Productivity Archives

2007 California

Salinity and water effects on 'Hass' avocado yields

Authors: Oster, J.; Stottlmyer, D.E.; Arpaia, M.L.

A field experiment was conducted between 1992 and 1997 in a commercial orchard of mature 'Hass' avocados on Mexican seedling rootstock (Persea antericana Mill.) to determine how yield was influenced by the amount of irrigation water applied and the frequency of application. Three amounts of water (targeted at 90%, 110%, and 130% of estimated crop evapotranspiration) were applied at three frequencies (one, twice, and seven times per week) with microsprinklers located beneath the tree canopy. The site was set up as a randomized complete block design with six blocks, each including one replicate of all irrigation treatments. One or two trees located at the center of the replicates were used to measure yields and tree size, and as the locations where samples of soil and soil water were obtained for analysis from beneath the tree canopy. The average electrical conductivity and chloride concentration of the irrigation water, corrected for rain, were 0.7 dS(.)m(-1) and 1.8 mmol(.)L(-1), respectively. From May 1994 to Nov. 1996, salinity of the saturated-paste extracts of soil samples obtained in the 0- to 120-cm depth interval averaged approximate to 2 dS(.)m(-1) for all irrigation treatments. Irrigation treatments also had little influence on the maximum soil-water salinity, approximate to 4 dS(.)m(-1), in and below the lower portion of the root zone. Consequently, irrigation treatments had little influence on the fraction of applied water that was not used by the crop, the leaching fraction. Chloride concentrations in leaves were affected by applied water but did not attain levels that are associated with leaf injury. Trees irrigated seven times per week had lower yields than trees that received less frequent irrigation. During the last 2 years of the experiment, when yields no longer increased with time, the yields for treatments irrigated once and twice per week increased with increasing amounts of applied water. We were able to explain the influence of both amount of applied water and soil salinity on avocado yields and leaching fraction using production function concepts. Yields increased with increasing amounts of applied water because of increased water availability for crop use before a soil-water salinity, of approximate to 4 dS(.)m(-1) restricted water uptake. The threshold salinity above which yield decline occurred was determined to be 0.57 dS(.)m(-1) and yield declined by 65% per unit of salinity above the threshold. Our results suggest that maximum yields of 'Hass' avocado on Mexican seedling rootstock are not achievable when the average annual salinity, of irrigation water, including rainfall, is greater than approximate to 0.6 dS(.)m(-1).

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2018 Ethiopia

Smallholders’ avocado production systems and tree productivity in the southern highlands of Ethiopia

Authors: Biazin, B.; Haileslassie, A.; Zewdie, T.; Mekasha, Y.; Gebremedhin, B.; Fekadu, A.; Shewage, T.

Ethiopia is one of the top five avocado producers in sub-Saharan Africa. Despite increasing recognition for its nutritional value and economic importance, information on smallholder avocado production systems across agro-climatic zones and determinants for tree productivity are literally lacking. Therefore, the objectives of this study were to examine the determinants for avocado tree holdings by smallholder farmers and investigate the effect of avocado production systems and management conditions

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2021 Ecuador

Techinical-economic study in avocado cultivation, Atahualpa Canton, El Oro Province

Authors: Vásquez-Aguilar, R.F.; García-Hevia, S.

Avocado presents a growing demand in the international market, as well as an increase in its price. Currently don't represent the most diversified cultivation in the study area. However, by a growing demand is required study that show its profitability and input to farmers income, those haven't identified the avocado production and marketing as economic alternative The research objective is realize technical-economic study for avocado small production, in El Tambo farm Atahualpa canton, El Oro province.

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