The coffee leaf miner (CLM) Leucoptera coffeella moth is a major threat to coffee production. Insect damage is related to the feeding behavior of the larvae on the leaf. During the immature life stages, the insect feeds in the mesophyll triggering necrosis and causing loss of photosynthetic capacity, defoliation and significant yield loss to coffee crops. Chemical control is used to support the coffee production chain, though market requirements move toward conscious consumption claiming for more sustainable methods. In this overview, we discuss aspects about the CLM concerning biology, history, geographical distribution, economic impacts, and the most relevant control strategies in progress. Insights to develop an integrated approach for a safer and eco-friendly control of the CLM are discussed here, including bio-extracts, nanotechnology, pheromones, and tolerant cultivars.

In this review of coffee leaf rust (CLR) in Brazil, we report: (i) the historical introduction of CLR in Brazil and the first control measures; (ii) favorable environmental conditions and times of year for the disease; (iii) breeding methods and strategies used for developing CLR-resistant cultivars; (iv) the levels, sources, and types of CLR resistance; (v) the development of Brazilian resistant cultivars; and (vi) chemical and cultural control methods. Most plantations are cultivated with susceptible cultivars, such as those of the Catuaí and Mundo Novo groups. Brazilian research institutes have developed dozens of cultivars with different levels of resistance, and significantly increased the planting of new resistant cultivars. The main sources of CLR resistance are genotypes from Híbrido de Timor, Icatu, BA series carrying the SH3 gene, and Ethiopian wild coffees. High CLR resistance is still observed in Sarchimor and SH3-carrying genotypes. Intermediate CLR resistance is observed in Ethiopian wild coffees and in Sarchimor and Icatu derivatives, where qualitative resistance has been supplanted by races of Hemileia vastatrix. Contact, mesostemic, and systemic fungicides are used for chemical control in Brazil. CLR incidence in Brazil begins to increase after the rainy season onset in November, reaches a peak in June, and remains high until August. Thus, chemical control is typically applied from December to April.

The objective of this work was to analyze coffee (Coffea arabica) genotypes resistant to the coffee leaf miner (Leucoptera coffeella) using microsatellite markers. Sixty-six loci were evaluated, of which 63 were obtained from the Brazilian Coffee Expressed Sequence Tag (EST) database. These loci were amplified in bulks of individuals from F5 progenies of 'Siriema' (C. arabica x C. racemosa) resistant and susceptible to the insect, in eight samples of C. racemosa, and in a F6 population of 'Siriema' with 91 individuals segregating for resistance to the leaf miner. Polymorphisms were verified for two simple sequence repeat (SSR) loci in bulks of the susceptible progenies. The two polymorphic alleles were present in around 70% of the susceptible genotypes in F5 and in approximately 90% of the susceptible individuals in F6. However, the polymorphic EST-SSR markers among populations contrasting for resistance to leaf miner were not correlated to the evaluated characteristics. SSR markers show inter- and intraspecific polymorphism in C. arabica and C. racemosa.

Vegetative propagation of arabica coffee plants selected by their agronomic value has been accomplished, routinely, for scientific purposes, through somatic embryogenesis and rooting of stem cuttings, in Brazil. Somatic embryogenesis is the election method when a very high number of cloned plants is demanded. Nevertheless, the costs of in vitro multiplication make difficult to explore it commercially. The experiments described herein aimed to amplify the number of in vitro cloned plants, post acclimatization, to reduce costs. Different concentrations of an auxin translocation inhibitor and its association with a cytokinin were applied, as successive pulses, in the 3^rd, 8^th and 13^th months after transference to the greenhouse, on the same sets of Catucaí and Siriema in vitro cloned plants,to induce sprouting. At the 8^th month, the experiments with in vitro cloned Catucaí plants were reproduced in the nursery, for comparison. Best results were observed for the association 2,3,5-triiodobenzoic acid (TIBA) 1000 + benzylaminopurine 60 mg.mL^-1 applied in the greenhouse, at the 13^th month, when 8.5 and 7.0 micro-cuttings above 1 cm in length were produced using sprouts taken from each Catucaí and Siriema acclimatized plant, respectively. Applying this treatment twice a year, and harvesting induced sprouts each six months after the induction treatments, approximately 15 plants per each acclimatized one can be produced. The most important effect of TIBA was the induction of sub-apical sprouting. Greenhouse would be the best environment to apply successive pulses of sprouting inducers to coffee in vitro cloned plants.

O objetivo deste trabalho foi avaliar características agronômicas e morfológicas de plantas de Coffea arabica, cultivar Catuaí Vermelho IAC 44, propagadas por embriogênese somática. O experimento foi instalado em janeiro de 2005, em delineamento experimental de blocos ao acaso, com dez repetições. As plantas foram avaliadas mensalmente quanto ao desenvolvimento vegetativo, de junho de 2005 a janeiro de 2006, e as avaliações agronômicas foram realizadas dois anos e meio após o início do experimento. A produtividade de grãos foi avaliada durante as quatro primeiras colheitas. Cafeeiros provenientes de embriogênese somática apresentam desenvolvimento inicial mais rápido do que as plantas obtidas de sementes e, aos 30 meses após plantio no campo, têm diâmetro de copa superior ao de plantas de origem seminal. O desempenho agronômico de plantas de C. arabica produzidas por embriogênese somática é semelhante ao de plantas oriundas de sementes, e não há restrições agronômicas para a sua utilização.