Agronomy and Crop Sciences Commons^™

The Effects Of Planting Density On The Dry Matter Yield And The Overwintering Ability Of The Dwarf And Normal Napiergrasses In Two Years After Planting, Yasuyuki Ishii, M. M. Mukhtar, Sayan Tudsri

IGC Proceedings (1977-2023)

The objective of this study is to determine the optimum planting density in napiergrass (Pennisetum purpureum Schumach) among two dwarf varieties introduced from Thailand and two normal ones under three levels of density. Dwarf varieties showed lower plant height and mean tiller weight, and higher leaf area index (LAI) and leaf blade percentage. Crop growth rate was positively correlated with LAI, and net assimilation rate and canopy extinction coefficient (K) were negatively correlated with LAI in the second year, including all dwarf and normal varieties, while K tended to be lower in the dwarf varieties. With the increase in …

Light Interception And Dry Matter Yield In Grass/Legume Mixtures, H. A. Jönsson

IGC Proceedings (1977-2023)

The influence of grass variety on light interception and dry matter yield in a grass/clover mixture was studied. Two varieties of timothy (Phleum pratense L.) and five varieties of ryegrass (Lolium spp) as components in a mixture were compared during the spring period up to the first cut of the third harvest year. By replacing the timothy variety in the mixture both light interception and dry matter yield were significantly affected. The leaf orientation was thought to be a contributing factor with erect leaves intercepting less light. There were no significant differences neither in light interception nor …

Photosynthetic Light Response Of Tanzania Grass Under Four Levels Of Leaf Temperature, A. C. L. De Mello, P. M. Santos, Carlos G. S. Pedreira, M. Corsi, C. T. Dos S. Dias

IGC Proceedings (1977-2023)

The purpose of this paper is to establish photosynthetic light response curves for Tanzania grass (Panicum maximum Jacq.) under four leaf temperature levels. Photosynthetic rate was measured as a response to levels of photosynthetic photon flux density (PPFD) on the youngest fully expanded leaves of 12 representative tillers with an infra red gas analyzer. The effect of PPFD was tested for each leaf temperature level in a randomized complete block design. Photosynthetic light response curves were adjusted for each leaf temperature using a non-linear hyperbolic model. The maximum photosynthetic response was 25,59; 31,43; 34,57 and 27,53 µmol CO_{2 …}

Nonstructural Carbohydrate Reserves Of Temperate Perennial Grasses In Autumn Early Growth, Y. Tamura, K. Matoba, A. Fushimi, M. Moriyama

IGC Proceedings (1977-2023)

The objective of this study was to determine levels of nonstructural carbohydrate reserves of four temperate perennial grasses: Orchardgrass (Dactylis glomerata L.), Timothy (Phleum pratense L.), Perennial ryegrass (Lolium perenne L.), and Reed canarygrass (Phalaris arundinacea L.) in their early growth stages during the cool autumn temperatures in northern Japan. At the time of sampling, all grasses were in their vegetative stage, and Reed canarygrass was not forming rhizomes. Fructosan concentration in reed canarygrass roots (8.04%) was 22 times that of the leaf blade (0.36%) and twice that of the stem (3.40%); the concentration in reed …

Effect Of Cutting Height On Tiller Population Density And Herbage Biomass Of Buffel Grass, L. S. Beltrán, P. J. Pérez, G. A. Hernández, M. E. García, S. J. Kohashi, H. J. G. Herrera

IGC Proceedings (1977-2023)

The aim of this trial was to investigate the effect of different cutting heights on tiller population density and herbage biomass of Buffel grass (Cenchrus ciliaris L) grown in miniature swards in a greenhouse. Four treatments with five replicates: five cm, ten cm, and 20 cm cutting height, and control (without cut) were randomly allocated. Intensity of defoliation affected the cumulative herbage harvested; the ten cm cutting height was greater (404.1 g DM m^-2) than 5 cm (317.6 g DM m^-2) and 20 cm (263.9 g DM m^-2), respectively. Cumulative herbage harvested in …

