scholarly journals Exploiting Scanning Behavior for Predators Can Reduce Rice Damage Caused by Birds

2015 ◽  
Vol 2015 ◽  
pp. 1-3
Author(s):  
Takeshi Honda
Keyword(s):  
Habitat Quality ◽  
Weed Management ◽  
Rice Fields ◽  
Crop Damage ◽  
Damage Rate ◽  
Low Visibility ◽  
Management Techniques ◽  
Bird Behavior ◽  
Scanning Behavior ◽  
The Relationship

Rice is often damaged by birds, especially sparrows, in Asia. Bird nets are sometimes used as countermeasures; however this approach is expensive and labor intensive. For this reason, farmers generally eschew bird nets, even though no alternative countermeasures are available. This study focused on exploiting the bird behavior of scanning for predators to reduce crop damage. When birds forage for seeds on the ground they often stop pecking and briefly raise their heads, apparently to scan for predators. Low visibility habitats increase scanning behavior and increased scanning behavior reduces habitat quality from the bird’s perspective; therefore, this study tested the relationship between rice damage rate and visibility at the periphery of rice fields, where tree sparrows rest after feeding. Overall, low visibility reduced damage to rice. Because visibility was mainly affected by weeds, weed management techniques contribute to crop damage management. To reduce damage, weeding can be decreased; therefore, this technique is cost- and labor-efficient.

Using a sensitivity analysis of a weed dynamics model to develop sustainable cropping systems. I. Annual interactions between crop management techniques and biophysical field state variables

2012 ◽  
Vol 151 (2) ◽  
pp. 229-245 ◽  
Author(s):  
N. COLBACH ◽  
D. MÉZIÈRE
Keyword(s):  
Weed Management ◽  
Cropping Systems ◽  
Crop Management ◽  
State Variables ◽  
Long Term Effects ◽  
Dynamics Model ◽  
Previous Crop ◽  
Field State ◽  
Management Techniques ◽  
Weed Dynamics

SUMMARYEnvironmental problems mean that herbicide applications must be drastically reduced and optimized. Models that quantify the effects of crop management techniques on weed dynamics are valuable tools for designing weed management strategies. Indeed, the techniques to be optimized are numerous and diverse, and their effects vary considerably with environmental conditions and the state of the weed flora. In the present study, a mechanistic weed dynamics model,AlomySys, was used to carry outin silicoexperiments in order to: (1) rank crop management components according to the resulting decrease in weed infestation, and (2) study the sensitivity of the major component effects to biophysical field state variables in order to identify indicators and thresholds that could serve for future decision-rules for farmers. The various results were compiled into rules for optimizing timing and other options (tillage tools, herbicide types) for the different crop management techniques. The rules were based on a series of biophysical field state variables, i.e. cumulated rainfall, thermal time, soil moisture and weed densities prior to the operation, in the previous and pre-previous crops. For instance, the first tillage should be delayed until the cumulated rainfall since harvest exceeds 50 mm and be carried out in moist conditions. Mouldboard ploughing is advised if the infestation of the previous crop exceeds 20 weeds/m2and particularly if this exceeds 0·3 times that of the pre-previous crop. Ploughing should occur when the cumulated rainfall since harvest reaches 100–200 mm. The effects of crop succession and long-term effects of management techniques have been studied in a companion paper (Colbachet al. 2012).

scholarly journals Preventing crop raiding by the Vulnerable common hippopotamus Hippopotamus amphibius in Guinea-Bissau

Oryx ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Luis M. González ◽  
Francisco G. D. Montoto ◽  
Tome Mereck ◽  
Junior Alves ◽  
José Pereira ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Rice Fields ◽  
Crop Damage ◽  
Running Water ◽  
Rice Farmers ◽  
Guinea Bissau ◽  
Hippopotamus Amphibius ◽  
Electric Fencing ◽  
Effective Deterrent ◽  
The Common

AbstractGuinea-Bissau is host to the westernmost subpopulation of the common hippopotamus Hippopotamus amphibius, which is one of only two known populations inhabiting coastal waters. The presence of hippopotamuses causes conflict with rice farmers as a result of crop damage and the absence of effective measures to protect crops. To develop an effective method for protecting rice fields, we studied the patterns of access to flooded and rain-fed rice fields by hippopotamuses and assessed the effect of the installation of electric fences. Hippopotamuses were detected in 54% of the flooded fields (n = 100) and in 31.9% of the rain-fed fields (n = 91). They were detected more frequently in fields on offshore islands than on the mainland, in unfenced than in fenced fields, and in fields closer to running water. Hippopotamuses entered fenced flooded fields less frequently than unfenced, and were detected most frequently at the end of the rainy season and the start of the dry season, and in the period of vegetative stem growth. Electric fences were an effective deterrent and facilitated increased rice production. The maintenance and cost of the electric fencing were acceptable to farmers, and therefore the use of such fencing is recommended to resolve the conflict between hippopotamuses and farmers in Guinea-Bissau and in other areas with similar conditions.

