Studies on macro and micro nutrient composition of soils and ground water quality assessment in factory areas of S.V. Sugar Mills, Kancheepuram district

Subbiah, B.V. and G.L. Asija. (1956). A rapid procedure for the estimation of available nitrogen in soils. Curr. Sci., 25: 259-260. Tandon, H. L. S. (Ed). (1995). Methods of analysis of soils, plants, waters and fertilizers. Fertilizer Development and consultation organization, New Delhi.

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United States Salinity Laboratory Staff. (1968). Diagnosis and improvement of saline and alkaline soils. Oxford and IBH Publishing Co., New Delhi. (Received : December 2004 Revised : July 2005)

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Research Notes

Nutrient management and optimization of sieve size to improve seed yield and quality in Amaranthus CV. CO5 C. MENAKA AND P. BALAMURUGAN Department of Seed Science and Technology, TNAU, Coimbatore -3

Vegetables play a vital role in the health and nutritional security of human beings in addition to improve the economy of the people of the country. Amaranthus is one of the ancient group of plants having great potential for combating under and malnutrition of the population in many parts of the world. It is the most important popular leafy vegetable also called “Poor man's spinach”. Amaranthus belongs to the family Amaranthacae which comprises of 65 genera and 850 species.

characters in Amaranthus. Size grading of the seed is one of the important factors besides varietal response. Seed production under variable environmental conditions may result in variation in seed size, weight and density ultimately affecting germination as well as subsequent plant vigour and seed production. The importance of seed size has been reported by Ramesh, (1996). Hence, determination of optimum seed size is very much important for better sowing quality of seeds.

The productivity of Amaranthus crop can be substantially altered under the influence of major nutrients. Nitrogen is an integral component of many compounds essential for plant growth. Phosphorus is an essential constituent of cellular protein and nucleic acids and it encourages meristem activities in plants (Black, 1973). Potassium also plays an important role in quality seed production and maintenance of viability and vigour in storage (Kursanov et al, 1965 ). Hence, adequate supply of nutrients become increasingly important for obtaining higher seed yield. There are various factors which influence seed yield and other economic

A field experiment was laid out during kharif 2000 to fix the optimum dose of N, P and K for realizing higher yield associated with good quality of seeds in Amaranthus CO 5. The treatment details of the experiment are Tl- 40:40:20, T2- 50:50:30, T 3-60:60:40, T 4- 70:40:10, T 5 - 80:50:20, T 6 90:60:30 NPK kg ha-1. The trial was laid out in randomized block design with four replications. The plot size adopted was 3 x 3 m2. Nitrogen was applied equally at sowing and 30th day after sowing. In all the treatments phosphorus and potash were applied at the time of sowing. All the agronomic and plant

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C. Menaka and P. Balamurugan

Table 1. Effect of fertilizer levels on germination (%), vigour index, electrical conductivity (dSm-1), protein content (%), seed yield and and 100 seed weight (g) Fertilizer NPK (kg/ha)

Germination (%)

Vigour index

40:40:20 (T1) 50:50:30 (T2) 60:60:40 (T3) 70:40:10 (T4) 80:50:20 (T5) 90:60:30 (T6) Mean

97 (81.35) 94 (76.02) 90 (71.65) 88 (69.86) 87 (69.03) 84 (66.50) 90 (72.40)

1332 846 717 620 587 500 767

SEd CD (P=0.05)

2.387 5.087

Electrical Protein conductivity content (%) (dSm 1)

Seed yield plant-1 (g)

kg ha-1

100 seed weight (g)

16.07 12.12 10.48 10.29 8.12 7.88 10.84

1643 1502 1303 1258 1058 950 1286

0.108 0.103 0.105 0.099 0.097 0.090 0.100

98.000 0.001 0.072 0.412 1.233 209.000 0.002 0.153 0.880 2.629 (Figures in parentheses indicate arc sine transformed values)