Leaf Appearance Rate In Brachiaria Decumbens Grown In Nitrogen And Potassium Rates, M. D. C. Ferragine, F. A. Monteiro, S. C. Da Silva

IGC Proceedings (1977-2023)

A greenhouse experiment was carried out with Brachiaria decumbens Stapf. cv. Basilisk grown in nutrient solution. Five nitrogen rates (42; 140; 238; 336 and 434 mg/L) and three potassium rates (78; 234 and 390 mg/L) were studied in a factorial experiment, in a randomized complete block design, with four replications. Green leaf number was evaluated in six times in the first period of growth (27, 30, 33, 36, 39 and 42 days after transplanting) and nine times in the second period (45, 48, 51, 54, 57, 60, 63, 66 and 69 days after transplanting). Data was registered in three plants …

Morphogenesis And Defoliation Frequency Of Italian Ryegrass (Lolium Multiflorum) And Paspalum Urvillei In Lowland Under Three Levels Of P And K, Fernando L. F. De Quadros, A. G. S. Pigatto, D. G. Bandinelli, E. Marchezan, Marta G. Da Rocha

IGC Proceedings (1977-2023)

This trial was conducted to evaluate growth dynamics and defoliation frequency of Italian ryegrass (Lolium multiflorum) and Paspalum urvillei in a lowland area under three levels of P and K. Using randomization tests we observed that, in a general way, fertilizer treatments were not the determinant factors of leaf appearance and elongation rates for both species. Only the leaf appearance rate of Paspalum urvillei at 100 % of recommendation level and the elongation rate for Italian ryegrass, in the same treatment, was different. Probably other factors, like drainage, are contributing to these results. I. ryegrass phyllochron ranged from …

Variability In Herbage Mass And Chemical Composition Within A Timothy Sward, O. Niemeläinen, E. Miettinen, P. Virkajärvi, L. Alakukku, K. Hakala

IGC Proceedings (1977-2023)

Variability in herbage mass (HM) and chemical composition of timothy (Phleum pratense L.) sward was studied in a three-hectare field. The field, which was flat, was divided into twelve sections and a sampling site was randomly selected in each. The study was carried out in Sotkamo (64^o 01’N, 28^o22’E) research station in Finland. Snow depth and frost conditions were measured in winter and soil water content was monitored in the growing season at each sampling site. Observations on the crop included assessment of herbage ground cover and winter damage percentage, stand height and HM and analysis …

Effects Of Temperature, Nitrogen Fertilisation And Leaf And Tiller Age On Specific Leaf Area Of Brachiaria Decumbens, J. Busqué, M. Herrero

IGC Proceedings (1977-2023)

Signal grass (Brachiaria decumbens Stapf) micro-swards were grown under controlled environmental conditions at different temperatures and nitrogen fertilisation rates. Specific leaf area was responsive both to temperature and nitrogen, but did not change with the level of insertion of the leaf in the tiller. Senescing leaves had higher specific leaf area than old extended green leaves and these had higher values than new extended green leaves. Changes in specific leaf area were more related to changes in leaf area and more exactly to changes in leaf width.

The Use Of Cover Crops After A Maize Crop In The North Of Spain, D. Báez, M. Pinto, M. Rodríguez, G. Besga, J. M. Estavillo

IGC Proceedings (1977-2023)

This work intends to study N leaching losses in a field assay when crimson clover (Trifolium incarnatum) and italian ryegrass (Lolium multiflorum) was incorporated into the soil and quantify the their effect on N₂O, N total gaseous losses under controlled soil moisture and temperature conditions. Field assay: A split-plot design where main plot was the cover crop and the subplot was the rate of fertilizer (0 and 150 kg N ha^-1) applied to the subsequent maize crop. Laboratory assay: Residues of italian ryegrass and crimson clover were mixed with soil in containers, …

Multi-Year Application Of Dairy Slurry On Grassland: Effects On Crop, Soil Biota, Soil Nutrients, And N2O Emission, Shabtai Bittman, C. G. Kowalenko, D. E. Hunt, N. Patni, J. Paul, D. Raworth, J. Hountin, T. A. Forge, C. M. Monreal, O. Schmidt

