RESUMO Foi realizado um experimento com o objetivo de avaliar o efeito da dose de fósforo na beterraba, em um Latossolo com alto teor de fósforo (P), na cidade de Jaboticabal, Brasil. Os tratamentos foram arranjados em esquema fatorial, em delineamento experimental de blocos casualizados com quatro repetições. Os fatores avaliados foram dose de P (0, 120, 240, 360 e 480 kg ha-1 de P2O5) e cultivar ('Early Wonder' e 'Kestrel'). Aos 50 dias após o transplante das mudas, foram avaliados os teores foliares de nitrogênio (N), P, potássio (K) e boro (B). Não houve efeito da interação dos fatores sobre os teores foliares de nutrientes. O acúmulo desses quatro nutrientes foi avaliado na colheita. Todos os nutrientes avaliados acumularam-se em níveis mais elevados na ‘Early Wonder’ do que na ‘Kestrel’, tanto na parte aérea quanto na raiz tuberosa. N, P e B acumularam-se preferencialmente na raiz tuberosa, enquanto K acumulou-se mais na parte aérea. A dose de P não influenciou no rendimento. Portanto, a fertilização com fosfato não é recomendada para as culturas de beterraba quando cultivadas em um solo Latossolo com alto teor (88 mg dm-3) de P disponível.

ABSTRACT An experiment was carried out aiming to evaluate the effect of phosphorus rates on beet, in an Oxisol with high phosphorus (P) content, in Jaboticabal city, São Paulo, Brazil. The treatments were arranged in a factorial scheme, in a randomized block experimental design with four replicates. The factors evaluated were P rates (0, 120, 240, 360 and 480 kg ha-1 P2O5) and cultivar ('Early Wonder' and 'Kestrel'). At 50 days after transplanting the seedlings, foliar nitrogen (N), P, potassium (K) and boron (B) contents were evaluated, and there was no effect of the interaction between factors on foliar nutrient contents. The accumulation of these four nutrients was evaluated at harvest. All evaluated nutrients accumulated to higher levels in ‘Early Wonder’ than in 'Kestrel' both in the shoots and tuberous root. N, P and B accumulated more in the tuberous root whilst K accumulated more in the shoots. P dose did not influence the yield. Therefore, phosphate fertilization is not recommended for beet crop when cultivated in an Oxisol with a high content (88 mg dm-3) of available P.

Resumen El cultivo intercalado de hortalizas tiene ventajas sobre el monocultivo en cuanto a su menor impacto ambiental. Sin embargo, para convencer al productor de que adopte este sistema de producción, es necesario demostrar mayor eficiencia en la producción de más alimentos por unidad de superficie, y por tanto, un aumento de la productividad. Se llevó a cabo un experimento con el fin de evaluar el efecto del tiempo de trasplante de la achicoria en los cultivos intercalados con la col en el rendimiento de los cultivos y el índice de eficiencia del uso de área (LUE). El diseño experimental fue en bloques aleatorios, con nueve tratamientos en un esquema factorial 2 x 4 + 1, y cuatro repeticiones. Se evaluaron los sistemas de cultivo (intercalado y monocultivo) y el tiempo de trasplante de la achicoria (0, 14, 28 y 42 días después del trasplante (DAT) de la col). El rendimiento de la col aumentó al retrasarse el tiempo de trasplante de la achicoria. El rendimiento total y por cosecha de la achicoria no se vio influido por su tiempo de trasplante. Independientemente del tiempo de trasplante de la achicoria, la col y el cultivo intercalado de achicoria proporcionaron una mayor LUE en comparación con los sistemas de monocultivos, y alcanzaron el valor máximo (52% más alto) cuando la achicoria se trasplantó 42 días después de la col.

Abstract Vegetable intercropping has advantages over single cultivation in terms of less environmental impact. However, to convince farmers to adopt this production system, it is necessary to prove greater efficiency in the production of more food per unit area and therefore an increase in productivity. An experiment was carried out aiming to evaluate the effect of the chicory transplant time in intercrops with collard greens on crop yields and land use efficiency index (LUE). The experimental design was a randomized block, with nine treatments in a 2 × 4 + 1 factorial scheme, and four replications. Crop systems (intercrop and monoculture) and chicory transplant time (0, 14, 28 and 42 days after transplant (DAT) of collard greens) were evaluated. The collard greens yield increased as the chicory transplant time was delayed. The total and per harvest yields of chicory were not influenced by its transplant time. Regardless of chicory transplant time, collard greens and chicory intercropping provided greater LUE than their monocultures and reached the maximum value (52% higher) when the chicory was transplanted 42 days after collard greens.

RESUMO Tabelas de recomendação de adubação para a cultura da beterraba foram elaboradas com base na resposta a doses de potássio (K) em solos com baixo teor do nutriente. Contudo, são escassas as pesquisas que avaliam a adubação potássica para a cultura da beterraba em solo com alto teor de K, condição comumente encontrada, o que permite melhor compreensão da resposta da cultura ao nutriente. Objetivou-se avaliar a resposta da beterraba a doses de K em Latossolo com alto teor do nutriente. O experimento foi realizado em campo, em delineamento de blocos ao acaso, em esquema fatorial 4 x 2, com quatro repetições. As doses de K foram 0, 60, 120 e 180 kg ha-1 de K2O e as cultivares foram 'Early Wonder' e 'Kestrel'. Aos 50 dias após o transplante avaliaram-se os teores de nitrogênio (N), fósforo (P), K e boro (B) na folha diagnose. A produtividade e o acúmulo destes quatro nutrientes foram analisados na colheita. As doses de K influenciaram positivamente o teor foliar de K; contudo, sem efeito na produtividade da cultura. Portanto, em Latossolo com alto teor de K disponível, não se recomenda a fertilização potássica. Para a manutenção da fertilidade do solo em nível alto de K, recomenda-se a fertilização com 162 e 126 kg ha-1 de K2O para ‘Early Wonder’ e 'Kestrel', respectivamente, doses equivalentes às quantidades exportadas pela raiz de beterraba.

ABSTRACT Fertiliser recommendation tables for beet culture have been prepared based on the response to potassium (K) doses in soils with a low nutrient content. However, there is little research that evaluates potassium fertilisation for beet crops in soil with high K content, a condition commonly found, which allows a better understanding of the crop’s response to the nutrient. The objective was to evaluate the response of beet to doses of K in Oxisol with a high K content. The experiment was carried out in the field, with an experimental design in randomised blocks, in a 4 x 2 factor scheme with four replications. The doses of K were 0, 60, 120 and 180 kg ha-1 of K2O, and the cultivars were ‘Early Wonder’ and ‘Kestrel’. At 50 days after transplantation, the levels of nitrogen (N), phosphorus (P), K and boron (B) in the diagnostic leaf were evaluated. Beet yield and accumulation of these four nutrients were analysed at harvest. The doses of K positively influenced the leaf content of K; however, without an effect on beet yield. Therefore, in Oxisol with a high K content available, potassium fertilisation is not recommended. To maintain soil fertility at a high potassium content, fertilisation with 162 and 126 kg ha-1 of K2O is recommended for ‘Early Wonder’ and ‘Kestrel’, respectively; doses equivalent to the quantities exported by the beet root.