EFFECT OF CROP ESTABLISHMENT TECHNIQUES ON MORPHOLOGICAL AND YIELD PARAMETERS IN AEROBICALLY CULTIVATED RICE ABSTRACT

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1 nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W...8 EFFECT OF CROP ESTLISHMENT TECHNIQUES ON MORPHOLOGICL ND YIELD PRMETERS IN EROICLLY CULTIVTED RICE R. Sudarshani, S.Pathmarajah and W.M.T.P. riyaratne STRCT griculture in Sri Lanka consumes more than 96% of the fresh water in which the share of rice is more than 8%. Normally water requirement for low land rice is about 5-6 feet (.-.5 m) for one season but, more than 5% of this is lost through evaporation, percolation and seepage during land preparation and crop growth. In contrast, rice cultivation is practiced in well-drained, non-puddled and nonsaturated soils with supplementary irrigation. Moisture status is maintained at or near field capacity. Therefore, water productivity is increased by reducing the water losses. Water productivity in rice farming is reported to be -88% higher when compared to rice. Hence, an alternative management option to deal with water shortage for rice cultivation is to raise rice in fields. t present, dry before the onset of rainfall is the common seed establishment technique in rice cultivation. However, it faces uncertain prospect due to unpredictable onset of rainfall. In this research, five crop establishment techniques namely,,, after one week and after two were tested with a / month rice variety (G5) to choose an appropriate crop establishment technique in s. Morphological and yield parameters were monitored and compared among the treatments. Method of establishment affected both, morphological and yield parameters significantly (p<.5). Lowland rice gave significantly better results than rice that was established through five different techniques, namely,,, after one week and transplant after two. However, when different establishment techniques were compared, after one week yielded superior results for all the parameters while yielded the poorest results. The second desirable was the and the third was wet of pre germinated seeds. Since involved intensive labour, can be considered for crop establishment for rice in fields. Keywords: erobic rice, crop establishment techniques, rice, morphological parameters, yield parameters.. INTRODUCTION In Sri Lanka, more than 96% of the fresh water use is on agriculture, with rice consuming more than 8% of this. Of the 5-6 feet (.-.5 m) of water requirement for low land rice in one season, productive water usage is only about 4%-45%. Rest is lost through evaporation, percolation and seepage during land preparation and crop growth period. There are many challenges in low land rice cultivation. availability Graduate Student, Postgraduate Institute of griculture (PGI), University of Peradeniya, Sri Lanka; E- mail: sudarshaniraja55@gmail.com Senior Lecturer, Department of gricultural Engineering, Faculty of griculture, University of Peradeniya, Sri Lanka; s_pathma@yahoo.com Senior Lecturer, Department of CropScience, Faculty of griculture, University of Peradeniya, Sri Lanka; mariyaratne@yahoo.com

2 nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W...8 and pattern of rainfall is changing due to climate change while domestic and nonagricultural sectors are contributing to the decline of quality and quantity of water available for agriculture. ccording to the indicator developed by the International Water Management Institute (marasinghe et al., 999), seven districts in Maha season (wet season) and eleven districts in Yala season (dry season) will be facing absolute water scarcity in 5. Therefore, adaptation strategies are required to sustain the rice production. Methane emission and higher labour and energy requirements are other problems in rice cultivation. erobic rice cultivation is practiced under well drained, non-puddle and non-saturated soils with supplementary irrigation. Moisture status is maintained at or near field capacity, increasing water productivity by -88% when compared to rice, due to cutting down the water losses through percolation, seepage and evaporation (Toung and ouman, ). erobic rice facilitates effective use of rain water that is received on the field. lso, rice emits 8-85% lesser methane gas into atmosphere relative to rice cultivation (Jain et al., 4). Therefore, an alternative management option to deal with increasing water shortage for rice cultivation is to practice rice cultivation instead. t present, dry before the onset of rainfall is the commonly practiced seed establishment technique in rice cultivation. However, due to unpredictability of the onset of rainfall, has to be often done under wet conditions. Therefore, dry may not be a viable option for rice cultivation. In this research, five crop establishment techniques namely,,, after one week and after two were tested for their performance under conditions.. METHODS The experiment was carried out in a rain sheltered plant house of the Faculty of griculture, University of Peradeniya, Sri Lanka. The maximum temperature inside the shelter varied from 5 C, to 8 C and minimum temperature varied from 8 C to C. Range of relative humidity was 6% to %. pot experiment ( L capacity, 7 cm diameter plastic pots) was carried out to compare the morphological and yield parameters under different crop establishment techniques. Soil columns were used to get measurements on root development. Drainage holes were made on the bottom of each pot. Two millimetre plastic mesh was placed at the bottom and cm sand layer was added on it to facilitate proper drainage. Then, it was covered again with a mm mesh and filled with soil leaving about 5 cm gap between the brim and soil surface at the top. PVC tubes with 9 cm diameter and 45 cm height were used for column experiment. Polythene bag was inserted into each tube to facilitate the removal of the column at the end of the experiment. Drainage holes were places at the bottom of the bags. Similer to the pots, a cm sand layer was placed at the bottom of each polyethylene bag to facilitate drainage. It was then filled with soil leaving 5 cm gap at top. Low HumicGley Soil, free from roots, straw and stones was used. Soil organic matter content was.8%. Soil ph was 6.4. Soil texture was sandy clay loam. short duration (½ months) rice variety (g5) seeds obtained from the Plant Genetic Resource Centre (PGRC), Gannoruwa, Sri Lanka were used in the experiment. Pre germinated seeds were made by using traditional of soaking overnight, wrapping in banana leaves and keeping under a weight for days. These pre-germinated seeds were used for nursery preparation and.

