Post-ratoon growth and yield of three hybrid papayas (Carica papaya L.) under mulched and bare-ground conditions

2002 ◽  
Vol 42 (1) ◽  
pp. 71 ◽  
Author(s):  
R. J. Elder ◽  
D. J. Reid ◽  
W. N. B. Macleod ◽  
R. L. Gillespie

At Yarwun (151.3°E, 23.75°S), a trial was conducted to compare 3 papaya hybrids (Hybrid 29, Hybrid 11 and Hybrid 13) under mulching with grass hay or in bare ground. The viability of ratooning a papaya crop was also investigated. After a 16-month cropping season plants were cut to a 750-mm stump (ratooned) about monthly over a 3.5-month period and, following a 4.5-month regrowth period, were harvested for a period of 11 months (post-ratoon). Hybrid 29 yielded (by weight) 54% more than Hybrid 11 and 92% more than Hybrid 13 during the 3.5-month ratooning period. At the commencement of ratooning, Hybrid 29 plants were 41–58 cm shorter than Hybrid 11 and 13 plants, allowing the Hybrid 29 plants to be retained for longer before being ratooned. Hybrid 29 also returned to fruiting more quickly with a greater proportion of plants (97%) with fruit at the first post-ratoon harvest compared with Hybrid 11 (87%). Following regrowth (post-ratoon) the 3 hybrids produced similar yields. All 3 hybrids were equally susceptible to the 3 phytoplasma diseases and to nematodes. The plots mulched with coarse grass hay yielded 70% more during the ratooning period and 116% more post-ratoon than the plots with bare ground. This difference was attributed in part to fewer root-knot nematodes, the roots being more heavily infected with vesicular arbuscular mycorrhiza, the use of the complete upper soil profile by the roots, reduced rainfall run off and less soil loss in the mulched treatment. The highest yielding treatment, mulched Hybrid 29, averaged the equivalent of 55 t/ha.year during ratooning, 43 t/ha.year over the 11-month post-ratoon harvest period and 65 t/ha.year over the entire plant–ratoon cycle. These yields were achieved in spite of drought conditions and quite severe outbreaks of the phytoplasma diseases, dieback, yellow crinkle and mosaic, with 60% of plant positions infected with dieback during the post-ratoon period. Theoretical yield estimations using the data from the plant and post-ratoon crops indicated that ratooning may give superior average monthly yields compared with 2 successive plant crops because of the reduced time required for the ratooned crop to return to production. The study demonstrated the benefits of mulching, the superiority of Hybrid 29 and that ratooning may be successfully used in papaya. In environments similar to Yarwun, Hybrid 29, or similar hybrids, with mulching is recommended for commercial production. If land, time or finances are limiting, consideration should be given to ratooning the plant crop based on monthly cut outs over a 3–4-month ratooning period with vacant plant positions replanted during ratooning.

2000 ◽  
Vol 40 (5) ◽  
pp. 747 ◽  
Author(s):  
R. J. Elder ◽  
W. N. B. Macleod ◽  
D. J. Reid ◽  
R. L. Gillespie

At Yarwun (151.3˚E, 23.75˚S), Australia, papaya Hybrid 29 yielded twice as much fruit as Hybrid 11 and 30% more than Hybrid 13. The plots mulched with coarse grass hay yielded 50% more fruit than the plots with bare ground. The highest yielding treatment, Hybrid 29 + mulch, averaged the equivalent of 81 t/ha.year over the 16.5-month harvest period. The yields were achieved in spite of inadequate water supply due to drought and the loss of 877 plants from 1441 plant positions (4 plants per position) due to the 3 phytoplasma diseases; dieback, yellow crinkle and mosaic. Hybrid 29 produced higher yields than the other hybrids by flowering early on shorter plants with thicker stems and setting more fruit that commenced lower down on the stem. Hybrid 13 was intermediate in size and the amount of fruit setting between Hybrid 29 and Hybrid 11 but was the slowest to flower and set fruit. Hybrid 11 had the thinnest and tallest stems, flowered at an intermediate time between the other 2 hybrids and produced fewer flowers and fruit resulting in the lowest yield. Mulching increased stem height and thickness, promoted earlier flowering and increased fruit set, yield and average fruit weight


2011 ◽  
Vol 162 (3) ◽  
pp. 65-70
Author(s):  
Andreas Zingg ◽  
Hansheinrich Bachofen

Between 1995 and 2008 the granting of the Binding Forest Award led to fresh cooperation between forest owners and research on silviculture, growth and yield at the Swiss Federal Institute for Forest, Snow and Landscape Research. Various topics were treated: a study of the beech coppices in Rothenfluh rapidly made it clear that very little was known about this formerly widespread type of forest management and its consequences. The same was true to a lesser extent for the conversion of rather uniform high forest into selection forest (in Plasselb), and for the selective management of light demanding tree species, such as the oak, in Rheinau. In Boudry, cooperation between practice and research already existed: the prize award here led to new approaches in the production of high quality oak, whilst taking ecological values into account. All these new projects are still in their earliest stages and will call for a great deal of “sustainability”, in both senses of the word, from all those involved. Considering the long periods of time required for the development of forest ecosystems, this is in fact self-evident.


