A simple irrigation scheduling approach for pecans

Samani, Zohrab; Bawazir, Salim; Skaggs, Rhonda K.; Longworth, John W.; Piñon, Aldo; Tran, Vien

doi:10.1016/j.agwat.2010.11.002

Cited by 25 publications

(13 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These K c-ref values gave extremely poor predictions of K c (R 2 =0.002) (Figure 1a) and therefore ET (R 2 =0.71 and MAPD=43%) (Figure 1c), with underestimations at the start and end of the season and overestimations in the middle of the season. However, when K c-ref values were adjusted for the local climate with GDD, as suggested by Samani et al (2011), using a simple polynomial function developed by Sammis et al (2004), a much better estimate of monthly ET totals was obtained (R 2 =0.74 and MAPD=8%) for the mature pecan orchard (Figure 1d). This improvement was particularly evident towards the end of the season, as the season in New Mexico ends with a sudden killing freeze, resulting in rapid leaf drop.…”

Section: Resultsmentioning

confidence: 99%

“…Initial modelling exercises to predict pecan ET from the mature orchard at Cullinan using the model of Samani et al (2011) and K c-ref values for New Mexico, offset by 6 months for southern hemisphere seasons, did not prove to be very successful. These K c-ref values gave extremely poor predictions of K c (R 2 =0.002) (Figure 1a) and therefore ET (R 2 =0.71 and MAPD=43%) (Figure 1c), with underestimations at the start and end of the season and overestimations in the middle of the season.…”

Section: Resultsmentioning

confidence: 99%

“…Evapotranspiration was estimated using a pecan specific model from New Mexico (Samani et al, 2011) which relates crop coefficients and orchard water use to canopy cover as follows: (Table 1). These values were offset by 6 months to account for seasons in the southern hemisphere.…”

Section: Single Crop Coefficient Modelling Approach To Estimate Watermentioning

confidence: 99%

“…However, due to their limited input requirements they are often more easily adopted by farmers. The FAO-56 model (Allen et al, 1998) and the pecan monthly water use simulator (Samani et al, 2011) are two such models, in which crop ET is calculated from meteorological data and single crop coefficients (K c ).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Are simple empirical crop coefficient approaches for determining pecan water use readily transferrable across a wide range of conditions?

Taylor¹,

Annandale²,

Ibraimo³

et al. 2017

Acta Hortic.

View full text Add to dashboard Cite

The accurate estimation of evapotranspiration (ET) of orchard crops is critical for judicious irrigation water management and planning. However, it is impossible to measure ET under all possible combinations of climate and management practices, which necessitates the use of ET models. Although empirical models are more likely to be adopted by consultants and growers, due to easier parameterization and the requirements for fewer, more easily measured input parameters, they may not always be transferable across a wide range of conditions. As a result these models may not always give acceptably accurate ET values outside of the area in which they were calibrated. This study therefore aimed to evaluate empirical crop coefficient models for pecans in two different orchards which differ in climate and/or fractional canopy cover from where the models were developed. When testing the FAO-56 approach it was found that pecans should not be grouped under stone fruit and that a six stage crop growth should be considered, instead of the traditional four stage curve. Improved accuracy in estimating ET of pecans could, however, be achieved by using a pecan specific reference crop coefficients for a mature orchard and scaling this with fractional canopy cover for different orchards, provided that an adjustment was made for the influence of climate on canopy development. This was achieved by using a published growing degree (GDD) day crop coefficient relationship, provided seasonal accumulated thermal time is below 1600 GDD and that crop coefficients do not exceed 1.1.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Single Crop Coefficient Modelling Approach To Estimate Watermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Are simple empirical crop coefficient approaches for determining pecan water use readily transferrable across a wide range of conditions?

Taylor¹,

Annandale²,

Ibraimo³

et al. 2017

Acta Hortic.

View full text Add to dashboard Cite

show abstract

“…Even though remote sensing is still a developing science, significant advances have been made in this field, and a more detailed coverage and updated literature in the book could provide valuable information for water management professionals. While describing crop coefficients, the authors omitted pecans, a major agricultural crop in the southern and southwestern United States and Mexico. In recent years, significant advances in measuring and estimating pecan ET and Kc have been reported (Samani et al, 2011). Also, some inconsistencies were noted the in Kc tables.…”

mentioning

confidence: 99%