3 nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W...8 Five establishment techniques namely,,, after one week and after two were practiced for rice establishment. Flood irrigated rice was used as the. Experimental design was Completely Randomized Design (CRD). Initially, except for the dry seeded pots, all the other pods were soaked, puddled and drained before crop establishment. Daily evaporation was measured by using an evaporation pan. Volume of water equal to daily evaporation was added daily to compensate the volume of water removed by evapotranspiration. Standard water of about cm was maintained throughout the growing season for rice. Fertilizer was applied according to recommendation of the Department of griculture, Sri Lanka. asudin TM was applied according to the recommendation to leaf eating caterpillars at late vegetative stage. Manual weeding was done onemonth after and.5 months after. oth destructive and non-destructive measurements were taken at booting stage. Dry weight of shoots and roots were taken as destructive measurements by keeping in the oven at 8 C for 4 hours. Relative chlorophyll content, plant height, number of tillers per plant and total leaf area per plant were taken as non-destructive measurements. SPD measurement (SPD-5 Plus, Konica Minolta Chlorophyll meter) was use as a proxy for relative chlorophyll content. Leaf area was calculated using the equation; Leaf area =.75 x length of leaf x width of leaf and volume of water transpired was calculated by using the equation; Volume of water transpired = depth of water evaporated x cross sectional area of the pot. Significance of treatment difference on the measured and calculated parameters was tested by analysis of variance (NOV). Means were separated by using Duncan s multiple range tests. Statistical software SS 9. was used to analyse the data.. RESULTS ND DISCUSSION. Plant height at the end of booting stage Plant height showed highly significant (p<.) variation with respect to establishment techniques studied. Lowland (flood irrigated) rice showed the highest plant height. mong the treatments, showed the lowest plant height. Other establishment techniques showed intermediate height (Fig.). Transplanting and showed relatively better results than and.. Number of tillers per plant Number of tillers per plant showed highly significant variation (p<.) with respect to establishment techniques. Lowland rice showed significantly high number of tillers than treatments.mong the treatments, after two showed relatively lowest number of tillers while showed the highest (Fig. ). Number of tillers per plant is reduced with time of nursery period. Since the variety used is a shortage variety, longer period in nursery may not be desirable.. Non-productive tillers per plant Non-productive tillers per plant showed significant variation (p<.5) with respect to establishment techniques. Direct wet showed the highest number of nonproductive tillers. Lowland rice which was also established through wet showed more number of non-productive tillers (Fig ). In general, treatments developed less number of non-productive tillers.

4 direct wet transpla nting after week parachut e transpla nting after direct dry Non-productive tillers/plant direct wet transplan ting after week parachut e transplan ting after Number of tillers per plant transplanti ng after transplanti ng after week Plant height (cm) nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W C CD D () Figure. Plant height at the end of booting stage C C C C 4 () Figure. Number of tillers per plant () Figure. Number of non-productive tillers 4

5 Root dry weight (g/plant) within st cm Shoot dry weight (g/plant) nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W Shoot dry weight (g/plant) at the end of booting stage Shoot dry weight showed highly significant variation (p<.) with respect to establishment techniques. Lowland rice showed significantly high shoot dry weight than treatments. This may be due to high nutrient availability under flooded conditions. Transplanting after two in this short aged variety showed unfavourable results (Fig. 4) C CD CD D.6.4. after week after () Figure 4. Shoot dry weight at the end of booting stage.5 Root dry weight within first cm at the end of booting stage Root dry weight (within first cm) showed significant variation (p<.) with respect to establishment techniques. Lowland rice showed the highest root dry weight within the first cm. Direct dry, showed the lowest root dry weight (Fig 5). Root development within first cm is less under conditions C C. C C.. after week after Figure 5. Root dry weight (within first cm) at the end of booting stage 5