IGC Proceedings (1977-2023)

The long-term effects of using manure as the principal nutrient source in intensive crop production systems are not well known. This paper reports on the effects of multi-year application of fertilizer or dairy slurry on a tall fescue (Festuca arundinacea Schreb.) sward. Slurry sustained greater grass yield than chemical fertilizer. Unlike fertilizer, slurry supplied 70 to 120 kg N/ha one year after application but little after one year; 4-years of manure applications built up the stable organic matter pool in the soil. Manure-N was less prone to leaching but more prone to N₂O emissions than fertilizer-N. Manured …

Sewage Sludge As An Alternative Fertilizer For Tropical Pasture Grasses, M. B. Adjei, J. E. Rechcigl

IGC Proceedings (1977-2023)

This study was conducted to determine the effects of source (Liquid sludge at pH 7 (LS7) or pH 11 (LS11), cake biosolid (CB) or ammonium nitrate (AM)) by rate (0, 80 or 160 kg ha^-1) of N application on bahiagrass forage yield, quality and tissue composition. Same plots were fertilized in March 1998 and 1999. Forage yield was measured at 30 d intervals from May through November and subsamples were dried and ground for quality analyses. The 2-year mean forage yield was similar for AM, LS7 and LS 11 fertilizer applications. Forage yield from CB application was 30% …

Phosphorus Fertilizer And Stocking Rate Effects On Soil Microbial Biomass Of A Long-Term Dairy Farmlet Experiment, S. R. Aarons, C. R. O’Connor, C. J. P. Gourley

IGC Proceedings (1977-2023)

The effects of a range of P fertilizer rates and dairy cow stocking rates on microbial biomass carbon and phosphorus were compared in a long-term farmlet trial in southeastern Australia. Pastures were stocked at 2, 3, or 4 cows/ha and received fertilizer at rates of 0, 35, 70 or 140 kgP/ha. There was no effect of either P fertilizer rate or stocking rate on microbial biomass C from 1995 to 1998. Increasing P application rate significantly increased the chloroform-released microbial P flush measured, but stocking rate had no effect on microbial P. There were significant temporal changes, with the seasonal …

Dry Matter Accumulation And Partitioning Between Vegetative And Reproductive Organs In Alfalfa (Medicago Sativa L.), E. D. Bolaños-Aguilar, Christian Huyghe, B. Julier, C. Ecalle

IGC Proceedings (1977-2023)

This work investigated the partitioning of dry matter between vegetative and reproductive plant organs in alfalfa during the reproductive period under field conditions. Two French varieties (Europe and Magali) were studied. Both varieties showed similar growth pattern of the different plant organs in 1998 and 1999. The mean dry matter of vegetative organs (shoots and leaves) over the two years was higher in Europe (567g/m²) than Magali (470g/m²). No vegetative growth was observed during the reproductive period. The root organs (measured to a depth of 0.20 m) and the reproductive organs showed an increase in dry …

Herbage Seed Production Possibilities In Finland, O. Niemeläinen, M. Kinnari

IGC Proceedings (1977-2023)

In the seed production variety experiments in Finland from 1977 to 1992 the mean seed yield of timothy (Phleum pratense) cultivar Alma was 717 kg ha^-1, of meadow fescue (Festuca pratensis) cv. Boris 622 kg ha^-1, of tall fescue (Festuca arundinacea) cv. Retu 350 kg ha^-1, of perennial ryegrass (Lolium perenne) cv. Riikka, of cocksfoot (Dactylis glomerata) cv. Haka 295 kg ha^-1, and red clover (Trifolium pratense) cv. Hankkijan Venla 403 kg ha^-1. From 1988 to 1998 annual …

Efficacy Study Of Selected Maize (Zea Mays L.) Genotypes Against The Asian Corn Borer, Ostrinia Furnacalis (Guenée), Yoryncita Marfori, Merdelyn Caasi-Lit, Tonette Laude

