ABSTRACT Safflower crops is usually intended for production of seeds to oil extraction. The objective of this work was to evaluate the chlorophyll index, biometric characteristics and water use efficiency of safflower plants grown under different nitrogen and potassium rates and controlled soil water tension. The experiment was conducted in a greenhouse, in pots containing 8 dm3 of a Oxisol. A complete randomized block experimental design in a 5x5 factorial arrangement was used, with four replications, consisting of five nitrogen rates (0, 60, 120, 180 and 240 mg dm-3) and five potassium rates (0, 50, 100, 150 and 200 mg dm-3). The safflower number of leaves, stem diameter, chlorophyll index, number of capitula, shoot, root and total dry weights, water consumption and water use efficiency were evaluated. Data were subjected to analysis of variance (F test) at 5% of probability and to polynomial regression. The nitrogen and potassium fertilization, as independent factors, affected the safflower plants. The chlorophyll index, biometric characteristics and water use efficiency of safflower showed better responses under nitrogen rates of 82 to 168 mg dm-3. The responses of chlorophyll index, biometric characteristics and water use efficiency of safflower increased 10 to 60% with potassium fertilization. | RESUMO O cártamo destina-se à produção de grãos para a obtenção de óleo vegetal. Objetivou-se avaliar o índice de clorofila, as características biométricas e a eficiência no uso da água de plantas de cártamo sob doses de nitrogênio e potássio. O experimento foi conduzido em casa de vegetação, em vasos contendo 8 dm3 de um Latossolo Vermelho. O delineamento experimental foi blocos casualizados, com esquema fatorial 5x5 correspondente a cinco doses de nitrogênio (0, 60, 120, 180 e 240 mg dm-3) e cinco doses de potássio (0, 50, 100, 150 e 200 mg dm-3), com quatro repetições. Avaliou-se o número de folhas, diâmetro de caule, índice de clorofila, número de capítulos, massa seca da parte aérea, massa seca de raízes, massa seca total, consumo de água e eficiência no uso da água. Os dados foram submetidos a 5% de probabilidade de erro a análise de variância pelo teste F e regressão polinomial. O índice de clorofila, as características biométricas e a eficiência no uso da água das plantas de cártamo apresentaram melhores respostas nas doses de nitrogênio entre 82 a 168 mg dm-3. A adubação potássica nas plantas de cártamo proporcionou respostas crescentes com incrementos de 10 a 60% para o índice de clorofila, nas características biométricas e na eficiência de uso da água. As respostas a adubação com nitrogênio e potássio no cártamo ocorrem com efeito isolado.

Safflower crops is usually intended for production of seeds to oil extraction. The objective of this work was to evaluate the chlorophyll index, biometric characteristics and water use efficiency of safflower plants grown under different nitrogen and potassium rates and controlled soil water tension. The experiment was conducted in a greenhouse, in pots containing 8 dm3 of a Oxisol. A complete randomized block experimental design in a 5x5 factorial arrangement was used, with four replications, consisting of five nitrogen rates (0, 60, 120, 180 and 240 mg dm-3) and five potassium rates (0, 50, 100, 150 and 200 mg dm-3). The safflower number of leaves, stem diameter, chlorophyll index, number of capitula, shoot, root and total dry weights, water consumption and water use efficiency were evaluated. Data were subjected to analysis of variance (F test) at 5% of probability and to polynomial regression. The nitrogen and potassium fertilization, as independent factors, affected the safflower plants. The chlorophyll index, biometric characteristics and water use efficiency of safflower showed better responses under nitrogen rates of 82 to 168 mg dm-3. The responses of chlorophyll index, biometric characteristics and water use efficiency of safflower increased 10 to 60% with potassium fertilization.

