ABSTRACT

Intensive field investigations carried out at the Crop Research Centre, Pantnagar, revealed the possibilities of introducing Brassica carinata in rainfed areas and under resource constraints in Northern plains of India, with higher seed yield and net returns. Recently released carinata variety PBC-9221 significantly out yielded mustard (Brassica juncea) and carinata cultivar DLSC-1 under rainfed conditions. When averaged over three years (1995-97), yield increase in PBC-9221 was 17.8% over prominent mustard variety Kranti and 6.8% over other carinata cultivar DLSC-1. Increase in seed yield was the additive effect of higher siliquae number, seed weight per plant and more number of branches with plant characteristics favouring increased photosynthetic efficiency. In addition, carinata being longer in duration had more period available for reproductive growth than mustard which lead to enhanced production of seed and oil. At 75% and 50% of recommended fertility levels, carinata yielded 18.0 and 27.8% higher than mustard. Although, oil content was slightly low but higher seed yield resulted in increased oil yield in carinata. Due to its capability to yield better than mustard even under resource constraints, the cultivation of carinata would be immensely useful for the marginal rainfed farmers having low investment capacity.

Oilseed crops play vital role in Indian Agriculture economy occupying sizeable share (15.2%) of the country’s gross cropped area. Rapeseed-mustard having prominence in northern India, rank second after Peanut and contribute nearly 30% of the total oilseed production in India. U.P. state account for 17.1 per cent area and 19.5 per cent rapeseed-mustard production of the country. However, 80% of oilseed production in this state is contributed by rapeseed-mustard. Fertilizer is the key input and is responsible for harnessing potential yield of a particular cultivar. Recently, improved varieties of mustard (Brassica juncea) and Abyssinian mustard (Brassica carinata) have been developed. Considering the new introduction of carinata, it became imperative to study the comparative performance with traditionally established mustard in northern plain zone of India.

METHODOLOGY

Field trials were conducted during winter seasons (1995-1997) at the Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar, India. Cultivars PR-8998, Kranti (mustard) PBC-9221 and DLSC-1 (carinata) were tested alongwith 50%, 75%, recommended and 125% of the recommended fertility levels in a R.B.D. design with three replications under rainfed conditions. The soil of the experiment site was silty clay loam in texture with pH 7.0. Sowing was done at 30 cm distance and plant spacing of 15 cm maintained by thinning. Basal application of phosphorus and potassium were made alongwith 75% nitrogen as per the treatment. Rest quantity of the nitrogen was applied at the time of first intercultural operation.

RESULTS

Under rainfed conditions, carinata variety PBC-9221 performed better than mustard during all the years. Variety PBC-9221 (Kiran) recorded significantly higher (17.8%) seed yield over check variety Kranti and 10.9% in comparison with other improved mustard cultivar PR-8988 when averaged over three years (Table 2). Cultivar DLSC-1 of carinata also recorded significantly higher seed yield over Kranti. The increase in seed yield was the additive effect of higher number of branches, siliquae per plant and seed weight per plant. Consequently all these yield attributes had higher value due to stronger vegetative phase. In carinata root depth was 30.5% more than mustard and also the photosynthetic activity enhanced due to presence of greener leaves for a longer duration and higher dry matter accumulation by 72.4% over mustard. The carinata crop took 170 days to mature and mustard matured in 140 days. Thus, due to longer period available for reproductive growth, the development of seed was pronounced in carinata. Oil content was higher in mustard but due to higher seed yield, oil yield per hectare was more in carinata.

The fertility levels differed significantly amongst themselves. However, the seed yield and yield attributes were recorded significantly higher at 125% of the fertility level. At 75 and 50 percent of the recommended fertility levels, carinata performed better than mustard. Similar, findings were reported by Kumar and Gangwar (1984). A decreasing trend in relation to fertility levels was recorded in oil content and significantly higher values were recorded at 50 percent of the fertility level during all the years. Similar findings were reported by Pramanik et al. (1996). Although oil content was low in carinata but at higher fertility levels, oil yield per hectare increased upto 125 percent of the recommended fertility level because of increased seed yield. These results are also supported by the findings of Singh et al. (1996).

