Avocados in the desert - Carlini brothers' farm Fundo Horno Alto, 130 Km (80 miles) north-east of Lima.
Most people would assume that Perú, being so close to the equator (latitude 4°-18° S along the coast), would be a tropical rainforest. However, due to conditions created by the cold Humboldt Current, the entire 2400 Km (1440 miles) of coastal Perú receives almost no rainfall, usually less than 19 mm (0.75 inch) per year. The coastal terrain is flat to hilly wastelands almost completely void of vegetation except where irrigation water is applied or along flowing rivers and oases. Within this desert a new and promising Hass avocado industry is emerging
Avocados are not new to Perú. It is thought that avocado was introduced to Perú around 1450 following an Inca conquest of the Palta Indians of southern Ecuador. As in many other South American countries, avocado is called "palta" in Perú. Native varieties, oily black skinned selections of the Mexican race are referred to as "Topa Topa" and are found in the higher elevations where rainfall abounds and in irrigated areas along the coast. The jungles of the eastern Andes have tropical varieties similar in form and color to the familiar greenskin varieties similar to theWest Indian race.
The Hass variety is planted in Perú for export purposes; although in the recent past it was planted as a backyard variety. In 1993 there were only 30 commercial hectares (75 acres) in Perú. This year, 2003, there are 2200 hectares (5500 acres). Approximately 600 hectares (1520 acres) are older than 5 years and the remaining are younger with 20% nonbearing. The Peruvian avocado industry is organized under the umbrella of ProHass with the goal to advance the local avocado industry and the marketing of quality Peruvian Hass avocados. More information about ProHass and the industry is provided at the web site http://www.prohass.com.pe.
Perú is blessed with some of the best growing conditions for avocado anywhere on earth. Growing in many locations is almost hydroponic with environmental stresses such as freezes, high temperatures and low relative humidity nonexistent. Dothiorella canker Dothiorella gregaria, verticillium wilt Verticillium albo-atrum, root rot Phytophthora cinnamomi Sun Blotch Viroid (ASBvd) and Potato Spindle Tuber Viroid (PSTvd) are all present but this far are of no economic significance in well managed groves. There are some pests which could become widespread. These Oligonychus punicae (brown mite), Aelothrips aemorroidalis (thrips), Aleurotrachelus sp. (white fly) and Oiketicus kirbyi .Three major genera of fruit flies are present. Mediterranean Ceratitis capitata, several species of Anastrepha sp. and Neosilva pendula. The temperatures in most locations are about 30°C (86°F) high and 16°C (60°F) low in the summer and 22°C (71.6°F) high and 10°C (50°F) low in the winter. Soil temperatures remain constant throughout the year at 15°C (59°F). Relative humidity is usually high in the morning (about 70%) dips to 45% in mid day, rises again to 70-80% in the late afternoon and may reach up to100% at night. Rainfall is minimal, averaging between 12.7 to 19.1 mm (0.5 to 0.75 inch) per year.
Avocado growing areas in coastal Perú are mostly located within riverbeds and their flood zone. Elevation is a major significant factor on deciding on where to plant as temperatures increase with elevation. Groves are best planted from 300 - 1000 m ASL (990 - 3300 ft). Good soils are neutral to alkaline with soil Ec (electric conductivity) ranging from 1-2 mmhos. Some soils are much more saline but are well managed by heavy leaching with good quality water. Once the salts are removed and without rain water pushing salts into the root zone, trees seem to do very well. Most of the rivers flow underground and only some manifest themselves with above ground flow. Most water in these valleys is accessed through shallow wells, 5 - 80 m deep (16 - 264 ft), that deliver very high quality water, with an Ec of 0.4 - 0.7 mmhos (Colorado River water ranges from 0.9 - 1.1 mmhos). Output rates of these river-wells often exceed 100 liters per second (1580 gallons per minute), and are usually limited by well and pump size and not by underground availability. Wells outside the river basins tend to have higher salinity water and may not flow as abundantly. Many localities benefit from canals that deliver water from irrigation projects and reservoirs constructed by the government. Canal water cost about $0.025 per cubic meter (264 gallons or $36.27 per acre-foot) while well water costs more since electricity and diesel are expensive.
