Study of the Effect of N, P and S Application on the Performance of Rapeseed-Mustard

Thesis

Siddiqui, Manzer H. . 2005

• رابط المنشور على الويب: Aligarh Muslim University
• نوع الإطروحة: Ph.D.
• المدرسة: Aligarh Muslim University

مستخلص المنشور

The present thesis comprises six chapters. In Chapter 1 (Introduction), the importance of the problem “Study of the Effect of N, P and S Application on the Performance of Rapeseed-mustard”, has been discussed briefly. In view of the lacunae in the understanding of the problem, justifications have been put forward for undertaking the present work. Moreover, the logical basis of each of the four experiments undertaken has been mentioned briefly.
            In Chapter 2 (Review of Literature), publications pertaining to general aspects of rapeseed-mustard, to inorganic nutrition in general, and to the physiological roles of nitrogen, phosphorus, potassium and sulphur as well as to the effect of their application to rapeseed-mustard have been reviewed with special reference to the work done in India.
            In Chapter 3 (Materials and Methods), details of the techniques and methodology employed for conducting the four field experiments have been given.
            Chapter 4 (Experimental Results) includes the detailed data regarding crop response based on growth, biochemical and physiological parameters, yield characteristics and oil quality. These were mostly found significant on statistical analysis at p>0.05. The salient data of the four field experiments, each conducted in the “rabi” (winter) season, are summarized below.
            Experiment 1 was planned as a variety trial. It was conducted during 2000-2001, according to a simple randomized block design, to study the physio-morphological response of seven cultivars of rapeseed-mustard, namely Hyola PAC-401 (Brassica napus L.), Jagannath, Kranti, Rohini and TERI (OE) M21-Swarna (Brassica juncea L.) and IGC-01 and Pusa Gaurav (Brassica carinata Braun). These were raised with a uniform recommended dose of 80 kg N + 18 kg P + 30 kg K/ha. The performance of the cultivars was assessed at two stages of growth, namely 45 and 60 DAS. The characteristics selected for this purpose were shoot length, leaf number, leaf area, leaf area index, fresh weight and dry weight. In addition, physiological and biochemical parameters (net assimilation rate, nitrogen, phosphorus and potassium content in leaves and carbonic anhydrase activity) were also studied at 45 and 60 DAS. Yield attributes (pod number per plant, seed number per pod, 1000-seed weight, seed yield, oil content and oil yield) and quality (fatty acid composition) were studied at harvest. Statistical analysis revealed the overall superiority of Hyola PAC-401, which gave maximum yield of seed and oil. It was followed by TERI (OE) M21-Swarna, which generally showed parity with Rohini. For example, Hyola PAC-401 gave 12.0% higher net assimilation rate, 22.6% higher seed yield and 17.4% higher oil yield than Jagannath which generally gave minimum value. Also, the oil of Hyola PAC-401 and TERI (OE) M21-Swarna was found to be almost free from erucic acid and their oil contained only about 0.18% of this undesirable fatty acid.
            Experiment 2, a factorial randomized block design field test, was conducted during 2001-2002 on three better performing cultivars of rapeseed-mustard selected on the basis of the data for seed yield and fatty acid composition of oil obtained in Experiment 1. They included the two erucic acid-free cultivars Hyola PAC-401 (Brassica napus L.) and TERI (0E) M21-Swarna (Brassica juncea L.) and the highest yielding locally popular variety Rohini (Brassica juncea L.) as test cultivars. The aim was to determine the best combination of basal doses of nitrogen and phosphorus, applied as urea and DAP respectively, alongwith a uniform dose of potassium (30 kg K/ha) under local agro-climatic conditions. Out of N0P0, N30P10, N60 P20, N90P 30 and N120P40 making allowance for the nitrogen in DAP while calculating the required quantity of urea in each combination. The data revealed that:

1. Application of 90 kg N + 30 kg P + 30 kg K/ha was best for most of the parameters studied. For example, this treatment increased net assimilation rate by 98.7%, seed yield by 78.6% and oil yield by 72.7% over the control.
2. Cultivar Hyola PAC-401, followed by TERI (OE) M21-Swarna, proved best, particularly on the basis of high seed yield and oil yield and low erucic acid content. Rohini proved a poor third, giving lower yield and high content of erucic acid. Hyola PAC-401 exhibited 8.0% higher net assimilation rate, 9.7% higher seed yield and 5.7% higher oil yield than Rohini. The oil of Hyola PAC-401 and TERI (OE) M21-Swarna contained almost negligible erucic acid (0.40% and 0.59% respectively) compared with that in Rohini (35.5%).
3. The interaction between N90P30 and Hyola PAC-401 proved best for most parameters. For example, this interaction enhanced net assimilation rate by 103.5%, seed yield by 100.4% and oil yield by 88.7% over N0P0 ´ Rohini which gave minimum value.