6 Total root dry weight (g/plant) transplanti ng after week transplanti ng after Root dry weight (g/plant) below cm nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W Root dry weight below cm at the end of booting stage Root dry weight (below cm) showed significant variation (p<.5) with respect to establishment techniques. Lowland rice showed significantly high root dry weight than treatments. ll other establishment technics showed no significant differences among the treatments (Fig 6). Lowland showed the best result probably due to the looseness of the soil under continuous flooding Figure 6. Root dry weight (below cm) at the end of booting stage.7 Total root dry weight at the end of booting stage Total root dry weight showed highly significant variation (p<.) with respect to establishment techniques. Lowland rice showed the highest root dry weight while all other treatments showed no significant differences among them. This could be due to the soil conditions under continuous flooding after week after Figure 7. Total root dry weight at the end of booting stage 6

7 Number of panicles/plant Total leaf area (cm /plant) nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W Total leaf area per plant at booting stage Total leaf area per plant showed significant variation (p<.5) with respect to establishment techniques. Lowland rice showed significantly highest total leaf area per plant. There is no significant variation among the treatments (Fig. 8). Vegetative growth is considerably less under conditions, but comparable for all the establishment s after after week Figure 8. Leaf area per plant at the end of booting stage.9 Number of panicles per plant Number of panicles per plant showed highest significant variation (p<.) with respect to establishment techniques. Lowland rice showed significantly high number of panicles per plant than the treatments. However, there is no significant difference among the establishment techniquesfor rice (Fig 9) after week after Figure 9. Number of panicles per plant 7

8 chlorophyll content (SPD reading) Nmber of grains/panicle nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W...8. Number of grains per panicle The number of grains per panicle showed significant variation (p<.5) with respect to establishment techniques. Except for dry, all other establishment techniques showed comparable results (Fig ) after week after Figure. Number of grains per panicle. SPD reading (relative chlorophyll content) at booting stage Relative chlorophyll content measured in terms of SPD reading showed significant variation (p<.) with respect to establishment techniques. Except for after and, all others, including rice showed no significant differences in SPD reading among them. It implies that nitrogen uptake is not impaired in, transpalanting after one week and under condition where the moisture content was maintained near at field capacity, C C C C after week after Figure. SPD reading (relative chlorophyll content) 8

9 nd World Irrigation Forum (WIF) 6-8 November 6, Chiang Mai, Thailand W...8. Summary of the results Performance of establishment techniques in terms of morphological and yield parameters under conditions are presented in Table. ccordingly, after one week yielded superior results for all the parameters while yielded the poorest results. The second desirable was the and the third was wet of pre germinated seeds. Since involved intensive labour, can be considered for crop establishment for rice cultivation in fields. Table. Establishment techniques showing best performance in terms of morphological and yield parameters under conditions Crop establishment techniques Plant height Number of tillers Non-productive tillers Shoot dry weight Root dry weight within cm Root dry weight below cm Total root dry weight Leaf area per plant Number of panicles per plant Number of grains per panicle SPD reading Transplanting after week Parachute Direct wet Transplanting after Direct dry 4. CONCLUTIONS Root development, morphological parameters and yield parameters are significantly affected by establishment technique. Lowland rice gave significantly better results than rice that was established through five different techniques, namely direct dry,,, after one week and transplant after two. However, when different establishment techniques for rice were compared, after one week yielded superior results for all the parameters while yielded the poorest results. The second desirable was the and the third was wet of pre germinated seeds. Since involved intensive labour, can be considered for crop establishment for rice cultivation in fields. REFERENCES marasinghe, U.., Muthuwaththa, L., and Sakthivadivel, R. (999). Water Scarcity Variations Within a Country: Case Study of Sri Lanka: International Water Management Institute (IWMI). vi, 8p. (IWMI Research Report ) [ Jain, N., Pathak, H., Mitra, S., and hatia,. (4). Emission of methane from rice fields review. Journal of Scientific and Industrial Reasearch. 6: - 5.[ Toung, T., and ouman,. ().Rice production in water scarce environments. IRRI [ protected/ ch4.pdf] 9