ABSTRACT Remote monitoring of the management of coffee crops is necessary as the demand in decision-making, where the aim is to rise production based on sustainable management is in a constant growth. In this work, it was evaluated the potential of images obtained by low-cost sensors in the discrimination of sources and doses of mineral and organomineral fertilizers in coffee. The experimental design was in randomized blocks, with five blocks and six treatments, as follows: (T1) - 100% of the organomineral treatment; (T2) - 70% of the organomineral treatment; (T3) - 50% of the organomineral treatment; (T4) - 100% of mineral fertilization; (T5) - standard treatment of the farm and (T6) - 70% of mineral fertilization. After management, we used the Mapir 3 Survey3W camera coupled to an ARP drone – Phantom4 to take images of the experiment over a 12-month vegetative period. Combined with image taking, it was collected agronomic parameters of coffee growth and productivity for two crops and concluded that different fertilization doses did not significantly affect the analyzed parameters. Based on the supervised classification of multispectral images, it was possible to discriminate treatments with a higher degree of accuracy (86.66% accuracy) than when analyzing coffee growth parameters.

RESUMO A longa persistência de alguns herbicidas auxínicos depende dos atributos do solo e pode causar intoxicação em cultivos em sucessão. O picloram é um dos principais herbicidas utilizados em pastagens, sendo que o mesmo apresenta período de meia-vida longo no solo. Objetivou-se avaliar, em casa-de-vegetação, as características fisiológicas e morfológicas de plantas de feijão cultivadas em solo contaminado com picloram. O delineamento utilizado foi em blocos ao acaso, sendo os tratamentos compostos pela aplicação de picloram (0 g ha-1; 7,5 g ha-1; 15 g ha-1; 30 g ha-1; 60 g ha-1; e 120 g ha-1 i.a.), com cinco repetições. Urochloa brizantha foi semeada em vasos, avaliando-se a sua altura e matéria fresca e seca da parte aérea. Nos mesmos vasos, semeou-se feijão (Phaseolus vulgaris), como bioindicador do picloram, sendo avaliados a altura das plantas, matéria fresca e seca, fitotoxicidade, área foliar, número de folhas por planta, eficiência fotossintética máxima e taxa relativa de transporte de elétrons. Resíduos de picloram no solo (até 30 g ha-1) são fitorremediados pelo cultivo de U. brizantha por 150 dias. As plantas de feijão apresentam bom potencial como indicador biológico da presença de resíduos de picloram no solo.

ABSTRACT The long lasting residual effect of some auxin herbicides depends on soil characteristics and may cause phytotoxicity on subsequent crops. Picloram is one of the main herbicides used in pastures, presenting a long lasting residual effect in the soil. This study aimed at determining the physiological and morphological characteristics of common bean plants grown in soil contaminated with picloram, under greenhouse conditions. A complete randomized blocks design, with treatments consisting of picloram doses (0 g ha-1, 7.5 g ha-1, 15 g ha-1, 30 g ha-1, 60 g ha-1 and 120 g ha-1 a.i.), with five replications, was used. Urochloa brizantha was sown in pots, and its height and shoot fresh and dry matter were evaluated. In the same pots, Phaseolus vulgaris was sown as a bio-indicator of picloram, and the following characteristics were measured: plant height, fresh and dry matter, phytotoxicity, leaf area, number of leaves per plant, maximum photosynthetic efficiency and relative electron transport rate. The phytoremediation process occurs in soil with picloram residues (up to 30 g ha-1) when covered by U. brizantha for 150 days. The common bean plants show a good potential as biological indicator of the presence of picloram residues in the soil.

O picloram é um herbicida que apresenta elevada persistência no solo, podendo causar danos severos a plantas cultivadas em sucessão e ao meio ambiente. A fitorremediação de áreas contaminadas vem sendo estudada como forma de redução da persistência e impacto ambiental desse herbicida. Este estudo objetivou avaliar a influência do tempo de cultivo de Urochloa brizantha cv. Piatã sobre a fitorremediação de solo contaminado com picloram. O delineamento experimental utilizado foi em blocos casualizados, com cinco repetições, e os tratamentos foram compostos por cinco períodos de cultivo (150, 210, 240, 270 e 300 dias). Concluiu-se que a braquiária atuou de maneira efetiva na fitorremediação dos solos contaminados, sendo que, quanto maior o período de cultivo, maior foi o seu potencial fitorremediador. Observou-se recuperação no aparato fotossintético das plantas bioindicadoras (Phaseolus vulgaris) estudadas, a partir de 240 dias de cultivo da braquiária.

Picloram is an herbicide that presents a high persistence in the soil and may severely harm crops in rotation and the environment. The phytoremediation of contaminated areas has been investigated in order to decrease the persistence and environmental impacts of this herbicide. This study aimed to evaluate the influence of the cultivation period of Urochloa brizantha cv. Piatã on the phytoremediation of soil contaminated with picloram. Arandomized blocks design, with five replications, was used and treatments consisted of five cultivation periods (150, 210, 240, 270 and 300 days). It was concluded that U. brizantha acted effectively in the phytoremediation of contaminated soils, and the higher the cultivation period, higher was its phytoremediation potential. A recovery in the photosynthetic apparatus of the bioindicator plants (Phaseolus vulgaris) studied was observed after 240 days of U. brizantha cultivation.