The effect of field size and position on mesopic spectral sensitivity

1963 ◽  
Author(s):  
Jo Ann S. Kinney
Keyword(s):  
Spectral Sensitivity ◽  
Field Size

Harvest Field Sizing as a Technique to Remove Undersize French Prunes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 452a-452
Author(s):  
Richard Buchner ◽  
Seeley Mudd ◽  
Bruce Carroll ◽  
Mark Gilles
Keyword(s):  
Sugar Content ◽  
Economic Value ◽  
Market Value ◽  
Dry Weight ◽  
Soluble Solids ◽  
Field Size ◽  
Test Machine ◽  
Test Field ◽  
Marginal Value ◽  
High Sugar Content

Overall profitability is a major goal in successful prune production and a major component in any prune management system. Large prune crops in 1996 and 1997 have stimulated considerable interest in undersize fruit. Undersize prunes currently have marginal value and may represent a net loss because of costs to haul, dry, and to market order payments on low value prunes. One technique to control delivery size is to field size at harvest. Field sizing involves installing size-sorting devices on harvesters, which allow small prunes to fall out while valuable fruit is collected. Field sizing is considered a “risky” strategy because of the potential to remove prunes with economic value. During the 1997 harvest, 21 infield harvest sizing evaluations were made in prune orchards throughout Tehama county. The first evaluation occurred on 12 Aug. 1997, at the start of prune harvest. The final evaluation was done on 5 Sept. 1997, at the tail end of harvest. The objective was to sample throughout the harvest period to test field sizing under various sugar, size, and fruit pressure scenarios. The test machine was 1-inch bar sizer. Of the 21 sample dates, undersize fruit was clearly not marketable in 20 of the 21 samples. Discarded fruit averaged 133 dry count per pound. Only one sample out of 21 may have had market value at 86 dry count per pound. Although small in size, these prunes had very high sugar content contributing to their dry weight. In this evaluation, a 1-inch bar sizer did a good job of separating fruit with and without market value under the 1997 price schedule. As harvest date becomes later and soluble solids increase, the chances of sorting out marketable prunes also increases.

scholarly journals In search of the spectral composition of an effective light trap for the mushroom pest Lycoriella ingenua (Diptera: Sciaridae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sándor Kecskeméti ◽  
András Geösel ◽  
József Fail ◽  
Ádám Egri
Keyword(s):  
Light Intensity ◽  
Spectral Sensitivity ◽  
Fungal Pathogens ◽  
Light Trap ◽  
Spectral Composition ◽  
Wavelength Dependence ◽  
Crop Damage ◽  
Photon Flux ◽  
Compound Eyes ◽  
Behavioural Experiments

AbstractCertain fungus gnats, like Lycoriella ingenua are notorious pests in agriculture, especially in mushroom production. While larvae cause mainly direct crop damage, adults are vectors of several dangerous fungal pathogens. To promote the development of pesticide-free management methods, such as light trapping, we measured the spectral sensitivity of L. ingenua compound eyes with electroretinography and performed two different behavioural experiments to reveal the wavelength dependence of phototaxis in this species. The spectral sensitivity of the compound eyes is bimodal with peaks at 370 nm (UV) and 526 nm (green). Behavioural experiments showed that attraction to light as a function of wavelength depends on light intensity. In our first experiment, where the minimal photon flux (105–109 photons/cm2/s) needed for eliciting a phototactic response was determined wavelength by wavelength, phototaxis was strongest in the green spectral range (~526 nm). In the other behavioural experiment, where wavelength preference was tested under a higher but constant light intensity (~1013 photons/cm2/s), the highest attraction was elicited by UV wavelengths (398 nm). Our results suggest that both UV and green are important spectral regions for L. ingenua thus we recommend to use both UV (~370-398 nm) and green (~526 nm) for trapping these insects.

scholarly journals Detection of the sign of expansion as a function of field size and eccentricity

1996 ◽  
Vol 58 (3) ◽  
pp. 401-408 ◽  
Author(s):  
Susan F. Te Pas ◽  
Astrid M. L. Kappers ◽  
Jan J. Koenderink
Keyword(s):  
Field Size
Sign in / Sign up

Export Citation Format

Share Document