Growth dynamics and yield of melon as influenced by nitrogen fertilizer

Abstract

Nitrogen (N) is an important nutrient for melon (Cucumis melo L.) production. However there is scanty information about the amount necessary to maintain an appropriate balance between growth and yield. Melon vegetative organs must develop sufficiently to intercept light and accumulate water and nutrients but it is also important to obtain a large reproductive-vegetative dry weight ratio to maximize the fruit yield. We evaluated the influence of different N amounts on the growth, production of dry matter and fruit yield of a melon 'Piel de sapo' type. A three-year field experiment was carried out from May to September. Melons were subjected to an irrigation depth of 100% crop evapotranspiration and to 11 N fertilization rates, ranging 11 to 393 kg ha -1 in the three years. The dry matter production of leaves and stems increased as the N amount increased. The dry matter of the whole plant was affected similarly, while the fruit dry matter decreased as the N amount was increased above 112, 93 and 95 kg ha -1 of N are sufficient for adequate plant growth, development and maximum production. To obtain fruit yield close to the maximum, the leaf N concentration at the end of the crop cycle should be higher than 19.5 g kg -1 . Key words: LAI, LAD, dry matter accumulation, production functions, leaf nitrogen concentration Dinâmica do crescimento e da produtividade do melão em resposta ao fertilizante nitrogenado RESUMO: O nitrogênio (N) é um nutriente importante para a produção de melão (Cucumis melo L.), porém existe pouca informação sobre a quantidade necessária para se obter um balanço entre o crescimento e a produtividade. Os órgãos vegetativos do melão precisam se desenvolver suficientemente para interceptor luz, acumular água e nutrients, mas também é importante alcançar uma grande relação de massa seca produtiva-vegetativa para maximizar a produção de frutos. Investigou-se a influência de quantidades de N no crescimento, na produção de matéria seca e na produtividade do melão tipo 'Pele de sapo'. Foi conduzido experimento com três anos de duração, de maio a setembro, com irrigações de 100% da evapotranspiração e 11 doses de adubação de N, no intervalo de 11 a 393 kg ha -1 em três anos. A produção de massa seca de folhas e caules aumentou com o aumento das doses de N. A matéria seca da planta toda foi afetada de maneira semelhante, enquanto a dos frutos decresceu com o aumento de N acima de 112, 93 e 95 kg ha A dose mais baixa de N reduziu a produtividade de frutos em 21%, enquanto a dose mais alta aumentou o crescimento vegetative, LAI e a duração de área foliar (LAD), mas reduziu a produtividade em 24% em relação ao tratamento N 93 . Aplicações excessivas de N aumentam o crescimento vegetativo às expensas do crescimento vegetativo. Para este tipo de melão, doses da ordem de 90-100 kg ha -1 de N são suficientes para crescimento adequado e produção máxima. Para obter produções próximas ao máximo, a concentração de N na folha no final do ciclo da cultura não deve ser maior que 19.5 g kg -1 . Palavras chave...

Nitrogen uptake dynamics, yield and quality as influenced by nitrogen fertilization in ‘Piel de sapo’ melon

“…If the N application continues increasing, FY decreases, as in tomato or melon (Pérez-Zamora et al, 2004;Kirnak et al, 2005;Castellanos et al, 2011). In our case, maximum yields were obtained with 112 and 93 kg N ha The positive correlations obtained between fruit N content and total yield in 2005 and 2007 arose because both are directly proportional to the fruit biomass, and also because the N concentration in this organ varied in the same way as the biomass.…”

“…The N absorption in melon and the length of the period when it is high depend not only on the variety but also on weather conditions (Pardossi et al, 2004), emphasizing the importance of determining absorption dynamics for each melon type and crop area in order to establish an appropriate fertilization schedule. The amount of N applied had a clear effect on N uptake due to an increase in both the biomass and N concentration of the plant organs (Castellanos et al, 2011). Halitligil et al (2002) and Kirnak et al (2005) obtained the same results for melon cv.…”

“…Except for fruit biomass in 2006, the biomass of different plant parts and the total aerial plant biomass increased with the applied N (Castellanos et al, 2011) and, therefore, the increase in N uptake was as a result of increases in both the biomass and N concentration. In 2006, N requirements were covered by the N 93 treatment, which had the highest yield, while the other two (N 243 and N 393 ) were surplus treatments and produced more vegetative and less reproductive biomass.…”

Winery distillery waste compost effect on the performance of melon crop under field conditions

“…Castellanos et al (2011) . Our control (D0) was supplied with 89 kg N ha -1 (2011) and 132 kg N ha -1 (2012) in irrigation water.…”

Determination of the uptake and translocation of nitrogen applied at different growth stages of a melon crop (Cucumis melo L.) using 15N isotope

“…In these crops, a proper N balance must be maintained, to obtain appropriate proportions of vegetative and reproductive parts (Tanemura et al, 2008;Castellanos et al, 2011). For this, information concerning the uptake and translocation by plants of N fertiliser applied at different times and the contribution of N to plant growth and fructification is vital for increasing crop yields through efficient use of N fertiliser.…”