The interaction effect between cultivars and fertility levels was recorded to be significant. Cultivar PBC-9221 had significantly higher seed yield at 125 percent of the recommended fertility level but remained at par with recommended fertility level. At 75 and 50 percent of the recommended fertility levels carinata cultivar PBC-9221 yielded 18.0 and 27.8 percent higher over mustard cultivar Kranti. It is, thus, evident that Brassica carinata has great promise under resource constraints in Northern plains of India.

REFERENCES

1. Kumar, A. and Gangwar, K.S. 1984. Growth, development and yield of Indian rape (Brassica campestris var. toria) as influenced by N-fertilizer and row spacing. Ann. agric. Res. 5 (1-2) : 6-13.

2. Pramanik, S.C.; Singh, N.P.; Singh, S. and Garnayak, L.M. 1996. Irrigation and nitrogen effects on oil yield and nitrogen uptake by Ethiopian mustard (Brassica carinata). Indian J. Agron. 41 (1) : 101-107.

3. Singh, R.P.; Kumar, A.; Pal, M.S. and Shukla, Anil. 1996. Performance of promising mustard (Brassica juncea) entries under different rates of nitrogen fertilization. Ann. agri. Res. 17 (2) : 178-180.

Table 1. Dry matter accumulation, yield attributes, oil content and oil yield as influenced by different varieties and fertility levels (three year’s average, 1995-97).

Treatment	Dry matter accumu-lation (g/plant)		Root depth (cm)	Branches per plant	Siliquae per plant	Seeds/ siliqua	Seed weight per plant (g)	1000 seed weight (g)	Oil content (%)	Oil yield (Kg/ha)
Varieties
PBC-9221		35.0	23.5	37	214	10.2	8.0	4.6	39.8	652
DLSC-1		31.7	20.6	19	172	10.3	7.6	4.5	38.7	592
PR-8988		20.4	19.0	15	162	10.8	7.0	4.7	40.8	603
Kranti		20.3	18.0	13	150	10.0	6.6	4.6	40.6	565
CD at 5%		2.7	1.8	2	40	0.6	1.2	0.2	0.6	47
Fertility levels
50% of rec.		20.0	17.2	13	127	9.1	5.9	4.7	40.4	522
75% of rec.		23.6	19.2	19	155	9.8	6.6	4.5	39.8	583
Recommended		30.3	21.1	25	201	11.1	8.2	4.6	39.8	641
125% of rec.		33.4	23.6	27	216	11.3	8.5	4.6	39.6	665
CD at 5%		2.7	1.8	2	40	0.6	1.2	0.2	0.6	47

Rec. = Recommended dose

Table 2. Seed yield (kg/ha) of carinata and mustard cultivars as influenced by fertility levels (Three year’s average, 1995-97)

Varieties (V)	Fertility levels (F)				Mean
	50% of rec.	75% of rec.	Rec.*	125% of rec.
PBC-9221	1436	1595	1724	1789	1636
	(572)	(635)	(686)	(712)	(652)
DLSC-1	1310	1515	1630	1669	1531
	(507)	(586)	(631)	(646)	(592)
PR-8988	1330	1363	1571	1636	1475
	(544)	(557)	(642)	(669)	(603)
Kranti	1149	1360	1489	1554	1388
	(468)	(553)	(605)	(632)	(565)
Mean	1306	1458	1603	1662
	(522)	(583)	(641)	(665)

*Recommended dose (60 kgN, 40 kg P₂O₅ and 20 kg K₂O/ha)

Figures in parenthesis denote oil yield per hectare.

