Abstract :
Orobanche aegyptiaca started to emerge above ground 40 DAS of Indian mustard. Significant difference was observed in number of Orobanche shoots m-2, fresh and dry weight of Orobanche shoots m-2 and visual control of Orobanche in mustard crop due to different treatments. At 60DAS, treatments T3, T7, T8 and T9 were observed most effective with no shoots, fresh weight and dry weight of Orobanche m-2, hence, providing 100 per cent control of Orobanche at 65DAS of mustard. At 90DAS, 120DAS and harvest, treatment T9 was found statistically at par with T7 and T8 in reducing the number, fresh and dry weight of Orobanche shoots, hence, providing the maximum visual control at 95, 125DAS and at harvest, respectively. Increasing the application of nitrogen in mustard decreased the population, fresh weight and dry weight of Orobanche and increased the control of Orobanche in T9 over T8 probably because of detrimental effect of the nitrogenous fertilizers on the parasitic infestation. A significant difference in plant height and dry matter accumulation plant-1 of mustard was observed due to different treatments. The plant height and dry matter accumulation plant-1 in treatment T9 i.e. 125 per cent of recommended fertilizer + foliar spray of glyphosate at 25 and 50g ha-1 + 1.0% solution of (NH4)2SO4 at 25 and 55DAS, respectively was higher due to higher dose of N and P and excellent control of Orobanche during its life cycle. Different treatments resulted in significant difference in crop growth rate of Indian mustard from sowing upto 130DAS and thereafter it remained non-significant. Among different treatments, 125 per cent of recommended fertilizer + foliar spray of glyphosate at 25 and 50g ha-1 + 1.0% solution of (NH4)2SO4 at 25 and 55DAS, respectively (T9) resulted in highest CGR which might be due to better control of Orobanche coupled with beneficial effects of higher dose of N and P on mustard at active vegetative stages as a result of enhancement in cell multiplication, cell elongation and cell expression in the plant body which ultimately increased the CGR. Among the different treatments, number of primary branches at harvest stage were found maximum in treatment T9 which was at par with treatment T7 but significantly higher over rest of the treatments. Number of siliquae plant-1 at harvest stage were recorded maximum in treatment T9 which was at par with treatment T7 but significantly higher over rest of the treatments. T9 recorded maximum number of siliquae because higher nutrients help in more number of branches, mainly the secondary branches and resulting higher number of siliquae plant-1 at higher dose of fertilizers. Similarly, number of siliquae branch-1 were maximum under 125 per cent of recommended fertilizer + foliar spray of glyphosate at 25 and 50g ha-1 + 1.0% solution of (NH4)2SO4 at 25 and 55DAS, respectively (T9) which was significantly superior over all other treatments. Maximum siliqua length (cm) and 1,000-grain weight (g) was observed with 125 per cent of recommended fertilizer + foliar spray of glyphosate at 25 and 50 g ha-1 + 1.0% solution of (NH4)2SO4 at 25 and 55DAS, respectively (T9) which was at par with foliar spray of glyphosate at 25 and 50g ha-1 + 1.0% solution of (NH4)2SO4 at 25 and 55DAS, respectively (T7) and superior over all other treatments. Similarly, grains siliqua-1 were recorded maximum in treatment T9 which was found statistically at par with T2, T3, T6, T7 and T8 and significantly higher than other treatments. Grain yield and biological yield of Indian mustard varied significantly due to different treatments. Treatment T9 i.e. 125 per cent of recommended fertilizer + foliar spray of glyphosate at 25 and 50g ha-1 + 1.0% solution of (NH4)2SO4 at 25 and 55DAS, respectively, produced highest grain yield and biological yield which was at par with T7 i.e. foliar spray of glyphosate at 25 and 50g ha-1 + 1.0% solution of (NH4)2SO4 at 25 and 55DAS, respectively. Treatment T9 and T7 produced 88.7 and 72.9 per cent more grain yield, respectively than weedy check (T11). The combined effect of higher dose of fertilizers and maximum control of Orobanche in treatment T9 provided ideal conditions for growth of mustard crop resulting in higher plant height, more primary and secondary branches plant-1, number of siliquae plant-1, more number of grains siliqua-1 and higher 1000-grain weight ultimately increased the grain and biological yield.
Keyword :
Neem, Orobanche, Brassica juncea, DAS, fertilizer