scholarly journals Initial decomposition of floating leaf blades of waterlilies: causes, damage types and impacts

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7158 ◽  
Author(s):  
Peter F. Klok ◽  
Gerard van der Velde
Keyword(s):  
Leaf Tissue ◽  
Nutrient Status ◽  
Phytopathogenic Fungi ◽  
Leaf Length ◽  
Leaf Damage ◽  
Invertebrate Species ◽  
Nymphaea Alba ◽  
Mechanical Factors ◽  
Floating Leaves ◽  
Floating Leaf

The initial decomposition of large floating-leaved macrophytes, such as waterlilies, can be studied by following changes in leaf damage and area loss of leaf blades tagged in their natural environment. This approach was taken in the present study to examine the initial decomposition patterns of floating leaf blades of Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida C. Presl at three freshwater sites differing in nutrient status, alkalinity and pH. Floating leaf blades of the three plant species were tagged and numbered within established replicate plots and the leaf length, percentages and types of damage and decay of all tagged leaves were recorded weekly during the growing season. Microbial decay, infection by phytopathogenic fungi (Colletotrichum nymphaeae) and oomycetes (Pythium sp.), consumption by pond snails, and mechanical factors were the most important causes of leaf damage. Several types of succession comprising different causes of damage were distinguished during the season. For example, young floating leaves are affected by more or less specialized invertebrate species consuming leaf tissue, followed by non-specialized invertebrate species feeding on the damaged floating leaves. In the two investigated hardwater lakes the seasonal patterns of initial decomposition differed between Nymphaea and Nuphar.

scholarly journals Plant traits and environment: floating leaf blade production and turnover of waterlilies

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3212 ◽  
Author(s):  
Peter F. Klok ◽  
Gerard van der Velde
Keyword(s):  
Plant Traits ◽  
Vegetation Period ◽  
Leaf Biomass ◽  
Leaf Life Span ◽  
Turnover Rates ◽  
Leaf Production ◽  
Nuphar Lutea ◽  
Nymphaea Alba ◽  
Floating Leaves ◽  
Floating Leaf

Floating leaf blades of waterlilies fulfill several functions in wetland ecosystems by production, decomposition and turnover as well as exchange processes. Production and turnover rates of floating leaf blades of three waterlily species, Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida Presl, were studied in three freshwater bodies, differing in trophic status, pH and alkalinity. Length and percentages of leaf loss of marked leaf blades were measured weekly during the growing season. Area and biomass were calculated based on leaf length and were used to calculate the turnover rate of floating leaf blades. Seasonal changes in floating leaf production showed that values decreased in the order: Nymphaea alba, Nuphar lutea, Nymphaea candida. The highest production was reached for Nuphar lutea and Nymphaea alba in alkaline, eutrophic water bodies. The production per leaf was relatively high for both species in the acid water body. Nymphaea candida showed a very short vegetation period and low turnover rates. The ratio Total potential leaf biomass/Maximum potential leaf biomass (P/Bmax) of the three species ranged from 1.35–2.25. The ratio Vegetation period (Period with floating leaves)/Mean leaf life span ranged from 2.94–4.63, the ratio Growth period (Period with appearance of new floating leaves)/Vegetation period from 0.53–0.73. The clear differences between Nymphaea candida versus Nuphar lutea and Nymphaea alba, may be due to adaptations of Nymphaea candida to an Euro-Siberic climate with short-lasting summer conditions.

Quackgrass (Agropyron repens) Interference on Corn (Zea mays)

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 226-234 ◽  
Author(s):  
Frank L. Young ◽  
Donald L. Wyse ◽  
Robert J. Jones
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Leaf Tissue ◽  
Nutrient Status ◽  
Growing Season ◽  
Field Studies ◽  
Growth And Yield ◽  
Limiting Factors ◽  
Corn Yield ◽  
Agropyron Repens

