Biometria e produção de cultivares de girassol irrigado com água de diferentes salinidades.

Abstract

The sunflower (Helianthus annuus L.) has important agronomic traits, such as increased tolerance to drought, cold and heat, when compared with most species grown in Brazil. This species presents desirable characteristics, such as short-cycle, high quality and good oil yield, however, due to the scarcity of water resources of good quality, it has been used saline water for irrigation. Against this background we sought, the present work aimed to study the tolerance of cultivars of irrigated sunflowers with water of different salinities. This work was performed in two experiments, first developed in a protected environment at the Federal University of Campina Grande (UFCG), Campus I, Campina Grande, PB. The experimental design was a randomized block design in a factorial scheme 2 x 4, comprising 2 levels of electrical conductivity (EC w) of irrigation water (N1 - 0,6 and N2 - 3,0 dS m - 1 to 25 ºC) and four sunflower cultivars (C1 - Helio 863, C2 - Embrapa 122- V2000, C3 - Catissol 01 and C4 - Multissol), with 3 replicates each of 3 plants, totaling 72 experimental units. The second field on the property developed in the property Macaquinhos site, located 8 km south of the municipality of San Remigio, PB. The experimental design was a randomized block, split-plot scheme analyzed in 5x4, the plots consisted of five levels of electrical conductivity (EC w) of irrigation water, N1 - ECw of 0,14 dS m-1 (water supply from the weir Macaquinho, PB), N2 - ECw of 1,50; N3 - ECw of 2,50; N4 - 3,50 and N5 - ECw of 4,50 dS m-1 at 25 ºC and 4 subplots cultivars C1 - Embrapa 122-V2000, C2 - Olisun 03, C3 - AG 963 and C4 - Multissol with 3 repetitions. In both experiments from 15 DAG biometric evaluations of cultivars under salt stress by determining plant height (PH), stem diameter (DC), number of leaves (NL) and leaf area (LA) were performed. For the first experiment the following parameters were evaluated: flowering index (FI), number of petals (NP), inner and external diameter of the head (DI and DE), the total weight of achenes (PAT), weight of filled achenes (CAP), achene weight of voids (PACH), number of achenes (NA), number of achenes chocho (NACH) and weight of 100 achenes (P100A). For Experiment II was evaluated variables internal diameter of the head (DI), total weight of achenes (PAT), the total weight of achenes (PAT), weight of filled achenes (CAP), achene weight of voids (PACH), number of achenes (NA), number of achenes chocho (NACH) and weight of 100 achenes (P100A). In general, it was found that it is possible to commercially produce sunflower with saline water in the northeast since it has good management.