In all groves, meteorological data are carefully collected by the growers and are readily available from the grove computer. Fertilizer and irrigation plans are also computerized and data tabulated. The growers keep amazing amount of data such as evapotranspiration, humidity, temperature of air and soil, tensiometer readings and more. At least in some groves the growers have large rhizotrons, glass plates placed vertically in a pit alongside the tree, to observe and measure root growth. In one grove, and likely in others, the grower has an under the canopy net which serves to count fruit drop throughout the season. Growers use an evaporation pan to measure the evaporative demand and use crop coefficients to decide how much water to apply. Groves are irrigated anywhere from twice a day to twice a week, depending on the soil and the type of emitter used. Leaf analyses are performed by either Peruvian or foreign Laboratories between February and April. Fertilizer is applied proportionally and in small quantities throughout most of the year (Fertigation) although some growers hand fertilize. All growers apply different types of foliar fertilizers including zinc although zinc has been shown not to translocate by Kadman in Israel and by Crowley in California. Given the absence of rain, there is a low incidence of fruit rots associated with moisture. The technical part of grove management is provided mainly by consultants either from Chile or Israel and some Peruvian agronomists with varying degrees of success; Perú's growing conditions are dissimilar to both Chile and Israel and cultural practices need to be developed for this unique growing environment.
Before planting a grove the terrain is usually sub-soiled and an irrigation system using drip or microsprinklers is installed. The Hass is mostly grafted on local Topa Topa seedlings with good results. In recent years, Israeli consultants have introduced West Indian seedling rootstocks from Avraham Ben Ya'acov's selections in Israel. Improved tree performance and yield has not yet been recorded from these rootstocks. It is possible that these rootstocks may not produce superior results under Peruvian conditions. Although Zutano is abundant as a pollinizer variety, Peruvian growers have not used this variety as a seedling rootstock. Given the optimal growing conditions and inexpensive labor, cloning trees may become established in Perú with the potential of finding superior local selections to serve as rootstock and scion material.
Trees are planted at a 4x6 m spacing (13x20 ft) while some newer groves are being planted at even greater densities such as 4x3 m (13x10 ft). Since most of the trees are young, the management of these higher densities is yet to be defined. All growers practice some sort of pruning for tree canopy management, but lack of timely follow-up is evident. Between the end of harvest and next season's bloom there are two months where pruning can be performed without harming the current year's crop, an option normally not available to Hass growers in more temperate zones like California and Chile. A significant advantage of having the fruit removed before bloom is the ability to apply plant growth regulators (PGRs) such as Sunny and Cultar during bloom without the possibility of contaminating current season fruit. The three main pollinizer varieties used are Zutano, Fuerte and Bacon with some growers experimenting with Edranol, Ettinger and Nabal. Five to eleven percent of the planting is planted with pollinizers either as interplants among the Hass trees or in individual rows. Most growers prefer the Zutano variety since its bloom better coincides with the Hass bloom, although microclimates appear to play a role in pollinizer efficacy. Bees are introduced into groves at 2-4 hives per hectare (1-2 per acre). This is a low number when compared to bee hive density in Chile, 10-12 per hectare (4-5 per acre). Since it does not rain in these regions there is no competing vegetation to distract honeybees from the avocado bloom other than what is cultivated in the vicinity. There are native insects that visit the avocado and may well be sufficient to pollinate the trees without the need for additional honeybees. One can establish in Perú the ultimate pollination trial, possibly without netting, in a truly isolated grove of 100% Hass with no pollinizers and learn if Hass can produce good crops without pollinizers and without a vector.
The Hass variety performs well in Perú. Production is early and by year 3 under 4x6 m density, production can range from 5-10 tons per hectare (4,250 - 8,500 lbs per acre) and even higher. By year 4-5, under good management, volume can increase to over 17 tons per hectare (over 15,500 lbs per acre). With new high density plantings and improved management techniques these production levels are likely to increase substantially.
