مرکز منطقه ای اطلاع رساني علوم و فناوري -

چكيده لاتين :

EFFECT OF SEEDING RATES, NITROGEN LEVELS AND HARVESTING DATES ON GROWTH, YIELD AND QUALITY OF JUTE (Corchorus capsularis, L.) ABSTRACT This investigation was carried out at the experimental farm of Sakha Agric. Res. Station during 2007 and 2008 seasons to study the effect of three seeding rates at 4, 5 and 6 kg/fed, three nitrogen levels 20, 30 and 40 kg/fed and two harvesting dates i.e., after 120 and 150 days from sowing on growth, yield quantity and quality of U.P.C. 94 jute cultivar. The main findings of the present study could be summarized as follows: The seeding rate at 5 kg/fed combined with the plant age at 102 days from sowing achieved the highest mean values of dry weight/plant (g), plant height (cm) and leaf area/plant (dm2), while, the leaf area index was in high magnitude by using 6 kg seeds/fed at 72 days old in both seasons. Planting jute with 4 kg/fed at the growth period of 87-102 days from sowing performed the highest average for CGR, RGR and NAR. The maximum contents of chlorophyll A, B and A + B occurred due to the seeding rate of 4 kg/fed at the two plant ages either 55 or 75 days from sowing, as well as, increased number of capsules/plant, seed index, seed yield/plant and fiber yield/plant in both seasons. Whereas, the highest means of capsules zone length, green yield/plant, fiber yield/fed, fiber percentage and fiber strength were obtained by sowing at the rate of 5 kg/fed, while planting with 6 kg/fed accomplished the highest estimates for technical length, fiber length and fiber fineness in both seasons. There was gradual increase in dry weight/plant due to increasing nitrogen level from 20 up to 40 kg/fed. This trait also increased when plant age increased from 57 to 102 days old, but the maximum estimates of plant height (cm), leaf area/plant (dm2) and leaf area index were obtained due to application of 30 kg N/fed when jute plants reached 102 days from sowing. The more estimates of CGR and NAR were obtained by applying 20 kg N/fed and at the growth period of 87-102 days old, while, the highest RGR was obtained by adding either 30 or 40 kg N/fed and during the growth period of 57-72 days old in both seasons. Gradual increment happened in each of chlorophyll A, B and A + B with increasing nitrogen level at the smallest age i.e., 55 days old. There were gradual increments for each green yield (ton), seed yield (kg) and their components in addition to fiber yield/fed (kg) with increasing N level up to 40 kg/fed, but reduction occurred in fiber percentage and fiber fineness in this case in both seasons. Delaying harvesting date to 150 days from sowing caused remarkable increase in all studied characters except that of fiber percentage, fiber strength and fiber fineness which were decreased in this case and as compared with the harvesting date of 120 days from sowing. Keywords:Jute, Corchorus capsularis, L., seeding rate, nitrogen fertilizer, harvesting date, growth, yield, quality. INTRODUCTION Jute is a natural fiber popularly known as