Field studies were conducted to evaluate the effect of quackgrass [Agropyron repens(L.) Beauv. ♯ AGRRE] density and soil moisture on corn (Zea maysL.) growth and yield. Quackgrass densities ranging from 65 to 390 shoots/m2reduced corn yield 12 to 16%. A quackgrass density of 745 shoots/m2reduced corn yields an average of 37% and significantly reduced corn height, ear length, ear-fill length, kernels/row, rows/ear, and seed weight. In the soil moisture study, quackgrass was shorter than corn throughout the growing season, and analyses of corn leaf tissue indicated that quackgrass did not interfere with the nutrient status of the corn. In 1979, soil moisture was not limiting and corn yields were similar in all treatments regardless of irrigation or the presence of quackgrass. In 1980, soil moisture was limited and irrigation increased the yield of quackgrass-free corn. Irrigation also increased the yield of quackgrass-infested corn to a level similar to irrigated corn. When light and nutrients are not limiting factors, an adequate supply of soil moisture can eliminate the effects of quackgrass interference on the growth, development, and yield of corn.

Nutrient status of sugar cane in relation to leaf nutrient concentration

1968 ◽  
Vol 8 (34) ◽  
pp. 606 ◽  
Author(s):  
ICR Holford
Keyword(s):  
Sugar Cane ◽  
Field Experiments ◽  
Leaf Tissue ◽  
Growth Period ◽  
Nutrient Status ◽  
Maximum Growth ◽  
Nutrient Concentrations ◽  
Ratoon Crop ◽  
Nutrient Levels ◽  
Leaf Nutrient Levels

The nitrogen, phosphorus, and potassium requirements of sugar cane were studied in relation to the concentration of these elements in the leaf tissue of three varieties of sugar cane grown commercially in Fiji. Percentage yields of sugar cane in fertilizer field experiments were highly correlated with leaf nutrient levels in the control plots, provided leaf sampling was carried out during the maximum growth period of mid- January to mid-May. For each nutrient there was a marginal zone of leaf concentration below which crops always gave significant yield responses to applied nutrients and above which crops failed to respond. Marginal zones for crops sampled during mid-March to mid-May were 1.4-2.0 per cent for nitrogen, 0.13-0.21 per cent for phosphorus, and 0.9-1.5 per cent oven dry leaf for potassium. Within the deficient range of leaf nutrient concentrations there was little relationship between optimum rates of fertilizer required to correct the deficiency and leaf nutrient levels of unfertilized cane. Because of the lateness of sampling, any indication of fertilizer requirement would only be applicable to a subsequent ratoon crop.

scholarly journals A NUTRITIONAL MANAGEMENT SYSTEM FOR TROPICAL FRUIT AND NUT ORCHARDS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 669d-669
Author(s):  
H.H. Hirae ◽  
M.A. Nagao
Keyword(s):  
Management System ◽  
Leaf Tissue ◽  
Nutrient Status ◽  
Tree Age ◽  
Nutritional Management ◽  
Nutrient Deficiencies ◽  
Tropical Fruit ◽  
Extension Agent ◽  
Fertilizer Recommendations ◽  
Macadamia Nut

Monitoring the nutrient status of a crop by soil and tissue analysis is an important tool in maximizing yields and avoiding nutrient deficiencies or toxicities. A nutritional management system is presented that uses a computer database to compile periodic soil and leaf tissue analyses to assist in the development of rational fertilizer recommendations for banana and macadamia nut orchards. Database management allows the Extension Agent to organize parameters (soil type, rainfall, elevation, tree age, tree spacing, and previous fertilizer practices) used in nutritional recommendations for individual farms. Graphs depicting nutrient trends over time and comparison of nutrient levels to nutritional standards, present visual illustrations of problems and encourage grower acceptance of fertilizer recommendations. Growers are also able to see graphic responses to application of corrective fertilizers and soil amendments.

scholarly journals High Soil Moisture and Low Soil Temperature Are Associated with Chlorosis Occurrence in Concord Grape

HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 418-422 ◽  
Author(s):  
Joan R. Davenport ◽  
Robert G. Stevens
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Leaf Tissue ◽  
Soil Surface ◽  
Nutrient Status ◽  
Past Research ◽  
Climatic Conditions ◽  
Nutrient Concentrations ◽  
Bud Burst ◽  
Concord Grape

