What is the most cost-effective management strategy for foliage-feeding lepidopterans in Alabama soybeans?

2016 ◽  
Author(s):  
Tim Reed
2013 ◽  
Vol 61 (7) ◽  
pp. 552 ◽  
Author(s):  
James C. Noble ◽  
Peter J. Diggle

We examined data obtained from two experiments running concurrently over an 8-year period, designed to investigate the survival of mallee eucalypts exposed to various decapitation treatments applied by either fire or axe at contrasting frequencies. Annual autumn decapitation, with or without combined spring decapitation, gave the most rapid rates of depletion. The estimated half-life, i.e. time to 50% mortality, ranged from 278 days when both autumn and spring fires were applied annually, up to 3366 days when plants were cut by axe every fourth autumn. These were followed in turn by autumn decapitation every second year, then spring annually and autumn every third year and finally autumn decapitation imposed every fourth year. With the marginal exception of one treatment (burnt every third autumn), the estimated rates of depletion were greater for the burning treatments than for their cutting counterparts. The ranking of the six treatments by estimated rates of depletion was the same in both the fire and cutting trials. Prescribed fire is a powerful and cost-effective management tool for manipulating semiarid woodlands in temperate Australia. In addition to reducing grass and litter fuel, prescribed fire has the potential to promote herbage production for domestic livestock. We provide clear evidence based on field experiments that a management strategy based on relatively frequent fires applied in the autumn will significantly reduce mallee density, thereby promoting herbage productivity.


Plant Disease ◽  
2005 ◽  
Vol 89 (10) ◽  
pp. 1114-1120 ◽  
Author(s):  
Sarah J. Pethybridge ◽  
Frank S. Hay ◽  
Calum R. Wilson ◽  
Tim Groom

The efficacy of a range of fungicides were assessed under in vitro conditions in four field trials over three seasons for the management of ray blight of pyrethrum, caused by the fungus Phoma ligulicola in Tasmania. Fungicides belonging to the demethylation inhibitor group, including prochloraz, tebuconazole, difenoconazole, and cyproconazole, produced the most significant reduction in mycelial growth in vitro compared with unamended controls. Significant reductions in germination of conidia resulted from low concentrations of azoxystrobin. In the field, azox-ystrobin (as Amistar) at a rate of 300 g of product/ha significantly decreased disease intensity and increased pyrethrin yield (kg/ha) in all seasons. Applications of either azoxystrobin or difenoconazole (as Score) at a rate of 250 ml of product/ha in early spring were the most effective, whereas no significant benefit was demonstrated from applications in autumn. Over all seasons, azoxystrobin applications resulted in double the weight of flowers produced compared with nontreated areas, whereas increases in pyrethrin content within the flowers were season and location specific. Application of azoxystrobin and chlorothalonil (as Bravo 720) at a rate of 1.4 liters of product/ha resulted in a 45 to 48% increase in flowers, reduced defoliation, and increased stem diameter. The weight of individual flowers and flower maturity was not significantly affected by fungicide application. These data provide the basis for cost-effective management of this disease.


2013 ◽  
Vol 206 (4) ◽  
pp. 472-477 ◽  
Author(s):  
Lawrence E. Tabone ◽  
Molly Conlon ◽  
Emil Fernando ◽  
Sophia Yi ◽  
Sharfi Sarker ◽  
...  

1998 ◽  
Vol 37 (3) ◽  
pp. 241-247 ◽  
Author(s):  
Peter Gerdes ◽  
Sabine Kunst

The bioavailability of phosphorus from different sources has been evaluated in the catchment area of the River Ilmenau (Lower-Saxony, Germany) by using algal assays. The P bioavailability describes the different potential of P from various sources of supporting eutrophication. Effluents from sewage treatment plants were highly bioavailable (72% of TP) whereas rainwater (26%) and erosion effluents (30%) showed a low bioavailability. In order to develop effective strategies to minimize P inputs into the river, source specific P bioavailability indices were determined and combined with a P balance to calculate inputs of vioavailable P (BAP) instead of total P (TP). It could be shown that the relative importance of the different P sources changes when applying BAP. Measures to reduce P inputs into the River Ilmenau will take P bioavailability into consideration and therefore lead to a more cost-effective management.


1984 ◽  
Vol 1 (2) ◽  
pp. 21-23 ◽  
Author(s):  
David A. Gansner ◽  
Owen W. Herrick

Abstract People who have to make decisions about cost-effective management for gypsy moth need help in predicting and evaluating its effects. Field plot data collected during recent outbreaks in Pennsylvania are being used to develop guides for predicting forest stand losses to the pest Presented here are some of the more useful products of that effort to date. Easy-to-measure data for forest characteristics such as species composition and crown condition can be collected and applied in models that estimate potential stand and tree mortality and changes in timber value. North. J. Appl. For. 2:21-23, June 1984.


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