RESUMO Objetivou-se com este trabalho avaliar a eficiência de recuperação de nitrogênio (N), fósforo (P) e potássio (K) pela cultura da cenoura. Foram implantados dois experimentos em área de cultivo localizada em Rio Paranaíba - MG. A cultivar "Juliana" foi semeada no período de verão e a cultivar "Nayarit" no período do inverno. Os tratamentos consistiram de seis combinações de fertilizações N-P2O5-K2O (kg ha-1): sem N (0-500-450), sem P (100-0-450), sem K (100-500-0), padrão (100-500-450), maior que o padrão (100-700-600) e menor que a padrão (100-300-300). A colheita foi realizada quando a maior parte das raízes apresentavam-se dentro do padrão comercial mais aceito pelos consumidores. Quantificaram-se as matérias fresca e seca das raízes e das folhas e com base na matéria fresca de raízes calculou-se a produtividade. Determinaram-se os teores de N, P e K em folhas e raízes por ocasião da colheita e com bases nesses teores e na matéria seca de raízes e de folhas determinaram-se a absorção e a exportação de nutrientes. As fertilizações testadas influenciaram a produtividade comercial de ambas as cultivares. A omissão da fertilização com N, com P ou com K reduziu a produtividade da cultivar "Juliana". Para a cultivar "Nayarit" apenas a omissão de P reduziu a produtividade. Para essa cultivar o incremento de P e K aumentou a produtividade. A cultivar "Nayarit", mais produtiva que "Juliana", absorveu maiores quantidades de N, P e K. As eficiências de recuperação desses nutrientes por ambas cultivares de cenoura foram baixas. | ABSTRACT The objective of this work was to evaluate the carrot crop recovery efficiency of nitrogen, phosphorus and potassium from fertilizers. Two experiments were conducted in an experimental area in Rio Paranaiba - MG. The cultivar ("Juliana‟) was sown during the summer period and the cultivar "Nayarit‟ during the winter period. In both experiments, the treatments consisted of six fertilization combinations of N, P2O, K2O (kg ha-1): fertilization without N (0-500-450), without P (100-0-450), without K (100-500-0), standard (100-500-450), higher than standard (100-700-600) and lower than standard (100-300-300). The harvest was carried out when most of the roots presented commercial standard well accepted by the consumers. The fresh and dry matter of roots and leaves were quantified, and the yield was calculated based on the fresh matter. The analysis of N, P and K contents in leaves and roots were carried out by harvest time, and the nutrients absorption and exportation were determined based on these contents and on the dry matter of roots and leaves. N, P and K omissions reduced the yield of the cultivar "Juliana‟. For the cultivar "Nayarit‟, only P omission reduced and P and K fertilizations increased the yield. The cultivar "Nayarity‟, which is more productive than "Juliana", absorbed more quantities of N, P and K. Carrot recovery efficiency of nitrogen, phosphorus and potassium is low.

The objective of this work was to evaluate the carrot crop recovery efficiency of nitrogen, phosphorus and potassium from fertilizers. Two experiments were conducted in an experimental area in Rio Paranaiba - MG. The cultivar („Juliana‟) was sown during the summer period and the cultivar „Nayarit‟ during the winter period. In both experiments, the treatments consisted of six fertilization combinations of N, P 2 O, K 2 O (kg ha - 1 ): fertilization without N (0 - 500 - 450), without P (100 - 0 - 450), without K (100 - 500 - 0), standard (100 - 500 - 450), higher than standard (100 - 700 - 600) and lower than standard (100 - 300 - 300). The harvest was carried out when most of the roots presented commercial standard well accepted by the consumers. The fresh and dry matter of roots and leaves were quantified, and the yield was calculated based on the fresh matter. The analysis of N, P and K contents in leaves and roots were carried out by harvest time, and the nutrients absorption and exportation were determined based on these contents and on the dry matter of roots and leaves. N, P and K omissions reduced the yield of the cultivar „Juliana‟. For the cultivar „Nayarit‟, only P omission reduced and P and K fertilizations increased the yield. The cultivar „Nayarity‟, which is more productive than „Juliana”, absorbed more quantities of N, P and K. Carrot recovery efficiency of nitrogen, phosphorus and potassium is low.