The Philippine Agricultural Scientist

Laboratory and screen house studies were conducted to assess the efficacy of selected twenty-six maize varieties against Asian corn borer (ACB), Ostrinia furnacalis (Guenée). Hierarchical tree based on resistance parameters clearly revealed that the twenty-six maize varieties are best classified into three groups, viz. resistant, intermediate, and susceptible. In laboratory test, the varieties RCS2, RCS4, RCS5, 'IPB Var13', Bt2, Bt3, and Bt4 were consistently identified as highly resistant. Further examinations in stalk feeding assay showed that the resistant varieties had sharp decline in larval survival (LS) on the 2^nd to the 5^th day of larval feeding in …

Effect Of Fungicide Application On Seed Yield Of Perennial Ryegrass, Piotr Goliński

IGC Proceedings (1977-2023)

In four plot experiments established according to random blocks, application effectiveness of propiconazol + carbendazim (Tilt), propiconazol + fenpropimorph (Archer), flusilazol + carbendazim (Alert) and epoxiconazol + crezoxim-metil (Juwel) pesticides regarding the infection by fungal diseases of plant inflorescence structure, biological floret site utilisation, thousand seed weight and harvested seed yield of perennial ryegrass cv. Anna (2n) and cv. Maja (4n) was analysed. The Archer preparation was found to be the most effective, both in the case of Anna and Maja cultivars. Its application was found to increase seed yield in Anna and Maja cultivars by, respectively, 21,5% and 14,5%. …

Genetic Control Of Parthenogenesis In Kentucky Bluegrass: Results From A Sexual X Apomictic Cross, E. Albertini, G. Barcaccia, A. Porceddu, D. Rosellini, Mario Falcinelli

IGC Proceedings (1977-2023)

Apomixis, as it exists in Poa pratensis L., permits to combine genotype fixation with propagation by seed. The process of apomictic seed production involves the formation of embryo sacs without meiotic reduction (apospory) and embryos without egg cell fertilization (parthenogenesis). Further information on the genetic control of apomixis was obtained by analyzing aposporous parthenogenesis and the segregation of molecular markers in a progeny resulting from a “sexual” (S) x “apomictic”(A) cross. Data from the 35 F₁ plants examined so far have shown that parthenogenesis segregated 1:1, confirming control by a dominant gene, simplex in the parthenogenetic parent. Analysis of …

Effects Of Water Stress On Seed Production In Ruzi Grass (Brachiaria Ruziziensis Germain And Everard), N. Wongsuwan, A. C. P. Chu, B. R. Watkin

IGC Proceedings (1977-2023)

Water stress at different stages of reproductive development influenced seed yield in Ruzi grass differently. Under mild water stress, the earlier in the reproductive developmental stage the stress was applied (before ear emergence) the faster the plants recovered and the less the ultimate damage to inflorescence structure and seed set compared with the situation where water stress occurred during the later stages after inflorescences had emerged. Conversely, severe water stress before ear emergence had a severe effect in damaging both inflorescence numbers and seed quality. Permanent damage to the reproductive structures resulted in deformed inflorescences. Moreover, basal vegetative tillers were …

Effect Of Temperature On Phenology In Triple-Awned Grass (Stipagrostis Plumosa), Hossein Azarnivand, H. Dastmalchi

IGC Proceedings (1977-2023)

Phenology of triple-awned grass in different stages of vegetative growth, flowering and seed falling was investigated. Each phenological stage was related to minimum and maximum air and soil surface temperatures. Soil surface temperature was measured two times per day during different seasons. Climate data were obtained from the nearest weather station. The study was carried out in sand dunes of band-e-rig of Kashan in the central region of Iran. This species is important in terms of wind erosion control and livestock feeding in arid areas. The results showed that air temperatures ranged from –22 ^oC to 41.5 ^oC …

Morphogenesis And Growth Analysis Of Mombaçagrass (Panicum Maximum) During Establishment And Regrowth, Carlos A. M. Gomide, J. A. Gomide, C. A. M. Huaman

IGC Proceedings (1977-2023)

Mombaçagrass grown in pots was evaluated regarding leaf appearance, elongation and senescence rates; leaf area indices, photosynthetcly active radiation (PAR) interception and the growth indices: leaf area ratio (LAR), net assimilation rate (NAR) and relative growth rate (RGR). Three growths were considered: seminal growth and regrowth after harvest take on the 16^th and 37^th day of the seminal growth.

