Hybrid pennisetum in a warm temperate climate: productivity span and effects of nitrogen fertilizer and irrigation on summer production and survival

1977 ◽  
Vol 17 (89) ◽  
pp. 982 ◽  
Author(s):  
DK Muldoon ◽  
CJ Pearson

Changes in dry matter yield and its components and plant survival were examined in hybrid pennisetum under different rates of nitrogen fertilization on irrigated and dryland areas throughout two growing seasons. The productivity of first, second and third year stands was studied. Production was markedly seasonal; almost half of the maximum annual yield of 11.4 t ha-1 came from six weeks regrowth in mid-summer. Summer production was restricted by drought and in 1975-76 by low temperatures and radiation. There was interaction between environmental conditions and responses to N. When conditions were favourable the dry weight and leaf area responses were linear. Under moisture stress, or low temperatures and radiation, plants responded only to intermediate levels of N because of suppressed leaf and tiller production. Protein concentration increased with N. Protein and digestibility were adequate for animal production except in mid-summer, when rapid plant development under irrigation and high N resulted in digestibility values of less than 60 per cent. Survival was high except when plants were cut just prior to winter, i.e. in April, or high rates of N fertilizer were applied. Production increased in the second year because of tiller multiplication; individual tiller weights decreased. Productivity was maintained into the third year.

1977 ◽  
Vol 17 (85) ◽  
pp. 284 ◽  
Author(s):  
CJ Pearson ◽  
DTW Anthony

Productivity of vegetatively propagated hybrid pennisetum (Pennisetum americanum x P. purpureum) was assessed throughout summer in two years at densities of 1,4 and 9 plants m-2 at two time of defoliation schedules under natural rainfall and with spray irrigation. In the establishment year the highest summer yield was 10 t ha-1 and in the second year 18 t ha-1. In both years yields did not increase above 4 plants m-2 under natural rainfall and did not differ more than 20 per cent according to the defoliation schedule or irrigation treatment. The regrowth after defoliation, perennation and attainment of higheryielding sward in the second season suggest hybrid pennisetum is more suited to certain multiple forage cropping systems than are annual tropical grasses, e.g. pearl millet, sorghum and corn.


Aerobiologia ◽  
2018 ◽  
Vol 35 (1) ◽  
pp. 57-71 ◽  
Author(s):  
I. Kasprzyk ◽  
T. Wójcik ◽  
P. Cariñanos ◽  
K. Borycka ◽  
A. Ćwik

1994 ◽  
Vol 72 (3) ◽  
pp. 378-383 ◽  
Author(s):  
Clinton F. Hodges ◽  
Douglas A. Campbell

Pathogenicity of several isolates of Pythium species to the adventitious roots of Agrostis palustris was evaluated at high (35:24, light:dark) and low (24:13 °C, light:dark) temperature regimes. Isolates of P. graminicola–arrhenomanes, P. rostratum, P. torulosum, P. vanterpoolii, and one unclassified species were evaluated. All isolates of all species infected roots. Some isolates of P. graminicola–arrhenomanes (PGA-5), P. torulosum (PT-1, PT-2, PT-3, PT-5), P. vanterpoolii (PV-1), and an unclassified species (UP-1) infected roots and decreased dry weight at both the high and low temperature regimes. Other isolates of P. graminicola–arrhenomanes (PGA-1, PGA-2, PGA-4, PGA-6, PGA-7) and P. torulosum (PT-4) infected roots and decreased dry weight only at the high temperatures. Isolate PGA-7 of P. graminicola–arrhenomanes also stimulated plant growth at low temperatures. The remaining isolates of P. graminicola–arrhenomanes (PGA-3), P. rostratum (PR-1), and P. vanterpoolii (PV-2) infected roots and decreased dry weight only at the low temperatures. Infection of roots was limited to root hairs, root tips, and epidermal and cortical tissues. The observations are discussed relative to the function of Pythium species as minor root pathogens and their potential function in disease complexes. Key words: disease complexes, infection, minor pathogens, pathogenesis, pathogenicity, Pythium arrhenomanes, P. graminicola, P. graminicola–arrhenomanes, P. rostratum, P. torulosum, P. vanterpoolii.


2012 ◽  
Vol 4 (11) ◽  
Author(s):  
Ali Hafeez Malik ◽  
Allan Andersson ◽  
Ramune Kuktaite ◽  
Muhammad Yaqub Mujahid ◽  
Bismillah Khan ◽  
...  