Trees flower mostly between September and November with peak bloom in mid October. During the late January 2003visit, there were some trees in bloom which, given the favorable growing conditions, are likely to produce off bloom fruit. Because of the warm weather these off bloom avocados are pear shaped and large, unlike the familiar round off bloom fruit in California, Chile and upper elevations in Michoacán. Many of the flowering panicles had male/female flower overlap relatively early in the day with the pollen not yet exposed. This is different than in California because male flowers early in the morning are usually flowers that have opened the previous afternoon and remained open overnight. Most trees of all varieties appear to have noticeable number of cukes (parthenocarpic fruit), which is thought to be associated with poor/inadequate conditions for normal fruit development, incomplete pollination, some irregularities in the ovule or the result of GA3 application. There was no explanation given for this phenomenon which was evident everywhere. Two to three vegetative flushes occur between November and May and root growth is almost continuous, given the favorable soil temperatures and lack of excessive rain. There are fruit drop periods similar to the June, July, August drops experienced in California. It takes 6-7 months after fruitset for the fruit to reach maturity.
The fruit is harvested for export during May - August with peak harvest during June and July. Harvest begins in May, when dry matter reaches 24.5%. The cost of harvest is extremely low in comparison to California; about 1 cent per Kg (0.45 cent per lb) with minimal wage between $5.00 and $7.50 per day.
The Peruvian Hass is considered to be of very high quality, with good internal and external color. Fruit size peaks at 220-280 grams which is the range for 48's and 40's. Postharvest diseases are almost none existence probably due to the absence of rainfall. The fruit is transported to well equipped packinghouses that are set up to meet the strict requirements of the European market. Exports in 1999: 450 MT (Metric tons), 2000: 2100 MT, 2001:2,700 MT, 2002: 4,300 MT (999,000; 4,620,000; 5,940,000; 9,460,000 lbs, respectively). Since the fruit is transported to Europe, a month's journey, transportation to the market is the most costly part of the enterprise. A CA (controlled atmosphere) container carrying 4500 4-Kg (8.8 lbs) cartons costs about $6000. Container harbors are found along the entire coast of Perú and transportation is readily available.
Peruvian Hass is not likely to enter the USA in the near future due to the existence of the Mediterranean fruit fly in Perú. Just like other countries such as South Africa, Argentina, Israel, Spain and Australia, Perú is looking forward to the day when a protocol is established by USDA-APHIS that will permit the entry of Peruvian Hass into the mainland USA. Neighboring Chile could become a market for the Peruvian Hass particularly since Chile already imports avocados from Argentina using a methyl bromide/cold treatment protocol established by APHIS. The per capita consumption of avocados in Perú is negligible and with 24 million habitants, there is a potential consumer base that must be developed to absorb oversupply and the 15-20% non exportable fruit.
The interaction with Peruvian growers was refreshing; one can feel the excitement and enthusiasm and willingness to learn and improve. The statement from ProHass web site "At ProHass we understand that the best way to achieve long-lasting business relationships is by providing excellent quality products and service consistently" spells out the positive approach this market driven industry has taken to position itself as a supplier of high quality Hass avocados to the world's markets.
The author would like to thank Zarem Adinaguyev, Klaus Bederski, Enrique Camet and Bruno Carlini for reviewing the article.
Further Reading
Zinc: Crowley, David E., W. Smith and B. Faber. 1991. Zinc Nutrition
of Avocado. California Avocado Society 1991 Yearbook. 78:155-165.
www.avocadosource.com/cas_yearbooks/cas_78_1994/cas_1994_155.htm
Rootstocks: Ben-Ya'acov, A. and M. Zilberstaine. 1999. Clonal avocado
(Persea americana Mill.) rootstocks in Israel. Revista Chapingo Serie
Horticultura 5: 39-42.
www.avocadosource.com/wac4/wac4_p039.htm.
Pollinizers: Gardiazabal, F. J. and S. Gandolfo. 1995. A study of
self-pollination and cross-pollination in avocado (Persea Americana
Mill.) cv. Hass of different varieties. Proceedings of The World Avocado
Congress III. Pages 52-56.
www.avocadosource.com/WAC3/WAC3_p052.htm
Parthenocarpic fruit: Zamet D.N. 1996. On Avocado Fruit Size I.
Parthenocarpic Fruit. California Avocado Society 1996 Yearbook. 80:133-149.
www.avocadosource.com/CAS_Yearbooks/CAS_80_1996/CAS_1996_133.htm