2009 ◽  
Vol 12 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Peter Aglua Gendua ◽  
Yoshinori Yamamoto ◽  
Akira Miyazaki ◽  
Tetsushi Yoshida ◽  
Yulong Wang

1995 ◽  
Vol 75 (1) ◽  
pp. 269-275 ◽  
Author(s):  
S. M. Boyetchko ◽  
J. P. Tewari

The relative susceptibility of selected barley cultivars produced in western Canada to vesicular-arbuscular mycorrhizal (VAM) fungi under field and greenhouse conditions was evaluated in this study. Cultivars tested under field conditions at the University of Alberta and Lacombe research stations showed no significant differences in VAM colonization of barley roots; colonization was light. Greenhouse trials at the University of Alberta with eight cultivars inoculated with individual mycorrhizal species illustrated significant differences among the barley cultivars in their reactions to Glomus dimorphicum, G. intraradices, and G. mosseae. Distinct differences were observed in the ability of each Glomus species to colonize the barley cultivars. The VAM fungi increased growth and yield in some cultivars, depending on the Glomus species. This study indicates that a degree of host-specificity exists in VAM fungi and that the host-mycorrhizal fungus genotypes may influence the effectiveness of the symbiosis. Key words: Barley, cultivars, susceptibility, VA mycorrhizal fungi


2020 ◽  
Vol 57 (2) ◽  
Author(s):  
Nataša Tozon ◽  
Majda Biasizzo ◽  
Leon Ščuka ◽  
Tamara Potočnik ◽  
Marjeta Redek ◽  
...  

A clinical study has been conducted to test the efficacy of Ecocid® S, a biocidal agent. The active substance is potassium peroxysulphate and is used in clinical practice after the mechanical cleaning of various surfaces that act as potential sources of infection transmission. We determined 29 swabbing points, from which 87 samples were collected with cotton swabs. Swabs were submitted for microbiological testing to evaluate microbial contamination before cleaning, and before and after disinfection with Ecocid® S. We submitted 63 swabs from 21 swabbing points for further statistical analysis. Five swabs were excluded because the presence of bacteria in the swabs before disinfection had not been determined. The clinical study on the efficacy of Ecocid® S disinfectant showed that it is effective with an average reduction in contamination of 95.75%. The disinfectant was also active with a significantly reduced time of action: it was removed with dry paper towels from all sampling points, except the floor scales, only 5 to 10 minutes after application. The time required for the proper preparation of examination tables and other equipment in clinical practice is of vital importance for a smooth workflow.Key words: animals; disinfection; potassium peroxysulphate; Ecocid® S ZMANJŠANJE ŠTEVILA BAKTERIJ PO UPORABI RAZKUŽILA ECOCID®S (RAZKUŽILO NA OSNOVI KALIJEVEGA PEROKSISULFATA) V PROSTORIH KLINIKE ZA MALE ŽIVALIPovzetek: S klinično študijo smo želeli ugotoviti učinkovitosti biocidnega razkužila ECOCID®S. Aktivna snov v razkužilu je kalijev peroksisulfat, ki se na klinikah uporablja za razkuževanje različnih površin, ki predstavljajo ključna mesta za prenos okužb, po njihovem mehaničnem čiščenju. Določili smo 29 vzorčnih mest, na katerih smo z uporabo bombažnih brisov odvzeli 87 vzorcev. Z mikrobiološkim testiranjem smo ugotavljali stopnjo kontaminacije pred čiščenjem, ter pred in po razkuževanju z ECOCID®S. Za statistično obdelavo smo uporabili 63 rezultatov z 21 vzorčnih mest. Pet rezultatov je bilo izločenih iz obdelave, ker je bila že pred razkuževanjem stopnja kontaminacije pod mejo detekcije uporabljene metode. S klinično študijo učinkovitosti razkužila Ecocid®S smo ugotovili povprečno 95,75 % zmanjšanje števila kontaminantov po uporabi razkužila. Razkužilo je bilo učinkovito tudi ob skrajšanem času delovanja le 5 do 10 minut po nanosu. Zaradi zagotavljanja tekočega dela na kliniki je izredno pomemben čas, ki je potreben za ustrezno pripravo površin in druge opreme za pregled živali, zato je razkužilo Ecocid® S primerno za uporabo na veterinarskih klinikah, saj hitro in učinkovito zmanjša bakterijsko kontaminacijo.Ključne besede: živali; dezinfekcija; kalijev peroksisulfat; Ecocid® S


