A B S T R A C TThe objective of the present study was to evaluate the response of eggplant, cv. 'Ciça' , with respect to yield, number of fruits and dry matter (root and stem), when grown in a greenhouse and conducted under fertigation with nitrogen and potassium. Resposta da cultura da berinjela fertirrigada com doses de nitrogênio e potássio R E S U M O Objetivou-se, no presente estudo, avaliar a resposta da cultura da berinjela, cultivar Ciça, com relação à produtividade, número de frutos e massa seca (raiz e caule), quando cultivada em ambiente protegido e conduzida sob fertirrigação com nitrogênio e potássio. O experimento foi conduzido no Centro Técnico de Irrigação da Universidade Estadual de Maringá, entre os meses de fevereiro e agosto de 2015. Foram testadas quatro doses de nitrogênio (0,0; 6,43; 12,86 e 25,72 g de N planta -1 ) e quatro doses de potássio (0,0; 5,18; 10,36 e 20,73 g de K planta -1 ), perfazendo 16 tratamentos em esquema fatorial 4 x 4, dispostos em delineamento inteiramente casualizado com quatro repetições, em Latossolo vermelho distrófico, de textura arenosa. O maior número de frutos por planta e produtividade foi obtido na dose entre 14-17 g de N planta -1 (145-177 kg ha -1 ). Doses isoladas de potássio não influenciaram estatisticamente a produtividade nem a massa seca de raiz.

No abstract

-Fertilization is important for the optimization of plant growth and yield, which are necessary for agronomic activities. Soil fertilization should increase net earnings that depend on nutrient use efficiency. The aim of this study was to evaluate the agronomic efficiency of eggplant under different doses of potassium (K) and nitrogen (N). Four levels of K (0, 54, 108, and 216 kg ha -1 ) and four levels of N (0, 67, 134, and 268 kg ha -1 ) were applied weekly by fertigation. The highest plant and the largest stem diameter were found with 165-175 kg ha -1 of N. Leaf area was more influenced by N than by K. Isolated application of different K doses did not statistically influence height plant, stem diameter, or leaf dry matter. The agronomic efficiency of nitrogen is reduced with increasing levels of N and K.

The netted melon requires special growing conditions, including a protected environment, an adequate staking system and proper water and nutrient management. This study aimed to assess the effect of irrigation levels and silicon doses on the yield and quality of Sunrise hybrid melons, in a greenhouse. A randomized block design was used, with a 5 x 3 factorial scheme and four replications. The first factor consisted of five silicon doses (0 kg ha-1, 50 kg ha-1, 100 kg ha-1, 150 kg ha-1 and 200 kg ha-1) and the second of three irrigation levels (40 %, 70 % and 100 % of the ETc). The results demonstrated that the applied irrigation levels and silicon doses have no influence on the yield traits of melon plants. The irrigation level corresponding to 100 % of the ETc promotes higher values for soluble solids (9.86 ºBrix) and maturation index (114.9) on fruits. The increase of silicon doses up to 200 kg ha-1 also increases the maturation index in the treatment with the greatest irrigation level and reduces this index at the shallowest level applied.

Adequate crop fertilization is one of the challenges for agriculture. Measuring gas exchange and biomass accumulation may be used to adjust crop management. The effect of fertigation with potassium (0 kg ha-1, 54 kg ha-1, 108 kg ha-1 and 216 kg ha-1) and nitrogen (0 kg ha-1, 67 kg ha-1, 134 kg ha-1 and 268 kg ha-1) on gas exchange and biomass accumulation in eggplant was assessed under greenhouse conditions. The net photosynthesis, stomatal conductance, transpiration, internal CO2 concentration, instantaneous carboxylation efficiency, water-use efficiency and total dry weight were evaluated. With the exception of K for water-use efficiency and N for internal CO2 concentration, all the other gas exchange parameters were significantly affected by the K and N doses. There was an interaction between N and K doses for net photosynthesis, stomatal conductance, transpiration and instantaneous carboxylation efficiency. The highest values for net photosynthesis, stomatal conductance, transpiration rate, carboxylation instantaneous efficiency and total dry weight were found in the range of 125-185 kg ha-1 of K and 215-268 kg ha-1 of N.