when nitrogen was added to reduce the carbon to nitrogen (C∶N) ratio to 9∶1. The petrochemical sludge was degraded most rapidly when nitrogen, phosphorus, and potassium were added at a rate of 124∶1, C∶NPK; CO2evolution from both wastes increased with increasing application rates, but the fraction of applied sludge which degraded decreased with increasing application rates. Small frequent applications resulted in a slight increase in respiration rate per unit applied over a single equivalent application, indicating that repeated applications of smaller amounts of sludge result in a more rapid rate of decomposition. The population of total soil bacteria was greatest when 1% of either sludge was added to the soil, whereas 5 and 10% sludge additions resulted in slightly lower microbial populations.

Spore Germination and Germ Tube Growth of a Vesicular-Arbuscular Mycorrhizal Fungusin Vitro

The effects of mineral nutrients, thiamine, pH, and organic substrates on germination and germ tube growth of a vesicular-arbuscular mycorrhizal fungus were examined. Surfacesterilized azygospores of Gigaspora margarita were plated on 1% water agar containing different components and incubated at 28 C up to 30 da. Maximum germination and germ tube growth occurred when 20 mg 1-1 CaH2PO4 was used, whereas 24 mg 1-~ NH4NO3 did not affect germination and depressed germ tube growth by 55%. Potassium or concentrations of soluble nutrient salts as high as those used to grow seedlings axenically had no effect on spore germination or germ tube growth. Thiamine at 0.1 mg 1-1 increased germination, and maximum germ tube growth occurred at 0.01 mg 1-1. The interaction between medium pH and medium composition was significant. Spore germination was not enhanced by any of the organic substrates. Low concentrations (4 g 1-1) of sucrose favored germ tube growth. Relation of these results to nutrition and root-colonizing ability of VA mycorrhizal spores is discussed.

Spore Germination and Germ Tube Growth of a Vesicular-Arbuscular Mycorrhizal Fungus in vitro

The effects of mineral nutrients, thiamine, pH, and organic substrates on germination and germ tube growth of a vesicular-arbuscular mycorrhizal fungus were examined. Surfacesterilized azygospores of Gigaspora margarita were plated on 1% water agar containing different components and incubated at 28 C up to 30 da. Maximum germination and germ tube growth occurred when 20 mg 1-1 CaH2PO4 was used, whereas 24 mg 1-1 NH4NO3 did not affect germination and depressed germ tube growth by 55%. Potassium or concentrations of soluble nutrient salts as high as those used to grow seedlings axenically had no effect on spore germination or germ tube growth. Thiamine at 0.1 mg 1-1 increased germination, and maximum germ tube growth occurred at 0.01 mg 1-1. The interaction between medium pH and medium composition was significant. Spore germination was not enhanced by any of the organic substrates. Low concentrations (4 g 1-1) of sucrose favored germ tube growth. Relation of these results to nutrition and root-colonizing ability of VA mycorrhizal spores is discussed.

Studies on the Initial Process of Adventitious Bud Differentiation in Torenia Stem Segments Cultured in vitro I. Effects of Cytokinin

Summary The effects of mineral nutrients and growth regulators added to culture medium on the initial stages of adventitious bud differentiation were investigated using Torenia internodal segments cultured In vitro. Meristematic zones (MZ) appeared prior to adventitious bud formation in the epidermal Cell layers of stem segments. Adventitious bud and Mz formation was rarely noted in the explants Cultured on the MS medium without benzyladenine (BA). When explants were cultured on a medium composed of only BA and sucrose, MZ were formed but no adventitious bud initiation was observed. While, both MZ and bud formation was strongly promoted when a medium consisting of mineral nutrients and BA was used. Applications of indole-3-acetic acid and gibberellic acid stimulated neither MZ nor bud formation. When explants were cultured on a medium containing only BA (1.0 mg/l) and sucrose during the first 6 d and then transferred to nutrient medium without BA, adventitious buds were differentiated at a high rate. Consequently, it seems that BA strongly promoted MZ formation (bud initiation) during initial period of culture and mineral nutrients play major role in subsequent development of MZ to bud primordia.

Effects of Mineral Nutrients on the Flower-Buds Differentiation of Crops (Part 4)

Effects of Mineral Nutrients on the Flower-Buds Differentiation of Crops (Part 4)

Effects of Mineral Nutrients on the Flower-buds Differentiation of Crops. (Part 1) : On the Nitrogen Metabolism of Tomato Plant in Relation to the First Flower Cluster Differentiation.

Effects of Mineral Nutrients on the Flower-buds Differentiation of Crops. (Part 1) : On the Nitrogen Metabolism of Tomato Plant in Relation to the First Flower Cluster Differentiation.

Effects of Mineral Nutrients on the Flower-buds Differentiation of Crops (Part 2) : On the Phosphorus Metabolism of Tomato Plant in relation to the First Flower Cluster differentiation

Effects of Mineral Nutrients on the Flower-buds Differentiation of Crops (Part 2) : On the Phosphorus Metabolism of Tomato Plant in relation to the First Flower Cluster differentiation

Sporeling Establishment in Pteridium Aquilinum: Effects of Mineral Nutrients

From the small number of records of sporelings of the common bracken fern (Pteridium aquilinum (L.) Kuhn.) which are known to have established themselves (Conway, 1953) it seems likely that, under natural conditions, a complex of factors acts on the prothallus and the young sporophyte, and that many of these factors may be climatic (Conway, 1957). But in years of high spore-production, numerous spores must fall on land which, either naturally or by agricultural treatment, has a higher complement of mineral nutrients than is normal. The present paper describes experiments carried out to see if developing spores and colonizing young plants of bracken are influenced by the presence of mineral nutrients in excess of their basic requirements. The experiments were designed to test (a) the extent to which the youngbracken plant is a calcifuge; (b) whether the sporeling becomes established more readily when nitrogen is available in the form of nitrates or ammonium salts; and (c) the degree of development of young plants on land rich in potash or phosphates. During the course of the present investigation, Schwabe (1951) published a review of the mineral nutrition of bracken in which he stressed the importance of nitrogen and phosphorus in the development of the prothallus, and he noted that potassium and sulphur deficiencies had a marked effect on the development of the plant. He found that in the young sporophyte, frond production was reduced by phosphorus and potassium deficiencies, and that length of life was shortened by potassium deficiency. In his opinion, nitrogen, potassium and phosphorus are important mineral nutrients in the establishment of young bracken plants. The present observations are based on the effect produced upon the young plant, not by deficiencies but by amounts of mineral nutrients normal in agricultural practice. The design of the experiments was ecological rather than physiological and no attempt has been made to define the amounts of the minerals used by the plant, our objective being to observe the reactions of the plant when certain minerals were available in plentiful supply. EXPERIMENT