Leaf yellowing (chlorosis) is not unique to Concord grape, yet occurs with great intensity in the arid, irrigated central Washington state growing region. Past research on nutrients has not shown a clear cause and effect relationship between soil and/or plant nutrient status and chlorosis. We investigated both nutritional and climatic conditions for their association with chlorosis occurrence. Six vineyard sites were selected, 2 each with no history of chlorosis (achlorotic), occasional chlorosis, and annually reoccuring chlorosis (chronically chlorotic) and monitoring sites in chlorotic and achlorotic areas were established. Nutrient elements K, Ca, Mg, Mn, and Cu plus the nonnutrient elements Na and Al were monitored in soil (surface, 0 to 30 cm, and subsurface, 30 to 75 cm, depths) and leaf tissue (both petioles and blades) prebud burst (soil only), at bloom, and preveraison at 650 degree days at all vineyard sites for the 2001, 2002, 2003, and 2004 growing seasons. In addition, both soil temperature and moisture were monitored. To evaluate the intensity of chlorosis at each site, chlorotic vines were GPS marked and mapped post-bloom each year. Overall, chlorosis incidence was more widespread in 2001 and 2003 than in 2002 or 2004. There were few relationships with soil or tissue nutrient concentrations. However, soil moisture was consistently higher and soil temperature lower in the period between bud burst and bloom in the chlorotic sites. This suggests that a cold, wet soil environment prior to bloom impedes grape root growth and/or function and triggers plant chlorosis. Yearly differences strongly support this finding.

Photosynthetic Apparatus Features of Nuphar Lutea and Nymphaea Alba Floating Leaves Can Affect Their Redistribution

2021 ◽  
Author(s):  
Vasyl Brykov ◽  
Оleksandr Polischuk ◽  
Оlena Bilous ◽  
Vladyslav Zhezherya ◽  
Ramilla Brykova ◽  
...  
Keyword(s):  
Photosynthetic Apparatus ◽  
Nuphar Lutea ◽  
Nymphaea Alba ◽  
Floating Leaves

scholarly journals Extrafloral nectary phenotypic plasticity is damage- and resource-dependent in Vicia faba

2006 ◽  
Vol 2 (4) ◽  
pp. 583-585 ◽  
Author(s):  
Edward B Mondor ◽  
Michelle N Tremblay ◽  
Russell H Messing
Keyword(s):  
Phenotypic Plasticity ◽  
Vicia Faba ◽  
General Pattern ◽  
Leaf Tissue ◽  
Leaf Damage ◽  
High Resource ◽  
Resource Limited ◽  
Npk Fertilizer ◽  
Resource Levels ◽  
Secretion Rates

Phenotypic plasticity enables many damaged plants to increase nectar secretion rates from extrafloral nectaries (EFNs), or in the case of broad bean, Vicia faba L., to produce additional EFNs, to attract natural enemies of herbivores. While plants benefit greatly from these defensive mutualisms, the costs of producing EFNs are largely unknown. We hypothesized that if EFN production is costly, then damaged plants with high resource levels would be able to produce more EFNs than plants that are resource-limited. Here, we show that this indirect inducible defence does follow this general pattern. Vicia faba enriched with 6 or 12 g of 14 : 14 : 14 NPK fertilizer increased EFN numbers after leaf damage by 46 and 60%, respectively, compared with nutrient-poor plants. Thus, EFN production is both damage- and resource-dependent. Analogous to direct defences, production of EFNs may limit the overall loss of leaf tissue when risk of herbivory increases.

Epicuticular wax forms on leaf surfaces of Zizania aquatica

1970 ◽  
Vol 48 (2) ◽  
pp. 201-205 ◽  
Author(s):  
W. R. Hawthorn ◽  
J. M. Stewart
Keyword(s):  
Continuous Light ◽  
Epicuticular Wax ◽  
Experimental Conditions ◽  
Zizania Aquatica ◽  
Leaf Surfaces ◽  
Young Leaves ◽  
Floating Leaves ◽  
Wax Production ◽  
The Relationship ◽  
Floating Leaf