The seminal growth exhibited the highest values for leaf appearance, elongation and senescence rates as compared to aftermath growths. LAI rose linearly from the 20^th to the 77^th day of the seminal growth, as well as during …

Tillering Dynamics In Mombaça Grass (Panicum Maximum, Jacq.) Under Grazing, E. M. Coelho, V. R. Herling, M. A. Gomes, R. J. Schmidt, C. G. Lima

IGC Proceedings (1977-2023)

An experiment was conducted in Pirassununga, Southeastern Brazil, to observe tillering pattern of Mombaça grass (Panicum maximum Jacq.) after grazing. A complete randomized block design was used with treatments arranged in factorial (3 herbage allowances X 2 grazing periods). There was high and positive correlations between the total tiller population and the number of tillers until the third week after grazing, giving evidence of a higher tillering until the second week and a slight reduction on the third one. The Mombaça grass tillering dynamics alters along the weeks according the allowance level adopted.

Response Of Mombaça Grass (Panicum Maximum Jacq.) To Nitrogen Doses And Clipping Frequency, Gustavo J. Braga, P. H. C. Luz, V. R. Herling, R. J. Schmidt, C. G. Lima

IGC Proceedings (1977-2023)

The present experiment had the objectives of determining the response of Mombaça grass (Panicum maximun Jacq.) to three levels of nitrogen fertilizer (0, 250, 500 kg/ha) and two clipping frequencies (28 and 42 days). Dry matter yield (DMY), density and the average weight of tillers and the mean stage count (MSC), value that represents the quantity of the plant phenological development were evaluated. Nitrogen levels affected DMY, with the 500 kg/ha of N resulting in highest yield, and highest MSC as well. The number of tillers responded positively until the 250 kg/ha level. The 42-day frequency gave higher numbers …

Herbage Allowance And Nitrogen Fertilization Effects On Morphological Characteristics Of Paspalum Notatum Flügge, P. Boggiano, G. E. Maraschin, Carlos Nabinger, J. Riboldi, Mónica Cadenazzi

IGC Proceedings (1977-2023)

The grazing study was conducted at the Estação Experimental Agronomica – UFRGS, 30^o S, on a native pasture, to evaluate the leaf area index and structural morphological traits of bahiagrass (Paspalum notatum Fl.), within the requirements of a Central Composite Rotatable experimental design, providing for equal precision, with two blocks, encompassing two factors at five levels each, namely: Herbage Allowance (HA) = 4.0; 5.5; 9.0; 12.5 and 14.0 kg green dry matter per 100 kg liveweight per day (% LW), in association with Nitrogen (N) fertilization levels of 0; 30; 100; 170 and 200 kg ha^-1 as …

Influence Of Fertilization On Botanical Composition And Productivity Of Rangeland In A Semi-Arid Climate Of South Africa, Hennie A. Snyman, I. B. Oosthuizen

IGC Proceedings (1977-2023)

The objective of this study was to determine the short-term response of rangeland to fertilization rangeland (all combinations of 0; 10; 30 and 50 kg ha^-1 nitrogen, with 0 and 10 kg ha^-1 of phosphorus) in terms of dry matter production and botanical composition. After three years of fertilization, the botanical composition of the high-N fertilized plots changed completely from a climax to sub-climax vegetation. Wire grass (Elionurus muticus) showed the greatest decrease in frequency (62%) due to N fertilization. Phosphorus fertilization had an insignificant influence on species composition over the three years. The increase (P< 0.01) in production with increased N fertilizer, peaked in the second season, declining afterwards. With N and P fertilizer applied together, the production increased constantly and peaked in the last season. After three years the production increased (P≤ 0.01) with the application of N together with P, compared to the applying of only N. The higher the amount of fertilizer, the more sensitive to drought the climax grasses became. The results confirm the vulnerability of native grasses in dry areas, due to change in soil fertility.