Weed management practices in glyphosate-tolerant and conventional cotton fields in Australia

2006 ◽  
Vol 46 (9) ◽  
pp. 1177 ◽  
Author(s):  
J. A. Werth ◽  
C. Preston ◽  
G. N. Roberts ◽  
I. N. Taylor
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Herbicide Application ◽  
Resistance Development ◽  
Roundup Ready ◽  
Use Patterns ◽  
Management Techniques ◽  
Cotton Fields ◽  
Herbicide Use

Forty growers in 4 major cotton-growing regions in Australia were surveyed in 2003 to investigate how the adoption of glyphosate-tolerant cotton (Roundup Ready) had influenced herbicide use, weed management techniques, and whether changes to the weed spectrum could be identified. The 10 most common weeds reported on cotton fields were the same in glyphosate-tolerant and conventional fields in this survey. Herbicide use patterns were altered by the adoption of glyphosate-tolerant cotton with up to 6 times more glyphosate usage, but 21% fewer growers applying pre-emergence herbicides in glyphosate-tolerant fields. Other weed control practices such as the use of post-emergence herbicides, inter-row cultivation and hand hoeing were only reduced marginally. However, growers indicated that management practices are likely to change over time, especially with the introduction of enhanced glyphosate tolerance technology (Roundup Ready Flex), and anticipate a 32% decrease in the number of growers using alternative weed management practices. To date, management practices other than glyphosate use have not changed markedly in glyphosate-tolerant cotton indicating a conservative approach by growers adopting this technology and reflecting the narrow window of herbicide application. The range of weed control options still being employed in glyphosate-tolerant cotton would not increase the risk of glyphosate resistance development.

scholarly journals Decision to use herbicide in wheat production by the farm households in Nepal: A probit regression analysis

2020 ◽  
Vol 3 (1) ◽  
pp. 12-19
Author(s):  
Surya P. Adhikari ◽  
Yuga N. Ghimire ◽  
Sanjiv Subedi ◽  
Hema K. Poudel
Keyword(s):  
Weed Management ◽  
Wheat Yield ◽  
Structured Interview ◽  
Probit Regression ◽  
Interview Schedule ◽  
Wheat Production ◽  
Wage Rates ◽  
Management Techniques ◽  
Major Factors ◽  
Significant Factors

The use of herbicides in wheat production is increasing in Nepal mainly due to labor shortage and higher wage rates, even if available. However, little information is available on what factors determine the use of herbicides. This study explored the major factors that affect the decision to use herbicide by the wheat farmers. The semi-structured interview schedule was administered to 343 farmers from four major wheat-growing districts. The study employed a probit regression model to identify the factors that influenced the decision to use herbicides. Educations, membership, migration, wheat cultivated area, amount of urea use were identified as the significant factors influencing the decision of farmers to use herbicides. Herbicides user farmers produced 220 kg more wheat grain yield from one hectare of land compared to non-users. This study suggests that the wheat yield of Nepal could be increased through adopting better weed management techniques.

scholarly journals Prediction of Early Season Beet Leafhopper Populations in Southern New Mexico

2020 ◽  
Vol 21 (1) ◽  
pp. 71-76
Author(s):  
Erik Lehnhoff ◽  
Rebecca Creamer
Keyword(s):  
New Mexico ◽  
Weed Management ◽  
Broad Host Range ◽  
Insect Vector ◽  
Early Season ◽  
Beet Leafhopper ◽  
Beet Curly Top Virus ◽  
Circulifer Tenellus ◽  
Sisymbrium Irio ◽  
The Relationship

Curly top is an important widespread disease in semiarid regions that can be caused by several Curtovirus and Becurtovirus species. The strains of beet curly top virus (BCTV) have been some of the most widely reported to be associated with curly top. The viruses causing curly top are phloem limited and transmitted by the beet leafhopper (BLH), Circulifer tenellus Baker (Hemiptera: Cicadellidae). The BLH can also transmit other important pathogens such as phytoplasmas. Both the virus and insect vector have a broad host range of crops and weeds, including the winter annual weed London rocket (Sisymbrium irio L.). Prior prediction of disease would allow growers a window of opportunity to make informed management choices. A prediction model of BLH abundance was developed for southern New Mexico based on fall precipitation, which corresponds with London rocket emergence, and BLH sticky trap catch data for 2001 to 2018. Regression analyses showed positive associations between BLH numbers and October + November rainfall (P < 0.001) for two areas within southern New Mexico. A third area, where good weed management was used, had lower BLH numbers, and the relationship with precipitation was not significant (P = 0.190). Cumulative-season BLH abundance was correlated with BLH abundance in late April (r = 0.43) and late May (r = 0.56), indicating that early season knowledge of BLH abundance is useful for planning later season management. Although models based on October + November precipitation are good predictors of BLH abundance through June, they may not predict year-long BLH abundance because other environmental and biological factors contribute to subsequent BLH success and movement.

The importance of superior-quality wildlife habitats

2004 ◽  
Vol 80 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Ian D Thompson
Keyword(s):  
Habitat Selection ◽  
Habitat Quality ◽  
Population Level ◽  
Individual Fitness ◽  
Animal Populations ◽  
Cumulative Change ◽  
Few Data ◽  
Managed Landscapes ◽  
The Relationship

While animals may use many habitat types, relatively few are preferred and fewer yet are superior in quality (referring to individual fitness as the measure of quality). Historical reduction in habitat quality for some wildlife species has occurred such that we may now have limited reference to original superior-quality habitats. As time passes, managers may be unaware that superior habitats are slowly disappearing and that the slow but cumulative change is significant to a species at the population level. The perception of superior-quality habitat also changes with each successive generation of managers based on their experiences. This paper raises the concern that retrospective work may often be required to determine past forest habitats and associated animal populations to avoid the risk of falling into a trap of not recognizing ever-declining habitat quality through time and relegating animals to what is in fact much poorer quality habitat than those to which they are actually best adapted. Further, the relationship between relative abundance and habitat quality may often be uncertain owing to maladaptive habitat selection by animals, inappropriate survey timing or interannual population differences. While we have begun to appreciate aspects of habitat selection for many forest species, few data are yet available that relate selected habitats to fitness of individual animals. Hence, while we may have models to predict habitat use, considerable research remains to be done to be able to predict long-term sustainability of species in managed landscapes. Key words: habitat quality, forest management, sustainability, biodiversity

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