The epicuticular wax forms on the leaves of the three varieties of Zizania aquatica L. were determined from control plants in the field and greenhouse, and served as a reference for interpreting changes in the wax forms of plants grown under different experimental conditions. Short stubby wax rodlets first appeared 15 cm below the water's surface on the portion of the adaxial surface of young leaves which eventually became floating (leaf numbers 4 to 6). Wax rodlets and platelets were present on both surfaces of the aerial leaves (leaf numbers 7 to 12). The relationship between wax appearance and leaf numbers could be varied by manipulating the water level; for as long as water surrounded the permanently submersed leaves or the submerged portions of the floating leaves, wax production was inhibited. Growth under continuous light and constant temperature conditions indicated that factors other than the day–night cycle were responsible for wax ultrastructure.

scholarly journals Stagonospora avenae Secretes Multiple Enzymes that Hydrolyze Oat Leaf Saponins

2000 ◽  
Vol 13 (10) ◽  
pp. 1041-1052 ◽  
Author(s):  
John P. Morrissey ◽  
Jos P. Wubben ◽  
Anne E. Osbourn
Keyword(s):  
Antifungal Activity ◽  
Leaf Tissue ◽  
Phytopathogenic Fungi ◽  
Comprehensive Analysis ◽  
Gaeumannomyces Graminis ◽  
Phytopathogenic Fungus ◽  
Gene Encoding ◽  
Sugar Chain ◽  
Hydrolyzing Enzymes ◽  
Hydrolysis Of

The phytopathogenic fungus Stagonospora avenae is able to infect oat leaves despite the presence of avenacoside saponins in the leaf tissue. In response to pathogen attack, avenacosides are converted into 26-desglucoavenacosides (26-DGAs), which possess antifungal activity. These molecules are comprised of a steroidal backbone linked to a branched sugar chain consisting of one α-L-rhamnose and two (avenacoside A) or three (avenacoside B) β-D-glucose residues. Isolates of the fungus that are pathogenic to oats are capable of sequential hydrolysis of the sugar residues from the 26-DGAs. Degradation is initiated by removal of the L-rhamnose, which abolishes antifungal activity. The D-glucose residues are then hydrolyzed by β-glucosidase activity. A comprehensive analysis of saponin-hydrolyzing activities was undertaken, and it was established that S. avenae isolate WAC1293 secretes three enzymes, one α-rhamnosidase and two β-glucosidases, that carry out this hydrolysis. The major β-glucosidase was purified and the gene encoding the enzyme cloned. The protein is similar to saponin-hydrolyzing enzymes produced by three other phytopathogenic fungi, Gaeumannomyces graminis, Septoria lycopersici, and Botrytis cinerea, and is a family 3 β-glucosidase. The gene encoding the β-glucosidase is expressed during infection of oat leaves but is not essential for pathogenicity.

Screening eucalypts for frost tolerance in breeding programs

1992 ◽  
Vol 22 (9) ◽  
pp. 1271-1277 ◽  
Author(s):  
C.A. Raymond ◽  
J.V. Owen ◽  
K.G. Eldridge ◽  
C.E. Harwood
Keyword(s):  
Data Analysis ◽  
Genetic Selection ◽  
Leaf Tissue ◽  
Frost Tolerance ◽  
Leaf Damage ◽  
Alternative Methods ◽  
Small Samples ◽  
Leaf Discs ◽  
Relative Conductivity ◽  
Highly Correlated

Improvements in a laboratory technique and statistical methods for screening eucalypts for relative frost tolerance using small samples of leaf tissue are described. As a contribution to more efficient genetic selection in a breeding program, these methods aim to provide reliable estimates of relative frost tolerance for ranking genotypes and to allow partitioning of total variation into components due to provenances, families, and individuals. Examination of sampling strategies indicated that four leaf discs per seedling at three frosting temperatures and 10 seedlings per family provided highly reliable estimates of frost tolerance. Mean relative conductivity values were found to be highly correlated with mean leaf damage sustained by a seedling across the whole range of values. Alternative methods of data analysis are compared. Estimation of LD50 values (the temperature at which 50% of leaf discs would be killed) and calculation of percent survival of leaf discs were found to be less efficient means of data analysis than directly analysing relative conductivity values. The nature of genetic control of frost tolerance and the assumptions underlying such nondestructive screening techniques are examined.

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