0.002 0.005

0.052 0.059 0.067 0.074 0.080 0.088 0.070

16.51 16.65 16.89 16.96 17.11 17.23 16.89

Table 2. Size grading on seed recovery (%), 100 seed weight (g), germination (%) and vigour index Size grades

Seed recovery (%)

100 seed weight (g)

Germination (%

Vigor Index

18 x 18 R

9.25

0.114

97 (80.12)

1418

20 x 20 R

20.92

0.108

92 (73.83)

1172

22 x 22 R

53.92

0.102

89(70.69)

1072

22 x 22 P

15.91

0.076

60 (50.77)

436

Ungraded Mean

20.00

0.086 0.098

80 (63.48) 84 (67.78)

662 951

SEd CD (P=0.05%)

0.350 0.004 2.739 0.760 0.008 5.836 (Figures in parentheses indicate are sine transformed values)

protection measures were carried out as and when required. Five plants were randomly marked in each plot for recording observations. From the cleaned seeds, the following quality evaluations were also carried out viz., 100 seed weight, germination, dry matter production and vigour index, electrical conductivity and protein content. The pre-cleaned seeds were size graded with BSS 18x18, 20x20, 22x22 square wire mesh sieves.

75.000 160.000

The following quality determinations were made on the above size grades as well as the control (precleaned but not size graded). Seed recovery, 100 seed weight, germination, dry matter production and vigour index. Electrical conductivity and protein content. In was observed from the results that seed yield (1643 kg ha-1) and 100 seed weight (0.108 g) were maximum at lower fertilizer level of 40:40:20 kg NPK ha-1 (Table 1) Higher dose of

Nutrient management and optimization of sieve size to improve seed yield and quality in Amaranthus CV. CO5

nutrient application did not show beneficial effect in the present study. Jayshree et al. (1996) also reported reduction in the seed yield by application of nutrients at higher levels in Amaranthus. Higher seed yield at lower levels of fertilizer might be due to less requirement of nutrients in the reproductive phase of plants. Higher levels might be encouraging vegetative growth of the plant at the expense of reproductive phase. The application of NPK at 40:40:20 kg ha-1 improved germination (97 %) of the resultant seeds and seedling vigour (1332) (Table 1). The quality characters did not show any improvement beyond this fertilizer level. In this study, seed protein content significantly increased with increased levels of nutrients. Seed protein content was more (17.23%) in 90:60:30 kg NPK ha-l. This may be ascribed that the higher rate of application of phosphorus might have enhanced the nitrogen uptake and resulted in more accumulation of protein with higher rate of N application. Seeds retained by BSS 22 x 22 sieve recorded higher recovery (53.92%) than those seeds retained by BSS 18 x 18 and BSS 20 x 20 sieves. The recovery of seeds comprising the size grades of 18, 20 and 22 was about 84 per cent (Table 2 ). The 100 seed weight differed due to seed size. The values were increased correspondingly with increase in seed size. The seeds retained by sieves 18, 20 and 22 recorded higher weight than by 22 passed and ungraded ones. Balamurugan (1993) reported a positive association between size and weight of seeds. The germination increased progressively with increasing seed size. The larger seeds retained by 18 x 18 recorded higher germination (97 %) followed by the seeds retained by 20 x 20 and 22 x 22 and ranged between 92 and 89 per cent (Table 2). The higher germination in large seeds may be due to the higher amount of

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food reserves and increased activity of redoxenzyme in the seeds help in break down of complex food reserve materials into simple soluble sugars. The other quality parameter namely vigour as measured through germination and dry matter production of seedling showed the superiority of large and medium size seeds retained by sieves 18, 20 and 22. This could be ascribed to more mature embryo containing adequate nutrient reserves both contributing its physiological stamina or viogur factors residing in it. The study indicated that the larger seeds retained by BSS 18 x 18 and 20 x 20 and medium size seeds retained by BSS 22 x 22 showed greater seed germination and vigour than smaller ones. The present study revealed the usefulness of application of 40:40:20 kg NPK ha-1 for quality seed production with better seed weight, germination and vigour and the usefulness of grading Amaranthus cv. Co 5 seeds with BSS 22 x 22 wire mesh sieve for better quality seeds with maximum recovery per cent.