            Experiment 3 was conducted concurrently with Experiment 2 according to a factorial randomized block design on the same cultivars as in Experiment 2. In view of their sulphur-rich nature, this experiment was aimed to check whether their productivity could be further enhanced by inclusion of sulphur in the basal nitrogen, phosphorus (and potassium) doses of Experiment 2. To supply sulphur, diammonium phosphate was replaced with single super-phosphate (a common source of phosphorus containing sulphur also). Thus, the treatments had 0, 17, 34, 50 and 69 kg S/ha in the respective nutrient doses of Experiment 2.The results showed:
            (i) An almost similar pattern for various growth, physiological and biochemical, yield and quality parameters as in Experiment 2 albeit with increased values. For example, the interaction N90P30 ´ Hyola PAC-401 (which proved best in this experiment also) gave 5.7% higher seed yield and 6.3% higher oil yield than the same interaction in Experiment 2. Thus, provision of sulphur in basal alongwith nitrogen, phosphorus (and potassium) proved beneficial for the rapeseed –mustard crop.
            The factorial randomized block design Experiment 4 was performed during 2002-2003 (i) to test whether or not the productivity of the three cultivars, selected in Experiments 2 and 3, could be further improved by exploiting the technique of foliar application of nitrogen and phosphorus and (ii) to examine if addition of a small quantity of sulphur in these sprays could further enhance the yields. The basal dose (N90P30 K30) found optimum in Experiment 2 formed the basis of the scheme of treatments of this experiment. The first aim was to be tested through foliar application of 20 kg/ha nitrogen and 2 kg/ha phosphorus. All plants except the control were grown with sub-optimal basal dose of nitrogen and phosphorus determined after substracting the amount of leaf-applied nutrients, phosphorus and/or nitrogen from it. To achieve the second aim, 2 kg S/ha was included in the spray treatment containing both nitrogen and phosphorus. For comparison, the full optimum basal dose was supplemented with spray of deionized water only to act as control. Thus, the basal (B) plus foliar (F) treatments, applied with 30 kg K/ha uniformly, included (i) BN90P30 + FW, (ii) BN­70P30 + FN20, (iii) BN70P28 + FN20P2 and (iv) BN70P28 + FN20P2S2. The sources of soil-applied nutrients were the same as in Experiment 2. Leaf-applied nitrogen, phosphorus and sulphur were supplied as urea, diammonium phosphate and single super phosphate respectively. The data revealed that:

1. Application of BN70P28 + FN20P2S2 proved best for all parameters. For example, this treatment increased net photosynthetic rate by 73.8%, seed yield by 84.5% and oil yield by 97.0% over the control (BN90 P30+Fw).
2. Cultivar Hyola PAC-401, equalled by TERI (0E) M21-Swarna for many parameters, including seed and oil yield, proved best in this experiment also. For example, Hyola PAC-401 gave 12.5% higher net photosynthetic rate and 9.6% higher seed yield than Rohini which gave the lowest value. In addition to being higher yielders, the oil of Hyola PAC-401 and TERI (OE) M21-Swarna possessed negligible (0.31-0.41%) erucic acid, whereas its percentage in Rohini was whopping (35.6%).
3. The interaction BN70P28 + FN20P2S2 ´ Hyola PAC-401 proved best for almost all parameters. For example, this treatment gave 103.1% higher net photosynthetic rate, 103.9% higher seed yield and 101.3% higher oil yield than BN90P30 + Fw ´ Rohini which gave the lowest value.

            In Chapter 5 (Discussion), the implications of the main results have been discussed in the light of the findings of earlier researches in our laboratory and elsewhere.
            The present chapter (Summary) is a resume of the thesis. It is followed by an up-to-date bibliography of the references cited in the text. Lastly, an appendix, containing the various formulations employed for chemical analysis, has been appended at the end.