Defoliation And Water Deficit: Their Influence On Pasture Growth And Water Use Of White Clover, F. H. Santiñaque

IGC Proceedings (1977-2023)

With the objective of understanding the physiological basis of defoliation and water use relationships of white clover (Trifolium repens L.) pastures during water deficits, an experiment in controlled conditions was carried out. Outdoors nine liters pots were filled with a loam-clay soil with a water content at field capacity (FC), of 35%(w/w), at a bulk density of 1.1 g/cm³. Pre-germinated and inoculated clover seeds were transplanted, and the number of plants was adjusted to permit the development of full plant cover. The level of P in the soil did not limit plant establishment or growth. The …

Seasonal Botanical Composition And Available Forage Of Natural Grasslands In The Southeastern Range Region Of Rio Grande Do Sul, Brazil, J. C. L. Reis, H. Alfaya, O. J. W. Siqueira, C. B. Farias Jr.

IGC Proceedings (1977-2023)

The objective of the study was to verify the influence of climatic seasons on botanical composition and on available dry matter of grasslands in the physiographic region known as Serra do Sudeste (Southeastern Range), RS, Brazil. The climate is Cfb according to Koëppen`s classification. The experiment was conducted in two natural grasslands submitted to two pre-experimental stocking rates [area 1: 0.65 AU ha^-1 (normal grazing); area 2: over 2.0 AU ha^-1 (overgrazing); AU: Animal Unit = 500kg live weight]. Stocking rates throughout the experimental period (June 1996–July 1997) were 0.4 and 0.65 AU ha^-1, over winter …

Effect Of Sowing Time On Phytomass Production During Early Growth Of Two Varieties Of Stylosanthes Guianensis (Aubl.) Sw., M. L.S. Paterniani, T. J. D. Rodrigues, G. T. Pereira, L. R. A. Rodrigues

IGC Proceedings (1977-2023)

The objective of this research was to determine the effect of two sowing times on phytomass production of two varieties of Stylosanthes guianensis (var. pauciflora and var. vulgaris). Two experimental periods were studied (1: January - May/1998 and 2: November/1998 - March/1999) using a completely randomized factorial design 2 x 2 x 14 (two periods, two varieties and fourteen ages of evaluation), with four replications. The results showed a difference between the periods concerning the growth and development of Stylosanthes, and that period 2 was the most favourable to this forage plant. There was, also, different adaptability between …

Influence Of Water Stress On Protein Concentration In Themeda Triandra Forsk. In A Semi-Arid Climate Of South Africa, I. B. Oosthuizen, Hennie A. Snyman

IGC Proceedings (1977-2023)

The objective of this study was to determine the influence of four water treatments (T1 = 75-100%, T2 = 50-75%, T3 = 25-50% and T4 = 0-25% of Field Water Capacity) on the concentration of water-soluble protein as growth reserve during three growth stages (vegetative, pipe and reproductive) in three plant parts (roots, stubble and leafs). The water-soluble protein concentration (WSPC) in the plants under the four water treatments differed (P≤0.01) among the plant parts as well as among growth stages (P≤0.05). WSPC in leafs increased (P≤0.01) with increased water stress from T1 to T4 for the pipe growth stage. …

Effects Of Photoperiod, Low Temperature And N Nutrition On Vsp Accumulation In Taproot Of Alfalfa, J. C. Avice, C. Noquet, A. Ourry, J. J. Volenec

IGC Proceedings (1977-2023)

In Medicago sativa L., vegetative storage protein (VSP), specifically accumulated in taproot, are strongly involved in nitrogen storage. How the accumulation of such VSPs is regulated remains largely unknown. Experiments were designed with non-nodulated alfalfa to determine if length of the photoperiod, a decrease of temperature, or high availability of mineral nitrogen may induce the accumulation of VSPs. ¹⁵N labelling was used to quantify nitrogen uptake and its further relative translocation within the plant while VSPs accumulation was analysed by ELISA quantification. Results showed that environmental factors such as shortening daylength or low temperature changed biomass allocation within the …