1980 ◽  
Vol 58 (20) ◽  
pp. 2200-2205 ◽  
Author(s):  
S. Asimi ◽  
V. Gianinazzi-Pearson ◽  
S. Gianinazzi

Growth and yield increases, obtained in nodulated soybeans growing in unamended sterile soil by inoculation with the vesicular–arbuscular (VA) mycorrhizal fungus Glomus mosseae, were accompanied by improved P uptake, lower root to shoot ratios, better nodulation with higher nitrogenase activity, and modifications in the pattern of the latter during plant growth. Stimulation of nitrogenase activity occurred early in plant development and preceded plant growth responses by about 2 weeks. Phosphate fertilization increased yield, percent P but not percent N of both mycorrhizal and nonmycorrhizal soybeans, and also modified the pattern and amount of nitrogenase activity during plant growth. Additions of 0.25 g KH2PO4/kg to the soil eliminated the mycorrhizal effect on plant growth, but nodule formation and nitrogenase activity were still significantly stimulated by the mycorrhizal infection. Mycorrhizal effects on nodulation were eliminated with 0.5 g KH2PO4 and on nitrogenase activity with the addition of 1.0 g KH2PO4. These higher levels of phosphate fertilization considerably diminished infection and, in particular, fungal spread within the roots.


2006 ◽  
Vol 41 (2) ◽  
pp. 107-119 ◽  
Author(s):  
Lawrence A. Lacey ◽  
David Granatstein ◽  
Steven P. Arthurs ◽  
Heather Headrick ◽  
Robert Fritts

Mulches were compared to test their utility for enhancing efficacy of entomopathogenic nematodes (EPNs) applied against over-wintering codling moth, Cydia pomonella (L.), larvae. Compared with bare ground, mulches may enhance control by providing cocooning sites for codling moth larvae and a substrate that is easy to treat, maintains moisture, and enhances nematode activity. Steinernema carpocapsae (Weiser) or S. feltiae (Filipjev) were applied at a rate of 2.5 × 109 infective juveniles (IJs)/ha against cocooned sentinel codling moth larvae in cardboard strips followed by 2 h of irrigation in plots that were covered with one of four mulches (clover, shredded paper, grass hay or wood chips) or to bare plots on 29 September 2003. Average mortalities of 97 and 98% were observed in paper-mulched plots treated with S. carpocapsae or S. feltiae IJs, respectively, compared to 80 and 76% mortality in bare plots. Larvicidal activity for S. feltiae against sentinel larvae in cardboard strips that were placed in crevices in the soil was nearly identical in all mulched and bare plots (97–100% mortality), but reduced for S. carpocapsae in wood chip and clover plots (76–79% mortality) relative to paper, grass hay and bare plots (93–97% mortality). A significant portion of sentinel larvae (25 and 14%) that were placed in crevices in the soil in hay- and paper-mulched control plots revealed the natural presence of EPNs (Heterorhabditis sp.). Applications of S. carpocapsae and S. feltiae at a reduced rate of 109 IJs/ha on 20 April 2004, followed by 1 h of irrigation resulted in 13.1 and 7.4% reduction in sentinel larvae in bare plots compared to 36 and 62% in mulched plots, respectively. Applications of S. carpocapsae and S. feltiae at a rate of 2.5 × 109 IJs/ha on 21 September 2004 to bare and wood chip-mulched plots followed by 1 h of irrigation resulted in 21 and 65% reduction in sentinel larvae in bare plots compared to 93 and 85% in mulched plots, respectively. Residual larvicidal activity of EPNs 3 d after applications in treated plots was low, but significant in the nonmulched plots (12–17% mortality) relative to untreated controls (1–2% mortality).


2018 ◽  
Vol 17 (05) ◽  
pp. 29-36
Author(s):  
Duong T. T. Pham

Using agricultural wastes to produce organic substrates for organic vegetable cultivation is one of the most eco-friendly practices to reduce environmental pollution caused by these wastes. The objective of this study was to determine the best substrate formulation for growth and yield of Limnophila rugosa under organic-oriented farming. A single factor experiment was laid out in a completely randomized design with seven substrate formulations and three replications. Seven types of substrates were designated based on the composed materials of coconut coir dust, vermicompost, rice husk ash, rice husk, peanut shells. The results showed that the mixed substrates of 10% vermicompost + 60% coconut coir dust + 30% peanut shells led to optimum crop performance and highest yield. Particularly at the third harvesting time, Limnophila rugosa performed the highest number of branches (24.3 branches/plant), branch length (14.9 cm/branch), number of pairs of leaves (5.7 pairs of leaves/branch), leaf chlorophyll content (40.3 SPAD value), plant fresh weight (70.6 g/plant), total theoretical yield (7,133.6 kg/1,000 m2), total absolute yield (5,487.3 kg/1,000 m2) and total commercial yield (4,891.8 kg/1,000m2).


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