Drought-induced alterations in the uptake of nitrogen, phosphorus and potassium, and the relation with drought tolerance in sugar cane

Abstract

Alterações induzidas pela seca na absorção de nitrogênio, fósforo e potássio, e as relações com a tolerância da cana-de-açúcar ao deficit hídrico July, 19, 2016 and approved in November 23, 2016 ABSTRACTAlthough there are evidences that the proper supply of mineral nutrients to plants relieves water stress, little is known on the approach of how the drought affects the absorption and accumulation of nutrients by distinct sugar cane genotypes, or in different parts of a same plant. Thus, the objective of this study was to determine the content and accumulation of N, P and K in the aerial part of plant from three genotypes of sugar cane, submitted to three water potentials in the soil, and check the relationship of these variables with the tolerance of plants to prolonged drought. In order to access this objective, an experiment under greenhouse conditions, comprised by a fatorial 3 × 3, in a randomized block design, and four replicates was carried out. After 90 days from treatment imposition, the plant transpiration rate, plant dry mass, concentration of N, P and K were determined in leaves and culms, as well as in total plant shoot were measured. It was found that tolerance to drought in sugar cane is related to higher levels of N and K in the leaves and stems, and larger accumulations of K and P in the plant shoot. There is high positive correlations among accumulation of N, P and K in the plant shoot and dry matter production by plants submitted to drought. There are intermediate correlations among plant transpiration and nutrient uptake by plants under drought. Plants of the genotype SP81-3250 are more tolerante to prolonged drought, than the RB855453 and IACSP95-5000 plants.Index terms: Saccharum officinarum L.; water limitations; mineral nutrition; soil water potentials; plant growth. RESUMOEmbora existam evidências de que o adequado fornecimento de nutrientes minerais para plantas alivia o estresse hídrico, pouco se sabe sobre a abordagem de como a seca afeta a absorção e acumulação de nutrientes por distintos genótipos de cana-de-açúcar, ou por diferentes partes de uma mesma planta. Assim, o objetivo deste estudo foi determinar o teor e acúmulo de N, P e K na parte aérea da planta de três genótipos de cana-de-açúcar, submetidos a três potenciais hídricos do solo e verificar se existe relação dessas variáveis com a tolerância das plantas ao déficit hídrico prolongado. Para isso, foi realizado um experimento em casa de vegetação, em um esquema fatorial 3×3, em delineamento de blocos casualizados, com quatro repetições. Após 90 dias da imposição dos tratamentos, foi determinada a massa seca e a taxa de transpiração das plantas, a concentração de N, P e K nas folhas e colmos, além do acúmulo desses nutrientes na parte aérea das plantas. Verificou-se que a tolerância à seca em cana está relacionada com níveis mais altos de N e K nas folhas e caules e maiores acumulações de K e P na parte aérea das plantas. Existem fortes correlações positivas entre acúmulo de N, P e K na parte aérea das plantas e produção...

Fruit characteristics of cantaloupe melon in protected environment subjected to irrigation frequencies and substrate volumes

“…These results show that when irrigation management is adopted with a fractional addition of water, the probability Table 3. Summary of analysis of variance and results of the comparison test of means for the evaluated variables of cantaloupe melon (variety Rock Hybrid Cantaloupe) subjected to different irrigation frequencies and substrate volumes ***, **, *, ns -Significant at p ≤ 0.001, 0.01, 0.05 and not significant, respectively, by F test; 1 Square-root-transformed data; DF -Degrees of freedom; CV -Coefficient of variation; Means followed by the same letter in the column did not differ significantly from each other by Tukey test, (p ≤ 0.001, 0.01 and 0.05) of occurrence of water deficit or loss of water by percolation decreases, thus the fractional addition of water allows the maintenance of micropores with sufficient water for the absorption of nutrients by the plants, because according to Silva et al (2017), it is evident that the movement of nutrients from the soil towards the root depends on the presence of water. The greater absorption of water and nutrients by the melon allows the plant to produce fruits of larger size and thicker pulp, since it is possible to produce a greater volume of photoassimilates.…”

Nitrogen use efficiency and drought tolerant ability of various sugarcane varieties under drought stress at early growth stage

“…Q50. Silva et al (2017) reported the uptake of nitrogen was reduced significantly under the effect of water stress. In this study, drought stress reduced TNU of all varieties, but not significantly.…”

“…In this study, drought stress reduced TNU of all varieties, but not significantly. Water shortage might reduce dissolved nitrogen ability (in the form of urea which was applied just 10 days before plant subjected to water stress) which leads to reducing the amount of nitrogen uptake in Silva et al (2017)'s experiment. Meanwhile, in this study, the dissolved nitrogen was applied weekly even during water stress period.…”

“…During this stage, macronutrients especially nitrogen are often fertilized to promote sugarcane growth. Drought stress, therefore, at first reduces nitrogen uptake (T. Silva, Cazetta, Carlin, & Telles, 2017), then affects the assimilation and remobilization processes of nitrogen by restricting enzyme activity e.g. nitrate reductase (Abayomi, 2001), and results in the decline of nitrogen use efficiency (NUE).…”

Effect of Micaschist Powder in Sugarcane (Saccharum officinarum) Farming on Ferrallitic Soils of Mbandjock (Cameroon, Central Africa)

“…It does not require concentration processes and chemical attacks [9]; it may be ready for use (as in the present situation) and production costs are minimal (extraction and crushing costs when needed, will not exceed US$ 10 per ton) [2,4,10]. The technology of rock fertilizers is widely developed in countries such as Brazil, China and Australia [11][12][13][14][15][16]. In addition, it has been noted that regions covered by recent volcanic rocks are excellence areas of intensive farming.…”