Crescimento e desenvolvimento do gergelim em estresse hídrico em substrato de biossólido e adubo químico.

Abstract

Sesame (Sesamum indicum L.) is one of the most important oilseed crops, having seeds and oil that are highly valued as a traditional health food. This research aimed to determine the rate of growth and yeld when submmeted to different leveis of water suplementation and rates of fertilization. The experimental design applied was the completily randomized design; at factorial 4x2 with 4 replicatation.The factors studied were: Factor A: range of turn of irrigation determined by the coefficient of depletion CD1 - coefficient of depletion of 0%; CD2 - coefficient of depletion of 20%; CD3 - coefficient of 40% and depletion of CD4 - coefficient of depletion of 60%. Factor B: Application of two different types of nitrogen fertilizer.: AB with biosolid fertilizer, in the dosage of 1375 kg.ha-1 and AM - mineral fertilizer with urea, in the dosage of 125 kg.ha-1.The experiment was carried out in the protected area, at the Federal University of Campina Grande, located at 7 ° 15'18 "S and 35 ° 52'28" W, and altitude of 552 meters. To calculate the leveis of soil moisture in each treatment (pot), it was determined the criticai weight of each vessel corresponding to the different coeffícients of depletion and once made the irrigation, were effective as daily weighings, whose weight, time and date were recorded in spreadsheet; each treatment was irrigated again, when it reached the criticai weight corresponding to the availability of water for that treatment; after germination, was made a thinning where only 4 remaining plants in each pot, and if cotelando, each 30 days, a plant for determination of the dry weight of the root. The data collection was performed twice, beginning 15 days after germination complete; variables collected are: diameter of collect; height of the plant, leaf area (width x length) of each; beginning of flowering; start of production of fruits; mass of dead roots and shoots of the plant and production. It was found that there were no signifícant differences for plant height, diameter of the stem, leaf area, the dry root and shoot dry matter (MSPA) at 30 and 45 DAE, but was no statistical difference in this variable at 60 , 75 and 90 DAE, in the different stages of development of the culture of sesame, depending on the leveis of water stress, although it occurred slight tendency to increase the stature of the plant up to 40% of water stress. The results induce that the sesame is tolerant to drought stress since the different leveis of water stress by removal of 60% of water (40% of available moisture in the soil) these variables had the same behavior. There was no difference of the effect of the different sources of nitrogen applied on the variables studied. The sesame presented better answers of the components of production in water levei of 40% of water stress, which corresponds to 60% of capacity in the field. The biosolid can replace the urea as nitrogen fertilizer for sesame crop.