2006 ◽  
Vol 36 (2) ◽  
pp. 397-403
Author(s):  
Amauri Bogo ◽  
Ricardo Trezi Casa ◽  
Luis Sangoi ◽  
Paulo Tarcísio Domatos Borba

The relationship between pre-flowering climatic conditions and sugary disease incidence was quantified in grain and forage sorghum genotypes at two sowing periods (mid November and mid December). The trials were carried out over the 2001/02 and 2002/03 growing seasons, in Lages, Santa Catarina State. Four commercial male-fertile sorghum hybrids (BR 600-forrage, BR 700-grain, BR 701-forage/silage and BR 800-forage) and one male-sterile inbred line (BR 001-A) were evaluated. When each genotype reached the flowering stage, 50 panicles were marked and sprayed with a suspension of Claviceps africana (1,000 spores mL-1). Air temperature, humidity and rainfall were recorded through out the growing cycle. Low temperatures three to four weeks prior to flowering, increased susceptibility. At both sowing periods, average night temperatures lower than 15°C during the critical period of pre-flowering turned the fertile hybrids as susceptible as the male-sterile inbred to ergot infection. The tested hybrids differed in their ability to tolerate pre-flowering cold stress. Seed set in uninoculated heads under pollination bags was also reduced, suggesting that increased susceptibility to sugary disease was the result of low temperature induced sterility.


2015 ◽  
Vol 50 (1) ◽  
pp. 1-12
Author(s):  
Deepak Banjade ◽  
Kabir Sharma ◽  
Khum N. Paudayal

The Thimi Formation is fluvio-deltaic deposit that constitutes the uppermost part of the sedimentary sequence in the Kathmandu Basin, and is featured by carbonaceous and diatomaceous clay, silty clay, silt, fine to medium grained sand beds, and thin to medium lignite beds. The Phaidhoka Section is located on the way to Nala from Chyamasingh, and is one of the major exposures of the Thimi Formation. Forty four samples were collected from 25 m thick surface exposure for palynological study. The study revealed the dominance of gymnosperm over the angiosperm and herbaceous members. The pollen diagram suggested Pinus, Picea and Quercus as the most dominant trees whereas Poaceae is other dominant among the grasses. Three major pollen assemblage zones were marked in the Thimi Formation. Zone P-I indicated warm temperate climate, whereas zone P-II and P-III indicated cold temperate climate. Molluscan operculum in the upper part indicated shallow water condition. The Bovid molars, limb and pelvic bones from the middle part of the section confirm the early findings of molar bones in this area.


1996 ◽  
Vol 121 (1) ◽  
pp. 115-122 ◽  
Author(s):  
K.I. Theron ◽  
G. Jacobs

Large Nerine bowdenii bulbs (>14 cm in circumference) were exposed to low ligbt intensities for different periods during two successive growing seasons. The flowering percentage and number of florets in the current season's inflorescence were recorded at anthesis. Small and large bulbs were subjected to continual defoliation starting at different times during the growing season. Bulbs were dissected at planting (26 Sept. 1992) and on 12 Jan. 1993 (nondefoliated control bulbs) to determine growth and developmental stage. At anthesis, inflorescences were harvested and the florets per inflorescence were counted. After anthesis in the fall, all bulbs were dissected and the following variables recorded: 1) percentage flowering, quiescence, or abortion of the current season's inflorescence; 2) developmental stage of quiescent inflorescences; 3) number of florets in the outermost inflorescence; 4) developmental stage of the innermost inflorescence; 5) number of leaves or leaf bases in each growth unit; 6) number of daughter bulbs; and 7) dry weight of new leaf bases. There were three reasons for nonflowering of the bulbs, viz., failure to initiate an inflorescence, inflorescences remaining quiescent, and inflorescence abortion. Individual florets that had not reached stage “Late G” (gynoecium elongated, carpels fused) at the start of rapid inflorescence elongation aborted. The more florets that aborted, the greater the probability that the entire inflorescence aborted. The inflorescence was more vulnerable to stress during the first half of the growing season due to its relatively weak position in the hierarchy of sinks within the bulb.