V F Interaction

C.D. at 5% 58 58 128

ABSTRACT

The productivity of mustard is low in intensive cropping system. To evaluate the contribution of inclusion of legumes and green manuring, five crop sequences were tested during 1995-97. Significantly higher seed and oil yield of mustard (Brassica juncea) was attained in green manuring (Sesbania aculeata) - mustard sequence followed by cowpea (fodder) - mustard and green gram - mustard sequences. Crop residues of green gram were incorporated after picking the pods. Mustard raised after rainy season maize yielded lowest and keeping the land fallow had no advantage in terms of seed yield. Enhanced number of branches, siliquae and seed weight per plant had their additive effect in increasing mustard yield in legume sequences. The fertility status of the soil increased when green manure/ legume crops were raised before mustard. Due to this fact, the response to nitrogen application was recorded up to 120 kg N/ha in the sequences where legume preceded mustard. However, mustard responded up to 160 kg N/ha in maize-mustard sequence. Inclusion of legume crop, therefore, is desirable for sustained productivity and enhanced net returns from mustard.

In prominent mustard growing areas mustard (Brassica juncea) is either grown as mono crop or after a cereal or legume crop in sequence. The inclusion of legumes in rotation have been reported to improve soil fertility particularly soil N and thereby increasing the productivity of subsequent crop (Mongia and Gangwar, 1988). Use of inorganic fertilizers although increased crop yield but their requirement varied in different cropping sequences (PDCSR, 1993). Prasad et al. (1990) reported that N dose to cereal can be reduced by 20-25 kg/ha with the inclusion of legumes. In intensive cropping system, the productivity status of mustard can be enhanced by inclusion of legumes and green manuring crop in sequence. To achieve sustained mustard productivity and assess contribution of legumes, the present investigation was planned on mollisols.

METHODOLOGY

Field experiments were conducted during winter seasons (1994-95 to 1996-97) at the Crop Research Centre of the G.B. Pant University of Agriculture and Technology, Pantnagar, India. Sowing was done in 30 cm apart rows in split-plot design with 3 replications taking six crop sequences including : maize-mustard, green gram-mustard, green manuring- mustard, cowpea (fodder)-mustard, fallow-mustard and soybean - mustard as main-plot treatment and five nitrogen levels (0, 40, 80, 120 and 160 kg N/ha) as sub-plot treatment. Nitrogen treatment was applied to only mustard crop. Recommended N dose was given in preceding rainy season crop. Fifty days old crop of Sesbania aculeata was incorporated into the soil for green manuring while in green gram-mustard sequence green gram residues were incorporated into the soil after plucking the pods once. Plant spacing of 15 cm was maintained by thinning. An uniform basal application of 40 kg P₂O₅ and 20 kg K₂O/ha was made along with 50% of the nitrogen as per the treatment. Remaining half quantity of nitrogen was applied after first irrigation (30 days after sowing) in mustard.

RESULTS

Significantly more seed yield was recorded in green manuring -mustard sequence but was at par with cowpea (fodder)-mustard sequence. The cowpea (fodder)-mustard sequence also recorded significantly higher seed yield over other sequences except green gram-mustard sequence. Keeping the land fallow in preceding season had no advantage in terms of seed yield, though fallow-mustard sequence yielded higher than maize - mustard sequence. The lowest seed yield was recorded in soybean- mustard sequence, mainly because of late planting (Table 2). Increase in seed yield was conspicuous upto a dose of 120 kg N/ha and thereafter the yield increase was non-significant.

Enhanced number of branches, siliquae and seed weight per plant lead to significant increase in mustard seed yield in the sequences where green manure legume crop was grown as preceding crop during rainy season (Table 1). These findings are in accordance with the results obtained by Kumar et al. (1995) on Indian rape. The effect of crop sequences on fertility status of the soil was recorded non-significant. However, total available nitrogen in soil was recorded maximum in green manuring-mustard sequence which was 2.7% higher than maize-mustard sequence. The effect of nitrogen levels on total available nitrogen status of the soil was recorded to be significant and significantly higher value was recorded at 160 kg N/ha. The interaction effect between crop sequences and nitrogen levels was also significant. Maximum mustard seed yield was recorded in cowpea (fodder) - mustard and green manuring - mustard sequences even at lower N doses. Mustard raised after maize yielded lowest. Response to nitrogen application was recorded upto 120 kg/ha in sequences where legumes were taken as preceding crop while it increased to 160 kg N/ha with the inclusion of maize. Thus, it is apparent that for improved soil health and higher mustard seed yield, inclusion of green manuring/legume crops is desirable compared to cultivation of cereals as preceding rainy season crop.