References Black, C.V. (1973). Soil plant relationships. John willey and Sons, Inc., New York. Balamurugan, P. (1993). Seed production techniques in BSH 1 and quality assessment in parental lines and hybrid of sunflower (Helianthus annus L.). Ph.D. Thesis, Tamil Nadu Agricultural University, Coimbatore. Jayshree, B., G.M. Bharad and S.N. Patil. (1996). Effect of plant population, nitrogen and phosphorus on grain Amaranth (Amaranthus species). Indian J. Agron., 41(1): 181-182. Kursanov, A.L., Byskrebentseva, I. Sveshnikova and M. Krasavina. (1965). Disorganization of

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C. Menaka and P. Balamurugan

energy metabolism in roots during potash metabolism. As quoted by Ovcharov, Amerind Publishing Company Pvt. Ltd., New Delhi.

Ramesh, D. (1996). Studies on enhancement of seed germination and vigour, in carrot (Daucus carota L.) cv. Zino. M.Sc. (Ag.) Thesis, Tamil Nadu Agricultural University, Coimbatore. (Received : December 2004 Revised : May 2005)

______________ Madras Agric. J. 92 (7-9) : 564-567 July-September 2005

Research Notes

Influence of Cocoa Pod Maturity on seed quality attributes C. VANITHA, A. VIJAYAKUMAR AND K. SIVASUBRAMANIAM Seed Science and Technology Unit, Department of Plant Breeding and Genetics, Agricultural College and Research Institute, Madurai 625 104

Cocoa (Theobroma cacao L.) is a beverage cum masticatory crop cultivated for its seeds. It was introduced by the Portuguese into India during the early part of 20 th century. Based on fruit characteristics cocoa is classified into three major groups viz., Criollo, Forastro and Trinitario. Cultivar Forastro is cultivated to a large extent in India. Cocoa generally flowers during the second year of planting and fruit set is observed 28 days after pollination (Falgue et al., 1995). The pods are considered ripe when the colour changes from yellow to reddish yellow and require about 140 to 160 days to mature. Cocoa seeds are collected from ripe pods, dried and sent to confectionary factories. At present cocoa is cultivated in 20,000 ha with an yield of 8000 tonnes per annum. Due to increase in area under cocoa which leads to an unprecedented plantation, there is huge demand for quality cocoa seeds. In order to standardize the quality seed production in cocoa it is necessary to delineate the pattern of fruit development and maturation so as to enable the harvesting of quality seed for propagation. Cocoa cv. Forestro trees available in a plantation near Pollachi, Coimbatore District, Tamil

Nadu were selected for the study. One hundred fruits were tagged daily at ten days interval from the date of fruit initiation. The tagged fruits were collected at different stages of maturity and classified based on size, colour and were designated as S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14 and S15. Twenty five randomly selected fruits were observed for the pod characteristics viz.,. fruit weight (g), fruit, diameter (cm) and fruit length (cm). The seeds collected from the above fruit categories were used for the following observations viz., seed moisture content (%), seed fresh weight (g), seed dry weight (g), fruit to seed recovery (%), germination (%) (ISTA,1999), seedling shoot length(cm), seedling rootlength (cm), seedling dry matter production(mg) and vigour index (Abul-Baki and Anderson, 1973). The results (Table 1) indicated that the mean fruit length increased linearly from 0.8 cm at S1 to 19.2 cm at S15 followed by reduction to 18.8cm at S16. The difference in 5 fruit diameter was also highly significant and increased from l.l cm at S1 to 27.4 (S15) and thereafter decreased to 26.6cm at S16. The reduction in length and weight of pod could be due to loss of moisture upon maturation.