2018 ◽  
Vol 42 (4) ◽  
pp. 484-505 ◽  
Author(s):  
Elisa Di Giuseppe ◽  
Simona Sabbatini ◽  
Nikita Cozzolino ◽  
Pierluigi Stipa ◽  
Marco D’Orazio

A remarkable advantage of clay tiles roof coverings in hot climates is the realization of a ventilated air layer between them and the roofing underlay that allows a natural and forced convection through the tiles joints and the channel from eaves to ridge, thus cooling the roof materials. However recently, in many countries, regulatory developments on buildings energy efficiency or buildings sustainability certification protocols are increasingly encouraging the use of alternative strategies, with the aim of reducing the urban heat island (UHI) effect and the buildings’ cooling consumptions. Among them, the use of ‘cool’ materials for roof covering. These mandatory or voluntary measures de facto push the construction products market towards specific directions, risking penalizing traditional components such as clay tiles. This article reports the results of experimental and numerical activities carried out in order to extensively characterize the optical properties of clay tile materials and investigate their impact, also coupled with above sheathing ventilation, on the thermal performance of a ventilated roof under warm-temperate climate. In the first phase of the research, the main optical properties of over 30 different clay products have been experimentally characterized in order to get a clear and extensive picture of such properties for the materials spread in the market. In a second phase, starting from the thermal data collected on an experimental real-scale building, a dynamic energy analysis tool was calibrated and used to perform simulations by varying the optical properties of the roof covering thus assessing the impact on the roof temperatures, also in comparison to a clay tiles roof. The results underline that the use of the above sheathing ventilation obtained through clay tiles is an effective strategy to reduce roof temperatures, even if covering materials are not qualified as ‘cool’, thus impacting on both UHI and indoor comfort.


1963 ◽  
Vol 41 (1) ◽  
pp. 2409-2421 ◽  
Author(s):  
Nobuo Aoki ◽  
Charles R. Harmison ◽  
Walter H. Seegers

A procedure is described for retaining bovine plasma Ac-globulin activity as one part of the protein from plasma for every 1000 parts removed. The yields averaged 15%. The procedure involves removal of prothrombin with barium carbonate, isoelectric fractionation, fractionation with ammonium sulphate, chromatography on Amberlite IRC-50, and a second fractionation with ammonium sulphate. The procedure requires 2 days; however, the first day completes up to chromatography and the concentrate at that time is quite useful for many purposes. It is more stable than the product obtained after chromatography and the yields are higher. In absence of salts Ac-globulin is quite insoluble at pH 5.0. The final product usually contained some impurity. With the analytical ultra-centrifuge the S20in 0.1 M potassium chloride solution was found to be 4.2 at a protein concentration of 12.4 mg/ml. The specific activity was 1500 U./mg dry weight. Bovine plasma contains 120 U./ml or about 9 mg/100 ml. Assuming the same specific activity for human plasma the concentration is most likely near 1 mg/100 ml. The best stability conditions found were: 50% glycerol, pH 7.0, and 0.1 M calcium chloride. Under those conditions at room temperature all activity was retained 6 to 7 hours, at refrigerator temperature 24 hours, and at −60 °C for 1 month. In rabbits, antibodies were readily produced. Oxidizing agents destroyed the activity, while reducing agents did not, nor did they tend to stabilize. SH blocking agents destroyed the activity. The loss of activity in the presence of 0.0025 M parachloromercuribenzoate was recovered with 0.04 M cysteine. The molecule deteriorated while attempts were made to obtain physical chemical data; consequently, the molecular weight was calculated from an amino acid analysis and found to be 98,800. The reliability of this value is problematical. Human plasma was analyzed and found to contain 13 U./ml Ac-globulin. After 4 days storage, at room temperature, the prolonged prothrombin time of that plasma was completely restored with 13 units of Ac-globulin, which is equivalent to 8 μg.


2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 642-644
Author(s):  
G. Kaup ◽  
K. Janowicz ◽  
K. Paruch

The studies were carried out in a greenhouse of the Agricultural University of Szczecin, during two growing seasons. The aim of this study was determine the effect of the product obtained from radiational SO<sub>2</sub> and NO<sub>x</sub> removal from combustion gases on the populations of Globodera rostochiensis nematodes — one of the most common quarantine organisms. The analysis of the effect of the applied product on the population of nematodes demonstrated their varied character of response. In the combination with the product of radiational purification of combustion gases, also significantly lower population density (number of eggs and larvae in 1 g of soil) and lower fecundity of Globodera rostochiensis females were observed compared to the control combination. And in the second year of the experiment, the number of cysts in the combination with the product of SO<sub>2</sub> and NO<sub>x</sub> removal from combustion gases was significantly lower compared to the control, and was less than half of the quantity of the previous year.


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