Yield and phosphorus use efficiency of carrot cultivars

Phosphate fertilization is indispensable for carrot cultivation, as it contributes to plant development, formation of marketable roots and higher yields. In this context, the objective of this study was to evaluate the production and nutritional efficiency of carrot cultivars under phosphate fertilization. The experiments were carried out from July to November 2016 and from June to October 2017, at the Rafael Fernandes experimental farm, District of Alagoinha, Mossoró, RN, Brazil. The experimental design was in randomized blocks, in a 4×4 factorial scheme with 4 replicates. The treatments consisted of the combination of carrot cultivars (Brasília, Planalto, Suprema and Nativa) with phosphorus (P) doses (0, 90, 180 and 270 kg ha-1 P2O5). The characteristics analyzed were: P content in the diagnostic leaf, plant dry matter, plant height, marketable and total yields, and the classification of cultivars for efficiency and response to phosphate fertilization. The increments promoted by phosphate fertilization were 64% in plant height, 444% in dry matter and 284% in marketable yield. The maximum marketable yield was obtained with doses from 186.8 to 243.5 kg ha-1, depending on the cultivar. The Native cultivar was classified as more efficient in the use of P.

Efficiency in the use of phosphorus by cowpea genotypes / Eficiência do uso de fósforo por genótipos de caupi

Cowpea (Vigna unguiculata (L.) Walp.) is an edible legume with good ability to fix nitrogen and not demanding soil fertility. However, some genotypes may have a greater ability to utilize the nutrients available in the soil for their growth. Thus, the objective of this work was to evaluate the efficiency of phosphorus (P) use in genotypes of cowpea. The experiment was conducted in the field and the experimental design was a randomized complete block design with four replicates arranged in a 2 x 5 factorial scheme. The treatments consisted of two P doses (0 and 60 kg ha-1 of P2O5) and five bean genotypes (Paulistinha, BRS Xiquexique, Pingo de Ouro, Corujinha, and Costela de Vaca). Each plot was formed by four plant rows, measuring 3.0 m in length, spaced 1.0 x 0.3 m, and with two plants per hole. The genotypes responded significantly to the increase in P levels in the soil, with increases in the number of seeds per pod, number of pods per plant, productivity, dry mass, and plant P accumulation. "BRS Xiquexique" was efficient and responsive, and it could be indicated as the most appropriate for cultivation in the region. "Corujinha" is the most suitable cultivar for production in high levels of P among the creole genotypes evaluated. "Costela de Vaca" and "Paulistinha" can be indicated for low P production in the soil.

O feijão-caupi (Vigna unguiculata (L.) Walp.) é uma leguminosa comestível com boa capacidade de fixar nitrogênio e pouco exigente em fertilidade do solo. No entanto, alguns genótipos podem apresentar uma maior capacidade em utilizar os nutrientes disponíveis no solo para seu crescimento. Assim, o objetivo deste trabalho foi avaliar a eficiência do uso de fósforo em genótipos de feijão-caupi. O experimento Non-efficient and non-responsive Efficient and non-responsive Pingo de Ouro BRS Xiquexique PaulistinhaCostela de Vaca Efficient and responsiveCorujinha Non-efficient and responsive foi conduzido em campo, e o solo classificado como Argissolo Vermelho-Amarelo. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, disposto em um esquema fatorial 2 x 5. Os tratamentos foram constituídos pela combinação de duas doses de fósforo (0 e 60 kg ha-1 de P2O5) e cinco genótipos de feijão-caupi (Paulistinha, BRS Xiquexique, Pingo de Ouro, Corujinha e Costela de Vaca). Cada parcela foi formada por quatro fileiras de planta, medindo 3,0 m de comprimento, espaçadas de 1,0 x 0,3 m, com duas plantas por cova. Os genótipos responderam de forma significativa ao aumento do nível de fósforo no solo, com incrementos no número de sementes por vagem, número de vagens por planta, produtividade, massa seca e acúmulo de P da planta. O BRS Xiquexique foi eficiente e responsivo, podendo ser indicado como o mais apropriado para o cultivo na região. Corujinha é a cultivar mais indicada para produção em níveis alto de fósforo entre os genótipos crioulos avaliados. Os genótipos crioulos costela de Vaca e Paulistinha podem ser indicados para produção em baixo nível de fósforo.