Morocco has always been considered a major and strategic producer of fruits and vegetables, delivering earlier harvests than southern Spain and achieving very good prices in the European market. When this country entered the avocado market, many predicted an early harvest concentrated in October and November, given the rapid dry matter intake due to the intense summer and warm autumn. However, this did not happen. While Moroccan producers were initially satisfied with prices of €1-1.5/kg, they gradually discovered that by developing a longer storage capacity, they not only increased the size of the fruit but also its price. Currently, the vast majority of Moroccan producers are harvesting in January and February, fetching high prices, and a few are venturing into March due to the low supply of Hass avocados in Europe at that time.

Currently, the area under cultivation is estimated at around 10,000 hectares, but with a low average production rate considering the favorable conditions this country offers for Hass avocado production. As it is a young and developing industry, it is normal to make mistakes, which will surely be corrected in the short term once a production protocol adapted to the country's specific circumstances is established. Learning takes time, but there is already enough experience to begin implementing the following changes:

- Nursery Management: This is generally the source of many problems that later manifest in the field. All avocado industries have started with poor nursery management, which later improves. The extreme heat and high relative humidity in summer necessitate the urgent replacement of the Zutano rootstock with West Indian rootstocks, as these are better adapted to heat waves and high salinity in irrigation water. Changing the genetics will increase stress tolerance during the summer, and the plants will be better able to withstand the wood-decay fungus complex that currently affects most Moroccan plantations. It is important to train nursery workers to identify plants that develop multiple roots and ultimately fail in the field because they develop a weak root system prone to root strangulation. Furthermore, it is essential to improve the collection of scions in the field and apply fungicides to the scion-rootstock union to sanitize the graft and prevent wood-decay fungus at an early stage.

- Physiology of Stress: It's important to understand that the plant is not what you see; it's underground, and the foliage is merely a reflection or expression of the plant. Given that the root system is the foundation of the tree, stress management should focus primarily on the avocado's shallow root system. Often, management practices are implemented during the summer to reduce stress, but they are ineffective because avocado leaves have very low absorption rates, and the products don't penetrate or translocate within the plant. Photo-oxidation is becoming increasingly severe and unavoidable, and the hot, dry winds from the Sahara cause significant fruit abortion and defoliation. The first step is to implement mulching from the planting site using organic materials that help maintain a more stable soil temperature, conserve water, and promote healthy soil. Work with three drip irrigation lines, placing two on the warm side facing the afternoon sun and only one on the cooler side, which experiences less stress. Avoid over-irrigation, as many areas have a high water table, requiring short, frequent irrigation cycles to prevent contact with deeper soil moisture. Wetting the area around the roots during heat waves is a well-established practice for greenhouse tomatoes, table grapes, pears, etc., with excellent results in lowering the temperature of the surface roots, subsequently improving fruit size. Separate irrigation lines to increase the wetting area, as roots tend to seek warmer temperatures and oxygen towards the periphery. Develop biofertilizer blends that improve stomatal regulation to maintain water movement within the plant, increasing tissue cooling. Increase carbon content in the soil profile and then study the endemic soil microbiology to enhance immunity and stress tolerance. Reduce the application of saline fertilizers, as the water has medium to high salinity.

Foliage Management: This is the main factor in achieving high, stable production with good fruit size. Increased stress causes the tissue to age faster, requiring accelerated renewal of fruit-bearing canes. Currently, the vast majority of mature orchards are overgrown and lack a clear understanding of pruning practices for the Moroccan context. Multi-axis rotation trials and foliage cleaning have been very successful in Morocco in rapidly restoring juvenile fruit, increasing tolerance to heat waves and salinity in the irrigation zone. While orchards in terra alpine areas tend to drop external fruit, the more protected internal fruit set shows less abortion, necessitating urgent tree opening to promote flower induction within the foliage.

Floral Nutrition: Avocados generally have an extended flowering period that progresses over time. In Morocco, avocados experience a single flowering period that begins in March with cooler temperatures and continues throughout April, culminating in physiological fruit drop in early May. As orchards extend southward, this flowering period is earlier and shorter, but throughout the Moroccan avocado-growing region, it is necessary to protect and stimulate flowering with complete Floral Nutrition. With flat, tractor-accessible orchards, it is easy to develop a spraying program to ensure fruit set during the first, second, and third flowering periods. Initially, low temperatures can stress the first embryos, causing significant abortion in the first flowering stage. Then, during the second flowering period, climatic conditions improve, and finally, during the third flowering period, high temperatures begin, leading to embryo death. Avocado panicles have very thin tissue that is sensitive to dehydration, but they also readily absorb foliar applications, which have proven highly effective in other countries for supporting fruit set. Currently, a program of 3 foliar applications is being proposed to cover all floral stages, seeking to strengthen embryo development under high stress conditions.

- Pollinators: Evaluate new pollinators to complement the Bacon and Zutano varieties, which currently flower very early, losing synchrony with Hass. Harvesting any variety early stimulates earlier flowering, and vice versa, requiring a delay in the harvest of pollinating varieties in this country.

Today, there is significant interest in developing new projects in Morocco, a country with a strong agricultural tradition, close proximity to the European market, and a harvest concentrated within a very attractive commercial window. The cold and rainy winters slow vegetative growth, allowing the plant to complete oil formation in the fruit at a more leisurely pace, resulting in excellent internal quality. Furthermore, Moroccan producers are not obligated to harvest the fruit prematurely, as the autumn-winter climate allows for storage, enabling them to manage the harvest carefully, aiming for larger fruit sizes and better prices.

Gonzalo Vargas

gvargascarranza@gmail.com