The oil content was more in fallow-mustard and maize-mustard sequences over other sequences. A decreasing trend in oil content in mustard seeds was recorded due to nitrogen application and significantly higher value was recorded in control which remained at par upto 40 kg N/ha.

The oil yield in mustard was significantly more in green manuring - mustard sequence but the differences were non-significant with the cropping sequences involving legumes as preceding crop. Oil yield also increased upto to 120 kg N/ha but the increase was non-significant at 160 kg N/ha.

REFERENCES

4. Kumar, A.; Shukla Anil and Singh, R.P. 1995. Effect of preceding kharif crop on the performance of Indian rape. National Symposium on Agriculture in relation to environment held at IARI, New Delhi from Jan. 16-18.

5. Mongia, A.D. and Gangwar, B. 1988. Effect of rice based cropping system on fertility status of a tropical entisol. Journal Andaman Sci. Asso. 4(2) : 108-110.

6. PDCSR. 1993. Technology recommendation from cropping system research. Bulletin I. Project Directorate for Cropping System Research, Modipuram.

7. Prasad, Rajendra; Sharma, S.N.; Singh Surendra and Prasad, Mangal. 1990. Efficient fertilizer management for a sustainable agriculture. Abs. Vol. 1.

Table 1. Yield attributes, oil content and oil yield of mustard as influenced by crop sequences and nitrogen doses (Averaged over three years, 1995-97).

Treatment	Branches per plant	Siliquae per plant	1000 seed weight (g)	Seed weight per plant (g)	Oil content (%)	Oil yield (kg/ha)	Total available nitrogen (kg/ha)
Crop sequences
Maize-mustard	11.4	195.6	4.3	7.9	39.2	638	244.7
Green gram -mustard	12.4	213.4	4.7	8.5	38.9	692	250.6
Green manuring-mustard	13.3	229.0	5.0	9.3	37.9	723	251.4
Cowpea(fodder) -mustard	13.0	223.0	4.9	9.0	37.6	699	249.8
Fallow -mustard	12.0	208.6	4.6	8.4	39.2	682	248.3
Soybean-mustard	8.5	146.8	3.2	5.8	37.1	454	249.1
CD at 5%	1.8	15.4	0.8	1.8	0.9	30	NS
Nitrogen levels (kg/ha)
0	9.2	158.0	3.8	6.4	39.8	527	225.8
40	10.9	186.7	4.1	7.5	39.2	610	235.5
80	11.9	204.1	4.5	8.2	38.3	651	253.5
120	13.2	227.0	5.0	9.1	37.8	715	254.8
160	14.0	239.6	5.2	9.6	36.6	731	275.4
CD at 5%	1.6	14.5	0.7	1.6	0.8	27	13.2

NS = Non-significant

Table 2. Seed yield (kg/ha) of mustard as influenced by different crop sequences and nitrogen doses (Averaged over three years, 1995-97).

Crop sequences	Nitrogen dose (kg/ha)					Mean
	0	40	80	120	160
Maize-mustard	1297	1535	1657	1790	1914	1630
Green gram -mustard	1487	1673	1775	1987	2062	1778
Green manuring-mustard	1500	1775	1959	2150	2164	1909
Cowpea(fodder) -mustard	1379	1684	1888	2116	2213	1859
Fallow -mustard	1327	1548	1683	2010	2129	1739
Soybean -mustard	955	1122	1242	1300	1501	1224
Mean	1324	1556	1701	1892	1997

CD at 5%

Crop sequences (S) 119

Nitrogen levels (N) 110

To compare N at the

same or different S level 508

To compare S at the

same N level 551